Meeting highlights from the Pharmacovigilance Risk Assessment Committee (PRAC) 2-5 June 2025

The EMA's PRAC has concluded that semaglutide medicines (Ozempic, Rybelsus, Wegovy) carry a 'very rare' risk of NAION, an eye condition potentially causing vision loss; product information will be updated accordingly, and treatment should cease if NAION is confirmed. Additionally, the PRAC is reviewing Varilrix and Varivax chickenpox vaccines following a fatal encephalitis case, assessing available evidence to determine if regulatory action is needed, though the vaccines can still be used per approved guidelines during the investigation.

Analysis

The European Medicines Agency's Pharmacovigilance Risk Assessment Committee (PRAC) has concluded its review of semaglutide-containing medicines, specifically Ozempic, Rybelsus, and Wegovy, determining that non-arteritic anterior ischemic optic neuropathy (NAION) is a 'very rare' side effect, with an incidence of up to 1 in 10,000 individuals. This finding will necessitate an update to the product information for these drugs, advising discontinuation of treatment if NAION occurs. While the 'very rare' classification may temper market concerns, it introduces a new, albeit infrequent, risk factor associated with these highly utilized treatments for diabetes and obesity. Concurrently, the PRAC is undertaking a review of the varicella vaccines Varilrix and Varivax concerning the known risk of encephalitis. This was prompted by a fatal case of encephalitis reported in Poland following vaccination with Varilrix. Encephalitis is already documented as a rare side effect for these vaccines; however, this review will assess all available evidence to determine if additional regulatory actions are required. Despite the ongoing investigation, the EMA has confirmed that these vaccines can continue to be administered according to their approved product information. The general sentiment signaled is 'mildly negative' with an anticipated low market impact, reflecting the low frequency of the semaglutide side effect and the ongoing nature of the vaccine review.

Key Decisions for Investors

• Investors should acknowledge the updated product information for semaglutide medicines (Ozempic, Rybelsus, Wegovy) now including NAION as a 'very rare' side effect; while the low incidence might limit immediate sales impact, this new safety data point warrants monitoring for any shifts in physician or patient sentiment.
• For companies involved with Varilrix and Varivax, the PRAC's ongoing review of encephalitis risk introduces a degree of uncertainty; closely watch for the review's conclusions, as any resultant regulatory action could influence vaccine recommendations or market perception.
• These regulatory actions highlight the continuous post-marketing surveillance in the pharmaceutical industry, reinforcing the need for investors to consider potential safety-related label updates and their implications as an inherent risk in drug development and commercialization.