Long-term safety and efficacy of tofogliflozin, a selective inhibitor of sodium-glucose cotransporter 2, as monotherapy or in combination with other oral antidiabetic agents in Japanese patients with type 2 diabetes mellitus: multicenter, open-label, randomized controlled trials

Objective: To evaluate long-term safety and efficacy of tofogliflozin in Japanese patients with type 2 diabetes as monotherapy or in combination with other oral antidiabetic agents, we conducted 52-week, open-label, randomized controlled trials. Research design and methods: The single-agent trial included patients with inadequate glycemic control on diet and exercise, whereas the add-on trial included those uncontrolled with any of the oral antidiabetic agents. In both trials, patients were randomly assigned to receive tofogliflozin 20 or 40 mg once daily orally for 52 weeks. Main outcome measures: Safety assessments. Results: A total of 194 patients (65, 20-mg group; 129, 40-mg group) were enrolled into the single-agent trial, whereas 602 (178 and 424, respectively) were enrolled into the add-on trial. Tofogliflozin was well tolerated for 52 weeks in both trials with < 6% of treatment discontinuation because of adverse events in each treatment group. It also reduced hemoglobin A1c. In the single-agent trial, mean reductions at 52 weeks were 0.67 and 0.66% in the 20- and 40-mg groups, respectively. In the add-on trial, mean reductions ranged from 0.71 to 0.93% across the subgroups by dose and background therapy. Conclusion: Tofogliflozin was well tolerated and showed sustained efficacy in both trials.