Efficacy and safety of once-daily oral semaglutide 25 mg and 50 mg compared with 14 mg in adults with type 2 diabetes (PIONEER PLUS): a multicentre, randomised, phase 3b trial

Background Once-daily oral semaglutide is an effective type 2 diabetes treatment. We aimed to investigate a new formulation of oral semaglutide at higher investigational doses versus the approved 14 mg dose in adults with inadequately controlled type 2 diabetes. Methods This global, multicentre, randomised, double-blind, phase 3b trial, carried out at 177 sites in 14 countries, enrolled adults with type 2 diabetes, glycated haemoglobin (HbA 1c) 8.0-10.5% (64-91 mmol/mol), a BMI of 25.0 kg/m(2) or greater, receiving stable daily doses of one to three oral glucose-lowering drugs. Participants were randomly assigned (1:1:1), by means of an interactive web response system, to once-daily oral semaglutide 14 mg, 25 mg, or 50 mg for 68 weeks. Investigators, site personnel, trial participants, and trial sponsor staff were masked to dose assignment throughout the trial. The primary endpoint was change in HbA 1c from baseline to week 52, evaluated with a treatment policy estimand in the intention-to-treat population. Safety was assessed in all participants who received at least one dose of trial drug. This trial is registered with ClinicalTrials.gov, NCT04707469, and the European Clinical Trials register, EudraCT 2020-000299-39, and is complete. Findings Between Jan 15 and Sept 29, 2021, of 2294 people screened, 1606 (n=936 [58.3%] male; n=670 [41.7%] female; mean [SD] age 58.2 [10.8] years) received oral semaglutide 14 mg (n=536), 25 mg (n=535), or 50 mg (n=535). At baseline, mean (SD) HbA 1c was 9.0% (0.8; 74.4 mmol/L [SD 8.3]) and mean bodyweight was 96.4 kg (21.6). Mean changes (SE) in HbA 1c at week 52 were -1.5 percentage points (SE 0.05) with oral semaglutide 14 mg, -1.8 percentage points (0.06) with 25 mg (estimated treatment difference [ETD] -0.27, 95% CI -0.42 to -0.12; p=0.0006), and -2.0 percentage points (0.06) with 50 mg (ETD -0.53, -0.68 to -0.38; p<0.0001). Adverse events were reported by 404 (76%) participants in the oral semaglutide 14 mg group, 422 (79%) in the 25 mg group, and 428 (80%) in the 50 mg group. Gastrointestinal disorders, which were mostly mild to moderate, occurred more frequently with oral semaglutide 25 mg and 50 mg than with 14 mg. Ten deaths occurred during the trial; none were judged to be treatment related. Interpretation Oral semaglutide 25 mg and 50 mg were superior to 14 mg in reducing HbA 1c and bodyweight in adults with inadequately controlled type 2 diabetes. No new safety concerns were identified.