November 28, 2022

Dear U.S. Duchenne Community,

It is with great pleasure that we share the news that the U.S. Food and Drug Administration (FDA) accepted for filing the Biologics License Application (BLA) for SRP-9001 (delandistrogene moxeparvovec). The filing of the BLA means that the FDA has decided that our application is sufficiently complete to enable a substantive review. FDA granted delandistrogene moxeparvovec a Priority Review, which means FDA’s goal is to take action on the BLA – that is, complete its review and announce its decision – within 6 months, and have set a target goal date of May 29, 2023 (referred to as the “PDUFA date”). Recall that in this application, Sarepta is requesting accelerated approval for ambulatory individuals living with Duchenne.

This marks an incredibly important day for the Duchenne community and Sarepta.  And while FDA is just beginning its review, we want to take a moment to express our gratitude to the families, physicians, and researchers who have supported our studies. We are thankful for the boldness, dedication and sacrifice exhibited by participants and families in these studies. We are also grateful to the incredibly talented and dedicated clinical investigators and clinical site staff members who helped bring these studies to you.  We would like to acknowledge and thank the community members, Patient Advocacy leaders, and thought leaders who provided input and advice as we constructed and conducted these studies.

Our work with delandistrogene moxeparvovec is not complete. In addition to supporting FDA’s review of the BLA, we are committed to ongoing evidence generation. We are continuing to gather data from studies 9001-101, 9001-102 and 9001-103 and will follow study participants to inform our longer-term understanding of safety and efficacy. What’s more, 125 families from the worldwide Duchenne community have volunteered as participants in SRP-9001-301 (known as the EMBARK study). Accelerated approval requires a post-marketing confirmatory study. Sarepta proposed that study 9001-301 (the EMBARK study) be considered as the confirmatory study to fulfill post-marketing requirements associated with a potential accelerated approval. The EMBARK study is fully enrolled and is expected to readout in late-2023.

In addition, we are finalizing SRP-9001-303 (known as the ENVISION study) and anticipate that the study will be initiated in the first half of 2023. The ENVISION study will be a double blind, placebo-controlled study of delandistrogene moxeparvovec for individuals who are older ambulatory and non-ambulatory. More details will be shared when the study is finalized. Also, we are exploring methods of overcoming pre-existing antibodies to potentially enable more individuals to access delandistrogene moxeparvovec in the future. More details will be shared as additional studies are progressed.

Below you will find answers to some anticipated questions around today’s announcement. If you have any additional questions, please reach out to the Sarepta Patient Affairs team via email [email protected].

Once again, we share a heartfelt word of thanks to the Duchenne families and Patient Advocacy Organizations who have contributed to this milestone moment and who continue to be pioneers in Patient-Focused Drug Development. Together, we are advancing science and therapeutic options for the Duchenne community.

Warmly,

The Patient Affairs Team
Sarepta Therapeutics

What is a BLA?

A Biologics License Application (BLA) is a formal process by which a company applies to FDA requesting permission to sell and market a new advanced therapy or biologic in the United States.  FDA makes a decision to approve or not approve a BLA based on a determination of the product’s safety and efficacy for the proposed use as outlined in the application.

What does ‘accepted’ for filing mean?

If a BLA application is accepted for filing, this means that the FDA has determined the application is sufficiently complete and the agency can move forward with a substantive review.

What is accelerated approval?

Sarepta submitted the BLA for SRP-9001 using the FDA’s Accelerated Approval program. The FDA established the program to expedite the availability of novel treatments that address urgent and unmet medical needs of patients with serious and often life-threatening diseases. The program allows the FDA to base approval on whether the drug has an effect on a surrogate or an intermediate clinical endpoint reasonably likely to predict a clinical benefit. Accelerated approval requires a post-marketing confirmatory trial to verify the predicted benefit. Sarepta proposed that study 9001-301 (the EMBARK study) be considered as the confirmatory study to fulfill post-marketing requirements associated with a potential accelerated approval.

What is a Priority Review?

A Priority Review designation means the FDA will aim to take action on an application within 6 months (compared to 10 months under standard review). Priority Review is granted to therapies that, if approved, would be significant improvements in the safety or effectiveness of the treatment, diagnosis or prevention of serious conditions when compared to standard applications.

What is an advisory committee and will there be an advisory committee for delandistrogene moxeparvovec?

In reviewing an application for a new medicine, FDA may convene an advisory committee of outside experts to review, ask questions and share perspectives on the information contained in the application in a public forum with regulators and the sponsoring company. Advisory committee meetings include an open public hearing session during which interested persons may present relevant information or perspectives orally or in writing. Additional information about advisory committees can be found here: https://www.fda.gov/patients/about-office-patient-affairs/learn-about-fda-advisory-committees. It is not yet known if the FDA will convene an Advisory Committee meeting during its review of delandistrogene moxeparvovec.

Why did Sarepta submit the BLA only for treatment of ambulant individuals with Duchenne muscular dystrophy?

We remain fully committed to, and are working toward, bringing SRP-9001 to non-ambulatory individuals and as many individuals with Duchenne as possible. Based on discussions with the Agency regarding currently available data from our studies, we submitted the BLA for the ambulant patient population. We plan to expand to other patient populations as we gather additional clinical data. We have experience with a small number of non-ambulatory individuals with Duchenne in the ENDEAVOR study and, as mentioned above, the ENVISION study, which is focused on older ambulatory and non-ambulatory individuals, is anticipated to begin in the first half of 2023.

What does this mean for patients outside the United States?

Sarepta’s partner, Roche, will discuss with regulatory agencies the most appropriate path for submission to bring delandistrogene moxeparvovec to patients outside of the U.S.