Is Mounjaro Gliding Toward an Obesity Approval?

Tirzepatide, marketed by Lilly under the  Mounjaro brand, may be gliding toward an FDA approval for obesity later this year.

A year ago, the first phase 3 study results for tirzepatide in obesity wowed us. Yesterday, Lilly revealed yet another impressive piece of the puzzle – impressive weight reduction in persons who have both obesity and type 2 diabetes. The results are impressive, said Lilly medical director Nadia Ahmad, because the weight loss seen in this trial – an average of 15.7 percent – has not been seen before with other medicines in these patients. Diabetes makes it much harder for patients to reduce their weight.

For instance, the weight reduction with semaglutide in this population was 9.6 percent. So yes, it does seem that tirzepatide may be delivering greater efficacy than semaglutide for obesity. In fact, Lilly appears to be confident enough about this to invest in a major head-to-head study to prove it. The SURMOUNT-5 study for this purpose started last week.

Fast-Track NDA Submission Near Completion

Lilly is now wrapping up their fast-track NDA submission for an indication in obesity treatment “in the coming weeks” and they expect approval is possible by sometime late this year.

Financial analysts are making some hyperbolic predictions about the possibility that tirzepatide becoming the biggest selling drug ever with estimates ranging to $50 billion in annual sales. For comparison, the best selling drug to date was Lipitor (atorvastatin), which peaked in 2006 at $13 billion in annual sales.

The Branding Shell Game

Publicly, Lilly is not saying if they will market this new indication under the Mounjaro brand name. Some people suggest that FDA has previously favored an artificial separation of obesity and diabetes therapeutics. Or maybe it serves some marketing purpose. But since the dosing is the same for tirzepatide in diabetes and obesity, there’s little need for it.

Whatever rationalizations might prop up the contrivance of a separate obesity brand, such fragmentation of branding remains a bad idea. First of all, we’ve seen that separate branding for obesity doesn’t get traction in the marketplace. Secondly, it flies in the face of the fact that obesity and diabetes are merging together in the real world. Pulling them apart is a practical impossibility. It creates confusion and reinforces the stigma attached to an obesity indication.

Great Changes Lie Ahead

An FDA approval for tirzepatide later this year will be a just one more step in the process toward a more objective approach to overcoming obesity. For the millions of people who find their health and lives harmed by this chronic disease, the options for medical care are getting better. Tirzepatide is one piece of the puzzle. More pieces will be falling into place soon. A new era for obesity care lies ahead, bringing changes that benefit many people and leave some others feeling unsettled.

Click here for the announcement from Lilly, here for slides with further details, here and here for further reporting.

Glider, photograph by L293D / Wikimedia Commons

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April 28, 2023