CHLA Enhances Gene Therapy Safety: Elevidys Protocol Revised for High-Risk Duchenne Patients

LOS ANGELES, CA — November 5, 2025 — Children’s Hospital Los Angeles (CHLA) has proactively enhanced its safety protocol for administering Elevidys, the FDA-approved gene therapy for Duchenne muscular dystrophy (DMD). In a significant update implemented in October, CHLA introduced a second immunosuppressant, mycophenolate mofetil (CellCept®), to the existing regimen for certain high-risk adolescents—specifically, boys who are older, heavier, and more advanced in their disease progression.

The expansion of the safety protocol is a direct response to recent high-profile safety concerns regarding the therapy. Earlier this year, reports of two non-ambulatory teenage patients at other hospitals dying from liver failure following Elevidys treatment led the manufacturer, Sarepta, to temporarily halt shipments for non-ambulatory boys. Further regulatory scrutiny followed in July after a death in a separate Sarepta gene therapy trial, prompting an FDA-requested pause for all patients.

“Rather than waiting for a dangerous inflammatory reaction, we want to prevent it up front,” says Dr. Leigh Ramos-Platt, Medical Director of CHLA’s Neuromuscular Disorders Center. “We hope this approach will protect the liver while sparing patients from the extreme steroid doses we’ve had to use.”

A Proactive Approach to Liver Risk

Liver inflammation is recognized as one of the most serious risks associated with the gene therapy, particularly in older, heavier patients, where the complication often results in severe liver enzyme elevations and requires escalating steroid doses.

To date, CHLA has treated 28 boys with Elevidys, making it one of the most experienced centers nationally. This experience, combined with the hospital’s leadership in pediatric cell and gene therapy, is guiding the development of the customized protocol.

Dr. Rohit Kohli, Chief of Gastroenterology, Hepatology, and Nutrition at CHLA, noted the urgency behind the change: “When we see elevated liver enzymes, it tells us there’s ongoing damage to the liver. The rapid onset of these elevations in higher-risk children is what prompted us to think about a different pre-emptive approach.”

The new regimen adds CellCept to the standard steroid course for higher-risk children, a strategy Dr. Ramos-Platt believes is gentler and easier to monitor than some alternatives being explored by other centers.

Clinical Observation and Patient Safety

CHLA clinicians observe a clear difference in patient response: “Younger boys under age 8 are doing phenomenal, and many are showing striking improvements,” Dr. Ramos-Platt states. “Older, heavier boys, even if they are still walking, are more complicated. That’s where we’re seeing the liver issues.”

The hospital’s multidisciplinary team, including experts in pediatric hepatology, cardiology, nephrology, and hematology, closely monitors each patient before and after treatment. They are also exploring advanced pre-treatment liver assessments, such as MR elastography, and have added a one-month post-infusion echocardiogram to the cardiac monitoring protocol.

“These therapies are still new, and we’re very tuned into these risks,” Dr. Kohli affirms. “We’re adjusting in real time.”

Dr. Ramos-Platt emphasized the commitment to patient safety: “While it doesn’t work for every patient, it’s the best treatment we have right now. We are continually working to make it as safe as possible for patients.”