IONIS PHARMACEUTICALS INC

Overview

For three decades as a pioneer in RNA-targeted medicines, we have focused on bringing better futures to people with serious diseases. Today, we continue to drive innovation in RNA therapies. A deep understanding of disease biology and an industry-leading drug discovery technology propels our work, coupled with a passion and urgency to deliver better futures for patients.

We currently have five marketed medicines to treat serious diseases: SPINRAZA (nusinersen), QALSODY (tofersen), WAINUA (eplontersen), TEGSEDI (inotersen) and WAYLIVRA (volanesorsen). We also have a rich innovative late- and mid-stage pipeline in neurology, cardiology and other areas of high patient need. We currently have nine medicines in Phase 3 development and multiple additional medicines in early and mid-stage development.

Over the past year, we made important progress executing on our vision to bring next-level value to patients and all stakeholders. We achieved this progress by focusing on a clear vision to prioritize and expand the Ionis wholly owned pipeline, deliver Ionis medicines directly to patients and enhance our technology leadership, all underscored by continued financial strength and responsibility. The United States, or U.S., Food and Drug Administration, or FDA, approved two Ionis-discovered medicines, QALSODY and WAINUA. We delivered positive Phase 3 data readouts for WAINUA, olezarsen and donidalorsen. Our Phase 3 pipeline expanded with study starts for bepirovirsen, IONIS-FB-LRx and zilganersen and we reported five additional positive data readouts from our mid- and late-stage pipeline. Our recent achievements position us to continue to deliver a steady cadence of potentially transformational medicines to patients in need in the near and mid-term. We also advanced our go-to-market plans for our near-term commercial opportunities, WAINUA, olezarsen and donidalorsen. And we expanded and diversified our technology when we advanced our first cardiac myocyte targeting medicine and medicines using ourmesyl phosphoramidate, or MsPA, backbone into preclinical development.

We accomplished all of this while earning revenues of $788 million for 2023 and ending the year with a cash and short-term investment balance of $2.3 billion. Our multiple sources of revenue and capital structure enable us to continue investing in our commercial readiness efforts for multiple late-stage programs, our innovative pipeline and our technology. By continuing to focus on these priorities, we believe we are well positioned to drive future growth and to bring next-level value to patients and shareholders.

Marketed Medicines

SPINRAZA is the global market leader for the treatment of patients with spinal muscular atrophy, or SMA, a progressive, debilitating and often fatal genetic disease. Our partner, Biogen, is responsible for commercializing SPINRAZA worldwide. From inception through December 31, 2023, we have earned more than $2.1 billion in revenues from our SPINRAZA collaboration, including more than $1.6 billion in royalties on sales of SPINRAZA.

QALSODY is an antisense medicine that received accelerated approval in April 2023 from the FDA for the treatment of adult patients with superoxide dismutase 1 amyotrophic lateral sclerosis, or SOD1-ALS, a rare, neurodegenerative disorder that causes progressive loss of motor neurons leading to death. Our partner, Biogen, is responsible for commercializing QALSODY worldwide. The European Medicines Agency, or EMA, is currently reviewing QALSODY for approval in the European Union, or EU.

WAINUA is a once monthly, self-administered subcutaneous LIgand-Conjugated Antisense, or LICA, medicine that received FDA approval in December 2023 for the treatment of adults with polyneuropathy of hereditary transthyretin-mediated amyloidosis, or ATTRv-PN, a debilitating, progressive, and fatal disease. WAINUA is the only approved medicine for the treatment of ATTRv-PN that can be self-administered via an auto-injector. We and AstraZeneca are commercializing WAINUA in the U.S. with the launch having commenced in January 2024. We and AstraZeneca are seeking regulatory approval for WAINUA in Europe and other parts of the world. AstraZeneca has exclusive rights to commercialize WAINUA outside of the U.S.

TEGSEDI is a once weekly, self-administered subcutaneous medicine approved in the U.S., Europe, Canada and Brazil for the treatment of patients with ATTRv-PN. We sell TEGSEDI in the U.S. and Canada (collectively, North America) and Europe through our distribution agreement with Swedish Orphan Biovitrum AB, or Sobi. In October 2023, our agreement for TEGSEDI in North America was terminated. As a result, Sobi is transitioning responsibilities to us. In February 2024, we began the process to withdraw the TEGSEDI New Drug Application, or NDA. In Latin America, PTC Therapeutics International Limited, or PTC, is commercializing TEGSEDI in Brazil and is pursuing access in additional Latin American countries through its exclusive license agreement with us.

WAYLIVRA is a once weekly, self-administered, subcutaneous medicine approved in Europe and Brazil as an adjunct to diet in adult patients with genetically confirmed familial chylomicronemia syndrome, or FCS, and at high risk for pancreatitis. We sell WAYLIVRA in Europe through our distribution agreement with Sobi. In Latin America, PTC is commercializing WAYLIVRA in Brazil for two indications, FCS and familial partial lipodystrophy, or FPL, and is pursuing access in additional Latin American countries through its exclusive license agreement with us.

Medicines in Registration and Phase 3 Studies

We currently have nine medicines in registration or Phase 3 studies for eleven indications, which are:

WAINUA (eplontersen) is our medicine to treat patients with transthyretin amyloidosis, or ATTR, that is approved in the U.S. for the treatment of adults with ATTRv-PN, under regulatory review in other countries for ATTRv-PN and in development for ATTR cardiomyopathy, or ATTR-CM. In September 2023, The Journal of the American Medical Association, or JAMA, published positive results from the Phase 3 NEURO-TTRansform study in patients with ATTRv-PN showing WAINUA halted disease progression and continuously improved quality of life at 35-, 66- and 85-week analyses. In July 2023, we completed enrollment of the Phase 3 CARDIO-TTRansform study of WAINUA in patients with ATTR-CM with data planned for as early as 2025. In February 2024, the FDA granted Fast Track designation to WAINUA for the treatment of patients with ATTR-CM. Additionally, in January 2022 and October 2023, the FDA and EMA, respectively, granted orphan drug designation to WAINUA for the treatment of ATTR.

Olezarsen is our medicine in development for FCS, an ultra-rare indication and severe hypertriglyceridemia, or SHTG, a much broader indication. In September 2023, we reported positive results from the Phase 3 Balance study in patients with FCS showing statistically significant triglyceride lowering and a substantial reduction in acute pancreatitis events in addition to a favorable safety and tolerability profile. Based on our positive Phase 3 results in FCS patients we are preparing regulatory submissions to the FDA and EMA. In January 2023, the FDA granted fast track designation to olezarsen for the treatment of patients with FCS. Additionally, we are currently conducting a broad Phase 3 development program for olezarsen for the treatment of SHTG including three Phase 3 studies supporting development (CORE, CORE2 and ESSENCE). In February 2024, the FDA granted Breakthrough Therapy designation and orphan drug designation to olezarsen for the treatment of FCS. Additionally, in January 2023, the FDA granted olezarsen Fast Track designation for the treatment of patients with FCS.

Donidalorsen is our medicine in development for hereditary angioedema, or HAE. In January 2024, we reported positive data from the Phase 3 OASIS-HAE study in patients treated every four weeks or patients treated every eight weeks. We are currently conducting OASIS-Plus, ouropen-label study in patients who were either previously treated with other prophylactic therapies or who have completed OASIS-HAE. Throughout 2022 and 2023, we reported positive data from the Phase 2 study and Phase 2 open-label extension, or OLE, study, including two-year OLE data. In December 2023, we licensed European commercialization rights of donidalorsen to Otsuka Pharmaceutical Co., Ltd., or Otsuka. We are preparing to submit an NDA to the FDA. Otsuka is preparing to submit a Marketing Authorization Application, or MAA, to the EMA. In September 2023 and February 2024, the FDA and EMA, respectively, granted orphan drug designation to donidalorsen.

Zilganersen is our medicine in development for Alexander disease, or AxD. In September 2023, we advanced zilganersen into the Phase 3 portion of its ongoing study for patients with AxD. In September 2020 and October 2019, the FDA and EMA, respectively, granted orphan drug designation to zilganersen. Additionally in August 2020, the FDA granted rare pediatric designation to zilganersen.

Ulefnersen is our medicine in development for amyotrophic lateral sclerosis, or ALS, with mutations in the fused in sarcoma gene, or FUS. We are currently conducting a Phase 3 study of ulefnersen in juvenile and adult patients with FUS-ALS. In August 2023 and September 2023, the FDA and EMA, respectively, granted orphan drug designation to ulefnersen.

QALSODY (tofersen) is our medicine to treat patients with SOD1-ALS. In April 2023, the FDA granted Biogen accelerated approval of QALSODY for patients with SOD1-ALS. QALSODY is currently under regulatory review in the EU. Additionally, Biogen is developing QALSODY to treat presymptomatic SOD1-ALS patients in the ongoing ATLAS study. In September 2016 and August 2016, the FDA and EMA, respectively, granted orphan drug designation to QALSODY.

Pelacarsen is our medicine in development to treat patients with elevated lipoprotein(a), or Lp(a)-driven cardiovascular disease, or CVD. Novartis is developing pelacarsen, including conducting the ongoing Lp(a) HORIZON Phase 3 cardiovascular outcome study in patients with elevated Lp(a)-driven CVD, which achieved full enrollment in July 2022 with more than 8,000 patients. In April 2020, the FDA granted Fast Track designation to pelacarsen.

Bepirovirsen is our medicine in development for chronic hepatitis B virus, or HBV. GSK is developing bepirovirsen, including conducting the ongoing B-Well Phase 3 program in patients with HBV. GSK reported positive results from Phase 2 studies in 2023, including durable response data from the Phase 2 B-Sure long-term follow-up study of bepirovirsen in complete responder patients from the Phase 2b B-Clear study of patients with HBV. In February 2024, the FDA granted Fast Track designation to bepirovirsen.

IONIS-FB-LRx is our medicine in development for immunoglobulin A, or IgA, nephropathy, or IgAN, and geographic atrophy, or GA. In the second quarter of 2023, Roche advanced IONIS-FB-LRx into Phase 3 development in patients with IgAN. In October 2023, we reported positive interim data from the ongoing Phase 2 study of IONIS-FB-LRx in patients with IgAN. Additionally, IONIS-FB-LRx is in an ongoing Phase 2 study in patients with GA, refer to the IONIS-FB-LRxdescription below for further details.

Our Marketed Medicines –Bringing Value to Patients Today

SPINRAZA– SPINRAZA (nusinersen) injection for intrathecal use is a survival motor neuron-2, or SMN2, directed antisense medicine indicated for the treatment of SMAin pediatric and adult patients.

SPINRAZA is the global market leader for the treatment of patients with SMA, a progressive, debilitating and often fatal genetic disease. Our partner, Biogen, is responsible for commercializing SPINRAZA worldwide.

SMA is characterized by loss of motor neurons in the spinal cord and lower brain stem. People with SMA have a deletion or defect in their SMN1 gene and rely on their SMN2 gene to produce functional SMN protein, which motor neurons need to maintain motor function and muscle strength. However, in untreated people the SMN2 gene can only produce approximately 10% of the SMN protein critical for motor neurons, resulting in severe and progressive loss of motor function and strength.

The rate and severity of degeneration varies depending on the amount of functional SMN protein a patient can produce. Type 1, or infantile-onset, SMA is the most severe form of the disease. Type 1 SMA patients produce very little SMN protein and often progress to death or permanent ventilation by the age of 2. Patients with Type 2 or Type 3, or later-onset, SMA produce more SMN protein, but also suffer from a progressive loss of muscle strength and function and a reduced life expectancy.

Biogen continues to expand the body of evidence supporting SPINRAZA’s durable efficacy and well-established safety profile to address the remaining needs of SMA patients of all ages. This includes the following ongoing studies:

Additionally, Biogen continues to conduct the Phase 2 NURTURE study, an open-label study investigating the benefit of SPINRAZA when administered before symptom onset in patients genetically diagnosed with SMA, and likely to develop Type 1 or Type 2 SMA. NURTURE was the first study to investigate the potential to slow or stop SMA disease progression in presymptomatic SMA patients. In 2022, Biogen reported new NURTURE study data, showing that early and sustained treatment with SPINRAZA helped participants to maintain and/or make progressive gains in motor function. These data showed that after 11 months of additional follow-up since the 2020 interim analysis, all children who were able to walk alone maintained this ability and one child gained the ability to walk alone, increasing the total percentage of study participants able to walk from 92% to 96%. Further, most children achieved motor milestones within age-appropriate timelines and no major motor milestones were lost. The safety of SPINRAZA over this extended follow-up period was consistent with previously reported findings.

The approval of SPINRAZA was based on efficacy and safety data from multiple clinical studies, including two randomized, placebo-controlled Phase 3 studies, ENDEAR, in patients with infantile-onset SMA, and CHERISH, in patients with later-onset SMA as well as from SHINE, an OLE study for patients with SMA who participated in prior SPINRAZA studies.

QALSODY –QALSODY (tofersen) is an antisense medicine used to treat ALS in adults who have a mutation in the superoxide dismutase 1, or SOD1, gene, or SOD1-ALS. The FDA granted QALSODY accelerated approval based on reduction in plasma neurofilament light chain, or NfL, observed in patients treated with QALSODY. Continued approval for this indication may be contingent upon verification of clinical benefit in confirmatory trial(s).

SOD1-ALS is a rare, fatal, neurodegenerative disorder caused by a mutation in the SOD1 gene leading to a progressive loss of motor neurons. As a result, people with SOD1-ALS experience increasing muscle weakness, loss of movement, difficulty breathing and swallowing and eventually succumb to the disease. Current treatment options for people with SOD1-ALS are extremely limited. It is estimated that there are approximately 1,400 patients with SOD1-ALS in the G7 countries (comprised of Canada, France, Germany, Italy, Japan, the United Kingdom and the U.S.).

Biogen is also evaluating QALSODY for treatment ofpresymptomatic individuals who have a SOD1 genetic mutation. See the “Tofersen” description under “Our Phase 3 Pipeline” section below for further information on the development program for presymptomatic individuals. Tofersen is one of three medicines we have in development to treat ALS.

QALSODY received accelerated approval from the U.S. FDA in April 2023 and is currently under regulatory review in the EU. The QALSODY NDA and MAA included results from a Phase 1 study in healthy volunteers, a Phase 1/2 study evaluating ascending dose levels, the Phase 3 VALOR study, and the Phase 3 OLE study, as well as 12-month integrated results from the Phase 3 VALOR study and the Phase 3 OLE study. The 12-month integrated data show that earlier initiation of QALSODY, compared to delayed initiation, slowed declines in clinical function, respiratory function, muscle strength and quality of life and build on the results previously observed in the initial readout. The 12-month data compare patients with early initiation of QALSODY (at the start of VALOR) to those who had a delayed initiation of QALSODY (six months later, in the OLE).

At the time of the 12-month analysis, because the majority of participants survived without permanent ventilation, the median time to death or permanent ventilation, could not be estimated. However, early survival data suggest a lower risk of death or permanent ventilation with earlier initiation of QALSODY. Additionally, the latest 12-month results showed that reductions in total SOD1 protein (a marker of target engagement) and neurofilament (a marker of axonal injury and neurodegeneration) were sustained over time. QALSODY reduced total CSF SOD1 protein and plasma neurofilament levels in both early- and delayed-start groups as follows:

QALSODY had a favorable safety and tolerability profile.

The FDA and EMA granted QALSODY orphan drug designation for the treatment of ALS in September 2016 and August 2016, respectively.

In December 2018, Biogen exercised its option to license QALSODY. As a result, Biogen is responsible for global development, regulatory and commercialization activities, and costs for QALSODY.

WAINUA –WAINUA (eplontersen)injection is a LICA medicine indicated for the treatment of adults with ATTRv-PN. WAINUA prevents the production of TTR protein, reducing the amount of amyloid buildup that damages organs and tissues. WAINUA was approved by the FDA in December 2023.

