Efficacy and safety of ipragliflozin as an add-on to pioglitazone in Japanese patients with inadequately controlled type 2 diabetes: a randomized, double-blind, placebo-controlled study (the SPOTLIGHT study)

Ipragliflozin is a novel oral sodium–glucose cotransporter 2 (SGLT2) inhibitor under development for the treatment of type 2 diabetes. We examined its efficacy and safety as an add-on to pioglitazone in Japanese patients with inadequately controlled diabetes. Japanese type 2 diabetes patients were randomized to 24 weeks of treatment with 50 mg ipragliflozin or placebo in a double-blind manner. At week 24, patients with hemoglobin (Hb)A1c <8.4 % were permitted to continue open-label ipragliflozin in a 28-week extension period. The primary endpoint was the change in HbA1c from baseline to week 24 (with last observation carried forward). Ninety-eight and 54 patients were randomized to ipragliflozin or placebo, respectively, and were prescribed the study drug. The mean HbA1c change from baseline to week 24 was −0.64 % and 0.22 % in the ipragliflozin and placebo groups, respectively, and the adjusted mean difference between the two groups was −0.88 % (P < 0.001). Changes in fasting plasma glucose (FPG) and body weight were significantly greater in the ipragliflozin group (both P < 0.001). Among patients who continued ipragliflozin in the extension period, reductions in HbA1c, FPG, and body weight were maintained until week 52. The incidence of treatment-emergent adverse events was not significantly different between the two groups. The most common event with a higher incidence in the ipragliflozin group than in the placebo group was pollakiuria (12/97 vs. 0/54 patients). Ipragliflozin improved glycemic control, promoted weight reduction, and had a good safety profile as an add-on to pioglitazone in Japanese type 2 diabetes patients.