Eli Lilly’s diabetes drug tirzepatide will get a speedy review from the Food and Drug Administration as an obesity treatment, the Indiana-based drugmaker said Thursday, allowing it to begin its formal submission after only one of two planned Phase 3 trials has reported data. But the drug will need to succeed in its second trial to get to market for the potentially lucrative indication.
The first trial in obesity, called SURMOUNT-1, produced positive data in April, showing that people who received an injection of Lilly's drug lost up to 21% of their body weight. The FDA’s decision to award a “fast track” designation enables Lilly to complete parts of its submission before waiting for the results of the second trial, called SURMOUNT-2, for which results are expected in April 2023.
As a result, parts of the review will be sped up, with Lilly able to file data related to SURMOUNT-1 as well as earlier experimental work while the second trial continues. Should SURMOUNT-2 report positive data, Lilly said it will “complete the submission shortly after.”
Still, the announcement is a sign the FDA may have pushed back on Lilly’s original plans, wrote Evercore ISI analyst Umer Raffat. The drugmaker “hinted” on its last earnings call that it aimed to file based on data from a single Phase 3 trial, as well as the studies that supported its approval in diabetes, for which it’s sold as Mounjaro. Lilly has now confirmed that results from the second study are required for tirzepatide get to market in obesity, Raffat wrote.
Obesity drug submissions have to be backed up by data from 3,000 people receiving the treatment and another 1,500 given a placebo. The combined population of the two SURMOUNT trials, along with two smaller studies reporting results around April 2023, should reach that threshold, Raffat added.
The first drug of its kind, tirzepatide was approved in diabetes earlier this year with high sales expectations. Similar types of diabetes treatments marketed by Novo Nordisk have become big sellers in obesity, under the names Wegovy and Saxenda, and Lilly hopes to win patients from Novo.
Novo reported combined Wegovy and Saxenda sales of 8.4 billion Danish krone ($1.3 billion) in 2021 and 7 billion krone for the first six months of 2022.
Novo’s Wegovy and Saxenda work by stimulating a hormone called glucagon-like peptide 1, which helps to lower blood sugar. Tirzepatide stimulates GLP-1 and a second hormone called glucose-dependent insulinotropic polypeptide.