Silence Therapeutics plc

Previous wording

We are a biotechnology company focused on discovering and developing novel molecules incorporating short interfering ribonucleic acid, or siRNA, to inhibit the expression of specific target genes thought to play a role in the pathology of diseases with significant unmet medical need. Our siRNA molecules are designed to harness the body’s natural mechanism of RNA interference, or RNAi, by specifically binding to and degrading messenger RNA, or mRNA, molecules that encode specific targeted disease-associated proteins in a cell. By degrading the message that encodes the disease-associated protein, the production of that protein is reduced, and its level of activity is lowered. In the field of RNAi therapeutics, this reduction of disease-associated protein production and activity is referred to as “gene silencing.” Our proprietary mRNAi GOLD™ (GalNAc Oligonucleotide Discovery) platform consists of siRNA product candidates designed to precisely target and ‘silence’ specific disease-associated genes in the liver. Using our mRNAi GOLD platform, we have generated siRNA product candidates both for our internal development pipeline as well as for out-licensed programs with third-party collaborators. Our wholly owned pipeline is currently focused on three therapeutic areas of high unmet need: cardiovascular disease, hematology and rare diseases.

Current wording

We are a biotechnology company focused on discovering and developing novel molecules incorporating short interfering ribonucleic acid, or siRNA, to inhibit the expression of specific target genes thought to play a role in the pathology of diseases with significant unmet medical need. Our siRNA molecules are designed to harness the body’s natural mechanism of RNAi by specifically binding to and degrading messenger RNA, or mRNA, molecules that encode specific targeted disease-associated proteins in a cell. By degrading the message that encodes the disease-associated protein, the production of that protein is reduced and its level of activity is lowered. In the field of RNAi therapeutics, this reduction of disease-associated protein production and activity is referred to as “gene silencing.” Our proprietary mRNAi GOLD™ (GalNAc Oligonucleotide Discovery) platform consists of siRNA product candidates designed to precisely target and ‘silence’ specific disease-associated genes in the liver. Using our mRNAi GOLD platform, we have generated siRNA product candidates targeting areas of high unmet need across rare and common diseases where treatments are limited or inadequate.

Previous wording

Divesiran (SLN124) is our wholly owned siRNA product candidate that works by temporarily silencing TMPRSS6 expression in the liver. TMPRSS6 is a negative regulator of hepcidin, the body's master regulator of iron metabolism, including its absorption, distribution and storage. Divesiran has shown promising pre-clinical potential in several hematological disorders and is a potentially first-in-class siRNA in Phase 2 development for polycythemia vera, or PV. PV is a rare, myeloproliferative neoplasm – a type of blood cancer – characterized by the excessive production of red blood cells, often resulting in elevated hematocrit, or HCT, levels. Elevated HCT, defined as 45% or higher, is associated with a four-times higher rate of death from cardiovascular or thrombotic events. PV is associated with a range of burdensome symptoms, including fatigue, cognitive disturbance and pruritus. Longer term, PV may also progress to myelofibrosis and acute myeloid leukemia. The aim of PV treatment is to maintain HCT less than 45%, a level that is associated with a reduced incidence of thrombosis and cardiovascular-associated death. The current standard of care includes repeated phlebotomies to reduce HCT and/or cytoreductive agents to reduce red blood cell production. There are currently no approved therapies that specifically target red blood cells and HCT. By silencing TMPRSS6 in people living with PV, divesiran aims to increase hepcidin levels and redirect iron delivery away from the bone marrow, lowering red blood cell production and potentially reducing the high red blood cell count. In the SANRECO Phase 1 clinical trial of divesiran in PV patients, divesiran lowered and maintained durable control of HCT and essentially eliminated the need for phlebotomies in phlebotomy-dependent PV patients. Importantly, divesiran was well tolerated with no dose-limiting toxicities. The ongoing SANRECO Phase 2 clinical trial is fully enrolled, and we anticipate the announcement of initial topline results from the trial in the third quarter of 2026. The U.S. Food and Drug Administration, or FDA, has granted divesiran Fast Track and orphan drug designations for PV. In December 2024, the European Commission, or EC, granted divesiran orphan drug designation for PV in Europe.

