UPDATED WITH COMMENTS DECEMBER 10, 2020 // Tirzepatide, a novel subcutaneously injected drug that acts via two related but separate pathways of glucose control, produced strikingly positive effects in top-line results from the phase 3, placebo-controlled study SURPASS-1 in 478 adults with type 2 diabetes, according to a December 9 press release from the manufacturer, Lilly.
The tirzepatide molecule exerts agonist effects at both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor, and has been called a “twincretin” for its activity encompassing two different incretins. Phase 2 trial results caused excitement, with one physician calling the data “unbelievable” when reported in 2018.
SURPASS-1 enrolled patients who were very early in the course of their disease, had on average relatively mild elevation in glucose levels, and few metabolic comorbidities. They took one of three doses of the agent (5, 10, or 15 mg) as monotherapy or placebo for 40 weeks.
Julio Rosenstock, MD, said in the Lilly statement: “The study took a bold approach in assessing A1c targets. Not only did nearly 90% of all participants taking tirzepatide meet the standard A1c goal of less than 7%, more than half taking the highest dose also achieved an A1c less than 5.7%, the level seen in people without diabetes.”
Rosenstock is principal investigator of SURPASS-1 and director of the Dallas Diabetes Research Center in Texas.
The discontinuation rate in the high-dose group was 21.5% compared with less than 10% in the two lower-dose cohorts. Lilly said most of the dropouts “were due to the pandemic and family or work reasons.” The dropout rate in the placebo group was 14.8%.
These data were not included in the efficacy analysis, however, which “muddied” the analysis somewhat, one pharma analyst told BioPharma Dive.
Commenting on the new trial data, Ildiko Lingvay, MD, told Medscape Medical News: “I am very impressed with these results,” which are “unprecedented for any glucose-lowering medication that has ever been tested.”
Lingvay, of the Department of Internal Medicine/E