ROCKET PHARMACEUTICALS, INC.

Previous wording

The Company’s activities during the quarter reflect continued execution across its prioritized cardiovascular gene therapy programs, alongside the FDA accelerated approval of KRESLADI™ in March 2026 for the treatment of severe LAD-I in pediatric patients without a suitable human leukocyte antigen (HLA)-matched sibling donor. The Company is advancing commercial readiness activities, including treatment center onboarding, supply chain preparation, and coordination of vein-to-vein logistics, in advance of anticipated product availability. Given the ultra-rare patient population and anticipated phased commercial rollout, the Company does not expect KRESLADI™ to generate material revenue in the near term.

Current wording

The Company’s activities during the quarter reflect continued execution across our prioritized cardiovascular genetic medicines programs, alongside commercial readiness activities for KRESLADI™. Given the ultra-rare patient population and anticipated phased commercial rollout, the Company does not expect KRESLADI™ to generate material revenue in the near term.

Previous wording

In July 2025, we announced a strategic corporate reorganization and pipeline prioritization initiative designed to maximize near-term value creation, extend our operational runway, and position the Company for sustainable long-term growth. The initiative focused resources on advancing our AAV cardiovascular gene therapy platform and supporting the submission of our response to the FDA’s CRL for KRESLADI™. As part of this strategic realignment, we de-prioritized further development activities related to our FA and PKD programs and implemented a workforce reduction of approximately 30%.

Current wording

In July 2025, we announced a strategic corporate reorganization and pipeline prioritization initiative designed to maximize near-term value creation, extend our operational runway, and position the Company for sustainable long-term growth. The initiative concentrated development resources on advancing our AAV-based cardiovascular genetic medicines portfolio and supporting the submission of our response to the FDA’s CRL for KRESLADI™. As part of this strategic realignment, we de-prioritized further development activities related to our FA and PKD programs and implemented a workforce reduction of approximately 30%.

Previous wording

In March 2026, KRESLADI™ (marnetegragene autotemcel) received accelerated approval from the FDA for the treatment of pediatric patients with severe LAD-I who do not have an available HLA-matched sibling donor. In connection with the approval, the Company was awarded a PRV and, in April 2026, entered into a definitive agreement to sell the PRV for $180 million. The Company intends to pursue a focused commercial strategy for KRESLADI™ that is appropriately scaled to the exceptionally small patient population affected by this ultra-rare disease.

Current wording

In March 2026, KRESLADI™ (marnetegragene autotemcel) received accelerated approval from the FDA for the treatment of pediatric patients with severe LAD-I who have biallelic mutations in the ITGB2 gene and do not have a suitable HLA-matched sibling donor. In connection with the approval, the Company was awarded a PRV and, in April 2026, entered into a definitive agreement to sell the PRV for $180 million. The transaction closed in June 2026. The Company intends to pursue a focused commercial strategy for KRESLADI™ that is appropriately scaled to the exceptionally small patient population affected by this ultra-rare disease.

Previous wording

Strategic Focus on Rare Cardiovascular Indications: Our near-term research and platform investments are focused on leveraging our AAV capabilities in rare cardiovascular diseases. Collectively, our clinical cardiovascular gene therapy programs target the major genetically defined causes of hypertrophic, arrhythmogenic, and dilated cardiomyopathies which represent a significant portion of inherited heart disease and impact more than 100,000 patients in the U.S. and EU.

Current wording

Strategic Focus on Rare Cardiovascular Indications: Our near-term research and development investments are focused on applying our AAV capabilities to genetically defined cardiovascular diseases. Collectively, our clinical cardiovascular genetic medicines programs address genetically defined forms of hypertrophic, arrhythmogenic and dilated cardiomyopathy, representing three major categories of inherited heart disease with significant unmet need.

Previous wording

Advancing our first-in-class product candidates targeting monogenic cardiovascular diseases with substantial unmet need from pre-IND to registrational trials.

Current wording

Advancing our portfolio of product candidates targeting monogenic cardiovascular diseases with substantial unmet need across stages of clinical development.

Previous wording

Gene therapy is a therapeutic approach in which an isolated gene sequence or segment of DNA is administered to a patient, most commonly for the purpose of treating a genetic disease that is caused by genetic mutations. Currently available therapies for many genetic diseases focus on administration of large proteins or enzymes and typically address only the symptoms of the disease. Gene therapy aims to address the disease-causing effects of absent or dysfunctional genes by delivering functional copies of the gene sequence directly into the patient’s cells, offering the potential for curing the genetic disease, rather than simply addressing symptoms.

Current wording

Genetic medicines are a therapeutic approach in which an isolated gene sequence or segment of DNA is administered to a patient, most commonly for the purpose of treating a genetic disease that is caused by genetic mutations. Currently available therapies for many genetic diseases focus on administration of large proteins or enzymes and typically address only the symptoms of the disease. Genetic medicines aim to address the disease-causing effects of absent or dysfunctional genes by delivering functional copies of the gene sequence directly into the patient’s cells, offering the potential for curing the genetic disease, rather than simply addressing symptoms.