Current wording

Divesiran (SLN124) is our potential first-in-class siRNA in Phase 2 development for polycythemia vera, or PV. PV is a rare myeloproliferative neoplasm characterized by the overproduction of red blood cells, or RBCs. Elevated hematocrit, or HCT, - an index of RBC mass - is a hallmark of the disease and HCT levels above 45% increase the risk of thrombotic and cardiovascular events. The current standard of care in all PV patients to control HCT is phlebotomy, daily low-dose aspirin therapy, sometimes in combination with cytoreductive therapies. PV patients have low levels of hepcidin the body’s master regulator of iron. Divesiran works by "silencing" the TMPRSS6 gene, lifting the natural brake on hepcidin - the body's master iron regulator. When TMPRSS6 is turned down in people living with PV, hepcidin levels rise, reducing iron availability to the bone marrow. With less iron available, the overproduction of RBCs seen in PV is reduced. This helps keep HCT levels in a safer range and can reduce or eliminate the need for phlebotomies. Additionally, siRNA therapies have a highly potent and durable effect - enabling less frequent and more convenient dosing. In the Phase 1 part of the SANRECO clinical trial evaluating divesiran treatment in 21 PV patients, divesiran produced durable HCT control and substantially reduced phlebotomy use following infrequent dosing (Q6W). Based on the strong durability observed in Phase 1, the ongoing Phase 2 part of the SANRECO trial is evaluating both a Q6W and Q12W dosing interval. The SANRECO Phase 2 trial is fully enrolled and topline results are anticipated in August 2026. The U.S. Food and Drug Administration, or FDA, has granted divesiran Fast Track and orphan drug designations for PV. Divesiran has also been granted orphan drug designation by the European Commission for PV in Europe. While our initial focus is on PV, divesiran has shown the potential in preclinical studies to address multiple hematological conditions through the unifying mechanism of elevating hepcidin in conditions with dysregulation of iron homeostasis.

Previous wording

based registry study in over 16,000 individuals showed that there is substantial risk of major cardiovascular events in individuals with elevated levels below the current accepted risk threshold of 125 nmol/L. Guidelines from the European Atherosclerosis Society and Canadian Cardiovascular Society suggest at least one test in an adult lifetime. The American College of Cardiology, or ACC, and American Heart Association, or AHA, recommend testing for those with a family history of premature atherosclerotic cardiovascular disease, or ASCVD, or personal history of ASCVD. In Phase 1 and Phase 2 clinical trials, zerlasiran substantially lowered Lp(a) levels in ASCVD patients with persisting effects following infrequent dosing. Importantly, zerlasiran was well tolerated with no major safety concerns. We received positive regulatory feedback from the FDA and European Medicines Agency, or EMA, on the Phase 3 cardiovascular, or CV, outcomes study design for zerlasiran in patients with high Lp(a). We have completed core Phase 3 readiness activities, including manufacturing and supply scale up, and we are seeking a third-party partner for Phase 3 development of zerlasiran as well as potential future commercialization.

Current wording

Zerlasiran (SLN360) is our Phase 3 ready siRNA product candidate for cardiovascular disease that works by "silencing" the LPA gene, lowering production of apolipoprotein(a), a key component of lipoprotein(a), or Lp(a), that has been associated with an increased risk of cardiovascular events. High Lp(a), defined as 125nmol/L or higher, is a genetically determined cardiovascular risk factor affecting at least 20% of the world’s population and is associated with a high risk of heart attack, stroke and aortic stenosis. Unlike low-density lipoprotein, or LDL, Lp(a) levels are predominantly genetically determined, typically by age five, and unaffected by diet or lifestyle. There are currently no approved medicines that selectively lower Lp(a). Guidelines from the European Atherosclerosis Society, or EAS, Canadian Cardiovascular Society, or CCS, and the National Lipid Association, or NLA, suggest at least one test in an adult lifetime. The American College of Cardiology, or ACC, and American Heart Association, or AHA, recommend testing for those with a family history of premature atherosclerotic cardiovascular disease, or ASCVD, or personal history of ASCVD. In Phase 1 and Phase 2 clinical trials, zerlasiran showed the potential to substantially lower Lp(a) levels in ASCVD patients with persisting effects following infrequent dosing and was well tolerated with no major safety concerns. We have received positive regulatory feedback from the FDA and European Medicines Agency, or EMA, on the Phase 3 cardiovascular outcomes study design for zerlasiran in patients with high Lp(a). In 2025, we completed core Phase 3 readiness activities, including manufacturing and supply scale up. Zerlasiran is Phase 3 ready and we are seeking a third-party partner for potential Phase 3 development as well as potential future commercialization.

