ELEVIDYS on Hold for Non-Ambulatory Patients

Since March 2025, there have been two reported deaths following treatment with ELEVIDYS. Both patients were non-ambulatory, ages 16 and 15 and both died related to acute liver failure.

ELEVIDYS is the only FDA approved gene therapy for patients with Duchenne Muscular Dystrophy (DMD). It was first approved on June 22, 2023, for the treatment of ambulatory pediatric patients aged 4 through 5 years with confirmed DMD gene mutation but excluded those with deletions in exon 8 and/or exon 9. On June 20, 2024, the FDA expanded the indication to include patients over the age of 4 years, ambulatory and non-ambulatory, with confirmed DMD gene mutation, but excluded those with deletions in exon 8 and/or exon 9. Worldwide, ELEVIDYS has been given to more than 900 individuals.

Following the second death, Sarepta issued press release on June 15, 2025, titled “Sarepta Provides Safety Update for ELEVIDYS and Initiates Steps to Strengthen Safety in Non-Ambulatory Individuals with Duchenne.” As it examines the data, the company has initiated several safety initiatives as noted in the following excerpts from the press release.

• Evaluating and Enhancing Immunosuppressive Regimen: As part of a comprehensive review of safety data, Sarepta is taking proactive steps to mitigate the risk of acute liver failure in non-ambulatory patients. Sarepta is working to immediately convene an independent group of leading experts in Duchenne and liver health to consider an enhanced immunosuppression regimen for ELEVIDYS. This panel will evaluate data and assess our proposed regimen, which includes sirolimus and is supported by preclinical data demonstrating the effectiveness of additional immunosuppression in moderating liver enzyme elevations, a key factor in mitigating potential safety events. Sarepta will share the panel's recommendations with the U.S. Food & Drug Administration (FDA), and implementation of any new regimen will be subject to FDA guidance and allowance.

• Suspending Shipments of ELEVIDYS for Non-Ambulatory Patients: Sarepta is temporarily suspending shipments of ELEVIDYS for non-ambulatory patients while an enhanced immunosuppressive regimen is evaluated, discussed with regulatory bodies, and put in place.

  For ambulatory patients, no treatment changes are being proposed and the current practice of administering corticosteroids before and after ELEVIDYS infusion, along with post-treatment monitoring, remains the same.

• ENVISION Study Paused: Sarepta has voluntarily paused dosing in the ENVISION clinical study (also known as Study SRP-9001-303). FDA concurs with this action. The pause will allow for the evaluation of a protocol amendment to incorporate an enhanced immunosuppressive regimen for the non-ambulatory patient cohort and incorporate any additional feedback from the FDA. Regulatory alignment is needed before screening and dosing in ENVISION may resume.

  ENVISION is a global, randomized, double-blind, placebo-controlled trial evaluating ELEVIDYS in older ambulatory and non-ambulatory individuals living with Duchenne muscular dystrophy. In the U.S., it serves as the confirmatory trial required under the FDA’s accelerated approval pathway for non-ambulatory patients.

Although gene therapies like ELEVIDYS offer an opportunity to address the underlying genetic cause rather than just managing symptoms for diseases with few alternatives, the benefit is not without risk. Severe immune system response is a known risk and continues to be a challenge for gene therapies that use adeno-associated viral vectors.

Article by Kathy Clark, RN, BSN, CMCN, RIT, Vice President, Director of Managed Care. For more information about how this may affect your plan, please contact your Summit ReSources care specialist. The following sources were used as reference material for this article: 

(1) Sarepta Provides Safety Update for ELEVIDYS and Initiates Steps to Strengthen Safety in Non-Ambulatory Individuals with Duchenne https://investorrelations.sarepta.com/news-releases/news-release-details/sarepta-provides-safety-update-ELEVIDYS-and-initiates-steps?_ga=2.137210743.63220694.1750092019-638846657.1750092019  Accessed 6/16/2025.

(2) Bilodeau, K. March 21, 2025. A recent gene therapy death shines a light on AAV safety. PharmaVoice. https://www.pharmavoice.com/news/sarepta-ELEVIDYS-gene-therapy-duchenne-death-aav-safety/743824/  Accessed 6/16/2025.