Previous wording

We are developing gene therapy product candidates utilizing modified, non-pathogenic viruses as delivery vehicles. Viruses are inherently effective for gene delivery due to their natural ability to enter cells and deliver genetic material. In engineering our viral vectors, the native viral genes are removed and replaced with a functional copy of the missing or mutated gene responsible for a patient’s genetic disorder. This functional copy, known as the therapeutic gene or “transgene,” is introduced through a process known as transduction. Once modified, the virus is termed a “viral vector,” capable of delivering the transgene to targeted tissues or organs.

Current wording

We are developing genetic medicine product candidates utilizing modified, non-pathogenic viruses as delivery vehicles. Viruses are inherently effective for gene delivery due to their natural ability to enter cells and deliver genetic material. In engineering our viral vectors, the native viral genes are removed and replaced with a functional copy of the missing or mutated gene responsible for a patient’s genetic disorder. This functional copy, known as the therapeutic gene or “transgene,” is introduced through a process known as transduction. Once modified, the virus is termed a “viral vector,” capable of delivering the transgene to targeted tissues or organs.

Previous wording

We are advancing gene therapy programs using two primary vector approaches: adeno-associated virus (AAV) vectors and lentiviral (LV) vectors. We believe our AAV- and LV-based programs have the potential to provide meaningful and durable therapeutic benefit by addressing the underlying genetic cause of disease. Our gene therapy product candidates are administered either (1) in vivo, in which an AAV vector is delivered directly to the patient, either systemically or through targeted tissue delivery, to enable in situ transduction of the desired cell populations, or (2) ex vivo, in which a patient’s hematopoietic stem cells (HSCs) are collected, genetically modified with an LV vector in a controlled laboratory environment, and then reinfused into the patient.

Current wording

We are advancing genetic medicine programs using two primary vector approaches: adeno-associated virus (AAV) vectors and lentiviral (LV) vectors. We believe our AAV- and LV-based programs have the potential to provide meaningful and durable therapeutic benefit by addressing the underlying genetic cause of disease. Our genetic medicine product candidates are administered either (1) in vivo, in which an AAV vector is delivered directly to the patient, either systemically or through targeted tissue delivery, to enable in situ transduction of the desired cell populations, or (2) ex vivo, in which a patient’s hematopoietic stem cells (HSCs) are collected, genetically modified with an LV vector in a controlled laboratory environment, and then reinfused into the patient.

Previous wording

We believe that scientific advances, clinical progress, and the greater regulatory acceptance of gene therapy have created a promising environment to advance gene therapy products as these products are being designed to restore cell function and improve clinical outcomes, which in many cases include prevention of death at an early age. The FDA approval of several gene therapies in recent years indicates that there is a regulatory pathway forward for gene therapy products.

Current wording

We believe that scientific advances, clinical progress, and the greater regulatory acceptance of genetic medicines have created a promising environment to advance genetic medicine products as these products are being designed to restore cell function and improve clinical outcomes, which in many cases include prevention of death at an early age. The FDA approval of several genetic medicines in recent years indicates that there is a regulatory pathway forward for genetic medicine products.

Previous wording

The Company has global commercialization and development rights to all of these product candidates under internally developed intellectual property rights and royalty-bearing license agreements.

Current wording

The Company has global commercialization and development rights to these products and product candidates under internally developed intellectual property rights and royalty-bearing license agreements.

Previous wording

RP-A501 is our investigational gene therapy for the treatment of DD and consists of a recombinant adeno-associated serotype 9 (AAV9) capsid containing a full-length, wild-type version of the human LAMP2B transgene which is administered as a single intravenous (IV) infusion. RP-A501 holds FDA RMAT, Fast Track, Rare Pediatric, and Orphan Drug designations in the U.S. along with ATMP and PRIME designations in the EU.

Current wording

RP-A501 is our investigational genetic medicine for the treatment of DD and consists of a recombinant adeno-associated serotype 9 (AAV9) capsid containing a full-length, wild-type version of the human LAMP2B transgene which is administered as a single intravenous (IV) infusion. RP-A501 holds FDA RMAT, Fast Track, Rare Pediatric, and Orphan Drug designations in the U.S. along with ATMP and PRIME designations in the EU.

Previous wording

LAMP2 gene expression in endomyocardial biopsy samples is measured via both immunohistochemistry and Western blot and confirms the presence of LAMP2 protein in DD cardiac tissue following RP-A501 treatment.

Current wording

LAMP2 protein expression in endomyocardial biopsy samples is measured via both immunohistochemistry and Western blot and confirms the presence of LAMP2 protein in DD cardiac tissue following RP-A501 treatment.

Previous wording

High sensitivity troponin I or hs-TnI and BNP are blood-based evaluations and a key marker of HF and cardiac injury. Both are frequently elevated in DD patients and have been shown to be markedly elevated in patients with advanced stage disease.

Current wording

High sensitivity troponin I or hs-TnI and BNP are blood-based biomarkers of heart failure and cardiac injury. Both are frequently elevated in DD patients and have been shown to be markedly elevated in patients with advanced stage disease.