Previous wording

In March 2020, we entered into a collaboration agreement with AstraZeneca, or the AstraZeneca Collaboration, to discover, develop and commercialize siRNA therapeutics for the treatment of cardiovascular, renal, metabolic and respiratory diseases. Under the AstraZeneca Collaboration, AstraZeneca made an upfront cash payment to us of $20.0 million in May 2020. AstraZeneca made an additional unconditional cash payment to us of $40.0 million, which was received in May 2021. In March 2020, an affiliate of AstraZeneca also subscribed for 4,276,580 new ordinary shares for an aggregate subscription price of $20.0 million.

Current wording

In March 2020, we entered into a collaboration agreement with AstraZeneca to discover, develop and commercialize siRNA therapeutics for the treatment of cardiovascular, renal, metabolic and respiratory diseases. Under this agreement, AstraZeneca made an upfront cash payment to us of $20.0 million in May 2020. AstraZeneca made an additional unconditional cash payment to us of $40.0 million which was received in May 2021. In March 2020, an affiliate of AstraZeneca also subscribed for 4,276,580 new ordinary shares for an aggregate subscription price of $20.0 million.

Previous wording

The AstraZeneca Collaboration covers five targets initially, with AstraZeneca having the option to extend the collaboration to a further five targets. AstraZeneca has agreed to pay us $10.0 million upon the exercise of each option to collaborate on an additional target. In May 2023, AstraZeneca nominated the first product candidate under the AstraZeneca Collaboration, triggering a $10 million option fee to us to advance development on an undisclosed program. In February 2024, AstraZeneca initiated a Phase 1 clinical trial for this undisclosed program which triggered another $10 million milestone payment to us. In March 2024, we completed our obligations for the second product candidate under the AstraZeneca Collaboration. For each target selected, we will be eligible to receive up to $140.0 million in potential milestone payments upon the achievement of milestones relating to the initiation of specified clinical trials, the acceptance of specified regulatory filings and the first commercial sale in specified jurisdictions. For each target selected, we will also be eligible to receive up to $250.0 million in potential commercial milestone payments, upon the achievement of specified annual net sales levels, as well as tiered royalties as a percentage of net sales ranging from the high single digits to the low double digits.

Current wording

The collaboration covered five targets initially with AstraZeneca opting to extend the collaboration to a further five targets. AstraZeneca agreed to pay us $10.0 million upon the exercise of each option to collaborate on an additional target. For each target selected, we are eligible to receive up to $140.0 million in potential milestone payments upon the achievement of milestones relating to the initiation of specified clinical trials, the acceptance of specified regulatory filings and the first commercial sale in specified jurisdictions. For each target selected, we are also eligible to receive up to $250.0 million in potential commercial milestone payments, upon the achievement of specified annual net sales levels, as well as tiered royalties as a percentage of net sales ranging from the high single digits to the low double digits.

Previous wording

We do not have any commercially approved products. Accordingly, we have not generated any revenue from product sales, and we do not expect to generate any revenue from the sale of any products unless and until we obtain regulatory approvals for, and commercialize any of, our product candidates. In the future, we will seek to generate revenue primarily from product sales and, potentially, regional or global strategic collaborations with third parties.

Current wording

We do not have any approved products. Accordingly, we have not generated any revenue from product sales, and we do not expect to generate any revenue from the sale of any products unless and until we obtain regulatory approvals for, and commercialize any of, our product candidates. In the future, we will seek to generate revenue primarily from product sales and, potentially, regional or global strategic collaborations with third parties.

Previous wording

Under the AstraZeneca Collaboration, we received an upfront cash payment of $20.0 million and an additional payment of $40.0 million in May 2021. We are also eligible to receive specified development and commercial milestone payments as well as tiered royalties on net sales, if any. We recognize the upfront payment and milestone payments over time. During the nine months ended September 30, 2025, we recognized a total of $0.5 million in revenue under the AstraZeneca Collaboration (nine months ended September 30, 2024: $16.3 million).

Current wording

Under the AstraZeneca collaboration, we received an upfront cash payment of $20.0 million and an additional payment of $40.0 million in May 2021. We are also eligible to receive specified development and commercial milestone payments as well as tiered royalties on net sales, if any. We recognize the upfront payment and milestone payments over time. During the three months ended March 31, 2026, we recognized a total of $0.4 million in revenue under the AstraZeneca collaboration (three months ended March 31, 2025: $0.1 million).