ATTR amyloidosis is a systemic, progressive and fatal disease in which patients experience multiple overlapping clinical manifestations caused by the inappropriate formation and aggregation of TTR amyloid deposits in various tissues and organs, including peripheral nerves, heart, intestinal tract, eyes, kidneys, central nervous system, thyroid and bone marrow. The progressive accumulation of TTR amyloid deposits in these tissues and organs leads to organ failure and eventually death.

ATTRv-PN is caused by the accumulation of misfolded mutated TTR protein in the peripheral nerves. Patients with ATTRv-PN experience ongoing debilitating nerve damage throughout their body resulting in the progressive loss of motor functions, such as walking. These patients also accumulate TTR in other major organs, which progressively compromises their function and eventually leads to death within five to fifteen years of disease onset. There are an estimated 40,000 addressable patients, which includes those with ATTRv-PN and those with ATTRv- mixed phenotype worldwide.

Often, patients with ATTRv-PN will have TTR build up in the heart and experience cardiomyopathy symptoms. Similarly, patients with ATTR-CM may often have TTR build up in their peripheral nerves and experience nerve damage and a variety of symptoms, including progressive difficulty with motor functions. As a result, we are developing WAINUA to treat all types of ATTR. See the “WAINUA” description under “Our Phase 3 Pipeline” section below for further information on our development program for ATTR-CM.

FDA approval was based on the interim analysis of the Phase 3 NEURO-TTRansform study in patients with ATTRv-PN. NEURO-TTRansform wasa global, multi-center, randomized, open-label study designed to evaluate the efficacy, safety and tolerability of WAINUA. The study compared WAINUA to the historical placebo arm from the TEGSEDI (inotersen) NEURO-TTR Phase 3 study. In the interim analysis, WAINUA demonstrated a statistically significant and clinically meaningful change from baseline for the co-primary and secondary endpoints at 35 weeks compared to the external placebo group. In the study, WAINUA achieved an 81% (p<0.0001) least squares, or LS, mean reduction in the co-primary endpoint of serum TTR concentration compared to baseline, demonstrating reduced TTR protein production. WAINUA also demonstrated a significant treatment effect on the co-primary endpoint of modified Neuropathy Impairment Score +7, or mNIS+7, a measure of neuropathic disease progression, with a statistically significant difference in mean change from baseline versus the external placebo group (p<0.0001). The study also met its key secondary endpoint of change from baseline in the Norfolk Quality of Life Questionnaire-Diabetic Neuropathy, or Norfolk QoL-DN, showing that treatment with WAINUA significantly improved patient-reported quality of life compared to the external placebo group (p<0.0001). In September 2023, The Journal of American Medical Association, or JAMA, published the Phase 3 NEURO-TTRansform study results.

Additionally, in April 2023, we presented positive data that WAINUA met all co-primary and secondary endpoints in the NEURO-TTRansform study at the final analysis at week 66. At week 66:

And in July 2023, we reported that WAINUA continued to halt neuropathy disease progression and improve quality of life in patients with ATTRv-PN through the end of treatment analysis at week 85.

WAINUA is currently under regulatory review in the EU and other countries for the treatment of patients with ATTRv-PN.

In January 2022 and October 2023, the FDA and EMA, respectively, granted orphan drug designation to WAINUA for the treatment of ATTR.

In December 2021, we entered into an agreement with AstraZeneca to jointly develop and commercialize WAINUA in the U.S. We initially granted AstraZeneca exclusive rights to commercialize WAINUA outside the U.S., except for certain Latin American countries. In July 2023, we expanded those rights to include Latin America.

TEGSEDI –TEGSEDI (inotersen) injection is an antisense medicine indicated for the treatment of ATTRv-PN in adults. TEGSEDI prevents the production of TTR protein, reducing the amount of amyloid buildup that damages organs and tissues.

TEGSEDI is commercially available in numerous countries, including the U.S., many European countries, Canada, and Latin America. We launched TEGSEDI in the U.S. and EU in late 2018. In 2021, we began selling TEGSEDI in the U.S., Canada and Europe through our distribution agreement with Sobi. Refer to the section titled, Overview, for further details on our distribution agreement with Sobi. In Latin America, PTC is commercializing TEGSEDI in Brazil and is pursuing access in additional Latin American countries through its exclusive license agreement with us.

The approvals of TEGSEDI were based on efficacy and safety data from the Phase 3 NEURO-TTR study in patients with ATTRv-PN.

WAYLIVRA –WAYLIVRA (volanesorsen) is an antisense medicine indicated as an adjunct to diet in adult patients with genetically confirmed FCS and at high risk for acute, potentially fatal pancreatitis, in whom response to diet and triglyceride lowering therapy has been inadequate. WAYLIVRA reduces triglyceride levels by inhibiting the production of apolipoprotein C-III, or apoC-III, a protein that is a key regulator of triglyceride levels.

FCS is a rare, genetic disease estimated to affect one to two individuals per million and characterized by extremely elevated triglyceride levels, typically greater than 1,000 mg/dl. FCS can lead to many chronic health issues including severe, recurrent abdominal pain, fatigue, high risk of life-threatening pancreatitis and abnormal enlargement of the liver or spleen. In addition, people with FCS are often unable to work, adding to their disease burden. In severe cases, patients can have bleeding into the pancreas, serious tissue damage, infection, and cyst formation, as well as damage to other vital organs such as the heart, lungs, and kidneys.

WAYLIVRA received conditional marketing authorization in May 2019 from the European Commission, or EC. WAYLIVRA is commercially available in multiple European countries and in Latin America. We launched WAYLIVRA in the EU in the third quarter of 2019. In 2021, we began selling WAYLIVRA in Europe through our distribution agreement with Sobi. In Latin America, WAYLIVRA is approved for two indications, FCS and FPL. PTC is commercializing WAYLIVRA in Brazil and is pursuing access in additional Latin American countries through its exclusive license agreement with us. In the fourth quarter of 2022, WAYLIVRA was approved in Brazil for a second indication, FPL.

WAYLIVRA’s conditional marketing authorization in the EU for FCS and approval in Brazil for FCS were basedon efficacy and safety data fromthe Phase 3 APPROACH study and supported by results from the Phase 3 COMPASS study. WAYLIVRA’s approval in Brazil for FPL was basedon efficacy and safety data fromthe Phase 3 BROADEN study in patients with FPL.

Our Innovative Pipeline of Investigational Medicines

As a pioneer in RNA-targeted therapeutics, we continue to drive innovation with a leading pipeline in neurology, cardiology and other areas of high patient need.

The table below lists the medicines in our clinical pipeline and includes the disease indication, the partner (if the medicine is partnered), and the development status of each medicine. We categorize first-in-patient studies to establish a medicine’s safety profile as Phase 1/2 and in the table below these are listed in the Phase 2 column. Studies in patients that are designed to establish an investigational medicine’s proof of concept and additional safety profile are also listed in Phase 2. Pivotal studies designed to enable registrational filing for marketing authorization are listed in Phase 3. We have included descriptions for each of our medicines in Phase 2 and Phase 3 development below.

Our Phase 3 Pipeline

We currently have nine medicines in our Phase 3 pipeline:

Eplontersen (TTR) – Eplontersen (TTR) –Eplontersen (formerly IONIS-TTR-LRx) is an investigational LICA medicine we designedto inhibit the production of TTR protein. As discussed above under “WAINUA” in our “Marketed Medicines” section, we are developing eplontersen as a monthly self-administered subcutaneous injection to treat all types of ATTR, including ATTR-CM.

ATTR-CM is caused by the accumulation of misfolded TTR protein in the cardiac muscle. Patients experience ongoing debilitating heart damage resulting in progressive heart failure, which results in death within three to five years from disease onset. ATTR-CM includes both the genetic and wild-type form of the disease. There are an estimated 300,000 to 500,000 patients with ATTR-CM worldwide.

Often, patients with ATTRv-PN will have TTR build up in the heart and experience cardiomyopathy symptoms. Similarly, patients with ATTR-CM may often have TTR build up in their peripheral nerves and experience nerve damage and a variety of symptoms, including progressive difficulty with motor functions.

In January 2020, we initiated the CARDIO-TTRansform Phase 3 cardiovascular outcome study of eplontersen in patients with ATTR-CM. CARDIO-TTRansform isa global, multi-center, randomized, double-blind, placebo-controlled study in approximately 1,400 patients with ATTR-CM. We designed the study to evaluate the efficacy, safety and tolerability of eplontersen in patients with ATTR-CM. The primary endpoint in the CARDIO-TTRansform study is a composite outcome of cardiovascular mortality and recurrent cardiovascular clinical events up to Week 140. In July 2023, we announced that the CARDIO-TTRansform study had completed enrollment.

In January 2022 and October 2023, the FDA and EMA, respectively, granted orphan drug designation to WAINUA for the treatment of ATTR.

Olezarsen (ApoC-III) –Olezarsen (formerly IONIS-APOCIII-LRx) is an investigational LICA medicine we designed to inhibit the production of apoC-III for patients who are at risk of disease due to elevated triglyceride levels. ApoC-III is a protein produced in the liver that regulates triglyceride metabolism in the blood. People with severely elevated triglycerides, such as people with FCS, are at high risk for acute pancreatitis and an increased risk of cardiovascular disease, or CVD. It is estimated that FCS affects one to two individuals per million worldwide and more than three million patients have SHTG in the U.S.

We are currently conducting a broad development program for olezarsen that includes the Phase 3 Balance study in patients with FCS and three Phase 3 studies supporting development for the treatment of SHTG: CORE, CORE2 and ESSENCE.

In September 2023, we reported positive topline data from the Phase 3 Balance study in patients with FCS. The study met its primary efficacy endpoint with a statistically significant reduction in triglyceride (TG) levels with the olezarsen 80 mg monthly dose at six months compared to placebo (p=0.0009); triglyceride lowering continued to improve at 12 months. In addition, olezarsen 80 mg showed a substantial reduction in acute pancreatitis events compared to placebo, a key secondary endpoint. Treatment with olezarsen 80 mg resulted in a >75% reduction in apoC-III, a protein produced in the liver that regulates TG metabolism in the blood. In addition to the 80 mg monthly dose, the study also evaluated a 50 mg monthly dose. Olezarsen demonstrated a dose-dependent effect, with both study doses showing a substantial reduction in acute pancreatitis compared to placebo. The 50 mg dose did not reach statistical significance at six months on the primary endpoint of triglyceride lowering (p=0.0775). Olezarsen demonstrated a favorable safety and tolerability profile in the study. Based on the positive results, we plan to file a New Drug Application, or NDA, in 2024 with the U.S. FDA in addition to EU regulatory filings for patients with FCS.

We are also conducting ongoing Phase 3 studies for the expanded SHTG patient population. CORE and CORE2 are global, multi-center, randomized, double-blind, placebo-controlled studies enrolling approximately 540 and 390 patients, respectively, designed to assess the efficacy, safety and tolerability of olezarsen in patients with SHTG. The CORE and CORE2 studies compare olezarsen to placebo in patients with triglyceride levels equal to or greater than 500 mg/dL who are on currently available therapies for elevated triglycerides. The primary endpoint of the studies is the percent change in fasting triglycerides from baseline at month six. Additionally, in November 2022, we initiated ESSENCE, a global, multi-center, randomized, double-blind, placebo-controlled study enrolling approximately 1,300 patients to provide a robust safety database. The primary endpoint of the study is the percent change in fasting triglycerides from baseline at month six.

In January 2020, we reported positive results from a Phase 2 clinical study in patients with hypertriglyceridemia and at high risk of or with established CVD. Olezarsen achieved statistically significant, dose-dependent reductions in fasting triglycerides compared to placebo at all dose levels. Olezarsen also achieved statistical significance in numerous key secondary endpoints, including significant reductions in apoC-III. Olezarsen had a favorable safety and tolerability profile supportive of continued development.

In February 2024, the FDA granted Breakthrough Therapy designation andorphan drug designation to olezarsen for the treatment of FCS. Additionally, in January 2023, the FDA granted olezarsen Fast Track designation for the treatment of patients with FCS.

Donidalorsen (PKK) –Donidalorsen (formerly IONIS-PKK-LRx) is an investigational LICA medicine we designed to inhibit the production of prekallikrein, or PKK. HAE is a rare genetic disease that is characterized by severe and potentially fatal swelling of the arms, legs, face and throat. PKK plays an important role in the activation of inflammatory mediators associated with acute attacks of HAE. By inhibiting the production of PKK, donidalorsen could be an effective prophylactic approach to preventing HAE attacks. It is estimated that there are more than 20,000 patients with HAE in the U.S. and Europe.

In January 2024, we reported positive topline data from the Phase 3 OASIS-HAE study in patients with HAE. The study met its primary efficacy endpoint with a statistically significant reduction in the rate of HAE attacks in patients treated with 80 mg of donidalorsen via subcutaneous injection dosed every four weeks, or Q4W, (p<0.001) or every eight weeks, or Q8W, (p=0.004) compared to placebo. In addition, the trial showed donidalorsen achieved statistical significance on all secondary endpoints in the Q4W group and key secondary endpoints in the Q8W group. Donidalorsen demonstrated a favorable safety and tolerability profile in the study. Based on the positive results, we plan to file a NDA in 2024 with the U.S. FDA. Otsuka, which has exclusive rights to commercialize donidalorsen in Europe, is preparing to submit a Marketing Authorization Application to the European Medicines Agency, or EMA.

In May 2022, we initiated OASIS-Plus, a multi-center, open-label, global study in approximately 110 patients who were either previously treated with other prophylactic therapies or who have completed OASIS-HAE.

In 2021 and 2022 we reported positive results from the Phase 2 clinical study of donidalorsen in patients with HAE. And in 2022 and 2023, we presented positive results from the Phase 2 OLE study of donidalorsen in patients with HAE. Following the 13-week blinded, placebo-controlled Phase 2 study with a fixed 13-week dosing period where they received donidalorsen 80 mg every four weeks, patients were eligible for enrollment in the OLE study. Of the 20 Phase 2 study participants, 17 entered the OLE study and were on a fixed 13-week dosing period where they received 80 mg every four weeks. From week 17 through two years, patients entered a flexible dosing period where they either received donidalorsen 80 mg every four weeks, 80 mg every eight weeks, or 100 mg every four weeks. Over the two years, patients treated with donidalorsen via subcutaneous injection showed an overall sustained mean reduction in HAE attack rates of 96% from baseline, from 2.70 to 0.06 attacks per month, across all dosing groups. Furthermore, all patients treated with donidalorsen reported a clinically meaningful improvement in quality of life as measured by the Angioedema Quality of Life Questionnaire (AE-QoL) over two years. Donidalorsen had a favorable safety and tolerability profile in the study.

In September 2023 and February 2024, the FDA and EMA granted orphan drug designation to donidalorsen.

In December 2023, we granted Otsuka exclusive rights to commercialize donidalorsen in Europe.

Pelacarsen (Apo(a))(TQJ230) –Pelacarsen (formerly IONIS-APO(a)-LRx) is an investigational LICA antisense medicine we designed to inhibit the production of apolipoprotein(a), or Apo(a), in the liver to offer a direct approach for reducing Lp(a). Elevated Lp(a) is recognized as an independent, genetic cause of CVD. Lp(a) levels are determined at birth and lifestyle modification, including diet and exercise, do not impact Lp(a) levels. Inhibiting the production of Apo(a) in the liver reduces the level of Lp(a) in blood, potentially slowing down or reversing CVD in people with hyperlipoproteinemia(a), a condition in which individuals have levels of Lp(a) greater than 50 mg/dL, the recognized threshold for risk of CVD. We believe antisense technology is well suited to address hyperlipoproteinemia(a) because it specifically targets the RNA that codes for all forms of the Apo(a) molecule. It is estimated that there are more than eight million people living with CVD and elevated levels of Lp(a).

