FDA warns of vision loss risk linked to popular GLP-1 drugs like Wegovy, Zepbound
The agency has found evidence of a potential increased risk of a rare eye condition linked to the use of GLP-1 drugs used for weight management and diabetes.
The U.S. Food and Drug Administration is requiring new safety warnings on all GLP-1 drugs after finding evidence of a potential increased risk of a rare eye condition, the agency said on Monday.
The condition, which can cause sudden vision loss, known as nonarteritic anterior ischemic optic neuropathy (NAION), is rare, and a causal relationship has not been established.
The FDA is requiring the makers of all GLP-1 medications to add a warning about the potential increased risk of NAION associated with use of these medications, it said.
NAION is a condition that can result in sudden decreased vision, including permanent vision loss. It is caused by decreased blood flow to the front part of the optic nerve, the underlying cause is not completely understood, however.
NAION cases have been reported for all currently marketed GLP-1 products, the FDA said.
CNBC has reached out to Ozempic and Wegovy maker Novo Nordisk and Eli Lilly, the company behind Mounjaro, Zepbound and Foundayo, for comment.
The FDA decision follows a review of clinical trials, real-world patient data, and published studies.
An analysis of 126 trials involving more than 134,000 patients found 6.4 cases of NAION per 100,000 patient-years among GLP-1 users, compared with 3.8 among patients receiving other treatments or placebos.
Several observational studies also identified an increased risk, supporting the FDA's concerns.
The FDA's class-wide labeling action is "likely to attract attention but should have limited impact on GLP-1 uptake," according to Citi analysts.
It may temporarily increase patient and investor concern, but the rarity of NAION and substantial weight, glycemic, cardiovascular, renal, and sleep apnea benefits should preserve a favorable benefit-risk profile and limit changes to prescribing the medicines, they added.
While GLP-1 drugs have been shown to lead to benefits beyond weight loss and controlling blood sugar levels, many also carry the FDA's strongest safety warning, known as a boxed warning, over a potential risk of thyroid tumors.
Studies have shown that semaglutide, the active ingredient in Wegovy and Ozempic, and tirzepatide, the active ingredient in Mounjaro, cause thyroid C-cell tumors in rodents. It remains unknown whether the drugs cause these tumors, including a rare form of thyroid cancer, in humans.