Previous wording

Our contracted development costs primarily consist of:

Current wording

Our contracted development costs primarily consists of:

Previous wording

Other research and development costs primarily consists of:

Current wording

Our other research and development costs primarily consists of:

Previous wording

costs of related facilities, equipment and other overhead expenses that are considered directly attributable to research and development;

Current wording

costs of related facilities, equipment and other overhead expenses that are considered directly attributable to research and development; and

Previous wording

the terms and timing of any regulatory approvals;

Current wording

the terms and timing of any regulatory approvals; and

Previous wording

General and administrative expenses consist of personnel costs, allocated expenses and other expenses for outside professional services, including legal, audit, tax and accounting services, public relations and investor relations services. Personnel costs consist of salaries, bonuses, benefits, recruitment costs and share-based payment expenses for personnel in executive, finance, business development and other support functions. Other administrative expenses include office space-related costs not otherwise allocated to research and development costs, insurance expenses, and costs of our information systems and costs for compliance with the day-to-day requirements of being a public company listed in the United States. We will continue to be prudent with administrative expenses required to support our continued research and development and potential commercialization of our product candidates. We also will continue to incur expenses related to being a public company, including expenses related to compliance with the rules and regulations of the SEC and the Nasdaq Stock Market, or Nasdaq, additional insurance expenses, expenses related to investor relations activities and other administrative and professional services.

Current wording

General and administrative expenses consist of personnel costs, allocated expenses and other expenses for outside professional services, including legal, audit, tax and accounting services, public relations and investor relations services. Personnel costs consist of salaries, bonuses, benefits, recruitment costs and share-based payment expenses for personnel in executive, finance, business development and other support functions. Other administrative expenses include office space-related costs not otherwise allocated to research and development costs, insurance expenses, and costs of our information systems and costs for compliance with the day-to-day requirements of being a public company listed in the United States. We anticipate that our administrative expenses will remain consistent to support our continued research and development and potential commercialization of our product candidates. We also expect to continue incurring additional expenses as a public company in the United States, including expenses related to compliance with the rules and regulations of the SEC and the Nasdaq Stock Market, or Nasdaq, additional insurance expenses, expenses related to investor relations activities and other administrative and professional services.

Previous wording

Taxation and Benefit from R&D credit

Current wording

Taxation and Benefit from R&D Tax Credit

Previous wording

As a company that carries out extensive research and development, or R&D, activities, we seek to benefit from the U.K. R&D tax credit regime. In respect of accounting periods in which we qualify as a Small and Medium-sized Enterprise, or SME, and in which our qualifying R&D expenditure represents 30% (for periods from April 1, 2024) or more of the total (meaning we also qualify as “R&D-intensive” during such accounting period), we may, under this regime, surrender the trading losses that arise from our R&D activities for a cash rebate of up to 26.97% of qualifying R&D expenditure. Accordingly, if we cease to qualify as an R&D-intensive SME, in future, we will either cease to be able to claim cash rebates in respect of our R&D activities, or only be able to receive cash payments or other tax relief (under other provisions of the U.K. R&D tax credit regime) at a significantly lower rate than at present. Further, the regime’s rules are complex, and if a tax authority were to challenge or seek to disallow our claims (in whole or in part), for example by asserting that we do not (or the relevant expenditure does not) meet the technical conditions to be granted tax credits (or cash rebates), then such challenge or disallowance, if successful, could have a material impact on our cash-flow and financial performance. In addition, future changes to the U.K. R&D tax credit regime may mean that we no longer qualify for it or have a material impact on the extent to which we can make claims (or benefit from them).

Current wording

Enterprise, or SME, and in which our qualifying R&D expenditure represents 30% (for periods from April 1, 2024) or more of the total (meaning we are considered as “R&D-intensive” during such accounting period), we may, under this regime, surrender the trading losses that arise from our R&D activities for a cash rebate of up to 26.97% of qualifying R&D expenditure. Based on our current forecast, we do not expect to meet the qualifying R&D expenditure threshold for the year ended December 31, 2026; however, we plan to still expect to claim at the R&D intensive rate as we expect to meet conditions for a grace period under the U.K. R&D tax credit regime. Accordingly, if we cease to qualify as an R&D-intensive SME, in future, we will either cease to be able to claim cash rebates in respect of our R&D activities, or only be able to receive cash payments or other tax relief (under other provisions of the U.K. R&D tax credit regime) at a significantly lower rate than at present. Further, the regime’s rules are complex, and if a tax authority were to challenge or seek to disallow our claims (in whole or in part), for example by asserting that we do not (or the relevant expenditure does not) meet the technical conditions to be granted tax credits (or cash rebates), then such challenge or disallowance, if successful, could have a material impact on our cash-flow and financial performance. In addition, future changes to the U.K. R&D tax credit regime may mean that we no longer qualify for it or have a material impact on the extent to which we can make claims (or benefit from them).