Previous wording

As previously announced, a patient receiving therapy on the high dose cohort (1.1e14 gc/kg dose) had progressive HF and underwent a heart transplant at month five following therapy. This patient had more advanced disease than the four other adult/older adolescent patients who received treatment in the low and high dose cohorts, as evidenced by diminished baseline left ventricle ejection fraction (32%) on echocardiogram and markedly elevated left ventricle filling pressure prior to treatment. The patient’s clinical course was characteristic of DD progression. The patient is doing well post-transplant.

Current wording

As previously announced, a patient receiving therapy in the high dose cohort (1.1e14 gc/kg dose) had progressive HF and underwent a heart transplant at month five following therapy. This patient had more advanced disease than the four other adult/older adolescent patients who received treatment in the low and high dose cohorts, as evidenced by diminished baseline left ventricular ejection fraction (32%) on echocardiogram and markedly elevated left ventricle filling pressure prior to treatment. The patient’s clinical course was characteristic of DD progression. The patient is doing well post-transplant.

Previous wording

In November 2024, we announced positive results and presented long-term safety and efficacy results of the Phase 1 study at the American Heart Association’s 2024 Late-Breaking Science sessions and simultaneously published these data in the New England Journal of Medicine. The long-term safety and efficacy results from the Phase 1 RP-A501 study showed that RP-A501 was generally well tolerated and all evaluable DD patients demonstrated LAMP2 protein expression at 12 months (sustained up to 60 months) and reduction of left ventricular mass index by ≥10% at 12 months (sustained up to 54 months) after treatment. Results from the Phase 1 DD trial represent one of the first and most comprehensive investigational gene therapy datasets for any cardiac condition.

Current wording

In November 2024, we announced positive results and presented long-term safety and efficacy results of the Phase 1 study at the American Heart Association’s 2024 Late-Breaking Science sessions and simultaneously published these data in the New England Journal of Medicine. The long-term safety and efficacy results from the Phase 1 RP-A501 study showed that RP-A501 was generally well tolerated and all evaluable DD patients demonstrated LAMP2 protein expression at 12 months (sustained up to 60 months) and reduction of left ventricular mass index by ≥10% at 12 months (sustained up to 54 months) after treatment. Results from the Phase 1 DD trial represent one of the first and most comprehensive investigational genetic medicine datasets for any cardiac condition.

Previous wording

In summary, all evaluable patients in the Phase 1 trial demonstrated:

Current wording

Collectively, these findings continue to support evidence of biologic activity, favorable long-term durability, and clinically meaningful improvements across multiple measures of disease. All evaluable patients in the Phase 1 trial demonstrated:

Previous wording

Preservation of normal left ventricle ejection fraction (LVEF);

Current wording

Preservation of normal left ventricular ejection fraction (LVEF);

Previous wording

In September 2023, we announced that alignment was reached with the FDA on the global Phase 2 pivotal trial of RP-A501 for DD to support accelerated approval. The global, single-arm, multi-center Phase 2 pivotal trial is evaluating the efficacy and safety of RP-A501 in 12 patients with DD, including a pediatric safety run-in (n=2), with a natural history comparator and a dose level of 6.7 x 1013 GC/kg. A global natural history study is also running concurrently to the Phase 2 pivotal trial and will serve as an external comparator.

Current wording

In September 2023, we announced that alignment was reached with the FDA on the global Phase 2 pivotal trial of RP-A501 for DD to support accelerated approval. The global, single-arm, multi-center Phase 2 pivotal trial is evaluating the efficacy and safety of RP-A501. A global natural history study is also running concurrently with the Phase 2 pivotal trial.

Previous wording

Drug product for the Phase 2 study is being produced in-house in our GMP manufacturing facility in Cranbury, NJ. We have successfully produced multiple commercial-grade Danon AAV cGMP batches since 2022. Furthermore, we have reached agreement with the FDA on the continued utilization of HEK-293 cell-based process through commercialization, our comparability approach and our potency assay.

Current wording

Drug product for the Phase 2 study is being produced in-house at our GMP manufacturing facility in Cranbury, New Jersey. We have successfully produced multiple Danon AAV cGMP batches at this facility since 2022.

Previous wording

In May 2025, two patients participating in the Phase 2 pivotal study of RP-A501 each experienced an unexpected SAE. The SAEs involved clinical complications related to a capillary leak syndrome resulting in multi-organ damage; one patient died as a result of these complications following an acute systemic infection. Rocket voluntarily paused further Phase 2 study dosing in the U.S. and EU, and the FDA subsequently placed the trial on clinical hold on May 23, 2025 to allow for further evaluation. In August 2025, the FDA lifted the clinical hold on the Phase 2 pivotal study following an investigation which concluded that the SAEs were likely the result of the combination of the C3 component inhibitor introduced into the immunomodulation regimen and RP-A501. The FDA authorized resumption of the Phase 2 pivotal study with a recalibrated dose of 3.8 x 10¹³ GC/kg of RP-A501 along with the first three patients to be treated sequentially with a minimum four-week interval between each treatment. This adjusted dose aligns with the lower range of administered doses that were associated with efficacy across multiple biomarkers, electrocardiogram and clinical endpoints in the Phase 1 study, and has been determined as most likely to confer the safety and efficacy identified in the low-dose Phase 1 cohorts.

