Efficacy, Safety, and Tolerability of Oral Semaglutide Versus Placebo Added to Insulin With or Without Metformin in Patients With Type 2 Diabetes: The PIONEER 8 Trial.

Objective: To investigate the efficacy, safety, and tolerability of oral semaglutide added to insulin with or without metformin.

Research Design And Methods: Patients with type 2 diabetes uncontrolled on insulin with or without metformin were randomized to oral semaglutide 3 mg ( = 184), 7 mg ( = 182), or 14 mg ( = 181) or to placebo ( = 184) in a 52-week, double-blind trial. End points were change from baseline to week 26 in HbA (primary) and body weight (confirmatory secondary). Two estimands were defined: treatment policy (effect regardless of trial product discontinuation or rescue medication) and trial product (effect assuming trial product continuation without rescue medication) in randomized patients.

Results: Oral semaglutide was superior to placebo in reducing HbA (estimated treatment difference [ETD] -0.5% [95% CI -0.7, -0.3], -0.9% [-1.1, -0.7], and -1.2% [-1.4, -1.0] for 3, 7, and 14 mg, respectively; < 0.001) and body weight (ETD -0.9 kg [95% CI -1.8, -0.0], -2.0 kg [-3.0, -1.0], and -3.3 kg [-4.2, -2.3]; = 0.0392 for 3 mg, ≤ 0.0001 for 7 and 14 mg) at week 26 (treatment policy estimand). Significantly greater dose-dependent HbA and body weight reductions versus placebo were achieved with oral semaglutide at weeks 26 and 52 (both estimands). The most frequent adverse event with oral semaglutide was nausea (11.4-23.2% of patients vs. 7.1% with placebo; mostly mild to moderate).

Conclusions: Oral semaglutide was superior to placebo in reducing HbA and body weight when added to insulin with or without metformin in patients with type 2 diabetes. The safety profile was consistent with other glucagon-like peptide 1 receptor agonists.