Previous wording

Unsurrendered U.K. tax losses may be carried forward indefinitely to be offset against future taxable profits, subject to numerous utilization criteria and restrictions. The amount that can be offset each year is limited to $6.5 million (£5.0 million) plus an incremental 50% of U.K. taxable profits. After accounting for tax credits receivable, we had accumulated tax losses for carry forward in the United Kingdom of $221.0 million as of September 30, 2025 ($236.8 million as of September 30, 2024). However, in the event of a change in ownership of a U.K. company, certain provisions may apply to restrict the utilization of carried forward tax losses in future periods. These provisions apply where there is a major change in the nature or conduct of a trade in connection with the change in ownership. For the avoidance of doubt, we do not recognize a deferred tax asset in respect of the accumulated tax losses. In addition to our accumulated tax losses in the United Kingdom, we also had $52.3 million of accumulated tax losses as of September 30, 2025 ($52.7 million as of September 30, 2024), related to our operations in Germany for corporate income taxes. We also had $50.6 million of accumulated losses related to trade taxes in our German entity ($51.1 million as of September 30, 2024). We had a foreign tax expense in Germany of nil for the nine months ended September 30, 2025 (nine months ended September 30, 2024: $0.03 million). Tax losses in the United States were negligible.

Current wording

Unsurrendered U.K. tax losses may be carried forward indefinitely to be offset against future taxable profits, subject to numerous utilization criteria and restrictions. The amount that can be offset each year is limited to $6.5 million (£5.0 million) plus an incremental 50% of U.K. taxable profits. After accounting for tax credits receivable, we had accumulated tax losses for carry forward in the United Kingdom of $237.0 million as of March 31, 2026 ($187.7 million as of March 31, 2025). However, in the event of a change in ownership of a U.K. company, certain provisions may apply to restrict the utilization of carried forward tax losses in future periods. These provisions apply where there is a major change in the nature or conduct of a trade in connection with the change in ownership. For the avoidance of doubt, we do not recognize a deferred tax asset in respect of the accumulated tax losses. In addition to our accumulated tax losses in the United Kingdom, we also had $50.5 million of accumulated tax losses as of March 31, 2026 ($48.7 million as of March 31, 2025), related to our operations in Germany for corporate income taxes. We also had $48.9 million of accumulated losses related to trade taxes in our German entity ($47.2 million as of March 31, 2025). We had a foreign tax expense in Germany of nil for the three months ended March 31, 2026 (three months ended March 31, 2025: nil). Tax losses in the United States were negligible.

Previous wording

Comparison of the three months and nine months ended September 30, 2025, and 2024

Current wording

Comparison of the three months ended March 31, 2026, and 2025

Previous wording

The following table summarizes the results of our operations for the three months and nine months ended September 30, 2025, and 2024 (in thousands).

Current wording

The following table summarizes the results of our operations for the three months ended March 31, 2026, and 2025 (in thousands).

Previous wording

Cost of sales decreased $3.6 million for the three months ended September 30, 2025, as compared to the same period in 2024. The change was due to activity associated with our collaboration agreements, which fluctuates based on the timing of activities and project progression.

Current wording

Cost of sales movement was negligible for the three months ended March 31, 2026, as compared to the same period in 2025. The change was due to activity associated with our collaboration agreements, which fluctuates based on the timing of activities and project progression.

Previous wording

The following table summarizes our research and development costs for the three and nine months ended September 30, 2025 and 2024, based on their classification (in thousands).

Current wording

The following table summarizes our research and development costs for the three months ended March 31, 2026 and 2025, based on their classification (in thousands).

Previous wording

Research and development costs for the three months ended September 30, 2025 increased by $0.4 million to $20.5 million. This change was mainly due to an increase in other costs of $1.4 million associated with the reduction of a prepayment to a manufacturing provider that we will no longer use for preferred access to manufacturing services, which was offset by a reduction in contracted development costs of $0.5 million as well as a decrease in personnel costs of $0.5 million.

