[Ad hoc announcement pursuant to Art. 53 LR] Roche provides safety update on Elevidys gene therapy for Duchenne muscular dystrophy in non-ambulatory patients

• After a thorough clinical review, the benefit-risk for the use of Elevidys in non-ambulatory patients with Duchenne has been re-assessed, following two cases of fatal acute liver failure
• Effective immediately, dosing of non-ambulatory patients, irrespective of age, is paused in the clinical setting; dosing of non-ambulatory patients is discontinued in the commercial setting
• Roche is working closely with relevant health authorities, investigators and prescribing physicians to ensure they are informed and patient care is being appropriately modified
• The benefit-risk of Elevidys treatment in ambulatory Duchenne patients remains positive and treatment guidance is unchanged

Basel, 15 June 2025 - Roche (SIX: RO, ROG; OTCQX: RHHBY) announced today new dosing restrictions, effective immediately, for ELEVIDYS (delandistrogene moxeparvovec), for non-ambulatory Duchenne muscular dystrophy (DMD) patients, irrespective of age, in both clinical and commercial settings. In the commercial setting, non-ambulatory patients should no longer receive Elevidys. In the clinical trial setting, enrolment and dosing of non-ambulatory patients will be immediately paused until additional risk mitigation measures (e.g. immune modulatory treatment) are implemented in the study protocol. Health authorities, investigators and physicians are being informed so that patient care can be quickly adjusted.

This decision follows careful assessment of two cases in non-ambulatory patients of fatal acute liver failure (ALF), an identified risk of Elevidys and other AAV-mediated gene therapies, which led to a reassessment of the benefit-risk profile as unfavourable for patients with DMD who are non-ambulatory.

The new dosing restrictions do not impact the treatment of ambulatory DMD patients of any age, and the benefit-risk ratio remains positive in the ambulatory patient population.

"We are deeply saddened by the loss of these two young men and are urgently working to  mitigate any risks related to the use of Elevidys,” said Levi Garraway, M.D., Ph.D., Chief Medical Officer and Head of Global Product Development, Roche. "Patient safety is always our highest priority. Therefore, we have recommended halting treatment with Elevidys in non-ambulatory patients with immediate effect.”