FDA Approves Tecelra, First T Cell Therapy for Solid Tumors

On August 2, 2024, the FDA granted accelerated approval for Tecelra (afamitresgene autoleucel) a melanoma-associated antigen A4 (MAGE-A4)-directed genetically modified autologous T cell immunotherapy indicated for the treatment of adults with unresectable or metastatic synovial sarcoma who have received prior chemotherapy, are HLA-A*02:01P, -A*02:02P, 16 -A*02:03P, or -A*02:06P positive and whose tumor expresses the MAGE-A4 antigen as determined by FDA-approved or cleared companion diagnostic devices. Tecelra is contra-indicated in adults who are heterozygous or 52 homozygous for HLA-A*02:05P.[i]

Synovial sarcoma is an uncommon and aggressive cancer that can form in soft tissues such as muscles, fat, joint linings, and ligaments. It is often found in the arm, leg, or foot, and near joints such as the wrist or ankle. It can also form in soft tissues in the lung or abdomen. Although synovial sarcoma can affect people at any age, it is known to occur more commonly in adolescents and adults younger than 30.[ii] Adults with metastatic synovial sarcoma at diagnosis have a 5-year overall survival rate of 10%, versus 76% for those with localized disease at diagnosis.[iii]

Synovial sarcoma (SS) accounts for up to 10% of all soft-tissue sarcomas. In the US, 800-1000 new cases of SS are diagnosed annually. According to an analysis of the Surveillance, Epidemiology, and End Results (SEER) database study, the age-adjusted incidence rate of SS in the US is 0.177 per 100,000 (approximately 580 incident cases) with a prevalence rate of 0.65 per 100,000 (approximately 2129 prevalent cases).[iv]

Tecelra is an autologous T cell immunotherapy composed of a patient’s own T cells. T cells in Tecelra are modified to express a TCR that targets MAGE-A4 expressed by cancer cells in synovial sarcoma. After the patient undergoes leukapheresis, cells are sent for manufacturing. It takes about six weeks for the Tecelra to be returned to the provider, though that time may vary.

The patient is admitted to the hospital and receives a lymphodepleting chemotherapy regimen of fludarabine 30 mg/m2/day intravenously for four days starting on the seventh day before Tecelra infusion (Day-7 to Day -4), and cyclophosphamide 600 mg/m2/day intravenously for 3 days starting the seventh day before Tecelra infusion (Day -7 to Day -5).  Tecelra is administered over an hour as a single intravenous infusion on Day 1.  The patient will remain hospitalized for at least seven days after the infusion. The patient should plan to stay close to a healthcare facility for at least four weeks.[v]

The safety and effectiveness of Tecelra were evaluated in a multicenter, open-label clinical trial. Effectiveness was evaluated based on overall response rate and the duration of response to treatment with Tecelra. Among the 44 patients in the trial who received Tecelra, the overall response rate was 43.2% and the median duration of response was six months. Tecelra was approved under an accelerated approval pathway and a confirmatory trial is ongoing to verify Tecelra’s clinical benefit.[vi]

A Black Box Warning has been issued because patients may experience cytokine release syndrome. Patients may also exhibit Immune Effector Cell-associated Neurotoxicity Syndrome (ICANS).

The current list price for  Tecelra is $727,000. This does not include the pre-treatment or hospitalization costs associated with the administration of the therapy.

Article by Kathy Clark, RN, BSN, CMCN, Vice President, Director of Managed Care. For more information about how this may affect your plan, please contact your Summit ReSources care specialist. The following sources were used as reference material for this article:

[i] FDA Package Insert-Tecelra. https://www.fda.gov/media/180565/download?attachment. Accessed 8/12/2024.

[ii] National Cancer Institute. Synovial Sarcoma. https://www.cancer.gov/pediatric-adult-rare-tumor/rare-tumors/rare-soft-tissue-tumors/synovial-sarcoma#:~:text=Synovial%20sarcoma%20is%20a%20cancer,also%20be%20called%20malignant%20synovioma. Accessed 8/12/2024.

[iii]Blay JY, von Mehren M, Jones RL, Martin-Broto J, Stacchiotti S, Bauer S, Gelderblom H, Orbach D, Hindi N, Dei Tos A, Nathenson M. Synovial sarcoma: characteristics, challenges, and evolving therapeutic strategies. ESMO Open. 2023 Oct;8(5):101618. doi: 10.1016/j.esmoop.2023.101618. Epub 2023 Aug 23. PMID: 37625194; PMCID: PMC10470271. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10470271/ Accessed 8/12/2024.

[iv] Mangla A, Gasalberti DP. Synovial Cell Sarcoma. [Updated 2023 May 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. https://www.ncbi.nlm.nih.gov/books/NBK587366/. Accessed  8/12/2024.

[v] FDA Package Insert-Tecelra. https://www.fda.gov/media/180565/download?attachment. Accessed 8/12/2024.

[vi] FDA. FDA Approves First Gene Therapy to Treat Adults with Metastatic Synovial Sarcoma. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapy-treat-adults-metastatic-synovial-sarcoma. Accessed 8/12/2024.