Tirzepatide Phase Three Obesity Results: Wow!

Make no mistake. The competition to deliver better therapies for obesity is heating up in an impressive way. This morning, Eli Lilly released topline results for their first phase three trial of tirzepatide in obesity. One word sums up the reaction from top clinical scientists in obesity: “Wow!”

Jeff Emmick is the vice president of product development for Lilly Diabetes. He tells us why these results are so impressive:

“Tirzepatide is the first investigational medicine to deliver more than 20 percent weight loss on average in a phase three study, reinforcing our confidence in its potential to help people living with obesity.”

Topline Only for Now

It’s important to note that these results for tirzepatide are a topline reading from a 72-week obesity study that has just now come to completion. So we don’t have the benefit of a detailed, peer-reviewed publication. The pivotal phase three studies of tirzepatide will continue into 2023 and 2024. So we will likely not see an FDA submission before then. In other words, there is much to learn about this new medicine for obesity.

22.5 Percent Weight Loss at the Top Dose

With all that said, these are very impressive results. This was a study with a placebo control of three different doses (5, 10, and 15 mg) of this weekly injection. A total of 2,539 persons participated for 72 weeks. In short, the study met all of its primary and secondary endpoints for success.

There was a clearly increasing response to the increasing doses. At the 5 mg dose, people lost an average of 16.0 percent of their weight after 72 weeks. For the 10 mg dose, that number was 21.4 percent. Finally, on the 15 mg dose, people lost an average of 22.5 percent. For comparison, on placebo people only lost 2.4 percent. All four groups received identical guidance for diet and and exercise, in addition to their drug (or placebo) treatment.

In terms of safety and tolerability, the results were comparable to other incretin therapies for obesity. Nausea and diarrhea were the most common side effects. Discontinuations due to adverse effects amounted to 6.2 percent of patients. Of course, we’ll learn more from detailed analyses of safety that are yet to come.

Very Impressive Results

Lee Kaplan, a leading clinical scientist in obesity, finds great encouragement in these results:

“The effectiveness of tirzepatide for treating obesity independent of diabetes, as reported in this press release, is extremely impressive and establishes that this new generation of peptide hormone-based, highly effective anti-obesity medications is here to stay, with even more likely to come down the pipeline.”

Caroline Apovian, who is co-director of the Center for Weight Management and Wellness at Brigham and Women’s Hospital, tells us:

“This is clearly good news for the future of obesity medicine. We can look forward to learning much more about these striking results in the coming days.”

Access to Innovation in Obesity Care

Until now, Novo Nordisk has faced little competition for innovation in obesity care. Clearly, these results for tirzepatide in obesity tell us this will be changing. President Joe Nadglowski of the Obesity Action Coalition offers perspective:

“We’re glad to see new options continuing to emerge for obesity treatment. Because success in this space is attracting competition and competition will benefit people with obesity in multiple ways.

“Now that we have more effective options coming to market, it’s more important than ever to reform coverage of obesity treatment to ensure equitable access to effective care.”

Obesity medicine physician Fatima Cody Stanford tells us that innovation lends more urgency to the need for better access to obesity care:

“Innovation in the field of the obesity treatment is of paramount importance. However, none of these innovations matter if we can’t get access to these therapies for our patients. It is like looking at a shiny item on the shelf at a store. When it’s out of reach, it’s useless.

“Because many health plans – including Medicare – deny access to anti-obesity medicines, I see huge disparities in access to care every day. This simply must change and I believe innovations like tirzepatide will shine a light on the need for change.”

Click here for the release of topline results from Lilly and here for more on tirzepatide. For more on access to care and disparities in obesity treatment, click here and here.

Race of Hero Spirits Pass, painting by Walter Crane / WikiArt

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April 28, 2022