In December 2019, Novartis initiated the Phase 3 study of pelacarsen, Lp(a) HORIZON, inpatients with elevated Lp(a) levels and a prior cardiovascular event. Lp(a) HORIZON isa global, multi-center, randomized, double-blind, placebo-controlled cardiovascular outcomes study in more than 8,000 patients designed to assess the efficacy, safety and tolerability of pelacarsen. Patients are treated with 80 mg of pelacarsen administered monthly by subcutaneous injection. The primary endpoint in Lp(a) HORIZON is the time to occurrence of first major adverse cardiovascular event, or MACE. In July 2022, we announced that the Lp(a) HORIZON study had completed enrollment.

In November 2018, at the American Heart Association, or AHA, annual meeting, we reported results of the Phase 2 study of pelacarsen in patients with hyperlipoproteinemia(a). In the Phase 2 study, we observed statistically significant and dose dependent reductions from baseline in Lp(a) levels. Approximately 98% of patients who received the highest dose in the study demonstrated a reduction in Lp(a) levels to below the recommended threshold for CVD events (<50 mg/dL). Pelacarsen had a favorable safety and tolerability profile supportive of continued development.

In February 2019, Novartis exercised its option to license pelacarsen. As a result, Novartis is responsible for global development, regulatory and commercialization activities, and costs for pelacarsen.

In April 2020, the FDA granted pelacarsen Fast Track designation for the treatment of patients with elevated Lp(a) and CVD. In December 2020, the Center for Drug Evaluation, or CDE, of China National Medical Products Administration granted breakthrough therapy designation to pelacarsen.

Zilganersen – Zilganersen (formerly ION373) is an investigational antisense medicine we designed to inhibit the production of glial fibrillary acidic protein, or GFAP. We are developing zilganersen as a potential therapy for AxD, a rare, progressive and fatal neurological disease that affects the myelin sheath which protects nerve fibers. AxD is caused by a gain-of-function mutation in the GFAP gene and is characterized by progressive deterioration, including loss of skills and independence, generally leading to death in childhood or early adulthood.

Two major types of AxD have been defined. Type I onset typically occurs before four years of age and patients can experience head enlargement, seizures, limb stiffness, delayed or declining cognition, and lack of growth. Type II onset typically occurs after the age of four and symptoms can include difficulty speaking, swallowing, and making coordinated movements. AxD is most often fatal. There are treatments that can relieve symptoms, but there is no disease modifying therapy yet available to patients.

In April 2021, we initiated a pivotal study of zilganersen in patients with AxD and in September 2023, we advanced zilganersen into the Phase 3 portion of the pivotal study. The pivotal study of zilganersen is a multi-center, double-blind, placebo-controlled, multiple-ascending dose study in approximately 55 patients with AxD designed to assess the efficacy, safety and tolerability of zilganersen. Patients will receive zilganersen or placebo for a 60-week period, after which all patients in the study will receive zilganersen for a 60-week open-label treatment period. The primary endpoint is the change from baseline in the 10-Meter Walk Test, or 10MWT.

In September 2020 and October 2019, the FDA and EMA, respectively, granted orphan drug designation to zilganersen. Additionally in August 2020, the FDA granted rare pediatric designation to zilganersen.

Ulefnersen (FUS) – Ulefnersen (formerly ION363) is an investigational antisense medicine we designed to reduce the production of the FUS protein to treat people with ALS caused by mutations in the FUS gene. Because antisense-mediated reduction of mutant FUS protein in a FUS-ALS mouse model demonstrated the ability to prevent motor neuron loss, it is hypothesized that reduction of FUS protein will reverse or prevent disease progression in FUS-ALS patients. It is estimated that there are approximately 350 patients with FUS-ALS in G7 countries.

In April 2021, we initiated a Phase 3 study of ulefnersen in patients with FUS-ALS. The Phase 3 trial of ulefnersen is a global, multi-center, randomized, double-blind, placebo-controlled study in approximately 75 patients designed to assess the efficacy, safety and tolerability of ulefnersen. Part 1 of the trial consists of patients randomized to receive a loading regimen of ulefnersen or placebo for days one, 28 and 85 after which patients are dosed quarterly for a total of 61 weeks, followed by a 12 week follow up for participants entering Part 2 or 40 week follow up for participants not entering Part 2. Part 2 is an open-label period in which all patients in the trial will receive ulefnersen or placebo loading regimen at week four followed by one dose every 12 weeks for 85 weeks. The primary endpoint is the change from baseline as measured by joint rank analysis of the combined assessment of the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale, or ALSFRS-R, Total Score, time of rescue or discontinuation from Part 1 and entering Part 2 due to a deterioration in function, and Ventilation Assistance-free survival, or VAFS.

In August 2023 and September 2023, the FDA and EMA, respectively, granted orphan drug designation to ulefnersen.

Tofersen (SOD1)(BIIB067) –Tofersen (formerly IONIS-SOD1 Rx) is an investigational antisense medicine we designed to inhibit the production of SOD1 protein, which is a well understood genetic cause of ALS. As discussed above under the “QALSODY” section in our “Marketed Medicines” section, Biogen is also evaluating tofersen for treatment ofpresymptomatic individuals who have a SOD1 genetic mutation.

In April 2021, Biogen initiated a Phase 3 study of tofersen, called ATLAS, in presymptomatic individuals with a SOD1 genetic mutation. ATLAS is a multi-center, randomized, double-blind, placebo-controlled study enrolling approximately 150 subjects designed to assess the efficacy, safety and tolerability of tofersen. Patients are only given tofersen if they meet a defined biomarker threshold or progress to develop clinically manifest SOD1-ALS.

In September 2016 and August 2016, the FDA and EMA, respectively, granted orphan drug designation to tofersen.

In December 2018, Biogen exercised its option to license tofersen. As a result, Biogen is responsible for global development, regulatory and commercialization activities, and costs for tofersen.

Bepirovirsen (HBV)(GSK3228836) –Bepirovirsen (formerly IONIS-HBVRx) is an investigational antisense medicine we designed to inhibit the production of viral proteins associated with HBV. These include proteins associated with infection and replication, including the hepatitis B surface antigen, or HBsAg, which is present in both acute and chronic infections and is associated with a poor prognosis in people with chronic HBV infection.

HBV infection is a serious health problem that can lead to significant and potentially fatal health conditions, including cirrhosis, liver failure and liver cancer. Chronic HBV infection is one of the most common persistent viral infections in the world, affecting nearly 300 million people and resulting in approximately 900,000 deaths annually. Currently available therapies, although effective in reducing circulating HBV in the blood, do not effectively inhibit HBV antigen production and secretion, which are associated with poor prognosis and increased risk of liver cancer.

In January 2023, GSK initiated the Phase 3 program of bepirovirsen, B-Well, inpatients with chronic HBV. B-Well 1 and B-Well 2 are global, multi-center, randomized, double-blind, placebo-controlled studies enrolling more than 500 patients each. GSK designed these studies to assess the efficacy, safety and tolerability of bepirovirsen. The arms will be stratified based on HBsAg levels at screening. The primary endpoint is the number of patients achieving functional cure with baseline HBsAg≤ 1,000 IU/mL. Functional cure is defined as a sustained suppression (24 weeks or longer) of HBV DNA (< Lower Limit of Quantification, or LLOQ) while off all HBV treatments with HBsAg loss (<0.05 IU/mL) with or without HBsAg after a finite duration of therapy.

In June 2022, GSK presented positive results from the Phase 2b B-CLEAR study of bepirovirsen in patients with chronic HBV infection. The end of study results showed that treatment with bepirovirsen in some patients resulted in sustained clearance of HBsAg and HBV DNA for 24 weeks after end of bepirovirsen treatment in people with chronic HBV infection. Treatment with bepirovirsen that was administered weekly at a dose of 300 mg per week for 24 weeks, with loading doses administered on day four and 11 (treatment arm 1), resulted in 9% of patients on NA treatment and 10% of patients not on NA treatment both achieving the primary outcome of HBsAg levels and HBV DNA levels below the LLOQ. This is defined as a sustained response and was observed for 24 weeks post last dose. Patients with low baseline HBsAg levels responded best to treatment with bepirovirsen with 16% and 25% of patients achieving the primary outcome in treatment arm one of the on NA and not on NA cohorts, respectively. Additionally in June 2023, GSK presented durable response data from the Phase 2 B-Sure long-term follow-up study of bepirovirsen in complete responder patients from the Phase 2b B-Clear study of patients with HBV. Bepirovirsenhad a favorable safety and tolerability profile supportive of continued development.

In October 2023, GSK reported data from the B-Together Phase 2b study of bepirovirsen in patients with chronic HBV infection at the AASLD Liver Meeting. The data showed that between 9-15% of patients attained the primary outcome of HBsAg and HBV DNA below the LLOQ for 24 weeks after planned end of sequential treatment with pegylated interferon, in the absence of newly initiated antiviral therapy. Additionally, all patients who achieved the primary endpoint had a baseline HBsAg ≤3000 IU/mL. Bepirovirsenhad a favorable safety and tolerability profile supportive of continued development.

In August 2019, GSK exercised its option to license our HBV program following the positive results of the Phase 2a study of bepirovirsen in patients with chronic HBV infection. As a result, GSK is responsible for global development, regulatory and commercialization activities, and costs for the HBV program.

In February 2024, the FDA granted bepirovirsen Fast Track designation for the treatment of patients with chronic HBV infection.

IONIS-FB-LRx (IgAN)(RG6299) – IONIS-FB-LRx is an investigational LICA medicine we designed to inhibit the production of complement factor B, or FB, and the alternative complement pathway. Genetic association studies have shown that overaction of the alternative complement pathway has been associated with the development of several complement-mediated diseases, including IgAN. As discussed below under the “IONIS-FB-LRx” section in our “Other Medicines in Development” section, we are also developing IONIS-FB-LRx for GA, secondary to age-related macular degeneration, or AMD.

IgAN is one of the most common causes of inflammation that impairs the filtering ability of kidneys and is an important cause of chronic kidney disease and kidney failure. Also known as Berger’s disease, IgAN is characterized by deposits of IgA in the kidneys, resulting in inflammation and tissue damage.

In April 2023, Roche initiated a Phase 3 study of IONIS-FB-LRx, called IMAGINATION, in patients with IgAN. IMAGINATION is a multi-center, randomized, double-blind, placebo-controlled study enrolling approximately 430 patients designed to assess the efficacy, safety and tolerability of IONIS-FB-LRx. The primary endpoint is the change from baseline in the urine protein-to-creatinine ratio, or UPCR, at week 37.

In November 2022, we presented positive results from the Phase 2 open-label study of IONIS-FB-LRx in patients with IgAN at the American Society of Nephrology’s, or ASN, Kidney Week. In the Phase 2 study, which included results from the first 10 patients treated with IONIS-FB-LRx, IONIS-FB-LRx met its primary endpoint of change in 24-hour urinary protein, demonstrating a 44% mean reduction in proteinuria from baseline to week 29. Kidney function, as measured by estimated glomerular filtration rate, or eGFR, was maintained in all patients in the study. The results from the Phase 2 study provided proof-of-concept for the potential of IONIS-FB-LRx to treat patients with IgAN by inhibiting complement FB and the alternative complement pathway. Additionally, in November 2023 at ASN Kidney Week, we presented new positive interim results from the ongoing Phase 2 study, which included results from 13 patients. The results showed that IONIS-FB-LRx effectively and selectively reduced circulating FB, Alternate Pathway Activity, or AH50 and urinary complement Ba. Additionally, IONIS-FB-LRx reduced established proteinuria in patients with IgAN after six-months of treatment. The Phase 2 open-label study remains ongoing and will evaluate IONIS-FB-LRx in approximately 25 patients with IgAN. IONIS-FB-LRx had a favorable safety and tolerability profile supportive of continued development.

In July 2022, Roche exercised its option to license IONIS-FB-LRx following the positive Phase 2 results described above. As a result, Roche is responsible for global development, regulatory and commercialization activities, and costs for IONIS-FB-LRx, except for the open label Phase 2 study in patients with IgAN and the Phase 2 study in patients with GA, both of which we are conducting and funding.

Our Neurological Medicines in Development

We have a leading neurology franchise that includes three approved medicines for serious neurological diseases and a pipeline of investigational potential disease-modifying treatments for a broad range of neurological diseases. As we look to expand our wholly owned pipeline, we are focused on four pillars within our neurology franchise. We are first focusing on two areas: rare pediatric neurology and dementia, with plans to move into neuromuscular and peripheral neuropathies and motor diseases and then common neurological diseases in the future. We recently added ION717 for prion disease to our pipeline with plans to add three additional medicines by the end of 2024.

Zilganersen– See the medicine description under “Our Phase 3 Pipeline” section above.

Ulefnersen – See the medicine description under “Our Phase 3 Pipeline” section above.

Tofersen– See the medicine description under “Our Phase 3 Pipeline” section above.

ION717 (PRNP) –ION717 is an investigational antisense medicine we designed to inhibit the production of prion protein, or PrP, for the potential treatment of prion disease. Prion disease is a rare, fatal neurodegenerative disease caused by misfolding of PrP which accumulates in the brain. People with prion disease often experience progressive memory impairment, personality changes, difficulties with movement and loss of independence. There are currently no effective disease-modifying treatments for prion disease. In most cases, a person succumbs to prion disease within a year following symptom onset.

In December 2023, we initiated the Phase 1/2, PrProfile, study of ION717 in patients with prion disease. The current study is a randomized, multi-center, double-blind, placebo-controlled study in approximately 55 patients designed to assess the safety, tolerability and pharmacokinetics of multiple dose levels of ION717 administered intrathecally.

IONIS-MAPTRx (TAU)(BIIB080) – IONIS-MAPTRx is an investigational antisense medicine we designed to selectively inhibit production of the microtubule-associated protein tau (MAPT), or tau protein in the brain. We are developing IONIS-MAPTRx to treat people with Alzheimer’s disease, or AD.

AD is characterized predominantly by memory impairment and behavioral changes, resulting in a person’s inability to independently perform daily activities. AD generally occurs late in life and may progress to death in five to 20 years after the onset of the disease.

In December 2022, Biogen initiated a Phase 2 clinical study of IONIS-MAPTRx in patients with mild cognitive impairment or mild dementia due to AD. The study is a randomized, double-blinded, placebo-controlled, dose-escalation study in approximately 735 patients designed to assess the efficacy, safety and tolerability of IONIS-MAPTRx administered intrathecally. The primary endpoint is the change from baseline to week 76 on the Clinical Dementia Rating scale Sum of Boxes, or CDR-SB.

In March 2023, Biogen presented new data from the Phase 1/2 study at the International Conference on Alzheimer's and Parkinson's Diseases. The data showed that IONIS-MAPTRx reduced soluble tau protein in CSF in a dose-dependent and sustained manner in patients with early-stage AD. IONIS-MAPTRx also reduced aggregated tau pathology, as measured by positron emission tomography, or PET, in all brain composites assessed. In October 2023, these data were published in JAMA. Additionally in October 2023, Biogen presented new data from the Phase 1/2 study at The Clinical Trials on Alzheimer’s Disease, or CTAD, conference. The data showed a numerical difference favoring IONIS-MAPTRx on multiple cognitive and functional scales for the patients receiving higher doses of IONIS-MAPTRx throughout the multiple ascending dose and long-term extension compared to matched external control patients receiving placebo. The assessments included: Clinical Dementia Rating Sum of Boxes, or CDR-SB, Mini-Mental State Examination, or MMSE and, Functional Activities Questionnaire, or FAQ.

In July 2021, we and Biogen reported positive topline data from our Phase 1/2 study of IONIS-MAPTRx in patients with mild AD at the Alzheimer’s Association International Conference, or AAIC. The Phase 1/2 study was a blinded, randomized, placebo-controlled, dose-escalation study of IONIS-MAPTRx to evaluate the safety and activity of once-monthly intrathecal injections of IONIS-MAPTRx in patients with mild AD. The study showed that IONIS-MAPTRx met its primary objective of safety and tolerability in patients with mild AD. The study demonstrated robust time and dose dependent lowering of tau protein in CSF over the three-month treatment period and sustained reductions during the six-month post-treatment period. IONIS-MAPTRx had a favorable safety and tolerability profile supportive of continued development.

