Efficacy and safety of switching from a dipeptidyl peptidase-4 inhibitor to oral semaglutide in Japanese patients with type 2 diabetes mellitus

Background Dipeptidyl peptidase-4 inhibitors (DPP-4is) are the most widely used oral hypoglycemic drugs in Japan. However, once-daily oral semaglutide has been reported to reduce glycated hemoglobin (HbA1c) and body weight (BW) without causing significant hypoglycemia. Here, we aimed to evaluate the efficacy and safety of switching from a DPP-4i to oral semaglutide in Japanese patients with type 2 diabetes (T2D). Methods We performed a single-center retrospective study of the changes in HbA1c and BW in 68 patients with T2D who were switched from a DPP-4i and took oral semaglutide for >= 6 months, without changes in any other oral hypoglycemic agent. Results Mean HbA1c decreased from 7.8 to 7.0% (p < 0.001) and BW decreased from 74.2 to 71.2 kg (p < 0.001) over 6 months. The decrease in HbA1c was more pronounced in participants with high baseline HbA1c (r = - 0.542, p < 0.001). There was also a trend (r = 0.236, p = 0.052) toward a decrease in BW in individuals with shorter disease duration. There were reductions in either HbA1c or BW in 65 participants (95.6%). In addition, the larger the decrease in HbA1c was, the greater was the decrease in BW (r = 0.480, p < 0.001). Eighteen participants (20.1%) discontinued the drug within 6 months, of whom 10 (11.6% of the total) did so because of suspected adverse effects and the discontinuation rate was the highest in older, non-obese patients. Conclusions Switching from a DPP-4i to oral semaglutide may be useful for Japanese patients with T2D who have inadequate glycemic or BW control. However, its utility may be limited by gastrointestinal adverse effects in certain patients.