Eli Lilly weight loss drug shines in phase 3 trials

April 27, 2023

Eli Lilly announced this week that its weight loss drug, tirzepatide, glowed in phase 3 trials, teeing up the company's regulatory submission.

The SURMOUNT-2 trial was the second phase 3 clinical study conducted worldwide to evaluate tirzepatide for managing chronic weight issues. The trial, which involved 938 adult participants who had type 2 diabetes and were either overweight or obese, met all its primary and secondary objectives. 

In the study, participants taking the drug had significant reductions in body weight compared to those taking a placebo, with Lilly reporting that the average weight reduction was higher in those taking 15 mg of tirzepatide (about 34.4 lbs.) compared to those taking 10 mg (about 29.8 lbs.). Patients had an average starting weight of about 222 lbs. and an average A1C level of 8.0%. Additionally, a higher percentage of people taking tirzepatide achieved at least a 5% body weight reduction compared to those taking a placebo. The trial also found that tirzepatide helped reduce A1C levels and other cardiometabolic parameters. 

Based on these results, Lilly plans to complete its FDA submission for tirzepatide in adults with obesity or overweight with weight-related comorbidities in the coming weeks and expects regulatory action as early as the end of the year.

Tirzepatide, branded as Mounjaro, was approved by the FDA last May to improve glycemic control in adults with type 2 diabetes. The injectable drug is a glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist .

Analysts say tirzepatide has the potential to usurp Humira to become the best-selling drug of all time. According to UBS analyst Colin Bristow, the drug is expected to generate annual sales of $25 billion — a figure that would exceed the previous record of $20.7 billion set by AbbVie's Humira in 2021.

Its been a busy few weeks for Eli Lilly, with the company selling its FDA-approved glucagon rescue treatment, Baqsimi,  to California-based Amphastar Pharmaceuticals. Per the deal — which could be worth up to $1.08 billion — Amphastar will pay Lilly $500 million in cash at closing and an additional $125 million in cash upon the one-year anniversary of closing. Lilly is also eligible to receive sales-based milestone payments of up to $450 million in aggregate. 

Last week, Eli Lilly also revealed plans to invest an additional $1.6 billion and add another 200 new jobs at its two new manufacturing sites in Boone County, Indiana — bringing the company's total commitment to $3.7 billion and up to 700 new jobs.