Current wording

Research and development costs for the three months ended March 31, 2026 decreased by $11.7 million to $9.1 million. This change was mainly due to a decrease in contracted development costs of $10.3 million associated with the Phase 3 readiness for zerlasiran in 2025 as well as a decrease in personnel costs of $1.4 million mainly due to reduced headcount.

Previous wording

General and administrative expenses decreased by $1.9 million for the three months ended September 30, 2025, and $2.7 million for the nine months ended September 30, 2025, as compared to the same periods in 2024. These decreases were mainly due to a reduction in SEC reporting and compliance requirements as we determined as of June 30, 2025 that we will not meet the eligibility criteria to be a large accelerated filer in fiscal year 2026. This was also due to an effort to reduce administrative costs in connection with our restructuring.

Current wording

General and administrative expenses decreased by $0.7 million for the three months ended March 31, 2026 compared to the same period in 2025. These decreases were mainly due to an effort to reduce administrative costs.

Previous wording

Net foreign exchange gains and losses result primarily from foreign currency (USD and EUR) denominated bank accounts. The foreign exchange losses and gains in the current year were primarily due to remeasurement of U.S. treasury bills held in USD to the related functional currency.

Current wording

As of January 1, 2026, the functional currency of our U.K. entity changed to USD and as a result, foreign currency activity included in net income for the three months ended March 31, 2026 was a loss of $0.5 million. In the prior year, foreign exchange gains and losses included in net income resulted primarily from foreign currency (USD and EUR) denominated bank accounts. The foreign exchange losses for the three months ended March 31, 2025 were primarily due to remeasurement of U.S. treasury bills held in USD to the related functional currency.

Previous wording

Benefit from R&D tax credit relates to U.K. research and development tax credits. The decrease in benefit in the current year was mainly related to changes in the U.K R&D tax credit regime which apply in respect of accounting periods commencing on or after April 1, 2024. These changes led to a reduction in costs that are eligible for the claim.

Current wording

Benefit from R&D tax credit relates to U.K. research and development tax credits. The decrease in benefit in the current year was mainly related to a reduction in research and development spend.

Previous wording

Since our inception, we have incurred significant operating losses and negative cash flows. We anticipate that we will continue to incur losses for the foreseeable future. We expect to continue to incur expenses in connection with our ongoing research and development activities related to our product candidates, including outsourced manufacturing activities and other associated costs. We also expect to continue to incur costs associated with operating as a domestic issuer listed on Nasdaq. As a result, we will need additional capital to fund our operations in the future, which we may obtain from additional equity financings, debt financings, research funding, collaborations, contract and grant revenue or other sources.

Current wording

Since our inception, we have incurred significant operating losses and negative cash flows. We anticipate that we will continue to incur losses for the foreseeable future. We expect that our research and development and administrative expenses will increase in connection with conducting clinical trials and seeking marketing approval for our product candidates, as well as costs associated with operating as a public company.

Previous wording

As of September 30, 2025, we had cash, cash equivalents, and short-term investments of $102.2 million. We believe that our cash, cash equivalents, and treasury instruments will be sufficient to fund our anticipated operating and capital expenditure requirements into 2028, which includes receipt of anticipated milestones from collaboration agreements in the aggregate amount of $20.0 million in the next three years.

Current wording

As of March 31, 2026, we had cash, cash equivalents, and short-term investments of $70.1 million. We believe that our cash, cash equivalents, and short-term investments will be sufficient to fund our anticipated operating and capital expenditure requirements into 2028.

Previous wording

On October 15, 2021, we entered into an Open Market Sale Agreement, or the Sales Agreement, with Jefferies LLC, or Jefferies, pursuant to which we may offer and sell, from time to time, our ADSs through Jefferies. In 2024, we raised additional proceeds of $27.7 million before deducting $0.9 million in placement agent fees and other expenses, from sales of ADSs under the Sales Agreement.

Current wording

On October 15, 2021, we entered into an Open Market Sale Agreement, or the Sales Agreement, with Jefferies LLC, or Jefferies, pursuant to which we may offer and sell, from time to time, our ADSs through Jefferies. In 2024, we raised proceeds of $27.7 million before deducting $0.9 million in placement agent fees and other expenses, from sales of ADSs under the Sales Agreement.