In December 2019, Biogen exercised its option to license IONIS-MAPTRx. Biogen has responsibility for global development, regulatory and commercialization activities, and costs for IONIS-MAPTRx.

ION859 (LRRK2)(BIIB094) – ION859 is an investigational antisense medicine we designed to inhibit the production of the Leucine Rich Repeat Kinase 2, or LRRK2, protein as a potential therapy for Parkinson’s disease, or PD. The most common genetic mutations in PD are found in the LRRK2 protein. It is believed that increased LRRK2 protein activity could be one of the key drivers for developing PD. PD is a progressive neurodegenerative disease characterized by loss of neurons in the motor system. Patients with PD can experience tremors, loss of balance and coordination, stiffness, slowing of movement, changes in speech and in some cases cognitive decline. PD is ultimately fatal. There are treatments that can relieve symptoms, but there are no approved disease modifying therapies.

In August 2019, Biogen initiated a Phase 1/2 study evaluating ION859 in patients with PD. The Phase 1/2 study is a global, multi-center, randomized, double-blinded, placebo-controlled study in approximately 80 patients designed to assess the safety, tolerability and activity of multiple ascending doses of ION859 administered intrathecally.

ION859 is being developed under our 2013 Strategic Neurology collaboration with Biogen.

ION464 (SNCA) (BIIB101) – ION464 is an investigational antisense medicine we designed to inhibit the production of the alpha-synuclein protein as a potential therapy for PD, Multiple System Atrophy, or MSA, and related synucleinopathies. Alpha-synuclein protein abnormally accumulates in the brains of PD and MSA patients and is thought to be one of the key drivers of these diseases. It is believed that decreasing the production of the alpha-synuclein protein will reduce the toxic effects of gain-of-function mutations.

In July 2020, we initiated a Phase 1/2 study evaluating ION464 in patients with MSA. The current study is a multi-center, randomized, double-blinded, placebo-controlled study in approximately 40 patients designed to assess the safety and tolerability of multiple ascending doses of ION464 administered intrathecally.

ION464 is being developed under our 2013 Strategic Neurology collaboration with Biogen.

ION541 (ATXN2)(BIIB105) – ION541 is an investigational antisense medicine we designed to reduce the production of the ataxin-2, or ATXN2, protein for the potential treatment of ALS. The reduction of ATXN2 has been shown to decrease toxic aggregation of TDP-43, an RNA binding protein found in most patients with ALS, including the approximately 90% of the ALS population with no known family history of ALS.

In October 2020, Biogen initiated a Phase 1/2 clinical study evaluating ION541 in patients with ALS. The current study is a randomized, blinded, placebo-controlled study in approximately 110 patients designed to assess the safety, tolerability, and pharmacokinetics of multiple ascending doses of ION541 administered intrathecally.

ION541 is being developed under our 2013 Strategic Neurology collaboration with Biogen.

ION582 (UBE3A) (BIIB121) – ION582 is an investigational antisense medicine we designed to inhibit the expression of the UBE3A antisense transcript, or UBE3A-ATS for the potential treatment of Angelman Syndrome, or AS. AS is a rare, genetic neurological disease caused by the loss of function of the maternally inherited UBE3A gene. AS typically presents in infancy and is characterized by intellectual disability, balance issues, motor impairment, and debilitating seizures. Some patients are unable to walk or speak. Some symptoms can be managed with existing drugs; however, there are no approved disease modifying therapies.

In December 2021, we initiated the Phase 1/2 study, HALOS, of ION582 in patients with AS. The study is an open label dose-escalation study enrolling approximately 50 patients designed to assess the safety, tolerability and activity of multiple ascending doses of ION582 administered intrathecally. In November 2023, we announced that the HALOS study had completed enrollment.

In November 2023, we presented initial observations from the ongoing Phase 1/2 study at the Foundation for Angelman Syndrome, or FAST, summit. The data demonstrated that approximately 70% of patients showed a reduction in slow-wave electroencephalogram, or EEG, delta activity and over 80% showed an increase in faster frequency rhythms. Additionally, a majority of patients showed improvement in overall functioning on the SAS-CGI-C scale. A majority of patients also showed improvement on the total Bayley score, which is a direct assessment of clinical functioning.

In May 2022 and June 2022, the FDA and EMA, respectively, granted orphan drug designation to ION582. Additionally in July 2022 and May 2022, the FDA granted Fast Track designation and rare pediatric designation to ION582, respectively.

ION582 is being developed under our 2012 Neurology collaboration with Biogen.

Tominersen (HTT) (RG6042) –Tominersen (formerly IONIS-HTTRx) is an investigational antisense medicine we designed to target the underlying cause of Huntington’s disease, or HD, by reducing the production of all forms of the huntingtin protein, or HTT, including its mutated variant, or mHTT. HD is an inherited genetic brain disorder that results in the progressive loss of both mental faculties and physical control. It is caused by the expansion of the cytosine-adenine-guanine, or CAG, trinucleotide sequence in the HTT gene. The resulting mutant HTT protein is toxic and gradually destroys neurons. Symptoms usually appear between the ages of 30 and 50 and worsen over a 10 to 25-year period. Ultimately, the weakened individual succumbs to pneumonia, heart failure or other complications. Presently, there is no effective treatment or cure for the disease, and currently available medicines only mask the patient’s symptoms but do not slow down the underlying loss of neurons.

In January 2023, Roche initiated the Phase 2, GENERATION HD2, study of tominersen in patients aged 25 to 50 years old with prodromal and early manifest HD. The Phase 2 study of tominersen is a multi-center, double-blind, placebo-controlled study in approximately 360 patients designed to assess the efficacy, safety and tolerability of tominersen. Patients will receive tominersen or placebo every 16 weeks for 16 months, after which patients may receive tominersen in an open-label study. The primary endpoint is the change from baseline in the composite Unified Huntington’s Disease Ratings Scale, or cUHDRS, (non-U.S.) and overall functional capacity, or TFC, (U.S.) at 16 months.

Roche conducted the Phase 3 study, GENERATION HD1, of tominersen in patients with HD. The Phase 3 study was a randomized, multicenter, double-blind, placebo-controlled study that recruited 791 participants. In March 2021, Roche announced that dosing would be stopped in the study following a recommendation from the independent data monitoring committee, or iDMC, based on an overall benefit/risk assessment. In January 2022, Roche announced findings from a post-hoc analysis of the GENERATION HD1 study that suggested tominersen may benefit younger adult patients with lower disease burden.

In December 2015 and March 2015, the FDA and EMA, respectively, granted orphan drug designation to tominersen. Additionally in August 2018, the EMA granted PRIME designation to tominersen.

In December 2017, Roche exercised its option to license tominersen. As a result, Roche is responsible for global development, regulatory and commercialization activities, and costs for tominersen.

Our Cardiovascular Medicines in Development

Our cardiovascular franchise includes investigational medicines that target the major risk factors of CVD.

Eplontersen– See the medicine description under “Our Phase 3 Pipeline” section above.

Olezarsen– See the medicine description under “Our Phase 3 Pipeline” section above.

Pelacarsen– See the medicine description under “Our Phase 3 Pipeline” section above.

Fesomersen (FXI) – Fesomersen (formerly IONIS-FXI-LRx) is an investigational LICA medicine we designed to inhibit the production of Factor XI. Factor XI is a clotting factor produced in the liver that is important in the growth of blood clots. Thrombosis, characterized by the formation of a blood clot inside blood vessels, can cause heart attacks and strokes. People who are deficient in Factor XI have a lower incidence of thromboembolic events with minimal increase in bleeding risk. Although currently available anticoagulants reduce the risk of thrombosis, physicians associate these anticoagulants with increased bleeding, which can be fatal. By inhibiting Factor XI production, we believe that fesomersen can be used for the treatment of a number of non-acute forms of thrombosis where additional safe and well tolerated anti-thrombotic medicines are needed.

In November 2022, Bayer presented positive results from the RE-THINc Phase 2b study of fesomersen in patients with end-stage renal disease, or ESRD, on hemodialysis at the ASN Kidney Week. In the study, fesomersen achieved its primary endpoint, demonstrating no increase in the incidence of the composite of major bleeding and clinically relevant non-major bleeding with 24 weeks of treatment. Fesomersen also achieved dose-dependent and sustained median reductions in steady-state FXI levels of 53.1%, 72.2% and 86.6% in the 40 mg, 80 mg, and 120 mg doses of fesomersen, respectively, administered once every four weeks. Incidences of dialysis circuit clotting and arteriovenous access, or AV-access, thrombosis diminished significantly with decreasing FXI levels, both of which were exploratory efficacy endpoints. Fesomersen had a favorable safety and tolerability profile supportive of continued development.

In November 2022, we regained all rights to fesomersen, which we had previously licensed to Bayer in February 2017.

ION904 (AGT) – ION904 is an investigational next-generation LICA medicine designed to inhibit the production of angiotensinogen to decrease blood pressure in people with uncontrolled hypertension. ION904 is a follow-on medicine targeting AGT, designed to enable less frequent dosing compared to IONIS-AGT-LRx.

In November 2023 at the AHA annual meeting we presented positive results from the Phase 2 clinical study of ION904 in patients with mild to moderate uncontrolled hypertension on one or more anti-hypertensive medications for at least one month. ION904 significantly reduced AGT levels compared to placebo. ION904 had a favorable safety and tolerability profile supportive of continued development.

Other Medicines for High Patient Need in Development

We also have other medicines for high patient need in development that are outside of our cardiovascular and neurological franchises that we believe could represent compelling opportunities for us, including our Specialty Rare medicines, donidalorsen and sapablursen.

Donidalorsen – See the medicine description under “Our Phase 3 Pipeline” section above.

Sapablursen (TMPRSS6) – Sapablursen (formerly IONIS-TMPRSS6-LRx) is an investigational LICA medicine we designed to target the TMPRSS6 gene to modulate the production of hepcidin, which is the key regulator of iron homeostasis. By modulating hepcidin expression, sapablursen has the potential to positively impact diseases characterized by iron deficiency, such as polycythemia vera, or PV.

PV is a rare disease driven by a mutation in the JAK2 gene that is potentially fatal and characterized by overproduction of red blood cells. This overproduction leads to a thickening of the blood, which increases patients’ risk of life-threatening blood clots, including in the lungs, heart and brain. Patients with PV also experience severe iron deficiency and symptoms such as fatigue and impaired cognitive function. There are no approved disease-modifying treatments for PV.

In January 2022, we initiated a Phase 2 study evaluating sapablursen in patients with phlebotomy dependent PV, or PD-PV. The Phase 2 study is a multi-center, randomized, open-label study in approximately 40 patients designed to assess the efficacy, safety and tolerability of sapablursen. The primary endpoint is the change in the frequency of phlebotomy comparing baseline with the last 20 weeks of the 37-week treatment period.

In December 2018, we presented positive data from our Phase 1 study of sapablursen in healthy volunteers at the American Society of Hematology Annual Meeting. The Phase 1 study demonstrated dose-dependent reductions of serum iron and serum transferrin saturation with sapablursen. Additionally, we observed an increase in serum hepcidin and predicted changes in hemoglobin. Sapablursen had a favorable safety and tolerability profile supportive of continued development.

In September 2020, the FDA granted Fast Track designation to sapablursen for polycythemia vera.

Bepirovirsen –See the medicine description under “Our Phase 3 Pipeline” section above.

IONIS-FB-LRx (IgAN) –See the medicine description under “Our Phase 3 Pipeline” section above.

ION224 (DGAT2) –ION224 is an investigational LICA medicine we designed to reduce the production of diacylglycerol acyltransferase 2, or DGAT2, to treat patients with nonalcoholic steatohepatitis, or NASH. NASH is a common liver disease characterized by liver steatosis, inflammation and scarring and can lead to increased risk of CVD, liver cancer, need for liver transplantation and early death. DGAT2 is an enzyme that catalyzes the final step in triglyceride synthesis in the liver. Reducing the production of DGAT2 should therefore decrease triglyceride synthesis in the liver. In animal studies, antisense inhibition of DGAT2 significantly improved liver steatosis, lowered blood lipid levels and reversed diet-induced insulin resistance.

Nonalcoholic fatty liver disease, or NAFLD, describes the full spectrum of liver disease progression from fatty liver to NASH to cirrhosis to hepatocellular carcinoma. NASH epidemiology studies have estimated 13% to 32% of the global population has NAFLD, 1.5% to 6.5% have NASH, and up to 10% of NASH patients progress to advanced liver disease. There are currently no commercially available medications to treat NASH.

NASH is sometimes considered a “silent” liver disease because people with early-stage NASH feel well, even though they are starting to accumulate fat in their livers and may not be aware that they have the disease. However, NASH can develop into more severe diseases such as liver cirrhosis and liver failure. Currently, liver transplant is the only therapeutic option for patients with liver cirrhosis. In addition, NASH has been shown to be a major risk factor for the development of liver cancer.

In June 2021, we initiated a Phase 2 study of ION224 in patients with confirmed non-alcoholic steatohepatitis. The Phase 2 study isa multi-center, randomized, double-blind, placebo-controlled clinical study in approximately 160 patients designed to assess the efficacy, safety and tolerability of multiple subcutaneous doses of ION224 on NASH histologic improvement.

IONIS-FB-LRx –IONIS-FB-LRx (RG6299) is an investigational LICA medicine we designed to inhibit the production of FB, and the alternative complement pathway. Genetic association studies have shown that overaction of the alternative complement pathway has been associated with the development of several complement-mediated diseases, including IgAN (see section above “Our Phase 3 Pipeline” for discussion of IgAN) and GA secondary to AMD.

AMD is the leading cause of central vision loss in developed countries. GA is an advanced form of AMD.

In June 2019, we initiated a Phase 2 GOLDEN study evaluating IONIS-FB-LRx in patients with GA secondary to AMD. The study is a randomized, masked, placebo-controlled study in approximately 330 patients designed to assess the efficacy, safety and tolerability of multiple ascending doses of IONIS-FB-LRx administered subcutaneously in adults with GA. The primary endpoint is the absolute change from baseline in GA area at week 49. In August 2023, we announced that the GOLDEN study had completed enrollment.

In July 2022, Roche exercised its option to license IONIS-FB-LRx following the positive Phase 2 results for IgAN. As a result, Roche is responsible for global development, regulatory and commercialization activities, and costs for IONIS-FB-LRx, except for the open label Phase 2 study in patients with IgAN and the Phase 2 study in patients with GA, both of which we are conducting and funding.

ION839 (PNPLA3) –ION839 (AZD2693) is an investigational LICA medicine we designed to inhibit the production of patatin-like phospholipase domain-containing 3, or PNPLA3, protein. PNPLA3 is a protein that is found on the surface of intracellular lipid droplets. Studies have shown that a common genetic mutation of PNPLA3 is strongly associated with an increased risk for NASH. The mutant PNPLA3 protein is resistant to degradation, causing it to accumulate on the surface of lipid droplets, which disrupts the normal process for degrading lipid droplets, leading to increased liver fat accumulation, the underlying pathology of NASH.

In March 2023, AstraZeneca initiated a Phase 2b study of ION839 in patients with confirmed NASH with fibrosis and who are carriers of the PNPLA3 mutation. The Phase 2b study isa multi-center, randomized, double-blind, placebo-controlled clinical study in approximately 180 patients designed to assess the efficacy, safety and tolerability of multiple subcutaneous doses of ION839. The primary endpoint is the proportion of patients achieving NASH resolution without worsening of fibrosis based on histology after 52 weeks of treatment.

In April 2018, AstraZeneca exercised its option to license ION839. As a result, AstraZeneca is responsible for global development, regulatory and commercialization activities, and costs for ION839.

Our Technology

For three decades through our innovations in science and technology, we have enhanced the profiles of RNA-targeted medicines and pursued new opportunities in emerging areas of genetic medicine. Our recent technology advancements have enabled us to advance programs with the potential for extended dosing and delivery to new tissues, such as muscle. We have also added capabilities to utilize RNA interference, or RNAi, and potentially gene editing in addition to our novel antisense technology, which gives us the potential to deliver medicines to a greater number of people living with serious diseases.

