FDA AEMS Fully Operational, Enhanced Safety Monitoring for Sarepta's Elevidys
Launch of Integrated Safety Surveillance Infrastructure
The U.S. Food and Drug Administration (FDA) launched the Adverse Event Monitoring System (AEMS) on March 11, 2026, to provide a single platform for querying and analyzing adverse events related to FDA-regulated products, including drugs, vaccines, and cosmetics. Designed to consolidate previously fragmented reporting systems, the platform enables faster access to safety signals for regulatory agencies, researchers, and the public. As of late May 2026, AEMS provides real-time adverse event reports for all regulated products. While individual reports do not confirm causality, they help identify recurring significant signals in large datasets, accelerating regulatory actions such as label changes, additional investigations, and post-marketing studies.
Transition to E2B(R3) Submission Standards
Starting October 1, 2026, all Individual Case Safety Reports (ICSRs) submitted via ESG NextGen must comply with the International Council for Harmonisation (ICH) E2B(R3) standard. Pharmaceutical companies may continue using E2B(R2) until September 30, 2026, but once the transition to R3 begins, all reports must follow the same standard. This shift necessitates investments in data conversion, validation, and pharmacovigilance systems. The global pharmacovigilance market is projected to grow from $860 million in 2025 to $920 million in 2026 and reach $1.35 billion by 2033, with the post-marketing phase accounting for 76.0% of 2025 revenue.
Elevidys and Real-World Regulatory Risks
Sarepta Therapeutics (SRPT)'s marketed gene therapy Elevidys, containing delandistrogene moxeparvovec-rokl, uses the AAVrh74 vector to deliver the microdystrophin gene to skeletal muscles for the treatment of Duchenne Muscular Dystrophy (DMD). While the FDA granted accelerated approval on June 22, 2023, and full approval for ambulatory patients on June 20, 2024, two cases of fatal acute liver failure in non-ambulatory patients led to a boxed warning and a restricted indication to ambulatory patients aged four and older on November 14, 2025. An FDA-mandated post-marketing prospective observational study of approximately 200 patients over at least 12 months has also been required, clarifying the pathway from AEMS signals to label changes, prescribing restrictions, and development costs.
Impact on Revenue and Competitive Landscape
Elevidys generated net product revenue of $898.7 million in 2025, but revenue declined by $273.8 million year-over-year due to the suspension of shipments to non-ambulatory patients, illustrating the financial impact of safety measures. The DMD treatment market is expected to grow from $2.3 billion in 2023 to $5.2 billion in 2033 in the seven major markets, but Elevidys faces competition from Italfarmaco's HDAC inhibitor Duvyzat (givinostat), and the glucocorticoid receptor modulators Agamree (vamorolone) from Catalyst Pharmaceuticals (CPRX) and Santhera Pharmaceuticals. While AEMS is not an automated mechanism for drug restrictions, its signal-detection-based approach means future competitiveness will depend more directly on major liver toxicity rates, adherence to weekly liver function tests, and post-marketing study outcomes than on initial prescription growth.
AEMS enables rapid comparison of adverse events for marketed drugs within a single data layer, shortening the time it takes for safety signals to translate into label changes and prescribing restrictions. Elevidys generated $898.7 million in revenue in 2025 but faced a boxed warning and removal of non-ambulatory patient indication following two cases of fatal acute liver failure, highlighting Sarepta Therapeutics (SRPT)'s revenue concentration risk. For researchers, the FDA-mandated post-marketing study of approximately 200 patients over at least 12 months will serve as key evidence to quantify the risk of liver toxicity in AAV-based gene therapies. The industry must enhance data validation and signal management capabilities in line with the mandatory E2B(R3) transition in October 2026 and the $920 million pharmacovigilance market expansion. While the DMD market is projected to grow to $5.2 billion by 2033, the presence of Duvyzat and Agamree means Elevidys' safety concerns could simultaneously constrain its market share and pricing power.