Current wording

In May 2025, two patients participating in the Phase 2 pivotal study of RP-A501 each experienced an unexpected SAE. The SAEs involved clinical complications related to a capillary leak syndrome resulting in multi-organ damage; one patient died as a result of these complications following an acute systemic infection. Rocket voluntarily paused further Phase 2 study dosing in the U.S. and EU, and the FDA subsequently placed the trial on clinical hold on May 23, 2025 to allow for further evaluation. In August 2025, the FDA lifted the clinical hold on the Phase 2 pivotal study following an investigation which concluded that the SAEs were likely the result of the combination of the C3 complement inhibitor introduced into the immunomodulation regimen and RP-A501. The FDA authorized resumption of the Phase 2 pivotal study with a recalibrated dose of 3.8 x 10¹³ GC/kg of RP-A501 along with the first three patients to be treated sequentially with a minimum four-week interval between each treatment. This adjusted dose aligns with the lower range of administered doses that were associated with efficacy across multiple biomarkers, electrocardiogram and clinical endpoints in the Phase 1 study.

Previous wording

Prior to the clinical hold, six patients with Danon disease were treated with RP-A501 in the Phase 2 study. Further updates on the Phase 2 study can be expected following review of data from the next three patients.

Current wording

Prior to the clinical hold, six patients with Danon disease were treated with RP-A501 in the Phase 2 study. Following resumption of dosing under the modified protocol, the initial three patients treated under the modified protocol received RP-A501 sequentially at the recalibrated dose of 3.8 × 10¹³ GC/kg together with a refined immunomodulatory regimen. As of August 3, 2026, no thrombotic microangiopathy, capillary leak syndrome or other significant safety concerns had been observed in these patients. The Company is actively engaging with the FDA to align on the path to dosing additional patients and completing the pivotal Phase 2 trial and expects to provide an update on the regulatory pathway in the second half of 2026. The Company also remains on track to provide a comprehensive Danon disease program update in the second half of 2026.

Previous wording

Plakophilin-2 related Arrhythmogenic cardiomyopathy, otherwise known as PKP2-ACM is an inheritable cardiac disorder caused by pathogenic variants in the PKP2 gene that is characterized by a high propensity for arrhythmias and sudden cardiac death. Most commonly, the cardiomyopathy initially manifests in the right ventricular free wall, so the disease was originally termed arrhythmogenic right ventricular dysplasia/cardiomyopathy or ARVD/C. However, since left dominant and biventricular forms have also been observed, this has led more recently to the use of the term ACM. Mutations in the PKP2 gene comprise the most frequent genetically identified etiology of familial ACM. Patients with mutations in PKP2 are typically heterozygous and demonstrate reduced expression of the PKP2 protein in the myocardium. PKP2 encodes for the protein Plakophilin-2, which is a component of the desmosome, an intercellular complex involved in cell-cell adhesion. The PKP2 protein is also involved in transcriptional regulation of calcium signaling between cardiomyocytes. PKP2-ACM is most commonly diagnosed in young adults with the mean age presentation at 35 years old, and patients have a very high lifetime risk of ventricular arrhythmias, structural ventricular abnormalities, and SCD.

Current wording

Plakophilin-2 related arrhythmogenic cardiomyopathy, otherwise known as PKP2-ACM, is an inherited cardiac disorder caused by pathogenic variants in the PKP2 gene and characterized by life-threatening ventricular arrhythmias, cardiac structural abnormalities, and sudden cardiac death. Most commonly, the cardiomyopathy initially manifests in the right ventricular free wall, so the disease was originally termed arrhythmogenic right ventricular dysplasia/cardiomyopathy or ARVD/C. However, since left dominant and biventricular forms have also been observed, this has led more recently to the use of the term ACM. Mutations in the PKP2 gene comprise the most frequent genetically identified etiology of familial ACM. Patients with mutations in PKP2 are typically heterozygous and demonstrate reduced expression of the PKP2 protein in the myocardium. PKP2 encodes for the protein Plakophilin-2, which is a component of the desmosome, an intercellular complex involved in cell-cell adhesion. The PKP2 protein is also involved in transcriptional regulation of calcium signaling between cardiomyocytes. PKP2-ACM is most commonly diagnosed in young adults, with a mean age at presentation of 35 years. Patients have a very high lifetime risk of life-threatening ventricular arrhythmias, with annual event rates of approximately 5% to 10% and rates as high as 10% to 20% among higher-risk patients (e.g., those with ICDs).

Previous wording

There are no specific available medical therapies available that have been shown to be highly effective for ACM, and current treatment protocols follow standard ventricular arrhythmia and cardiomyopathy guidelines, which involve lifestyle modifications (i.e. exercise limitation) and include drug treatments such as beta blockers, anti-arrhythmics and diuretics. The use of these therapies is driven by the arrhythmia burden and severity of cardiomyopathy. These therapies do not modify the course of the disease and generally provide only symptomatic and/or palliative support. Upon diagnosis, a substantial percentage of patients receive an ICD for primary or secondary prevention of ventricular arrhythmias and SCD. Of note, ICDs are not curative, and breakthrough life-threatening arrythmias may persist with ongoing risk of death. Furthermore, ICDs do not prevent the progression to end-stage HF. ICD firings, although lifesaving, are physically and emotionally traumatic events. Patients whose condition progresses to end-stage HF are considered for cardiac transplantation which, while curative of underlying disease, is associated with significant morbidity and mortality. Hence, there exists a high unmet medical need in this population. PKP2-ACM is estimated to have a prevalence of 50,000 patients in the U.S. and the EU.