Overview of Ionis’ Technology

All of the medicines currently in our clinical pipeline use our antisense technology — an innovative platform for discovering first-in-class and/or best-in-class medicines. Antisense medicines target RNA, the intermediary that conveys genetic information from a gene to the protein synthesis machinery in the cell. By targeting RNA instead of proteins, we can use antisense technology to increase, decrease or alter the production of specific proteins. Most of our antisense medicines are designed to bind to mRNAs and inhibit the production of disease-causing proteins. Examples of these include WAINUA, olezarsen and donidalorsen. SPINRAZA is an example of an antisense medicine that modulates RNA splicing to increase protein production of the SMN protein, which is critical to the health and survival of nerve cells in the spinal cord that are responsible for neuro-muscular function. The SMN protein is deficient in people with SMA. Our antisense technology is also broadly applicable to many additional antisense mechanisms including decreasing toxic RNAs.

We also now use small interfering RNA (siRNA) technology, in addition to antisense technology, in the development of new medicines. Like antisense, siRNA medicines target RNA, and can decrease the production of specific proteins involved in disease. For each program we work on, we choose the approach which demonstrates the best potential product profile for the indication we are pursuing.

Our advanced LICA technology is a chemical technology we developed that involves attaching a molecule called a ligand that binds with receptors on the surface of cells in a highly specific manner. Because these receptors are often found only on certain cell types, LICA allows us to increase effective delivery of our antisense medicines with higher specificity to certain cell types that express these receptors relative to non-conjugated antisense medicines. We currently have an integrated assessment of data from multiple LICA medicines and clinical programs which demonstrates that our LICA technology for liver targets can increase potency by 20-30-fold over our non-LICA antisense medicines. Our LICA medicines have also demonstrated consistently favorable safety and tolerability in clinical trials, including in our Phase 3 studies of WAINUA (for ATTRv-PN), olezarsen (for FCS patients) and donidalorsen (for HAE).

Emerging Technology Advancements

Our recent technology advancements have enabled usto create even more potent medicines amenable to more potential targets and tissue types. We have also diversified theapproaches we can use in designing our medicines in order to reach more patients with severe diseases. Today our medicines and those entering our pipeline utilize our key technology advances, including our Bicycle LICA technology, siRNA technology and MsPA backbone chemistry. And through our Metagenomi collaboration, we added the potential to use gene editing, which modifies DNA.

Mesyl phosphoramidate Backbone Chemistry

We designed our MsPA backbone chemistry to improve both therapeutic index and durability. It does this by increasing metabolic stability relative to the other backbone chemistries we utilize. We have also shown it can improve potency in certain circumstances and reduce non-specific interactions with proteins that can cause undesirable effects, such as proinflammatory effects. We currently have multiple new programs using our MsPA backbone, designed to improve both efficacy and durability, in preclinical development.

Bicycle Collaboration

In 2021, we entered into a collaboration with Bicycle Therapeutics that we expect can expand our LICA platform to target both skeletal and cardiac muscle, and potentially deliver medicines across the blood brain barrier. Bicycles are small, bicyclic peptides that have high affinity and selectivity for protein targets. Our collaboration with Bicycle allows us to utilize Bicycles that bind transferrin receptor 1 to facilitate the tissue specific delivery of oligonucleotide drugs (both antisense and siRNAs). We advanced our first Bicycle LICA program into preclinical development in 2023.

Gene Editing and Metagenomi Collaboration

In 2022, we entered into a collaboration with Metagenomi that leverages our extensive expertise in RNA-targeted therapeutics and Metagenomi’s versatile next-generation gene editing systems to pursue a mix of validated and novel genetic targets with the goal of discovering and developing new drugs. These targets have the potential to expand therapeutic options for patients.

Gene editing utilizes specific RNA-guided nucleases known as Cas enzymes to precisely and permanently modify a DNA sequence. Because of this, gene editing holds the promise of treatments that could provide long-term, potentially permanent, therapeutic benefits.

Gene editing is highly complementary and synergistic with RNA-targeted therapeutics. Both platforms rely on the same nucleic acid hybridization principals to precisely target nucleases to either RNA, in the case of RNase H and siRNA drugs, or to DNA in the case of Clustered Regularly Interspaced Short Palindromic Repeats, or CRISPR-Cas systems. This enables us to leverage our expertise in nucleic acids and modified nucleic acid chemistry with the goal to enhance gene editing’s ability to treat diseases for which there are limited treatment options.

Collaborative Arrangements

We have established alliances with a cadre of leading global pharmaceutical companies. Our partners include the following companies, among others: AstraZeneca, Biogen, GSK, Novartis, Otsuka and Roche. Through our partnerships, we have earned both commercial revenue and a broad and sustaining base of R&D revenue in the form of license fees, upfront payments and milestone payments. In addition, we are eligible to receive royalties under our partnerships. Below, we include the significant terms of our collaboration agreements. For additional details, including other financial information, refer to Part IV, Item 15, Note 4, Collaborative Arrangements and Licensing Agreements, in the Notes to the Consolidated Financial Statements.

Strategic Partnership

Biogen

We have several strategic collaborations with Biogen focused on using antisense technology to advance the treatment of neurological disorders. These collaborations combine our expertise in creating antisense medicines with Biogen’s expertise in developing therapies for neurological disorders. We developed and licensed to Biogen SPINRAZA, our approved medicine to treat people with SMA. In April 2023, the FDA granted accelerated approval for QALSODY (tofersen) in the U.S. to treat patients with SOD1-ALS. Biogen developed QALSODY under our 2013 strategic neurology collaboration. In addition, we and Biogen are currently developing numerous other investigational medicines to treat neurodegenerative diseases, including medicines in development to treat people with ALS, SMA, AS, AD, and PD. From inception through December 31, 2023, we have generated more than $3.8 billion in payments from our Biogen collaborations.

Spinal Muscular Atrophy Collaborations

In 2012, we entered into a collaboration agreement with Biogen to develop and commercialize SPINRAZA, an RNA-targeted therapy for the treatment of SMA. We are receiving tiered royalties ranging from 11 percent to 15 percent on sales of SPINRAZA. We have exclusively in-licensed patents related to SPINRAZA from Cold Spring Harbor Laboratory and the University of Massachusetts. We pay Cold Spring Harbor Laboratory and the University of Massachusetts a low single digit royalty on net sales of SPINRAZA. Under our agreement, Biogen is responsible for global development, regulatory and commercialization activities and costs for SPINRAZA. From inception through December 31, 2023, we recognized more than $2.0 billion in total revenue under our SPINRAZA collaboration, including more than $1.6 billion in revenue from SPINRAZA royalties and more than $425 million in R&D revenue.

New antisense medicines for the treatment of SMA

In 2017, we entered into a collaboration agreement with Biogen to identify new antisense medicines for the treatment of SMA. Biogen has the option to license therapies arising out of this collaboration following the completion of preclinical studies. Upon licensing, Biogen will be responsible for global development, regulatory and commercialization activities and costs for such therapies.

In 2021, Biogen exercised its option to license ION306. Biogen is solely responsible for the costs and expenses related to the development, manufacturing and potential future commercialization of ION306 following the option exercise. We will receive development and regulatory milestone payments from Biogen if new medicines, including ION306, advance towards marketing approval.

Over the term of this collaboration, we are eligible to receive development, regulatory and sales milestone payments. In addition, we are eligible to receive tiered royalties from the mid-teens to mid-20 percent range on net sales from any product that Biogen successfully commercializes under this collaboration. From inception through December 31, 2023, we have generated $85 million in payments under this collaboration.

Neurology Collaborations

2018 Strategic Neurology

In 2018, we and Biogen entered into a strategic collaboration to develop novel antisense medicines for a broad range of neurological diseases. We also entered into a Stock Purchase Agreement, or SPA. As a result, we received a payment related to the SPA in addition to an upfront payment at the commencement of this collaboration. As part of the collaboration, Biogen gained exclusive rights to the use of our antisense technology to develop therapies for these diseases for 10 years. We are responsible for the identification of antisense drug candidates based on selected targets. In most cases, Biogen will be responsible for conducting IND-enabling toxicology studies for the selected medicine. Biogen has the option to license the selected medicine after it completes the IND-enabling toxicology study. If Biogen exercises its option to license a medicine, it will assume global development, regulatory and commercialization responsibilities and costs for that medicine.

For each medicine under this collaboration, we are eligible to receive a license fee, development milestone payments and regulatory milestone payments. In addition, we are eligible to receive tiered royalties up to the 20 percent range on net sales from any product that Biogen successfully commercializes under this collaboration. We are currently advancing multiple programs under this collaboration. From inception through December 31, 2023, we have generated nearly $1.1 billion in payments under this collaboration.

2013 Strategic Neurology

In 2013, we and Biogen entered into a strategic relationship focused on applying antisense technology to advance the treatment of neurodegenerative diseases. As part of the collaboration, Biogen gained exclusive rights to the use of our antisense technology to develop therapies for neurological diseases and has the option to license medicines resulting from this collaboration. In most cases, we are responsible for drug discovery and early development of antisense medicines and Biogen has the option to license antisense medicines after Phase 2 proof-of-concept. In 2016, we expanded our collaboration to include additional research activities we will perform. If Biogen exercises its option to license a medicine, it will assume global development, regulatory and commercialization responsibilities and costs for that medicine.

We are currently advancing four investigational medicines in development under this collaboration, including a medicine for Parkinson’s disease (ION859), two medicines for ALS (QALSODY and ION541) and a medicine for multiple system atrophy (ION464). In 2018, Biogen exercised its option to license QALSODY, our medicine that received accelerated approval in April 2023 from the FDA for the treatment of adult patients with SOD1-ALS. As a result, Biogen is responsible for global development, regulatory and commercialization activities and costs for QALSODY.

Under the terms of the agreement, we are eligible to receive milestone payments, license fees and royalty payments for all medicines developed under this collaboration, with the specific amounts dependent upon the modality of the molecule advanced by Biogen.

Over the term of the collaboration for QALSODY, we are eligible to receive a license fee, development milestone payments and regulatory milestone payments. In addition, we are eligible to receive tiered royalties ranging from 11 percent to 15 percent on net sales of QALSODY.

For each of the other antisense molecules that are chosen for drug discovery and development under this collaboration, we are eligible to receive a license fee, development milestone payments and regulatory milestone payments. In addition, we are eligible to receive tiered royalties up to the mid-teens on net sales from any product that Biogen successfully commercializes under this collaboration. From inception through December 31, 2023, we have generated more than $325 million in payments under our 2013 strategic neurology collaboration.

2012 Neurology

In 2012, we and Biogen entered into a collaboration agreement to develop and commercialize novel antisense medicines to treat neurodegenerative diseases. We are responsible for the development of each of the medicines through the completion of the initial Phase 2 clinical study for such medicine. Biogen has the option to license a medicine from each of the programs through the completion of the first Phase 2 study for each program. Under this collaboration, Biogen is conducting the IONIS-MAPTRx study for AD and we are currently advancing ION582 for AS. If Biogen exercises its option to license a medicine, it will assume global development, regulatory and commercialization responsibilities and costs for that medicine. In 2019, Biogen exercised its option to license IONIS-MAPTRx and as a result Biogen is responsible for global development, regulatory and commercialization activities and costs for IONIS-MAPTRx.

For each program under this collaboration, we are eligible to receive a license fee, development milestone payments and regulatory milestone payments, plus a mark-up on the costs of the Phase 1 and 2 studies. In addition, we are eligible to receive tiered royalties up to the mid-teens on net sales from any product that Biogen successfully commercializes under this collaboration. From inception through December 31, 2023, we have generated more than $230 million in payments under this collaboration.

Joint Development and Commercialization Arrangement

WAINUA (Eplontersen) Collaboration

In 2021, we entered into a joint development and commercialization agreement with AstraZeneca to develop and commercialize eplontersen for the treatment of ATTR. In December 2023, the FDA approved eplontersen with the brand name, WAINUA, in the U.S. for ATTRv-PN. We are jointly developing and commercializing WAINUA with AstraZeneca in the U.S. We initially granted AstraZeneca exclusive rights to commercialize WAINUA outside the U.S., except for certain Latin American countries. In July 2023, we expanded those rights to include Latin America.

The collaboration includes territory-specific development, commercial and medical affairs cost-sharing provisions. AstraZeneca is currently responsible for 55 percent of the costs associated with the ongoing global Phase 3 development program. AstraZeneca is responsible for the majority of the commercial and medical affairs costs in the U.S. and all costs associated with bringing WAINUA to market outside the U.S.

Over the term of the collaboration, we are eligible to receive an upfront payment, license fee, development and approval milestone payments and sales milestone payments. In addition, we are eligible to receive up to mid-20 percent royalties for sales in the U.S. and tiered royalties ranging from mid to high teens for sales outside the U.S. From inception through December 31, 2023, we have generated more than $425 million in payments under this collaboration, including a milestone payment for the approval of WAINUA in the U.S. and revenue we earned from cost sharing provisions.

Research and Development Partners

In addition to our collaboration for WAINUA, we have a collaboration with AstraZeneca focused on discovering and developing treatments for cardiovascular, renal and metabolic diseases, which we formed in 2015. Under our collaboration, AstraZeneca has licensed multiple medicines from us. AstraZeneca is responsible for global development, regulatory and commercialization activities and costs for each of the medicines it has licensed from us.

Over the term of the collaboration, we are eligible to receive an upfront payment, license fees, development milestone payments and regulatory milestone payments. In addition, we are eligible to receive tiered royalties up to the low teens on net sales from any product that AstraZeneca successfully commercializes under this collaboration agreement. From inception through December 31, 2023, we have generated more than $340 million in payments under this collaboration.

GSK

In 2010, we entered into a collaboration with GSK using our antisense drug discovery platform to discover and develop new medicines against targets for serious and rare diseases, including infectious diseases. Under our collaboration, GSK is developing bepirovirsen for the treatment of chronic HBV infection. In 2019, following positive Phase 2 results, GSK licensed our HBV program. GSK is responsible for all global development, regulatory and commercialization activities and costs for the HBV program.

Over the term of the collaboration, we are eligible to receive an upfront payment, a license fee, development milestone payments, regulatory milestone payments and sales milestone payments if GSK successfully develops and commercializes bepirovirsen. In addition, we are eligible to receive tiered royalties up to the low-teens on net sales of bepirovirsen. From inception through December 31, 2023, we have generated more than $105 million in payments under the HBV program collaboration.

Novartis

Pelacarsen Collaboration

In 2017, we initiated a collaboration with Novartis to develop and commercialize pelacarsen. Novartis is responsible for conducting and funding development and regulatory activities for pelacarsen, including a global Phase 3 cardiovascular outcomes study that Novartis initiated in 2019.

Over the term of the collaboration, we are eligible to receive an upfront payment, a license fee, a development milestone payment, regulatory milestone payments and sales milestone payments. We are also eligible to receive tiered royalties in the mid-teens to low 20 percent range on net sales of pelacarsen. From inception through December 31, 2023, we have generated more than $275 million in payments under this collaboration.

New Medicine for the Treatment of Lp(a)-Driven Cardiovascular Disease

In August 2023, we entered into a collaboration and license agreement with Novartis for the discovery, development and commercialization of a novel medicine for patients with Lp(a)-driven cardiovascular disease, or CVD. Novartis is solely responsible for the development, manufacturing and potential commercialization of the next generation Lp(a) therapy.

Over the term of the collaboration, we are eligible to receive an upfront payment, development milestone payments, regulatory milestone payments and sales milestone payments. In addition, we are eligible to receive tiered royalties ranging from 10 percent to 20 percent on net sales. From inception through December 31, 2023, we have generated $60 million in payments under this collaboration.

Roche

Huntington’s Disease

In 2013, we entered into an agreement with Hoffmann-La Roche Inc and F. Hoffmann-La Roche Ltd, collectively Roche, to develop treatments for HD based on our antisense technology. Under the agreement, we discovered and developed tominersen, an investigational medicine targeting HTT protein. We developed tominersen through completion of our Phase 1/2 clinical study in people with early-stage HD. In 2017, upon completion of the Phase 1/2 study, Roche exercised its option to license tominersen. As a result, Roche is responsible for all global development, regulatory and commercialization activities and costs for tominersen.

