Lilly wins NICE endorsement for tirzepatide in obesity—with a catch

A little less than a year after Eli Lilly won the blessing of England's drug value watchdog for tirzepatide in Type 2 diabetes, the National Institute for Health and Care Excellence (NICE) has returned with an endorsement in obesity.

However, this time, the organization’s green light comes with some caveats.

In draft guidance issued Tuesday, NICE signed off on Lilly’s tirzepatide to help adults manage overweight and obesity alongside a change in diet and exercise. The endorsement paves the way for coverage of tirzepatide by England’s National Health Service (NHS).

That said, NICE’s recommendation only covers a subgroup of people with obesity. Specifically, the drug cost watchdog has endorsed tirzepatide in patients with an initial body mass index (BMI) of at least 35 kg/m2 and at least 1 weight-related comorbidity. NICE’s guidance is stricter than Lilly’s proposal for the government to cover the drug in patients with a BMI of at least 30 kg/m2, which NICE argued wouldn’t be an efficient use of NHS resources.

Lilly's drug is approved under the name Mounjaro in both obesity and Type 2 diabetes in the U.K. Stateside, tirzepatide carries the Zepbound moniker for obesity and Mounjaro in diabetes. 

In justifying its decision, NICE pointed to clinical evidence showing that Mounjaro—plus changes in diet and exercise—were more effective at helping patients lose weight than diet and exercise changes alone. Plus, Lilly’s drug may be more effective than Novo Nordisk’s rival GLP-1 injection semaglutide, according to indirect analyses provided by Eli Lilly, NICE pointed out.

Still, NICE cautioned that there is a “high level of uncertainty” around its cost-benefit calculus. Notably, the group flagged concerns about Mounjaro's long-term treatment effects and the impact of a previously higher BMI on long-term outcomes for patients. Further, NICE noted that its endorsement is risky given the sheer number of people in the U.K. who could end up taking Mounjaro to help manage their weight.

Experts were pleased with NICE’s decision, though they noted that tirzepatide’s cost could pose an issue.

While drugs like Mounjaro help reduce the risks of developing “distressing and expensive complications” like Type 2 diabetes, heart attacks and kidney failure, “their cost provides an immediate financial challenge at a time when NHS budgets are tight,” Stephen O’Rahilly, M.D., director of the medical research council metabolic diseases unit at the University of Cambridge, said, as quoted in Science Media Centre.

NICE’s obesity green light marks the watchdog’s second endorsement for tirzepatide following a thumbs up in Type 2 diabetes in September. At the time, NICE noted that most type 2 diabetes patients didn’t have their disease under control with existing treatments.

The sign-off likely came as welcome news for Eli Lilly after NICE snubbed the drug last June, arguing that it needed more evidence on tirzepatide’s clinical efficacy and cost-effectiveness.

Alongside Novo Nordisk’s respective diabetes and obesity counterparts, Ozempic and Wegovy, Lilly’s Mounjaro and Zepbound have garnered intense mainstream popularity thanks to their weight-reducing effects.

In 2024’s first quarter, Mounjaro brought home $1.8 billion in sales, while Zepbound—which was approved in the U.S. in November—generated around $517 million.