Eli Lilly weight loss drug beats Ozempic in head-to-head study

Patients taking Eli Lilly's new drug Mounjaro achieved significantly greater weight loss than those on Novo Nordisk's Ozempic, a head-to-head study published Monday showed.

Researchers analyzed the electronic health records of more than 18,000 US patients between May 2022 and September 2023 to compare outcomes among those receiving the two injected medicines, and published the results in JAMA Internal Medicine.

The average age of the patients was 52, more than 70 percent were female, and the average baseline weight was 110 kilograms (242 lbs). Fifty-two percent had type 2 diabetes.

Most patients achieved five percent or greater weight loss after a year, but those on Mounjaro were more likely to lose weight and achieved greater weight loss.

Both drugs, also known by their generic names tirzepatide (Mounjaro) and semaglutide (Ozempic),  belong to a class known as GLP-1 analogs that mimic a naturally occurring hormone and make people feel full.

Overall, nearly 82 percent of the Mounjaro group saw five percent or greater weight loss compared to 67 percent of the Ozempic group.

The results were 62 percent versus 37 percent for 10 percent or greater weight loss, and 42 percent versus 18 percent for 15 percent or greater weight loss, all in favor of Mounjaro.

At 12 months, the average patient on Mounjaro lost seven percent more weight than the average for Ozempic.

The stronger efficacy of Mounjaro echoed results seen in the clinical trial that led to its approval, but this was the first time the two drugs were tested against one another.

No significant differences were noted in the rates of adverse events between the two groups, though discontinuation of the drug was common among both sets of patients.

Studies have shown side effects like indigestion, dizziness and mildly elevated heart rate are common with GLP-1 analogs. Severe but rare events include bowel obstruction and pancreatitis.

On the other hand, they can also lower people's risks of heart attacks and strokes, and there is emerging evidence of benefits against certain obesity-related cancers including kidney, pancreatic, esophageal, ovarian, liver and colorectal cancers.

Ozempic was approved in the United States in 2017 and has since gone on to achieve blockbuster status, while Mounjaro received approval in 2022.

A global health scourge, obesity is a risk factor for cardiovascular disease, diabetes, certain cancers and complications from diseases such as Covid-19.

Difficult to treat, it is costly for healthcare systems. While its causes can be lifestyle-related, it can also be influenced by genetics.