Over the term of the collaboration, we are eligible to receive a license fee, development milestone payments, regulatory milestone payments and sales milestone payments as tominersen advances. In addition, we are eligible to receive milestone payments for each additional medicine successfully developed. We are also eligible to receive tiered royalties up to the mid-teens on net sales of any product resulting from this collaboration. From inception through December 31, 2023, we have generated more than $150 million in payments under this collaboration.

IONIS-FB-LRx for Complement-Mediated Diseases

In 2018, we entered into a collaboration agreement with Roche to develop IONIS-FB-LRx for the treatment of complement-mediated diseases. We are currently conducting Phase 2 studies in two disease indications for IONIS-FB-LRx, one for the treatment of patients with IgAN and one for the treatment of patients with GA, the advanced stage of dry AMD. In April 2023, Roche initiated a Phase 3 study of IONIS-FB-LRx in patients with IgAN.

After positive data from a Phase 2 clinical study in patients with IgAN, Roche licensed IONIS-FB-LRx in 2022. As a result, Roche is responsible for global development, regulatory and commercialization activities, and costs for IONIS-FB-LRx, except for the open label Phase 2 study in patients with IgAN and the Phase 2 study in patients with GA, both of which we are conducting and funding.

Over the term of the collaboration, we are eligible to receive an upfront payment, a license fee, development milestone payments, regulatory milestone payments and sales milestone payments. In addition, we are also eligible to receive tiered royalties from the high teens to 20 percent on net sales. From inception through December 31, 2023, we have generated more than $135 million in payments under this collaboration.

RNA-Targeting Medicines for Alzheimer's Disease and Huntington's Disease

In September 2023, we entered into an agreement with Roche to develop two undisclosed early-stage programs for RNA-targeting investigational medicines for the treatment of AD and HD. Under the agreement, we are responsible for advancing the two programs through preclinical studies and Roche is responsible for clinical development, manufacturing and commercialization of the medicines if they receive regulatory approval.

Over the term of the collaboration, we are eligible to receive an upfront payment, development milestone payments and sales milestone payments. In addition, we are eligible to receive tiered royalties up to the mid-teens on net sales. From inception through December 31, 2023, we have generated $60 million in payments under this collaboration.

Commercialization Partnerships

Otsuka

In December 2023, we entered into an agreement with Otsuka Pharmaceutical Co., Ltd., or Otsuka, to commercialize donidalorsen in Europe. We are responsible for the ongoing development of donidalorsen. We retained the rights to commercialize donidalorsen in the U.S. and in the rest of the world assuming regulatory approval.

Over the term of the collaboration, we are eligible to receive an upfront payment, regulatory milestone payments and sales milestone payments. In addition, we are eligible to receive tiered royalties ranging from 20 percent to 30 percent on net sales of donidalorsen in Europe. From inception through December 31, 2023, we have generated $65 million in payments under this collaboration.

PTC Therapeutics

In August 2018, we entered into an exclusive license agreement with PTC Therapeutics to commercialize TEGSEDI and WAYLIVRA in Latin America and certain Caribbean countries. Under the license agreement, we are eligible to receive royalties from PTC in the mid-20 percent range on net sales for each medicine. In December 2021 and September 2023, we started receiving royalties from PTC for TEGSEDI and WAYLIVRA sales, respectively.

Swedish Orphan Biovitrum AB (Sobi)

We began commercializing TEGSEDI and WAYLIVRA in Europe in January 2021 and TEGSEDI in North America in April 2021 through distribution agreements with Sobi. Under our agreements, we are responsible for supplying finished goods inventory to Sobi and Sobi is responsible for selling each medicine to the end customer. In exchange, we earn a distribution fee on net sales from Sobi for each medicine. Refer to the section titled, Overview, for further details on our distribution agreement with Sobi.

Technology Enhancement Collaborations

Bicycle Therapeutics

In 2020, we entered into a collaboration agreement with Bicycle Therapeutics, or Bicycle, and obtained an option to license its peptide technology to potentially increase the delivery capabilities of our LICA medicines. In 2021, we exercised our option to license Bicycle's technology. Our payment to Bicycle for licensing its technology included an equity investment in Bicycle.

Metagenomi

In 2022, we entered into a collaboration and license agreement with Metagenomi to research, develop and commercialize investigational medicines for up to four initial genetic targets, and, upon the achievement of certain development milestones, four additional genetic targets using gene editing technologies. As a result, we paid Metagenomi to license its technologies and will pay Metagenomi certain fees for the selection of genetic targets. In addition, we will pay Metagenomi milestone payments and royalties that are contingent on the achievement of certain development, regulatory and sales events. We will also reimburse Metagenomi for certain of its costs in conducting its research and drug discovery activities under the collaboration.

Vect-Horus

In December 2023, we entered into a license agreement with Vect-Horus to provide us with worldwide, exclusive license for a specified number of targets using Vect-Horus’ platform technology ”VECTrans” for systemic delivery of RNA-targeted therapeutics that can cross the blood-brain barrier and address targets in the central nervous system. As a result, we paid Vect-Horus to license its technologies. In addition, we will pay Vect-Horus milestone payments and royalties that are contingent on the achievement of certain development, regulatory and sales events.

Other Agreements

Alnylam Pharmaceuticals, Inc.

Under the terms of our agreement with Alnylam, we co-exclusively (with ourselves) licensed to Alnylam our patent estate relating to antisense motifs and mechanisms and oligonucleotide chemistry for double-stranded RNAi therapeutics, with Alnylam having the exclusive right to grant platform sublicenses for double-stranded RNAi. In exchange for such rights, Alnylam gave us a technology access fee, participation in fees from Alnylam’s partnering programs, as well as future milestone and royalty payments from Alnylam. We retained exclusive rights to our patents for single-stranded antisense therapeutics and for a limited number of double-stranded RNAi therapeutic targets and all rights to single-stranded RNAi, or ssRNAi, therapeutics. In turn, Alnylam nonexclusively licensed to us its patent estate relating to antisense motifs and mechanisms and oligonucleotide chemistry to research, develop and commercialize single-stranded antisense therapeutics, ssRNAi therapeutics, and to research double-stranded RNAi compounds. We also received a license to develop and commercialize double-stranded RNAi therapeutics targeting a limited number of therapeutic targets on a nonexclusive basis. Additionally, in 2015, we and Alnylam entered into an alliance in which we cross-licensed intellectual property. Under this alliance, we and Alnylam each obtained exclusive license rights to four therapeutic programs. Alnylam granted us an exclusive, royalty-bearing license to its chemistry, RNA targeting mechanism and target-specific intellectual property for oligonucleotides against four targets, including FXI and Apo(a) and two other targets. In exchange, we granted Alnylam an exclusive, royalty-bearing license to our chemistry, RNA targeting mechanism and target-specific intellectual property for oligonucleotides against four other targets. Alnylam also granted us a royalty-bearing, non-exclusive license to new platform technology arising from May 2014 through April 2019 for single-stranded antisense therapeutics. In turn, we granted Alnylam a royalty-bearing, non-exclusive license to new platform technology arising from May 2014 through April 2019 for double-stranded RNAi therapeutics.

Manufacturing

We manufacture most of the active pharmaceutical ingredient, or API, we use for our research and development, or R&D, activities ourselves. We have also manufactured API and commercial supply for our approved medicines. We have dedicated significant resources to develop ways to improve manufacturing efficiency and capacity. Since we can use variants of the same nucleotide building blocks and the same type of equipment to produce our oligonucleotide medicines, we found that the same techniques we used to efficiently manufacture one oligonucleotide medicine could help improve the manufacturing processes for our other medicines. By developing several proprietary chemical processes to scale up our manufacturing capabilities, we have greatly reduced the cost of producing oligonucleotide medicines. For example, we have significantly reduced the cost of raw materials through improved yield efficiency, while at the same time increasing our capacity to make our medicines. Through both our internal research and development programs and collaborations with outside vendors, we may achieve even greater efficiency and further cost reductions.

Our manufacturing facility is located in a 26,800 square foot building in Carlsbad, California. We purchased this building in 2017. In addition, we have a 25,800 square foot building that houses support functions for our manufacturing activities. We lease this facility under a lease that has a term ending in August 2026 with an option to extend the lease for an additional five-year period. Our manufacturing facility is subject to periodic inspections by the FDA and foreign equivalents to ensure that it is operating in compliance with current Good Manufacturing Practices, or cGMP, requirements.

As part of our collaborations, we may agree to manufacture clinical trial material and/or commercial drug supply for our partners. For example, in the past we have manufactured clinical trial material for AstraZeneca, Biogen, GSK and Novartis and commercial drug supply for Biogen.

We believe we have sufficient manufacturing capacity at our own facility or at contract manufacturing organizations, or CMOs, to meet our current internal research, development and potential commercial needs, as well as our obligations under existing agreements with our partners for research, development and commercial material. We and/or our CMOs manufacture process performance qualification batches and pre-approval inspection batches of our Phase 3 medicines that may be used for regulatory submissions and, pending regulatory approval, commercial sale. We believe our current network of CMOs are capable of providing sufficient quantities to meet anticipated commercial demands. Additionally, we continue to evaluate relationships with additional suppliers to increase overall capacity and diversify our supply chain. While we believe that there are alternate sources of supply that can satisfy our commercial requirements, it is possible that identifying and establishing relationships with such sources, if necessary, could result in significant delay or material additional costs. We also could experience a disruption in supply from our current CMOs.

CMOs are subject to the FDA’s cGMP requirements and other rules and regulations prescribed by foreign regulatory authorities. We depend on our CMOs for continued compliance with cGMP requirements and applicable foreign standards.

Specifically, we have the following in place for our commercial medicines and our medicines in Phase 3 development.

Biogen is responsible for SPINRAZA drug supply.

QALSODY

Biogen is responsible for QALSODY drug supply.

WAINUA

AstraZeneca is responsible for WAINUA's commercial drug supply. Our CMOs supplied the API and the finished drug product for WAINUA’s Phase 3 program. Pursuant to our collaboration with AstraZeneca, we will manufacture and supply WAINUA using CMOs for the ongoing clinical trials, process performance qualification batches and pre-approval inspection batches.

TEGSEDI and WAYLIVRA

For TEGSEDI’s commercial drug supply, we are using CMOs to produce API and finished goods. For WAYLIVRA’s commercial drug supply, we are using API that we have manufactured and CMOs to produce the finished goods.

Olezarsen, Donidalorsen, Zilganersen, Ulefnersen

We and/or our CMOs have supplied the API and the finished drug product forolezarsen, donidalorsen, zilganersen and ulefnersen that we believe will besufficient through the completion of the Phase 3 programs for each medicine, including process performance qualification batches and pre-approval inspection batches. We plan to leverage our relationships with CMOs to maintain long-term supply at competitive prices in the future.

Pelacarsen

We supplied API and finished drug product for pelacarsen’s Phase 3 program. Pursuant to our collaboration with Novartis, Novartis is responsible for any further pelacarsen drug supply.

Bepirovirsen

We supplied API for bepirovirsen’s Phase 1 and Phase 2 programs. Pursuant to our collaboration with GSK, GSK is responsible for any further bepirovirsen drug supply.

IONIS-FB-LRx

We supplied API for the IONIS-FB-LRx Phase 1 and Phase 2 IgAN programs. Pursuant to our collaboration with Roche, Roche is responsible for any further drug supply for the IONIS-FB-LRx program.

Commercial Operations

We have established sales and marketing capabilities to support our commercial launch of WAINUA in the U.S. and anticipated near-term commercial launches of olezarsen and donidalorsen. We began with our co-commercialization partnership with AstraZeneca for WAINUA in which we combine our experience in RNA-targeted therapeutics and deep knowledge of the TTR amyloidosis market with AstraZeneca's global scale in drug development and commercialization to enable market penetration for the benefit of patients.

As we approach our first potential independent commercial launches of olezarsen and donidalorsen in the U.S., we have been refining our portfolio strategy and recruiting experienced professionals with relevant backgrounds in sales, marketing, patient education, market access, portfolio planning and market insight, new product commercial strategy and commercial operations in the pharmaceutical industry. We are focused on developing a unique and innovative approach to bring our medicines to patients living with serious diseases. We have built core capabilities and a commercial platform with the ability to scale as needed to meet our current and future commercialization needs. We plan to build our field sales teams as we approach each of our launches.

In addition, we recently entered into a European licensing agreement with Otsuka for donidalorsen in HAE in which we will leverage Otsuka's strong commercial infrastructure and rare disease experience to reach European HAE patients.

Medical Affairs

We have built medical affairs capabilities to disseminate information about our medicines and increase disease awareness through various channels of communication with key stakeholders. Our medical affairs function is responsible for funding and coordinating investigator-sponsored trials, communicating scientific and clinical information to healthcare providers, medical professionals and patients, and managing publications.

Intellectual Proprietary Rights

We rely on patents, trademarks, trade secrets, and proprietary know-how to develop and maintain a competitive position in RNA-targeted therapeutics generally and to protect our investment in specific products. To this end, we focus our resources on intellectual property, or IP, that drives value for our company.

Product-Specific IP

Each of our medicines is protected worldwide by product-specific patents claiming oligonucleotides having the nucleobase sequences and chemical modifications of our medicines; and methods of achieving cellular or clinical endpoints using such oligonucleotides. We pursue such patents in significant markets and/or countries for each medicine in development. We also seek to maximize patent term. In some cases, the patent term can be extended to recapture a portion of the term lost during regulatory review. Expiration dates listed below do not reflect any such extensions.

Commercial products are also protected by trademarks filed throughout the world.

Marketed Products

SPINRAZA and Survival Motor Neuron 2

Patents

We believe SPINRAZA (nusinersen) is protected from generic competition in the U.S. until at least 2035 and in Europe until at least 2030 by a suite of patents. These issued patents include: (i) patents licensed from the University of Massachusetts drawn to antisense compounds having the sequence of SPINRAZA, independent of chemical modification, and uses of such compounds for treating SMA, (ii) joint patents with Cold Spring Harbor Laboratory claiming fully modified 2’-MOE compounds targeting SMN2, including the precise composition of matter of SPINRAZA and methods of using such compositions; and (iii) dosing and therapeutic methods of using such compounds and compositions. With Biogen’s license of SPINRAZA, we assigned our interest in these patents to Biogen. The table below lists some key issued patents protecting SPINRAZA in the U.S. and Europe:

The name “SPINRAZA” is protected throughout the world by trademarks owned by our commercial partner Biogen. Particulars for the United States and European marks are listed below:

QALSODY and SOD-1

Patents

We believe QALSODY is protected from generic competition in the U.S. and Europe until at least 2035. Additional patent applications designed to protect QALSODY in other foreign jurisdictions are being pursued. With Biogen’s license of QALSODY, we assigned our interest in these patents to Biogen. The table below lists some key issued patents protecting QALSODY in the U.S. and Europe:

The name “QALSODY” is protected throughout the world by trademarks owned by our commercial partner Biogen. Particulars for the United States and European marks are listed below:

WAINUAand Transthyretin

Patents

We believe WAINUA (eplontersen) is protected from generic competition in the U.S. and Europe until at least 2034. Additional patent applications to protect WAINUA in other foreign jurisdictions are being pursued. The table below lists some key issued patents protecting WAINUA in the U.S. and Europe:

The name “WAINUA” is protected by trademarks owned by our commercial partner Astra Zeneca. Particulars for the United States marks are listed below:

TEGSEDI and Transthyretin

Patents

We believe TEGSEDI (inotersen) is protected from generic competition in the U.S. and Europe until at least 2031. The table below lists some key issued patents protecting TEGSEDI in the U.S. and Europe:

The name “TEGSEDI” is protected by trademark throughout the world. Particulars for the United States and European marks are listed below:

WAYLIVRA and Apolipoprotein C-III

Patents

We believe WAYLIVRA (volanesorsen) is protected from generic competition in Europe until at least 2034. We have obtained patent claims in the U.S. and Europe drawn to the use of antisense compounds complementary to a broad active region of human apoC-III, including the site targeted by WAYLIVRA. We have also obtained issued patents claiming the specific sequence and chemical composition of WAYLIVRA in the U.S. and Europe. The table below lists some key issued patents protecting WAYLIVRA in the U.S. and Europe:

Trademark

The name “WAYLIVRA” is protected by trademark in Europe. Particulars for the European mark are listed below:

Phase 3 Programs

Olezarsen and ApoC-III

We believe olezarsen is protected from generic competition in the U.S. and Europe until at least 2034. Additional patent applications to protect olezarsen in other foreign jurisdictions are being pursued. The table below lists some key issued patents protecting olezarsen in the U.S. and Europe.

