By Nancy Lapid
London: Patients using Novo Nordisk‘s wildly popular weigh-loss drug Wegovy and its similar medicines for type 2 diabetes may be at increased risk for a sight-threatening eye condition, according to data from a study published on Wednesday.
Wegovy and Novo’s diabetes drugs Ozempic and Rybelsus all contain the same active ingredient, semaglutide, and belong to a class of medications known as GLP1 receptor agonists.
The rate of the eye problem known as nonarteritic anterior ischemic optic neuropathy, or NAION, was 8.9% for those taking semaglutide for type 2 diabetes, compared with 1.8% for patients taking non-GLP-1 diabetes medications, researchers reported in JAMA Ophthalmology.
Among those prescribed semaglutide for overweight or obesity, the rate of the eye condition was 6.7%, versus 0.8% for those receiving other types of medications for weight reduction.
The 36-month observational study involved 710 adults with type 2 diabetes and 979 taking medications for weight loss.
NAION develops from insufficient blood flow to the optic nerve and causes sudden painless vision loss in one eye. It is the second most common cause of blindness due to optic nerve damage, after glaucoma.
After taking patients’ other risk factors for the condition into account, such as high blood pressure and obstructive sleep apnea, use of semaglutide was associated with a more than four times higher risk of NAION in those receiving it for diabetes and a more than seven times higher risk in patients taking it for obesity.
Novo Nordisk in an emailed statement noted several limitations of the study design, which was not a randomized controlled trial.
“Overall, the data published in the study is not sufficient to establish a causal association between GLP-1 receptor agonist use and NAION,” the Danish drugmaker said, adding that the condition “is not an adverse drug reaction for the marketed formulations of semaglutide.”
NAION more often affects older individuals. In the overall U.S. population, the estimated annual incidence is 0.54 per 100,000 people, rising to 2.3 to 10.2 per 100,000 in adults above age 50, according to the American Academy of Ophthalmology.
The prognosis for visual recovery is better for younger patients, the AAO says. Mean ages in the study were 46 among patients using semaglutide for obesity and 57 among those using it for diabetes.
“This work has been carried out to a high level of quality and… does suggest an association between semaglutide treatment and one form of sight-threatening optic neuropathy, but this would ideally be tested in larger studies,” Graham McGeown of Queen’s University Belfast, who studies diabetic eye disease but was not involved in the new research, said in a statement.
“Given the rapid increase in semaglutide use and its possible licensing for a range of problems other than obesity and type-2 diabetes, this issue deserves further study, but possible drug side effects always need to be balanced against likely benefits,” McGeown said.
The researchers involved in the study were not immediately available to comment on their findings.
(Reporting by Nancy Lapid; Editing by Bill Berkrot)