Serepta and global partner Roche have discontinued the commercial and clinical use of Duchenne muscular dystrophy (DMD) gene therapy Elevidys (delandistrogene moxeparvovec) in non-ambulatory patients after a safety profile re-assessment following two patient deaths.

Roche said that the dosing restrictions are effective immediately, with commercial use stopped and enrolment in clinical trials paused until additional risk mitigation measures are implemented in the study protocol.

In a separate announcement, Sarepta said it is working to immediately convene an independent group of leading experts in Duchenne and liver health to consider an enhanced immunosuppression regimen for the therapy. The biopharma added it is temporarily suspending shipments of Elevidys for non-ambulatory patients while an enhanced immunosuppressive regimen is evaluated.

The re-assessment of the benefit-risk ratio for non-ambulatory patients follows a second fatal acute liver failure (ALF) case in a DMD patient administered with Elevidys. Two fatal ALF cases have occurred in the gene therapy’s use to date.

Shares in Swiss-listed Roche fell 1% at market open following the development, while Sarepta was down 31.34% in pre-market trading on the Nasdaq.

“While we ultimately believe the implementation of a modified immunosuppression regimen could prevent future safety events in non-ambulatory patients, we recognise that another patient death will amplify investor concerns surrounding the potential removal of Elevidys from the commercial market, which we continue to view as an unlikely scenario,” said William Blair analyst Sami Corwin in a research note.

Corwin added that Elevidys’s label will likely be updated to reflect the risk of ALF.

Elevidys is approved in the US for the treatment of ambulatory and non-ambulatory individuals aged four and older with DMD with a confirmed mutation in the DMD gene. It is the only gene therapy approved in the country for the rare musculoskeletal disease. Elevidys works by inserting a functional copy of the DMD gene, providing the missing instructions used to make the protein dystrophin.

Sarepta Therapeutics, who developed the therapy, holds US rights to the drug, while Roche gained rights to other global territories through a 2019 agreement.

The first death due to ALF, announced in March 2025, prompted the suspension of multiple clinical trials evaluating the gene therapy in different patient populations with DMD. The clinical holds are still in effect, whilst dosing will be paused in trials operating outside of Europe. Roche and Sarepta jointly manage the clinical studies for Elevidys.