Donidalorsen and PKK

We believe donidalorsen is protected from generic competition in the U.S. and Europe until at least 2035. Additional patent applications to protect donidalorsen in other foreign jurisdictions are being pursued. The table below lists some key issued patents protecting donidalorsen in the U.S. and Europe.

Zilganersen and GFAP

We believe zilganersen is protected from generic competition in the U.S. until at least 2041. A patent application designed to protect zilganersen from generic competition is being pursued in Europe; a patent issuing from that application would have term until at least 2041. The table below lists a key issued patent protecting zilganersen in the U.S. and a pending application in Europe:

Ulefnersen and FUS

Patent applications designed to protect ulefnersen from generic competition are being pursued in the U.S. and Europe. Patents issued from these applications would have terms until at least 2040. The table below lists some key pending patent applications designed to protect ulefnersen in the U.S. and Europe:

Pelacarsen and Apo(a)

We believe pelacarsen is protected from generic competition in the U.S. and Europe until at least 2034. Additional patent protection designed to protect pelacarsen in other foreign jurisdictions are being pursued. The table below lists some key issued patents protecting pelacarsen in the U.S. and Europe:

Bepirovirsen and Hepatitis B Virus

We believe bepirovirsen is protected from generic competition in the U.S. and Europe until at least 2032. Additional patent protection designed to protect bepirovirsen in other foreign jurisdictions are being pursued. With GSK’s license of bepirovirsen, we assigned our interest in these patents to GSK. The table below lists some key issued patents protecting bepirovirsen in the U.S. and Europe:

IONIS-FB-LRx and Factor B

We believe IONIS-FB-LRx is protected from generic competition in the U.S. and Europe until at least 2035. Additional patent protection designed to protect IONIS-FB-LRx in other foreign jurisdictions are being pursued. The table below lists some key issued patents protecting IONIS-FB-LRx in the U.S. and Europe:

Platform IP

In addition to the IP that provides exclusivity for specific products, we also pursue IP that provides exclusivity for our core technology in the field of oligonucleotides and RNA-targeting therapeutics more generally. Our core technology patents include claims to chemically modified oligonucleotides as well as designs utilizing these chemical modifications. Because these core claims are independent of specific therapeutic target, nucleic acid sequence, or clinical indication, they may reach several products.

Chemically Modified Nucleosides and Oligonucleotides

The most broadly applicable of our patents are those that claim modified nucleosides and oligonucleotides comprising the modified nucleosides that we incorporate into our medicines to increase their therapeutic efficacy. The following are some of our patents in this category in the U.S. and Europe:

LIgand-Conjugated Antisense (LICA) Technology

We also have patent claims to new chemistries created to enhance targeting of antisense medicines to specific tissues and cells to improve a drug’s properties. We designed our GalNAc LICA medicines to provide an increase in potency for targets in the liver. We have successfully obtained issued patent claims covering our LICA technology conjugated to any modified oligonucleotide, including gapmers, double-stranded siRNA compounds, and fully modified oligonucleotides. The following patents are some examples of our issued patents in this category:

Manufacturing

We also own patents claiming methods of manufacturing and purifying oligonucleotides and related compounds. These patents claim methods for improving oligonucleotide drug manufacturing, including processes for large-scale oligonucleotide synthesis and purification.

Government Regulation

Regulation by government authorities in the U.S. and other countries is a significant component in the development, manufacture and commercialization of pharmaceutical products and services. In addition to regulations enforced by the FDA and relevant foreign regulatory authorities, we are also subject to regulation under the Occupational Safety and Health Act, the Environmental Protection Act, the Toxic Substances Control Act, the Resource Conservation and Recovery Act and other present and potential future federal, state and local regulations.

Extensive regulation by the U.S. and foreign governmental authorities governs the development, manufacture and sale of our medicines. In particular, our medicines are subject to a number of approval requirements by the FDA in the U.S. under the Federal Food, Drug and Cosmetic Act, or FDCA, and other laws and by comparable agencies in those foreign countries in which we conduct business. The FDCA and other various federal, state and foreign statutes govern or influence the research, testing, manufacture, safety, labeling, storage, recordkeeping, approval, promotion, marketing, distribution, post-approval monitoring and reporting, sampling, quality, and import and export of our medicines. State, local, and other authorities also regulate pharmaceutical manufacturing facilities and procedures.

Our manufacturing facility and our CMOs are subject to periodic inspection by the FDA and other foreign equivalents to ensure that they are operating in compliance with cGMP requirements. In addition, marketing authorization for each new medicine may require a rigorous manufacturing pre-approval inspection by regulatory authorities. Post approval, there are strict regulations regarding changes to the manufacturing process, and, depending on the significance of the change, changes may require prior FDA approval. FDA regulations also require investigation and correction of any deviations from cGMP and impose reporting and documentation requirements upon us and any third-party manufacturers that we may decide to use.

The FDA must approve any new medicine before a manufacturer can market it in the U.S. In order to obtain approval, we and our partners must complete clinical studies and prepare and submit an NDA to the FDA. If the FDA approves a medicine, it will issue an approval letter authorizing commercial marketing of the medicine and may require a risk evaluation and mitigation strategy, or REMS, to help ensure the benefits of the medicine outweigh the potential risks. The requirements for REMS can materially affect the potential market and profitability of our medicines. In foreign jurisdictions, the drug approval process is similarly demanding.

Pricing and Reimbursement

For any approved medicine, domestic and foreign sales of the medicine depend, in part, on the availability and amount of coverage and adequate reimbursement by third-party payers, including governments and private health plans. The process for determining whether a payer will provide coverage for a product may be separate from the process for setting the reimbursement rate that the payer will pay for the product, or procedures that utilize such product. Private health plans may seek to manage cost and use of our medicines by implementing coverage and reimbursement limitations. For example, third-party payers may limit coverage to specific products on an approved list, or formulary, which might not include all U.S. FDA-approved products for a particular indication. Moreover, a payer's decision to provide coverage for a medicine does not imply that an adequate reimbursement rate will be approved. Additionally, coverage and reimbursement for drugs can differ significantly from payer to payer. One third-party payer's decision to cover a particular medicine does not ensure that other payers will also provide coverage for the medicine or will provide coverage at an adequate reimbursement rate.

Third-party payers are increasingly challenging the price and examining the medical necessity and cost-effectiveness of medicines and services, in addition to their safety and efficacy. To obtain coverage and reimbursement for any medicine that might be approved for sale, we may need to conduct expensive pharmacoeconomic studies to demonstrate the medical necessity and cost-effectiveness of our medicine. These studies will be in addition to the studies required to obtain regulatory approvals. If third-party payers do not consider a medicine to be cost-effective compared to other available therapies, they may not cover the medicine after approval as a benefit under their plans or, if they do, the level of payment may not be sufficient to sell such medicine at a profit.

In certain jurisdictions, governments may also regulate or influence coverage, reimbursement and/or pricing of our medicines to control cost or affect use. In the European community, governments influence the price of drugs through their pricing and reimbursement rules and control of national health care systems that fund a large part of the cost of those medicines to consumers. Some jurisdictions operate positive and negative list systems under which medicines may only be marketed once a reimbursement price has been agreed to by the government. To obtain reimbursement or pricing approval, some of these countries may require the completion of clinical studies that compare the cost effectiveness of a particular drug candidate to currently available therapies. Other member states allow companies to fix their own prices for medicines but monitor and control company profits.

The marketability of any medicine for which we receive regulatory approval for commercial sale may suffer if the government and third-party payers fail to provide adequate coverage and reimbursement. In addition, the focus on cost containment measures in the U.S. and other countries has increased and we expect will continue to increase the pressure on pharmaceutical pricing. Coverage policies and third-party reimbursement rates may change at any time. Even if we attain favorable coverage and reimbursement status for one or more medicines for which we receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future.

Healthcare Reform

Both the federal and state governments in the U.S. and foreign governments continue to propose and pass new legislation and regulations designed to contain or reduce the cost of healthcare. For example, in July 2021, the Biden administration released an executive order, “Promoting Competition in the American Economy,” with multiple provisions aimed at prescription drugs. In response to Biden’s executive order, on September 9, 2021, the U.S. Department of Health and Human Services, or HHS, released a report that outlined principles for drug pricing reform and set out a variety of potential legislative policies that Congress could pursue as well as potential administrative actions HHS could take to advance these principles. Congress is also considering additional health reform measures that may result in decreased reimbursement, which may further exacerbate industry-wide pressure to reduce the prices charged for medical products.

There has also been heightened governmental scrutiny over the manner in which manufacturers set prices for their marketed products, which has resulted in efforts to bring more transparency to drug pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for medicines. For example, in August 2022, President Biden signed the Inflation Reduction Act of 2022, or the IRA, into law, which includes key actions aimed at reducing the costs of prescription drugs and allows HHS to negotiate the price of certain single-source drugs covered under Medicare and establish a price cap on such drugs, known as the Maximum Fair Price. There are important exemptions to the Maximum Fair Price, including for medications that are orphan drug designated and approved for only one rare disease, and drugs with low Medicare spend as defined by the Centers for Medicare & Medicaid Services. Specifically, in an effort to curb Medicare patients’ out-of-pocket costs for prescription drugs, the Part D redesign legislation under the IRA requires, among other things, (1) a cap on out-of-pocket drug spending under Part D, (2) drug manufacturers to pay a rebate to the federal government if prices for drugs covered under Part D and Part B increase faster than the rate of inflation, and (3) drug manufacturers to contribute to the catastrophic coverage phase for Part D drugs as discounts through a manufacturer discount program. The IRA permits HHS to implement many of these provisions through guidance, as opposed to regulation, for the initial years. These provisions take effect progressively starting in fiscal year 2023. On August 29, 2023, HHS announced the list of the first ten drugs that will be subject to price negotiations, although the Medicare drug price negotiation program is currently subject to legal challenges. In response to the Biden administration’s October 2022 executive order, on February 14, 2023, HHS released a report outlining three new models for testing by the CMS Innovation Center which will be evaluated on their ability to lower the cost of drugs, promote accessibility, and improve quality of care. It is unclear whether the models will be utilized in any health reform measures in the future. Further, on December 7, 2023, the Biden administration announced an initiative to control the price of prescription drugs using march-in rights under the Bayh-Dole Act. On December 8, 2023, the National Institute of Standards and Technology published for comment a Draft Interagency Guidance Framework for Considering the Exercise of March-In Rights which for the first time includes the price of a product as one factor an agency can use when deciding to exercise march-in rights. While march-in rights have not previously been exercised, it is uncertain if that will continue under the new framework.

Any reduction in reimbursement from Medicare and other government programs may result in a similar reduction in payments from private payers. Our future product sales may be subject to additional discounts from list price in the form of rebates and discounts provided to 340B covered entities. Changes to the 340B program or to Medicare or Medicaid programs at the federal or state level, including outcomes of ongoing litigation in our industry, may impact our product prices and rebate liability.

In addition, the distribution of prescription pharmaceutical products is subject to the Drug Supply Chain Security Act, or DSCA, which regulates the distribution and tracing of prescription drugs and prescription drug samples at the federal level and sets minimum standards for the regulation of drug distributors by the states. The DSCA imposes requirements to ensure accountability in distribution and to identify and remove counterfeit and other illegitimate products from the market.

Other healthcare laws that may affect our ability to operate include, for example, the following:

Sales and Marketing

Numerous regulatory authorities in addition to the FDA, including, in the U.S., the Centers for Medicare and Medicaid Services, other divisions of the HHS, the U.S. Department of Justice, and similar foreign, state and local government authorities, regulate sales, promotion and other activities following drug approval. As described above, the FDA regulates all advertising and promotion activities for drugs under its jurisdiction both prior to and after approval. Only those claims relating to safety and efficacy that the FDA has approved may be used in labeling. Physicians may prescribe legally available drugs for uses that are not described in the drug’s labeling and that differ from those tested and the FDA approved. The FDA does not regulate the behavior of physicians in their choice of treatments, but FDA regulations do impose stringent restrictions on manufacturers’ communications regarding off-label uses. If we do not comply with applicable FDA requirements, we may face adverse publicity, enforcement action by the FDA, corrective advertising, consent decrees and the full range of civil and criminal penalties available to the FDA. Promotion of off-label uses of drugs can also implicate the false claims laws described below.

In the U.S., sales, marketing and scientific/educational programs must also comply with various federal and state laws pertaining to healthcare “fraud and abuse,” including anti-kickback laws and false claims laws. Anti-kickback laws make it illegal for a prescription drug manufacturer to solicit, offer, receive, or pay any remuneration in exchange for, or to induce, the referral of business, including the purchase or prescription of a particular drug. Due to the breadth of the statutory provisions, limited statutory exceptions and regulatory safe harbors, and the absence of guidance in the form of regulations and very few court decisions addressing industry practices, it is possible that our practices might be challenged under anti-kickback or similar laws. Moreover, healthcare reform legislation has strengthened these laws. For example, the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010, or Affordable Care Act, among other things, amends the intent requirement of the federal anti-kickback and criminal healthcare fraud statutes to clarify that a person or entity does not need to have actual knowledge of this statute or specific intent to violate it. In addition, the Affordable Care Act clarifies that the government may assert that a claim that includes items or services resulting from a violation of the federal anti-kickback statute constitutes a false or fraudulent claim for purposes of the false claims statutes. False claims laws prohibit anyone from knowingly and willingly presenting, or causing to be presented for payment, to third-party payers (including Medicare and Medicaid) claims for reimbursed drugs or services that are false or fraudulent, claims for items or services not provided as claimed, or claims for medically unnecessary items or services. Our activities relating to the sale and marketing of our drugs may be subject to scrutiny under these laws. Further, HIPAA also prohibits, among other things, executing or attempting to execute a scheme to defraud any healthcare benefit program or making false statements relating to healthcare matters. Violations of fraud and abuse laws may be punishable by criminal and civil sanctions, including fines and civil monetary penalties, the possibility of exclusion from federal healthcare programs (including Medicare and Medicaid) and corporate integrity agreements, which impose, among other things, rigorous operational and monitoring requirements on companies. Similar sanctions and penalties also can be imposed upon executive officers and employees, including criminal sanctions against executive officers under the so-called “responsible corporate officer” doctrine, even in situations where the executive officer did not intend to violate the law and was unaware of any wrongdoing.

Given the significant penalties and fines that can be imposed on companies and individuals if convicted, allegations of such violations often result in settlements even if the company or individual being investigated admits no wrongdoing. Settlements often include significant civil sanctions, including fines and civil monetary penalties, corporate integrity agreements, and could include criminal penalties. If the government were to allege or convict us or our executive officers of violating these laws, our business could be harmed. In addition, private individuals can bring similar actions. Our activities could be subject to challenge for the reasons discussed above and due to the broad scope of these laws and the increasing attention being given to them by law enforcement authorities. As described above, other healthcare laws that may affect our ability to operate include HIPAA, analogous state laws governing the privacy and security of health information, some of which are more stringent than HIPAA and many of which differ from each other in significant ways and may not have the same effect, and the Physician Payments Sunshine Act. Further, there are an increasing number of state laws that require manufacturers to make reports to states on pricing and marketing information. Many of these laws contain ambiguities as to what is required to comply with the laws. Given the lack of clarity in laws and their implementation, our reporting actions could be subject to the penalty provisions of the pertinent state authorities.

