Background and Aims: an exploratory analysis of data from the global Phase 3a PIONEER programme (PIONEER 1–5, 7 and 8 trials) evaluated the efficacy of once daily oral semaglutide 3, 7, 14 mg versus comparators by duration of diabetes at baseline. Methods: patients in PIONEER 1–5, 7 and 8 (n=5657) were grouped according to diabetes duration (<5, 5–<10 and ≥10 years) and by trial. In the PIONEER trials, patients received oral semaglutide (3, 7 or 14 mg) or comparator (placebo, empagliflozin, sitagliptin or liraglutide). Endpoints were change from baseline in HbA1c (%) and body weight (kg) at week 26 (week 52 in PIONEER 7). Results: at baseline, mean HbA1c (%) was similar across diabetes duration subgroups within trials, whereas mean body weight was higher and age was lower in the duration <5 years subgroup. Reductions in HbA1c were generally greater with increasing oral semaglutide dose but were not affected by diabetes duration and there were generally no statistically significant interactions between treatment and diabetes duration (Table). Estimated treatment differences in HbA1c (%) at week 26 (week 52 in PIONEER 7) were consistent across the diabetes duration subgroups. Conclusions: across the PIONEER trials, oral semaglutide improved glycaemic control versus comparators, with an effect that was consistent across subgroups of diabetes duration. These findings support the use of oral semaglutide across a broad population of patients with type 2 diabetes.