Current wording

There are no specific medical therapies that have been shown to be highly effective for ACM, and current treatment protocols follow standard ventricular arrhythmia and cardiomyopathy/heart failure guidelines, which involve lifestyle modifications (e.g. exercise limitation) and include drug treatments such as beta blockers, anti-arrhythmics and diuretics. The use of these therapies is driven by the arrhythmia burden and severity of cardiomyopathy. These therapies do not modify the course of the disease and generally provide only symptomatic and/or palliative support. Upon diagnosis, a substantial percentage of patients receive an ICD for primary or secondary prevention of ventricular arrhythmias and SCD. Of note, ICDs are not curative, and breakthrough life-threatening arrhythmias may persist with ongoing risk of death. Furthermore, ICDs do not prevent the progression to end-stage HF. ICD firings, although lifesaving, are physically and emotionally traumatic events. Patients whose condition progresses to end-stage HF are considered for cardiac transplantation which, while curative of underlying disease, is associated with significant morbidity and mortality. Hence, there exists a high unmet medical need in this population. PKP2-ACM is estimated to have a prevalence of 50,000 patients in the U.S. and the EU.

Previous wording

RP-A601 is our investigational gene therapy for the treatment of PKP2-ACM and consists of a recombinant adeno-associated serotype rh74 capsid containing a functional version of the human PKP2 transgene (AAVrh74.PKP2) which is administered as a single IV infusion. RP-A601 holds FDA RMAT and Fast Track and designations in the US and Orphan drug designations in both the U.S. and EU.

Current wording

RP-A601 is our investigational genetic medicine for the treatment of PKP2-ACM and consists of a recombinant adeno-associated serotype rh74 capsid containing a functional version of the human PKP2 transgene (AAVrh74.PKP2) which is administered as a single IV infusion. RP-A601 holds FDA RMAT and Fast Track designations in the US and Orphan Drug designations in both the U.S. and EU.

Previous wording

Enrollment in the U.S. Phase 1 study is ongoing, and the trial remains open and actively enrolling to further characterize biological activity across a broader range of disease severity. The ongoing single-arm, open-label, multi-center Phase 1 study is evaluating the safety and preliminary efficacy of RP-A601 in adult PKP2-ACM patients with ICDs and overall high risk for arrhythmias. To date, three patients have been treated in the study and is assessing the impact of RP-A601 on PKP2 myocardial protein expression, cardiac biomarkers, and clinical predictors of life-threatening ventricular arrhythmias and SCD. Patients in the Phase 1 study received a single dose of RP-A601 starting at 8 x 1013 GC/kg. We are continuing to work closely with the FDA to advance alignment on the design and potential endpoints of a pivotal Phase 2 trial of a pivotal Phase 2 trial intended to further evaluate the safety and efficacy of RP-A601 in this patient population.

Current wording

Enrollment in the U.S. Phase 1 study is ongoing, and the trial remains open and actively enrolling to further characterize biological activity across a broader range of disease severity. The ongoing single-arm, open-label, multi-center Phase 1 study is evaluating the safety and preliminary efficacy of RP-A601 in adult PKP2-ACM patients with ICDs and overall high risk for arrhythmias. To date, three patients have been treated in the study to assess the impact of RP-A601 on PKP2 myocardial protein expression, arrhythmia burden, cardiac biomarkers, and clinical predictors of life-threatening ventricular arrhythmias and SCD. Patients in the Phase 1 study received a single dose of RP-A601 at 8 x 1013 GC/kg. We are continuing to work closely with the FDA to advance alignment on the design and potential endpoints of a pivotal Phase 2 trial intended to further evaluate the safety and efficacy of RP-A601 in this patient population.

Previous wording

In May 2025, we presented preliminary data from the Phase 1 study of RP-A601 for adult patients with PKP2-ACM at the ASGCT 28 th Annual Meeting in the Late-Breaking Scientific Sessions. Initial data from the Phase 1 study (safety cut-off May 6, 2025; efficacy cut-off April 2025) showed that RP-A601 was generally well-tolerated with no dose-limiting toxicities observed in all patients followed for up to 12 months. Most treatment emergent adverse events were mild/moderate in severity and self-limited with only one patient experiencing an SAE which resolved without clinical sequelae within two months post-treatment, believed to be associated with the immunomodulatory regimen.