Previous wording

On February 2, 2024, we entered into a securities purchase agreement, or the Purchase Agreement, with the purchasers named therein, or the Investors. Pursuant to the Purchase Agreement, we agreed to sell an aggregate of 5,714,286 of our ADSs to the Investors, at a purchase price equal to $21.00 per ADS, or the Private Placement. The Purchase Agreement contained customary representations and warranties from us and the investors and customary closing conditions. The closing of the Private Placement occurred on February 7, 2024, and we received aggregate gross proceeds from the Private Placement of approximately $120.0 million before deducting $7.7 million in placement agent fees and other expenses.

Current wording

On February 2, 2024, we entered into a securities purchase agreement, or the Purchase Agreement, with the purchasers named therein, or the Investors. Pursuant to the Purchase Agreement, we agreed to sell an aggregate of 5,714,286 of our ADSs to the Investors, at a purchase price equal to $21.00 per ADS, or the Private Placement. The

Previous wording

In 2024, we raised aggregate gross proceeds from the Private Placement of $120 million before deducting $7.7 million in placement agent fees and other expenses. The remainder of the inflow was due to

Current wording

Purchase Agreement contained customary representations and warranties from us and the investors and customary closing conditions. The closing of the Private Placement occurred on February 7, 2024, and we received aggregate gross proceeds from the Private Placement of approximately $120.0 million before deducting $7.7 million in placement agent fees and other expenses.

Previous wording

The following table summarizes the results of our cash flows for the nine months ended September 30, 2025 and 2024.

Current wording

The following table summarizes the results of our cash flows for the three months ended March 31, 2026 and 2025.

Previous wording

Net cash outflow from investing activities relates to redemptions of U.S. treasury bills offset by purchases for the nine months ended September 30, 2025.

Current wording

Net cash inflow from investing activities relates to redemptions of U.S. treasury bills, offset by purchases for the three months ended March 31, 2026. The same period in 2025 reflected $70.1 million in purchases of U.S. treasury bills offset by $25.7 million in redemptions.

Previous wording

the costs of hiring additional skilled employees to support our continued growth and the related costs of leasing additional office space.

Current wording

the costs of hiring additional skilled employees to support our growth and the related costs of leasing additional office space.

Previous wording

During the nine months ended September 30, 2025, our revenue from collaboration agreements was derived from the AstraZeneca Collaboration (nine months ended September 30, 2024, revenue was from our collaborations with Mallinckrodt, AstraZeneca, and Hansoh).

Current wording

During the three months ended March 31, 2026 and 2025, our revenue from collaboration agreements was derived from the AstraZeneca collaboration.

Previous wording

We have out-licensed the rights to some of our intellectual property associated with our siRNA stabilization chemistry technology to AstraZeneca in the context of a Research Collaboration, Option and License Agreement dated March 24, 2020, under which we and AstraZeneca will collaborate to discover, develop and commercialize siRNA therapeutics for the treatment of cardiovascular, renal, metabolic and respiratory diseases. AstraZeneca made an upfront cash payment of $60 million, of which $20 million was paid in May 2020 and the remaining $40 million was paid in May 2021. The upfront payment has been allocated evenly between the ten targets on the basis of a benchmarking exercise that took into account the standalone selling price per target, of similar precedent transactions that had been publicly announced by comparable companies. Subsequent milestones are allocated to the target to which they are related. The upfront and milestone payments will be recognized as revenue as the services are provided. We anticipate initiating work on up to five targets in the early stages of the collaboration, with AstraZeneca having the option to extend the collaboration to a further five targets. Under the collaboration, utilizing our technology, we are responsible for designing siRNA molecules against gene targets selected by AstraZeneca, and for manufacturing of material to support GLP toxicology studies and phase 1 clinical trials. We and AstraZeneca will collaborate during the discovery phase, and AstraZeneca will lead clinical development and commercialization of molecules arising from the collaboration. For each target selected under the collaboration, we will be eligible to receive up to $140 million in milestone payments upon the achievement of milestones relating to the initiation of specified clinical trials, the acceptance of specified regulatory filings and the first commercial sale in specified jurisdictions. AstraZeneca has the right to terminate the agreement in its entirety or on a target-by-target basis, for any reason upon specified prior written notice to us. We may terminate the agreement on a target-by-target basis in the event that AstraZeneca begins a legal or administrative proceeding challenging the patentability, validity, ownership or enforceability of our patents. Either party may terminate the agreement on a target-by-target basis upon a material breach by the other party that is not cured within a specified period after receiving written notice, or in its entirety upon giving written notice following the other party’s bankruptcy, insolvency or similar instance. The license of the intellectual property and the R&D services are not distinct, as AstraZeneca cannot benefit from the intellectual property absent the R&D services, as those R&D services are used to discover and develop a drug candidate and to enhance the value in the underlying intellectual property, which could not be performed by another party, indicating that the two are …

Excerpt shortened here; the source contains the full paragraph.

