The European Medicines Agency (EMA) has initiated a review to investigate a potential link between semaglutide, found in drugs like Ozempic and Wegovy, and an increased risk of non-arteritic anterior ischemic optic neuropathy (NAION), a rare eye condition. This decision follows concerns raised by two studies from the University of Southern Denmark, which suggest a possible association between semaglutide use and the development of NAION.
Danish Studies Prompt EMA Review
The Danish Medicines Agency requested the EMA's Pharmacovigilance Risk Assessment Committee (PRAC) to assess the register-based studies. These studies, utilizing Danish and Norwegian registry data, indicate that semaglutide use may more than double the likelihood of developing NAION. Line Michan, director of the department of Pharmacovigilance at the Danish Medicines Agency, stated that the new register-based studies provide comprehensive data for the PRAC to consider.
NAION: A Rare but Serious Eye Condition
NAION is characterized by a sudden loss of vision due to insufficient blood flow to the optic nerve. While rare, it can lead to permanent vision impairment. Within the U.S., NAION affects between 2.3 and 10.2 patients per 100,000 people for the population over 50 years old annually, according to the American Academy of Ophthalmology. Risk factors include diabetes, hypertension, sleep apnea, and smoking.
Prior Research and Increasing Concerns
Prior research had not established a strong link between semaglutide and NAION. However, a Harvard study in July 2024 also suggested a potential association between GLP-1 receptor agonists like semaglutide and NAION. The increasing use of GLP-1 RA drugs, with weekly new-to-brand prescriptions increasing by approximately 60% from 2021 to 2023 in the US, has heightened concerns.
Novo Nordisk's Perspective
Novo Nordisk, the manufacturer of Ozempic and Wegovy, stated that NAION is a very rare eye disease and not listed as an adverse drug reaction for marketed semaglutide formulations. The company believes the benefit-risk profile of semaglutide remains unchanged. Novo Nordisk also conducted an analysis across randomized controlled clinical trials with GLP-1 receptor agonists, identifying very few ophthalmologist-confirmed NAION cases with no imbalance disfavoring Novo Nordisk GLP-1 receptor agonists.
EMA's Assessment and Next Steps
The EMA's PRAC will review all available data on NAION and semaglutide, including clinical trial data, postmarketing surveillance reports, and mechanistic and observational studies. The agency will determine whether patients treated with semaglutide have an elevated risk of developing NAION and take appropriate measures, including updating the drug's package leaflet if new evidence arises.
