The U.S. Food and Drug Administration (FDA) is requiring makers of all glucagon-like peptide-1 receptor agonist (GLP-1 RA) drugs to add a warning about a rare eye condition, non-arteritic anterior ischemic optic neuropathy (NAION), citing a "potential increased risk."
The agency announced the requirement Monday in a Drug Safety Communication. FDA said NAION can cause acute, painless decreased vision in one eye, including permanent vision loss. GLP-1 RAs mimic a natural hormone and are widely used to treat type 2 diabetes or reduce excess body weight. The class includes Ozempic and Wegovy, made by Novo Nordisk (NYSE: NVO), and Mounjaro, Zepbound, and Foundayo, made by Eli Lilly and Co. (NYSE: LLY)
126 Trials and the NAION Rate
FDA pooled 126 randomized trials with 134,253 patients. It found 6.4 NAION cases per 100,000 person-years of exposure among GLP-1 RA users, versus 3.8 among patients on a placebo or a non-GLP-1 glucose-lowering drug. That was 15 probable events: 10 in the GLP-1 group and five in the placebo group, with none in patients on other diabetes drugs.
In a separate study of adults with type 2 diabetes who began treatment between 2019 and 2024, the FDA found no statistically significant increase in risk versus SGLT-2 inhibitors, a class of diabetes drugs. It did find an increased risk versus another class, DPP-4 inhibitors. FDA’s review of animal data did not identify a mechanism for how the drugs could raise the risk.
Novo Nordisk on the Warning
When reached for comment by Benzinga, Novo Nordisk said it continues to believe the available data do not establish a cause-and-effect relationship between GLP-1 medicines and NAION, adding that it remains confident in the benefit-risk profile of its medicines. The company also reiterated that "patient safety is a top priority for Novo."
Citi analysts said the action may temporarily raise patient and investor concern but should have limited impact on prescribing, CNBC reported on Tuesday.
Eli Lilly and Co. did not immediately respond to Benzinga’s request for comment.
Earlier Semaglutide Eye Studies
In 2024, an observational study of patients at Mass Eye and Ear found that people with type 2 diabetes prescribed semaglutide, the active ingredient in Ozempic and Wegovy, had 4.28 times the risk of an NAION diagnosis compared with those on non-GLP-1 diabetes drugs. The study did not establish causality, the researchers said.
Later that year, a Danish and Norwegian study of semaglutide users found 32 NAION events and an adjusted hazard ratio of 2.81 versus SGLT-2 inhibitor users. It estimated an absolute increase of 1.41 events per 10,000 person-years, which the study called minimal.
In September, Gerald Commissiong, interim co-CEO of DataMEDS AI Inc. (NASDAQ: MEDS), told Benzinga that vision loss is among the significant side effects that have emerged amid the boom in GLP-1 apps.
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