Similar rigid restrictions are imposed on the promotion and marketing of drugs in the E.U. and other countries. Even in those countries where we may not be directly responsible for the promotion and marketing of our medicines, if our potential international distribution partners engage in inappropriate activity, it can have adverse implications for us.

As discussed above, both the federal and state governments in the U.S. and foreign governments continue to propose and pass new legislation and regulations designed to contain or reduce the cost of healthcare, including new models aimed to lower of cost of drugs, promote accessibility, and improve quality of care and initiatives to control the price of prescription drugs using march-in rights under the Bayh-Dole Act.

The Foreign Corrupt Practices Act

The U.S. Foreign Corrupt Practices Act, or FCPA, prohibits certain individuals and entities, including us, from promising, paying, offering to pay, or authorizing the payment of anything of value to any foreign government official, directly or indirectly, to obtain or retain business or an improper advantage. If we violate the FCPA, it could result in large civil and criminal penalties as well as an adverse effect on our reputation, operations, and financial condition. We could also face collateral consequences such as debarment and the loss of export privileges. In addition, in many other countries, the healthcare providers who prescribe pharmaceuticals are employed by their government, and the purchasers of pharmaceuticals are government entities; therefore, any dealings with these prescribers and purchasers may be subject to regulation under the FCPA. There is no certainty that all employees and third-party business partners (including our contract research organizations, contract manufacturing organizations, distributors, wholesalers, agents, contractors and other partners) will comply with anti-bribery laws. Importantly, we do not control the actions of manufacturers and other third-party agents, although we may be liable for their actions.

Competition

Our Business in General

Some of our medicines may compete with existing therapies for market share and some of our medicines in development may compete for patients in clinical trials. In addition, there are a number of companies pursuing the development of genetic medicines and the development of pharmaceuticals utilizing these technologies. These companies include biopharmaceutical companies and large pharmaceutical companies acting either independently or together. Our medicines are differentiated from traditional small molecule medicines by their chemistry, how they move in the body, how they act in the body, delivery technology, and formulations.

Our commercial medicines and our medicines in development address numerous markets. The diseases our medicines target for which we have or may receive marketing authorization will determine our competition. For some of our medicines, an important factor may be the timing of market introduction of competitive products. Accordingly, the relative speed with which we can develop medicines, complete the clinical trials and marketing authorization processes and supply commercial quantities of the medicines to the market are important competitive factors. We expect to compete with products approved for sale based on a variety of factors, including, among other things, product efficacy, safety, mechanism of action, dosing administration, marketing and sales strategy and tactics, availability, price, and reimbursement.

Below we have included what we believe to be medicines that compete or may compete directly with our marketed medicines and the medicines we currently have in Phase 3 trials. We included competitors, potential competitors that are past Phase 1 development or potential competitors that plan to start a pivotal study this year.

We consider the following medicines as competitors to SPINRAZA for the indication of SMA:

QALSODY

We believe that the following medicine could compete with QALSODY in SOD1-ALS:

WAINUA and TEGSEDI

We consider the following medicines as competitors and potential future competitors to WAINUA and TEGSEDI for ATTRv-PN and/or ATTR-CM:

WAYLIVRA and Olezarsen

We believe that the following medicines could compete with WAYLIVRA and olezarsen in FCS and SHTG:

Donidalorsen

We believe that the following medicines could compete with donidalorsen as a prophylactic treatment for patients with HAE:

Zilganersen

We believe there are no medicines in clinical development for AxD.

Ulefnersen

We believe there are no medicines in clinical development for FUS-ALS.

Pelacarsen

We believe that the following medicines could compete with pelacarsen in CVD in patients with elevated LP(a):

Bepirovirsen

We believe that the following medicines could compete with bepirovirsen in HBV:

IONIS-FB-LRx

We believe that the following medicines could compete with IONIS-FB-LRx in IgAN:

We believe that the following medicines could compete with IONIS-FB-LRx in GA:

Corporate Responsibility and Environmental, Social and Governance Initiatives

We believe operating responsibly and sustainably creates long-term value for our company and our stakeholders. We recognize the importance of Corporate Responsibility, or CR, and Environmental, Social and Governance, or ESG, initiatives as it relates to our business strategy and risk assessment. In 2023, we continued to evolve our CR program by building on our foundation and further defining our strategic direction. This includes completing our first CR materiality assessment, updating our CR framework to better focus on our ESG priorities and developing goals to drive and measure our performance.

We began reporting on CR metrics in 2021 and have continued to expand disclosure since then. In 2023, we established three strategic CR pillars that we believe are most important to our business:

Ionis Corporate Responsibility Strategic Pillars

Our CR initiatives are driven by our Chief Executive Officer and executive-level CR Steering Committee, or CR Committee. The CR Committee consists of senior leaders in key functions across the company, including legal, finance, investor relations, human resources, research and development, manufacturing, commercial, compliance and corporate affairs. In 2023, we expanded our CR Committee to include a broader cross-section of senior leaders to ensure we continue to develop the right programs and policies.

The CR Committee is part of our governance framework, which defines responsibilities and ensures we have the right systems and controls to oversee ethical and sustainable operations across our business. Our Board of Directors oversees our overall CR strategy and management of material ESG risks and opportunities and receives updates related to corporate governance and corporate responsibility from the CR Committee at least once annually. In 2023, the Nominating, Governance and Review Committee assumed responsibility for CR and ESG-related matters.

We look to our stakeholders and third-party frameworks such as the Sustainability Accounting Standards Board Health Care – Biotechnology and Pharmaceuticals Standard and the Task Force on Climate-Related Financial Disclosures to inform our approach and our disclosures.

We will share more details on our updated CR framework, goals and ESG initiatives in our 2023 CR Report, which will be published in April 2024 and available on our website. Nothing in the report or on our website shall be deemed incorporated by reference into this Annual Report on Form 10-K.

Employees and Human Capital

As of February 15, 2024, we employed 927 people, the vast majority of whom reside in the U.S. A significant number of our management and professional employees have had prior experience with pharmaceutical, biotechnology or medical product companies. Our average employee turnover rate in 2023 was 7 percent, while the turnover for life sciences and medical device companies over this period was 23 percent according to a survey published by Radford – an Aon Hewitt Company. Given the uniqueness and complexity of our technology, it is critical to retain the knowledge and experience of outstanding long service employees. The experience and seniority of our employees is as critical to our future success as it has been to the success we have enjoyed to date.

Collective bargaining agreements do not cover any of our employees, and management considers relations with our employees to be good. We believe that the future will be defined by outstanding people and we are committed to recruiting, developing, motivating, and rewarding them.

We encourage you to visit our website for more detailed information regarding our Human Capital programs and initiatives. Nothing on our website shall be deemed incorporated by reference into this Annual Report on Form 10-K.

Benefits

We reward our employees individually on the basis of their responsibilities and accomplishments. We offer competitive compensation and benefits to our employees. In addition to salary and bonus programs, we also offer:

We recognize achievements with salary increases, equity awards, promotions, and bonus opportunities.

Pay Equity

We are committed to paying our employees fairly, regardless of their gender, ethnicity, race, age or other personal characteristics. To ensure we are achieving our commitment, we benchmark and evaluate pay based on market data and consider factors such as an employee’s role and experience, an employee’s performance and internal equity. We also regularly review our compensation practices, in terms of our overall workforce and individual employees, to ensure our pay is fair and equitable.

On an annual basis, we monitor our pay equity status and market competitiveness, and perform a pay equity analysis that reviews pay equity by gender, ethnicity, race and age. Our 2023 pay equity analysis confirmed we do not have a statistically significant difference in pay for the same or similar work, regardless of gender, ethnicity, race or age.

Diversity, Equity and Inclusion

At Ionis, we encourage diversity in our workforce. Prejudicial barriers to human potential and productivity are foreign to our values. We recognize that for the full potential of our workforce to be realized, we must cultivate an inclusive culture where all employees feel empowered to contribute fully in an environment that values different perspectives, leading to better ​​​​​​​ideas and increased innovation. We have several employee-led resource groups dedicated to different aspects of diversity and a diverse management team and board of directors.

Training and Development

We designed our training and development programs to help employees gain important Ionis knowledge and develop the skills to be successful at Ionis. All of our trainings from new hire through senior leader, are focused on the Ionis culture and core principles and learning what we mean when we say: “Working the Ionis Way.”

We empower our employees to build rewarding careers at Ionis, driven by a culture of having a bias to act that encourages personal and professional employee growth. Ionis offers robust training opportunities with course offerings and events available to every employee regardless of level or function. In addition, employees also have access to Ionis’ learning and development library that houses important information on career growth and planning. By supporting our employees, we know that each professional development milestone enables our continued success.

Information about our Executive Officers

The following sets forth certain information regarding our executive officers as of February 15, 2024:

BRETT P. MONIA, Ph.D.

Chief Executive Officer

Dr. Monia was promoted to Chief Executive Officer in January 2020. From January 2018 to December 2019, Dr. Monia served as Chief Operating Officer. From January 2012 to January 2018, Dr. Monia served as Senior Vice President. From February 2009 to January 2012, Dr. Monia served as our Vice President, Drug Discovery and Corporate Development and from October 2000 to February 2009, he served as our Vice President, Preclinical Drug Discovery. From October 1989 to October 2000 he held various positions within our Molecular Pharmacology department.

JOSEPH T. BAROLDI, M.A., M.B.A., M.S.

Executive Vice President, Chief Business Officer

Mr. Baroldi has served as Ionis’ Executive Vice President, Chief Business Officer since January 2022. Prior to Ionis, Mr. Baroldi was the chief operating officer at Avidity Biosciences, a biotechnology company focused on oligonucleotide-based therapies. Prior to Avidity, Mr. Baroldi was Vice President, Business Development at Ionis, where he held several roles of increasing responsibility from 2009 to 2020. Mr. Baroldi has also held positions in strategic planning and scientific research for Gen-Probe Inc.

BRIAN BIRCHLER

Executive Vice President, Corporate and Development Operations

Mr. Birchler has served as Ionis’ Executive Vice President, Corporate and Development Operations since March 2022. From January 2008 to March 2022, Mr. Birchler served as our Senior Vice President, Drug Development Operations. From January 2005 to January 2008 he served as our Vice President, Drug Development Operations and from January 2003 to January 2005, as our Vice President, Development Chemistry and Operations. Mr. Birchler joined Ionis in 1995 as Senior Scientist/Senior Research Associate. Prior to joining Ionis, Mr. Birchler was employed by CIBA Vision Corp. and Burroughs Wellcome Pharmaceuticals in various engineering, development and commercial positions.

C. FRANK BENNETT, Ph.D.

Executive Vice President, Chief Scientific Officer

Dr. Bennett has served as Ionis’ Executive Vice President, Chief Scientific Officer since April 2020. In January 2020, Dr. Bennett was promoted to Chief Scientific Officer. From January 2006 to December 2019, Dr. Bennett served as Senior Vice President, Antisense Research. From June 1995 to January 2006, Dr. Bennett served as our Vice President, Research. From March 1993 to June 1995, he was Director, Molecular Pharmacology, and from May 1992 to March 1993, he was an Associate Director in our Molecular and Cellular Biology department. Prior to joining Ionis in 1989, Dr. Bennett was employed by SmithKline and French Laboratories in various research positions. He is a member of the Board of Directors for Flamingo Therapeutics and an external member of the Hereditary Disease Foundation.

ONAIZA CADORET-MANIER

Executive Vice President, Chief Global Product Strategy and Operations Officer

Ms. Cadoret-Manier has served as Ionis’ Executive Vice President, Chief Product Strategy and Operations Officer since February 2022. From April 2020 to February 2022, Ms. Cadoret-Manier served as our Executive Vice President, Chief Corporate Development and Commercial Officer. Ms. Cadoret-Manier joined Ionis as Chief Corporate Development and Commercial Officer in January 2020. Prior to joining Ionis, from 2018 to 2019 Ms. Cadoret-Manier was the chief commercial officer for Grail Biosciences, an early detection genomics company. Prior to Grail, Ms. Cadoret-Manier was vice president of the Respiratory Franchise at Genentech where she worked from 2011 to 2018. Ms. Cadoret-Manier also has held multiple senior management positions overseeing corporate strategy, alliances, and marketing and sales for numerous disease areas for Genentech, Pfizer and Amylin Pharmaceuticals.

RICHARD S. GEARY, Ph.D.

Executive Vice President, Chief Development Officer

Dr. Geary has served as Ionis’ Executive Vice President, Chief Development Officer since January 2021. From April 2020 to December 2020, Dr. Geary served as our Executive Vice President, Development and from August 2008 to March 2020, was our Senior Vice President, Development. From August 2003 to August 2008, Dr. Geary served as our Vice President, Preclinical Development. From November 1995 to August 2003, he held various positions within the Preclinical Development department. Prior to joining Ionis in 1995, Dr. Geary was Senior Research Scientist and Group Leader for the bioanalytical and preclinical pharmacokinetics group in the Applied Chemistry Department at Southwest Research Institute.

ELIZABETH L. HOUGEN

Executive Vice President, Finance and Chief Financial Officer

Ms. Hougen has served as Ionis’ Executive Vice President and Chief Financial Officer since April 2020. From January 2013 to March 2020, Ms. Hougen served as our Senior Vice President, Finance and Chief Financial Officer. From January 2007 to December 2012, Ms. Hougen served as our Vice President, Finance and Chief Accounting Officer and from May 2000 to January 2007, she served as our Vice President, Finance. Prior to joining Ionis in 2000, Ms. Hougen was Executive Director, Finance and Chief Financial Officer for Molecular Biosystems, Inc., a public biotechnology company.

PATRICK R. O’NEIL, Esq.

Chief Legal Officer, General Counsel and Corporate Secretary

Mr. O’Neil has served as Ionis’ Chief Legal Officer and General Counsel since September 2021. Mr. O’Neil also serves as our Corporate Secretary. From March 2020 to September 2021, Mr. O’Neil served as our Executive Vice President, Legal & General Counsel and Chief Compliance Officer. From January 2013 to March 2020, Mr. O’Neil served as our Senior Vice President, Legal and General Counsel. From September 2010 to January 2013, Mr. O’Neil served as our Vice President, Legal and General Counsel and from January 2009 to September 2010, he served as our Vice President, Legal and Senior Transactions Counsel. From October 2001 to January 2009 he held various positions within our Legal department. Prior to joining Ionis, Mr. O’Neil was an associate at Cooley LLP.

EUGENE SCHNEIDER, M.D.

Executive Vice President, Chief Clinical Development and Operations Officer

Dr. Schneider has served as Ionis’ Executive Vice President and Chief Clinical Development and Operations Officer since September 2023. From January 2021 to September 2023, Dr. Schneider served as our Executive Vice President and Chief Clinical Development Officer. From August 2018 to December 2020, Dr. Schneider served as our Senior Vice President, Head of Clinical Development. From April 2015 to July 2018, Dr. Schneider was our Vice President, Clinical Development, Severe and Rare Diseases. Dr. Schneider joined Ionis in December 2013 as Executive Director, Clinical Development. Dr. Schneider has two decades of experience in clinical development primarily in the rare diseases space. Prior to joining Ionis, Dr. Schneider was senior medical director at both Synageva BioPharma and Biovail Technologies Ltd.

ERIC E. SWAYZE, Ph.D.

Executive Vice President, Research

Dr. Swayze has served as Ionis’ Executive Vice President, Research since April 2020 and is responsible for leading preclinical antisense drug discovery and antisense technology research. In January 2020, Dr. Swayze was promoted to Senior Vice President of Research. Previously, Dr. Swayze was Vice President of Chemistry and Neuroscience Drug Discovery at Ionis, overseeing the advancement of multiple programs to clinical development. He joined Ionis in 1994 and has contributed to key technology advancements, including Ionis’ Generation 2.5 chemistry and LICA technology.