Current wording

We have out-licensed the rights to some of our intellectual property associated with our siRNA stabilization chemistry technology to AstraZeneca in the context of a Research Collaboration, Option and License Agreement dated March 24, 2020, under which we and AstraZeneca will collaborate to discover, develop and commercialize siRNA therapeutics for the treatment of cardiovascular, renal, metabolic and respiratory diseases. AstraZeneca made an upfront cash payment of $60.0 million, of which $20.0 million was paid in May 2020 and the remaining $40.0 million was paid in May 2021. The upfront payment has been allocated evenly between the ten targets on the basis of a benchmarking exercise that took into account the standalone selling price per target, of similar precedent transactions that had been publicly announced by comparable companies. Subsequent milestones are allocated to the target to which they are related. The upfront and milestone payments will be recognized as revenue as the services are provided. We anticipate initiating work on up to five targets in the early stages of the collaboration, with AstraZeneca having the option to extend the collaboration to a further five targets. Under the collaboration, utilizing our technology, we are responsible for designing siRNA molecules against gene targets selected by AstraZeneca, and for manufacturing of material to support GLP toxicology studies and phase 1 clinical trials. We and AstraZeneca will collaborate during the discovery phase, and AstraZeneca will lead clinical development and commercialization of molecules arising from the collaboration. For each target selected under the collaboration, we will be eligible to receive up to $140.0 million in milestone payments upon the achievement of milestones relating to the initiation of specified clinical trials, the acceptance of specified regulatory filings and the first commercial sale in specified jurisdictions. AstraZeneca has the right to terminate the agreement in its entirety or on a target-by-target basis, for any reason upon specified prior written notice to us. We may terminate the agreement on a target-by-target basis in the event that AstraZeneca begins a legal or administrative proceeding challenging the patentability, validity, ownership or enforceability of our patents. Either party may terminate the agreement on a target-by-target basis upon a material breach by the other party that is not cured within a specified period after receiving written notice, or in its entirety upon giving written notice following the other party’s bankruptcy, insolvency or similar instance. The license of the intellectual property and the R&D services are not distinct, as AstraZeneca cannot benefit from the intellectual property absent the R&D services, as those R&D services are used to discover and develop a drug candidate and to enhance the value in the underlying intellectual property, which could not be performed by another party, indicating that the …

Excerpt shortened here; the source contains the full paragraph.

Previous wording

For the nine months ended September 30, 2025 and 2024, we determined actual costs and forecast costs for the remainder of the contract. We calculated total contract costs across the contract term, including costs that will be reimbursed to us, and costs incurred to date as a percentage of total contract costs. We multiplied this percentage by the consideration deemed highly probable of not having a significant reversal, calculating the cumulative revenue to be recognized. When variable consideration increases due to a further milestone becoming highly probable that a significant reversal of revenue will not occur, a catch-up in revenue is recorded to reflect efforts already expended by us up to that point.

Current wording

For the three months ended March 31, 2026 and 2025, we determined actual costs and forecast costs for the remainder of the contract. We calculated total contract costs across the contract term, including costs that will be reimbursed to us, and costs incurred to date as a percentage of total contract costs. We multiplied this percentage by the consideration deemed highly probable of not having a significant reversal, calculating the cumulative revenue to be recognized. When variable consideration increases due to a further milestone becoming highly probable that a significant reversal of revenue will not occur, a catch-up in revenue is recorded to reflect efforts already expended by us up to that point. In the three months ended March 31, 2026, the estimated forecasted cost for partnered programs was not material and the related judgment was not significant.

Previous wording

We discuss the effect of recently issued and adopted pronouncements in Note 2.20, “Summary of Significant Accounting Policies” to the condensed consolidated financial statements in our Annual Report.

Current wording

We discuss the effect of recently issued and adopted pronouncements in Note 2.6, "Recently Issued Accounting Pronouncements" to the condensed consolidated financial statements included elsewhere in this Quarterly Report on Form 10-Q and Note 2.20, “Summary of Significant Accounting Policies” to our audited consolidated financial statements in our Annual Report on Form 10-K for the year ended December 31, 2025.