Sarepta Therapeutics, Inc.  the leader in precision genetic medicine for rare diseases, announced that the U.S. Food and Drug Administration (FDA) has approved dosing in Cohort 8 of ENDEAVOR (Study 9001-103). The purpose of Cohort 8 is to evaluate the use of an enhanced immunosuppressive regimen as part of treatment with ELEVIDYS (delandistrogene moxeparvovec-rokl) for non-ambulant individuals with Duchenne muscular dystrophy.

Data from Cohort 8 will be used to determine whether administering sirolimus prior to and after ELEVIDYS infusion can help reduce acute liver injury (ALI), a known risk associated with AAV gene therapy. The cohort will enroll approximately 25 participants in the U.S. who are non-ambulatory. The immunosuppression regimen will include 14 days of peri-infusion sirolimus dosing (prior to ELEVIDYS administration) and will continue for 12 weeks after ELEVIDYS administration. Primary endpoints include incidence of ALI and ELEVIDYS-dystrophin expression at 12 weeks. The approach is based on preclinical data and shaped by real-world clinical experience, including guidance from independent specialists in Duchenne and liver health.

“We remain deeply committed to serving all individuals living with Duchenne, including those who have lost the ability to walk. Guided by real-world experience, external clinician expertise, and FDA input, Cohort 8 of the ENDEAVOR study will evaluate integrating sirolimus into our immunosuppression approach, with the goals of mitigating the risk of acute liver injury and restoring access for non-ambulant individuals living with Duchenne,” said Louise Rodino-Klapac, Ph.D., president of research & development and technical operations. “We plan to initiate Cohort 8 by the end of this year and pending enrollment, complete primary endpoint data collection in the second half of 2026.”

ELEVIDYS is the only approved gene therapy for Duchenne. To date, ELEVIDYS has been administered to over 1,100 patients globally in clinical and real-world settings. Sarepta continues to work closely with the FDA to ensure that all regulatory decisions are grounded in science and the best interests of patients who face a rare, irreversibly progressive and ultimately fatal disease. ELEVIDYS remains available as appropriate to ambulatory individuals ages 4 and over per an updated label announced earlier this month.