Clinical Characterization of Enzyme and Transporter Precipitants to Evaluate Drug-Drug Interactions for Orforglipron, a Small Molecule Glucagon-Like Peptide-1 Receptor Agonist.

Orforglipron is an orally administered, small-molecule glucagon-like peptide-1 receptor agonist in clinical development for the treatment of type 2 diabetes and obesity. Orforglipron is a substrate of CYP3A4, organic anion transporting polypeptides (OATPs) 1B/1B3, and P-glycoprotein (P-gp); however, precipitants commonly used to define these mechanisms have not been fully characterized. The enzyme- and transporter-mediated DDI profile of orforglipron and that of CYP3A4/OATP1B/P-gp precipitants were characterized in six phase 1 clinical studies in healthy participants. Orforglipron pharmacokinetics were assessed with clarithromycin, carbamazepine, cyclosporine, and quinidine. Precipitant effects on CYP3A and OATP1B activity were measured using midazolam and coproporphyrin-I (CP-I). Orforglipron effects on CYP3A, P-gp, BCRP, and OATP1B were evaluated using midazolam, digoxin, rosuvastatin, simvastatin, atorvastatin, and CP-I. Mechanistic interrogation of the simvastatin interaction was also conducted. Clarithromycin, carbamazepine, and quinidine had minimal effect on CP-I pharmacokinetics, while the cyclosporine effect was substantial. Cyclosporine and quinidine weakly increased midazolam exposure. Orforglipron exposure increased in the presence of clarithromycin and cyclosporine and decreased with carbamazepine, demonstrating orforglipron exposure is affected by precipitants of CYP3A4 and OATP1B. Quinidine did not meaningfully change orforglipron exposure. Orforglipron had no clinically meaningful effect on the exposure of midazolam, digoxin, or atorvastatin. A weak increase in rosuvastatin exposure was consistent with BCRP inhibition, as CP-I data confirmed orforglipron does not affect OATP1B. Increase in simvastatin acid exposure was attributed to the unique disposition of simvastatin rather than enzyme or transporter inhibition. These findings address mechanistic precipitant knowledge gaps and provide a framework for managing potential orforglipron DDIs in clinical practice.