People with Type 2 diabetes lost an average of nearly 50 pounds on the highest dose of Eli Lilly's next-generation experimental GLP-1 medication retatrutide, the company said.
Lilly said a late-stage study found people taking 12 mg dose of retatrutide over 80 weeks lost an average of 49.6 pounds − or nearly 21% of their body weight. People with a body mass index of 35 or higher lost even more weight, an average of nearly 61 pounds while on the 12 mg dose of the medication, Lilly said.
People on two lower doses also reported average weight loss of 12.7% and 19.1%, Lilly said, and the medication lowered A1C, a measure of blood sugar, in study participants. Common side effects included diarrhea, nausea, constipation, decreased appetite and vomiting.
The pharmaceutical giant this week has reported study results on its pipeline of weight-loss medications during a medical conference in Europe. The latest results for retatrutide, also published Sept. 29 in the medical journal Lancet, follow earlier studies showing dramatic results for a drug that some experts say rivals weight loss achieved through bariatric surgery.
Lilly already markets the popular weight-loss drug Zepbound and the Type 2 diabetes medication Mounjaro. The company expects to seek Food and Drug Administration approval for retatrutide before the end of March 2027.
On Sept. 30, the Indianapolis drugmaker shared study results for another experimental weight-loss drug, EloraTZP. In a mid-stage trial of of 367 adults with Type 2 diabetes and obesity or overweight, those who took a high-dose combination of EloraTZP and Zepbound lost up to 54 pounds, or more than 23% of body weight, Lilly said.
Why Lilly is seeking this FDA approval category
Existing weight-loss drugs such as Wegovy, commonly referred to as GLP-1s, mimic the effects of glucagon-like peptide-1, a hormone that regulates metabolism.
Retatrutide is different because it mimics three gut hormones − GIP, GLP-1 and glucagon triple hormone receptor agonists.
Lilly said it will file an application seeking FDA approval for retatrutide as a biologic medication. The company also said it will unveil details on retatrutide's effectiveness as a potential treatment for obstructive sleep apnea at a future medical meeting, as well as a peer-reviewed journal.
Drug-pricing experts said Lilly's move to classify retatrutide as a biologic drug rather than another category, called small molecule, might be an effort to fend off competition longer. Brand-name biologic drugs get 12 years of exclusive sales before a competitor can gain approval for a biosimilar drug. That's longer than the five year window most "small molecule" pills or tablets get before facing generic competition.
"Biologics get a lot of additional protections that small molecule drugs don't get. They get longer exclusivity guaranteed by the FDA," said Dr. Benjamin Rome, a Harvard Medical School professor and drug pricing expert.
Another potential benefit for Lilly is "we haven't seen prices fall as much with biosimilars as we have with generic competition," Rome said.
Lilly also has sought to block counterfeit versions of retatrutide that have surfaced. In August, Lilly filed six lawsuits against compounding pharmacies, medical spas and others it said illegally marketed black-market versions of retatrutide.
This article originally appeared on USA TODAY: Lilly's retatrutide GLP-1 delivers average weight loss of 50 pounds
