San Francisco Frontiers - Korea Reviews GLP-1 Vision Loss Warnings Following US FDA Action

South Korea’s Ministry of Food and Drug Safety (MFDS) announced Wednesday that it is evaluating broader safety warnings for 38 approved GLP-1-based obesity and diabetes treatments. This regulatory review follows a recent United States Food and Drug Administration decision requiring manufacturers to label these drugs with risks associated with non-arteritic anterior ischemic optic neuropathy, a condition linked to sudden vision loss.

The MFDS issued a safety alert on Tuesday covering the 38 products from four pharmaceutical companies regarding the potential risk of NAION. The affected products include various strengths and formulations of semaglutide, liraglutide, tirzepatide, efpeglenatide, and insulin combinations. Specific brands listed in the alert include Novo’s Wegovy, Ozempic, and Rybelsus; Saxenda and Xultophy FlexTouch; Lilly Korea’s Mounjaro and Trulicity; Hanmi Pharmaceutical’s eppe; and Sanofi-Aventis Korea’s Soliqua Pen.

NAION is a condition caused by reduced blood flow to the optic nerve that can lead to sudden, painless vision loss and, in some cases, permanent blindness. The Korean regulator’s move mirrors a Nov. 9 decision by the U.S. FDA, which required manufacturers of all GLP-1 receptor agonist drugs approved in the United States to add information about the potential increased risk of NAION to the warnings and precautions sections of their product labels.

The FDA’s requirement was based on a review of clinical trial data, observational studies, and post-marketing adverse event reports submitted to its Adverse Event Reporting System. An analysis of 126 clinical trials involving more than 134,000 participants found that NAION occurred at a rate of 6.4 cases per 100,000 person-years among GLP-1 users, compared with 3.8 cases in control groups. This data suggests a potential increase in relative risk for patients using these medications.

In response to the international regulatory developments, the MFDS has asked pharmaceutical companies marketing GLP-1-based medicines in Korea to submit relevant safety information and plans for potential labeling changes. The ministry stated it will review these submissions before deciding whether to revise the precautions in their prescribing information.

Under the current safety guidance, healthcare professionals are advised to tell patients to report sudden, painless vision loss, visual field defects, or other visual disturbances immediately. If NAION is suspected, patients should be referred to an ophthalmologist for evaluation. For those who develop the condition, discontinuation of GLP-1 treatment should be considered unless the therapeutic benefits clearly outweigh the risks.

Patients are also advised to seek medical attention if they experience sudden vision loss in one eye, blurred vision, blind spots, tunnel vision, or changes in color perception. Korea previously received one reported case of NAION following semaglutide treatment in January 2024.

During a parliamentary audit on Oct. 13, Food and Drug Safety Minister Oh Yu-kyoung noted that NAION had already been added as a very rare adverse reaction to the prescribing information for Wegovy and Ozempic. However, experts caution that the risk may not be uniform across all GLP-1-based treatments.

Kim Dae-jung, a professor of endocrinology and metabolism at Ajou University Hospital, stated in a Facebook post on Tuesday that most reported NAION cases had been associated with semaglutide rather than other drugs in the class. He noted that only 15 cases had been identified in clinical trials and that the underlying mechanism had not been established in animal studies.

Kim cautioned against patients discontinuing GLP-1 treatment solely because of the warning, saying the cardiovascular and kidney benefits of the medicines generally outweigh the potential risk. The MFDS said it would continue monitoring adverse events associated with GLP-1-based medicines and take additional regulatory measures when necessary.

E.Cruz--SFF