Current wording

In May 2025, we presented preliminary data from the Phase 1 study of RP-A601 for adult patients with PKP2-ACM at the ASGCT 28 th Annual Meeting in the Late-Breaking Scientific Sessions. Initial data from the Phase 1 study (safety cut-off May 6, 2025; efficacy cut-off April 2025) showed that RP-A601 was generally well-tolerated with no dose-limiting toxicities observed in all patients followed for up to 12 months. Most treatment-emergent adverse events were mild or moderate in severity and self-limited. One patient experienced an SAE that was believed to be associated with the immunomodulatory regimen and resolved without clinical sequelae within two months after treatment.

Previous wording

Cardiac biopsies showed RP-A601 increased PKP2 protein expression in all three patients. In the patients with low baseline PKP2 expression (n=2), improvements in PKP2 protein expression relative to total cell protein were approximately 110% and 398%, respectively, from baseline to six months follow-up. In all three patients, RP-A601 promoted desmosome localization of PKP2 and associated transmembrane interpolated disc proteins between 3 and 12 months after treatment. In addition, preliminary observations suggest potential improvement or stabilization in arrhythmia burden, cardiac function, and quality of life, although these findings are based on a limited number of patients and require further evaluation. Based on available data to date, we have selected 8 x 10¹³ GC/kg as the dose to be further evaluated in subsequent clinical development, and we do not currently plan to evaluate higher dose levels in this study.

Current wording

Cardiac biopsies showed RP-A601 increased PKP2 protein expression in all three patients. In the patients with low baseline PKP2 expression (n=2), improvements in PKP2 protein expression relative to total cell protein were approximately 110% and 398%, respectively, from baseline to six months follow-up. In all three patients, RP-A601 promoted desmosome localization of PKP2 and associated transmembrane intercalated disc proteins between 3 and 12 months after treatment. In addition, preliminary observations suggest potential improvement or stabilization in arrhythmia burden, cardiac function, and quality of life, although these findings are based on a limited number of patients and require further evaluation. Based on available data to date, we have selected 8 x 10¹³ GC/kg as the dose to be further evaluated in subsequent clinical development, and we do not currently plan to evaluate higher dose levels in this study. Collectively, these findings continue to support the Company's disease-modifying approach for genetically defined arrhythmogenic cardiomyopathy and further inform ongoing development of the program.

Previous wording

DCM is the most common form of cardiomyopathy and is characterized by progressive thinning of the walls of the heart resulting in enlarged heart chambers that are unable to pump blood. A familial association of DCM can be identified in 20-50% of DCM patients, with up to 40% of familial patients having an identifiable genetic cause. Mutations in the BAG3 gene are among the more common pathogenic genetic variants observed in familial DCM and these variants are highly penetrant, with approximately 80% of individuals with disease-causing genetic variants in the BAG3 gene developing DCM at > 40 years of age. Pathogenic variants in BAG3 are estimated to cause from 2.3% to 6.7% of DCM cases in the U.S., Europe, and Japan. BAG3 protein is associated with a variety of cellular functions including cardiac contractility, protein quality control (as a co-chaperone), cardiomyocyte structural support and anti-apoptosis. BAG3-DCM leads to early onset, rapidly progressing heart failure and significant mortality and morbidity. The age of diagnosis in BAG3-DCM varies from adolescence to adulthood, with the mean age at clinical diagnosis in the mid-30s. The prevalence of BAG3-associated DCM in the U.S. is estimated to be as many as 30,000 individuals.

Current wording

Dilated cardiomyopathy is the most common form of cardiomyopathy and is characterized by enlargement of the heart chambers and progressive impairment of cardiac function. Pathogenic variants in the BAG3 gene are among the more common genetic causes of familial DCM and are associated with early-onset, progressive heart failure, significant morbidity and mortality. The prevalence of BAG3-associated DCM in the United States is estimated to be as many as 30,000 individuals.

Previous wording

In June 2025, the Company received FDA clearance of an IND application for RP-A701, an AAVrh74-based gene therapy candidate for the treatment of BAG3-DCM. In July 2025, the FDA granted Fast Track designation to RP-A701 for the treatment of BAG3-DCM. The first-in-human Phase 1 clinical trial will be a multi-center, dose-escalation study designed to evaluate the safety, biological activity, and preliminary efficacy of RP-A701 in adults with BAG3-DCM.

Current wording

In June 2025, we received FDA clearance of our IND application for RP-A701. In July 2025, the FDA granted Fast Track designation to RP-A701 for the treatment of BAG3-associated DCM. Our ongoing Phase 1 clinical trial is a multicenter, dose-escalation study designed to evaluate the safety, biological activity and preliminary efficacy of RP-A701 in adults with BAG3-associated DCM. We continue to advance RP-A701 as part of our strategy to build a differentiated pipeline of genetic medicines targeting inherited cardiovascular diseases.

Previous wording

KRESLADI™, formerly known as RP-L201 (marnetegragene autotemcel), is our gene therapy consisting of autologous (patient-derived) hematopoietic stem cells genetically modified with a LV to deliver a functional copy of the ITGB2 gene. The program has received RMAT, Rare Pediatric Disease, and Fast Track designations from the FDA, as well as PRIME and ATMP designations in the European Union, and Orphan Drug designations in both the U.S. and EU. KRESLADI™ was in-licensed from the Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Centro de Investigación Biomédica en Red de Enfermedades Raras, and Instituto de Investigación Sanitaria Fundación Jiménez Díaz. The lentiviral vector was developed in collaboration with University College London and CIEMAT.

