A box of Ozempic with contents sits on a table in Dudley, North Tyneside, UK on October 31, 2023.
George Frey | Reuters
Novo Nordisk investors were unimpressed on Thursday by a critical Harvard report that linked weight-loss drugs to a rare eye disease.
Semaglutide, found in weight-loss drugs such as Novo Nordisk's Ozempic and Wegovy, may be linked to an increased risk of a rare eye disease, according to a study from Harvard Medical School.
However, analysts said the trial results were “hardly groundbreaking.” Shares in the Danish pharmaceutical company were unchanged on Thursday, slipping in morning trade and rising 0.1 percent at 11:17 a.m. London time.
The Harvard report found that patients with type 2 diabetes or obesity who are prescribed semaglutide have an increased risk of nonarteritic anterior ischemic optic neuropathy (NAION) – a condition that can lead to loss of vision in one eye. Patients were diagnosed with the eye condition more often than those who were not prescribed the weight-loss drugs, the study found.
Although the research suggests “some connection” to a rare eye event, the quality of the evidence is “very low and the margin for error very high,” said Emmanuel Papadakis, an analyst at Deutsche Bank.
The worst-case scenario would likely be another update to the warnings on drug labels, but that would “hardly be a groundbreaking change,” Papadakis said.
He added that Deutsche Bank generally views semaglutide drugs as “one of the lowest-risk classes of therapy in the history of the industry.”
A Novo Nordisk spokesman said the optic nerve disease NATIONAL is not an “adverse reaction for the commercially available formulations of semaglutide,” according to the approved labels. They added that there were “important methodological limitations” of the study, such as the “small number of people” with type 2 diabetes or obesity who were exposed to semaglutide and included in the study.
“Patient safety is Novo Nordisk’s highest priority and we take all reports of adverse reactions related to the use of our medicines very seriously,” the spokesman said.
The popularity of its blockbuster drugs has made Novo Nordisk the most valuable company in Europe; its valuation last year was higher than Denmark's entire gross domestic product.
Wegovy also has health benefits beyond weight loss and blood sugar regulation. The Food and Drug Administration approved it in March to reduce the risk of heart disease.
However, the drugs have come under fire after some patients reported experiencing stomach paralysis and suicidal thoughts while taking the drugs. A study by researchers at the University of British Columbia found an increased risk of intestinal obstruction, a condition in which food is prevented from passing through the small or large intestine, and pancreatitis, or inflammation of the pancreas.
The drug labels already contain warnings about pancreatitis and certain types of intestinal obstruction. A change in vision is also listed as a possible side effect for both Ozempic and Wegovy.
The US study, published on Wednesday, analyzed data from 16,827 patients from December 2017 to November last year. The researchers pointed out that further studies are needed to determine whether semaglutide causes the eye disease.
CNBC's Jenni Reid contributed to this report.
