Dive Brief:

• Weekly injections of tirzepatide, the drug Eli Lilly sells as Mounjaro and Zepbound, substantially lowered the likelihood people who received it in a clinical trial developed diabetes, according to results the company disclosed Tuesday.
• Called SURMOUNT-1, the trial tested tirzepatide treatment over three years in adults considered to be pre-diabetic and who also had obesity or were overweight. The drug reduced the risk of progression to Type 2 diabetes by 94% compared to a placebo, Lilly said.
• Adults who were given the highest dose of tirzepatide, 15 milligrams, lost about 23% of their body weight on average through three years, significantly more than the average 2% lost by those on placebo.

Dive Insight:

The summary results that Lilly disclosed Tuesday are follow-up findings from SURMOUNT-1, which met its main goal in 2022. Data then, from 72 weeks of treatment, showed tirzepatide could dramatically lower body weight, helping support the drug’s approval for obesity late last year.

A second phase of the trial tracked the 1,032 participants who had pre-diabetes at the study’s start to assess how well tirzepatide could prevent progression to a diabetes diagnosis.

The risk reduction Lilly shared Tuesday is “exceptional,” wrote David Risinger, an analyst at Leerink Partners, in a note to clients. But, he added, securing a Food and Drug Administration approval for diabetes prevention may be a high hurdle.

The company plans to discuss the data with regulators, according to Risinger, who expects the new data will be included on tirzepatide’s labeling but not formally part of a prevention indication.

In its statement, Lilly said it will submit SURMOUNT-1 results to a medical journal and present detailed data at the ObesityWeek conference in early November. Shares in the company rose by nearly 5% Tuesday on the news, pushing Lilly’s market value above $900 billion.

After the 176-week study phase, Lilly followed participants for a 17-week “off-treatment” period. During that time, participants who discontinued tirzepatide regained some weight, while progression to Type 2 diabetes increased slightly.

Side effects were consistent with previously published results from SURMOUNT-1, Lilly said. Most frequently, participants on tirzepatide experienced diarrhea, nausea, constipation and vomiting.

Lower doses of tirzepatide also led to weight loss versus placebo. People given a 5 milligram dose lost 15.4% of their body weight on average, while those on 10 milligrams lost 19.9%.

Lilly sells tirzepatide as Mounjaro for the treatment of Type 2 diabetes, and as Zepbound for weight loss. Both versions have been in such demand that Lilly has struggled to make enough of the product, although it recently resolved shortages in the U.S.

The company has been building out evidence supporting tirzepatide’s benefits beyond diabetes and weight loss, recently disclosing data that showed benefits in sleep apnea and heart failure.