Diabetes patients who use GLP-1s may have a higher risk of serious eye disease: study

A recent study in JAMA Ophthalmology found that diabetes patients using GLP-1 drugs, particularly Novo Nordisk's semaglutide, had twice the risk of developing neovascular age-related macular degeneration (nAMD) compared to non-users, although the overall risk remained low. The study, which analyzed data from over 139,000 Canadian patients, adds to growing concerns about potential ocular side effects associated with GLP-1 therapies; previously, the EMA recommended labeling changes for semaglutide to include nonarteritic anterior ischemic optic neuropathy (NAION) as a very rare side effect.

Analysis

A recent study published in JAMA Ophthalmology indicates a potential increased risk of neovascular age-related macular degeneration (nAMD) for diabetes patients using GLP-1 therapies, finding users were twice as likely to develop the condition compared to non-users. The study, involving over 139,000 Canadian diabetes patients aged 66 and older, observed that 0.2% of GLP-1 users developed nAMD over a three-year period (2020-2023), compared to 0.1% in the non-user group. Significantly, 97.5% of the GLP-1 users in this cohort were taking Novo Nordisk's semaglutide products (Wegovy, Ozempic, Rybelsus), with the remaining 2.5% on Sanofi's lixisenatide. While the study authors acknowledged the overall absolute risk of developing nAMD remained low and emphasized the findings represent an association rather than a definitive causal link, they also noted the risk appeared higher with longer duration of GLP-1 use. This research contributes to an expanding body of literature raising concerns about potential ocular side effects of GLP-1 drugs. It follows previous findings linking semaglutide to nonarteritic anterior ischemic optic neuropathy (NAION), which prompted the European Medicines Agency's safety committee on June 6 to recommend updating semaglutide's product information to include NAION as a 'very rare' side effect. This EMA recommendation is now progressing through further regulatory review. These cumulative findings may intensify scrutiny on the long-term safety profiles of GLP-1 medications, particularly for market leaders like Novo Nordisk, and could have implications for regulatory oversight.

Key Decisions for Investors

• Investors should closely monitor ongoing regulatory reviews by bodies such as the EMA and potential product labeling changes for GLP-1 drugs, particularly Novo Nordisk's semaglutide, following these recent ocular safety findings.
• Consider the potential for increased headline risk and heightened patient or prescriber caution, which could temper future prescription growth rates for GLP-1s if safety concerns gain further traction, despite the low absolute risk highlighted in this specific nAMD study.
• Evaluate the long-term risk-reward profile for companies with significant revenue exposure to GLP-1 drugs, such as Novo Nordisk (NVO), factoring in the accumulation of studies pointing to potential rare but serious adverse events and the ensuing regulatory attention.