Current wording

KRESLADI™, formerly known as RP-L201 (marnetegragene autotemcel), is our genetic medicine consisting of autologous (patient-derived) hematopoietic stem cells genetically modified with a LV to deliver a functional copy of the ITGB2 gene. The program has received RMAT, Rare Pediatric Disease, and Fast Track designations from the FDA, as well as PRIME and ATMP designations in the European Union, and Orphan Drug designations in both the U.S. and EU. KRESLADI™ was in-licensed from the Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Centro de Investigación Biomédica en Red de Enfermedades Raras, and Instituto de Investigación Sanitaria Fundación Jiménez Díaz. The lentiviral vector was developed in collaboration with University College London and CIEMAT.

Previous wording

On March 26, 2026, the FDA granted accelerated approval to KRESLADI™ for the treatment of severe LAD-I in pediatric patients with biallelic mutations in the ITGB2 gene who do not have a suitable HLA-matched sibling donor. The approval was based on an increase in neutrophil CD18 and CD11a surface expression. Continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).

Current wording

On March 26, 2026, the FDA granted accelerated approval to KRESLADI™ for the treatment of pediatric patients with severe LAD-I who have biallelic mutations in the ITGB2 gene and do not have a suitable HLA-matched sibling donor. The approval was based on an increase in neutrophil CD18 and CD11a surface expression. Continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial or trials.

Previous wording

On April 26, 2026, the Company entered into a definitive agreement to sell its PRV that was originally issued in connection with the FDA’s approval of the BLA for KRESLADI™ for $180 million. The transaction is subject to customary closing conditions, including the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976.

Current wording

On April 26, 2026, the Company entered into a definitive agreement to sell its PRV that was originally issued in connection with the FDA’s approval of the BLA for KRESLADI™ for $180 million. The transaction was subject to customary closing conditions, including the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 and the Company announced the closing of the transaction on June 12, 2026.

Previous wording

Although improvements in allogeneic (donor-mediated) HSCT, currently the most frequently utilized therapy for FA, have resulted in frequent hematologic correction of the disorder, HSCT is associated with both acute and long-term risks, including transplant-related mortality, graft failure, and graft versus host disease, a sometimes fatal side effect of allogeneic transplant characterized by painful ulcers in the GI tract, liver toxicity and skin rashes, as well as increased risk of subsequent cancers. Our gene therapy program in FA is designed to enable a minimally toxic hematologic correction using a patient’s own stem cells early in the disease course and administered without conditioning. We believe that the development of a broadly applicable autologous gene therapy can be transformative for these patients. In light of the efficacy seen in non-conditioned patients, the addressable annual market opportunity is now believed to be 400 to 500 patients collectively in the U.S. and EU.

Current wording

Although improvements in allogeneic (donor-mediated) HSCT, currently the most frequently utilized therapy for FA, have resulted in frequent hematologic correction of the disorder, HSCT is associated with both acute and long-term risks, including transplant-related mortality, graft failure, and graft versus host disease, a sometimes fatal side effect of allogeneic transplant characterized by painful ulcers in the GI tract, liver toxicity and skin rashes, as well as increased risk of subsequent cancers. Our genetic medicine program in FA is designed to enable a minimally toxic hematologic correction using a patient’s own stem cells early in the disease course and administered without conditioning. We believe that the development of a broadly applicable autologous genetic medicine can be transformative for these patients. In light of the efficacy seen in non-conditioned patients, the addressable annual market opportunity is now believed to be 400 to 500 patients collectively in the U.S. and EU.

Previous wording

RP-L102 is our investigational LV vector-based gene therapy for the treatment of FA. RP-L102’s LV carries the FANCA gene as part of the PGK-FANCA-WPRE expression cassette which includes a phosphoglycerate kinase (PKG) promoter and an optimized woodchuck hepatitis virus post transcriptional regulatory element (WPRE). The Phase 2 study of RP-L102 for the treatment of FA type A without the use of myeloablative conditioning treated a total of 14 patients from the U.S. and EU. Patients received a single intravenous infusion of RP-L102 that utilizes fresh cells and an improved process which incorporates a modified stem cell enrichment process, transduction enhancers, as well as commercial-grade vector and final drug product. The Company holds FDA RMAT, Rare Pediatric, and Fast Track designations in the U.S., PRIME and ATMP designations in the EU, and Orphan Drug designations in both regions for the program.

Current wording

RP-L102 is our investigational LV vector-based genetic medicine for the treatment of FA. RP-L102’s LV carries the FANCA gene as part of the PGK-FANCA-WPRE expression cassette which includes a phosphoglycerate kinase (PGK) promoter and an optimized woodchuck hepatitis virus post transcriptional regulatory element (WPRE). The Phase 2 study of RP-L102 for the treatment of FA type A without the use of myeloablative conditioning treated a total of 14 patients from the U.S. and EU. Patients received a single intravenous infusion of RP-L102 that utilizes fresh cells and an improved process which incorporates a modified stem cell enrichment process, transduction enhancers, as well as commercial-grade vector and final drug product. The Company holds FDA RMAT, Rare Pediatric, and Fast Track designations in the U.S., PRIME and ATMP designations in the EU, and Orphan Drug designations in both regions for the program.

Previous wording

RP-L301 is our investigational gene therapy that contains autologous hematopoietic stem cells that have been genetically modified with a lentiviral vector to contain a functional copy of the PKLR gene for the treatment of PKD. The Company holds FDA RMAT and Fast Track designations in the U.S., EMA PRIME designation in the EU, and Orphan Drug designation in both regions for the program. RP-L301 was in-licensed from CIEMAT, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) and Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz (IIS-FJD).

Current wording

RP-L301 is our investigational genetic medicine that contains autologous hematopoietic stem cells that have been genetically modified with a lentiviral vector to contain a functional copy of the PKLR gene for the treatment of PKD. The Company holds FDA RMAT and Fast Track designations in the U.S., EMA PRIME designation in the EU, and Orphan Drug designation in both regions for the program. RP-L301 was in-licensed from CIEMAT, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) and Instituto de Investigación Sanitaria de la Fundación Jiménez Díaz (IIS-FJD).

Previous wording

Based on positive safety and efficacy data from the Phase 1 study, we have aligned with the FDA on the pivotal study design to support accelerated approval with a 10-patient, single-arm Phase 2 pivotal trial with a primary endpoint of ≥1.5 point hemoglobin Hgb improvement at 12 months. However, the Company is no longer allocating internal resources towards RP-L301 and does not plan to initiate enrollment in a Phase 2 RP-L301 study at this time. Similar to our FA program, we are actively exploring external partnership options to provide a path forward for RP-L301 and the PKD community.

Current wording

Based on positive safety and efficacy data from the Phase 1 study, we have aligned with the FDA on the pivotal study design to support accelerated approval with a 10-patient, single-arm Phase 2 pivotal trial with a primary endpoint of ≥1.5 g/dL increase in hemoglobin at 12 months post-infusion. However, the Company is no longer allocating internal resources towards RP-L301 and does not plan to initiate enrollment in a Phase 2 RP-L301 study at this time. Similar to our FA program, we are actively exploring external partnership options to provide a path forward for RP-L301 and the PKD community.

Previous wording

We have a 103,720 square foot manufacturing facility located in Cranbury, New Jersey. This facility supports clinical development of our pipeline of AAV gene therapy product candidates from discovery through pivotal trials, with space for potential future expansion and commercialization.

Current wording

We have a 103,720 square foot manufacturing facility located in Cranbury, New Jersey. This facility supports clinical development of our pipeline of AAV genetic medicine product candidates from discovery through pivotal trials, with space for potential future expansion and commercialization.

Previous wording

In April 2026, the Company entered into an agreement to sell its PRV for $180 million, providing non-dilutive capital to support advancement of its cardiovascular gene therapy pipeline.

Current wording

In April 2026, the Company entered into an agreement to sell its PRV for $180 million, which closed in June 2026, providing non-dilutive capital to support advancement of its cardiovascular genetic medicines pipeline.

Previous wording

The following table presents R&D expenses tracked on a program-by-program basis as well as by type and nature of expense for the three months ended March 31, 2026 and 2025:

Current wording

The following table presents R&D expenses tracked on a program-by-program basis as well as by type and nature of expense for the three and six months ended June 30, 2026 and 2025:

Previous wording

General and administrative expenses consist primarily of salaries and related benefit costs for personnel, including stock-based compensation and travel expenses for our employees in commercial, executive, operational, finance, legal, business development, and human resource functions. In addition, other significant general and administrative expenses include professional fees for legal, consulting, investor and public relations, auditing, and tax services as well as other expenses for rent and maintenance of facilities, insurance and other supplies used in general and administrative activities. We expect general and administrative expenses to be significant for the foreseeable future due to anticipated significant headcount to support the continued advancement of our product candidates and our progression to commercial operations. We also anticipate that as we continue to operate as a public company with increasing complexity, we will continue to incur increased accounting, audit, legal, regulatory, compliance and director and officer insurance costs as well as investor and public relations expenses.

Current wording

General and administrative expenses consist primarily of salaries and related benefit costs for personnel, including stock-based compensation and travel expenses for our employees in commercial, executive, operational, finance, legal, business development, and human resource functions. In addition, other significant general and administrative expenses include professional fees for legal, consulting, investor and public relations, auditing, and tax services as well as other expenses for rent and maintenance of facilities, insurance and other supplies used in general and administrative activities. We expect general and administrative expenses to remain significant as we support the continued advancement of our product candidates, the commercialization of KRESLADI™ and the requirements of operating as a public company. These expenses include accounting, audit, legal, regulatory, compliance, director and officer insurance, and investor and public relations costs. We expect general and administrative expenses to be significant for the foreseeable future due to anticipated significant headcount to support the continued advancement of our product candidates and our progression to commercial operations. We also anticipate that as we continue to operate as a public company with increasing complexity, we will continue to incur increased accounting, audit, legal, regulatory, compliance and director and officer insurance costs as well as investor and public relations expenses.