INT131 besylate is a potent, nonthiazolidinedione, selective peroxisome proliferator–activated receptor γ (PPARγ) modulator (SPPARM) designed to improve glucose metabolism while minimizing the side effects of full PPARγ agonists. This placebo-controlled study compared the efficacy and side effects of INT131 besylate versus 45 mg pioglitazone HCl in subjects with type 2 diabetes (T2D).

This was a 24-week randomized, double-blind, placebo- and active-controlled study of 0.5–3.0 mg INT131 versus 45 mg pioglitazone or placebo daily in 367 subjects with T2D on sulfonylurea or sulfonylurea plus metformin. The primary efficacy analysis was the comparison of change from baseline to week 24 in hemoglobin A_1c (HbA_1c) across treatment groups. Fluid status was assessed with a prospective scoring system for lower-extremity pitting edema.

INT131 had a steep dose response for efficacy as measured by changes in HbA_1c. After 24 weeks’ treatment, the 0.5-mg dose demonstrated minimal efficacy (HbA_1c −0.3 ± 0.12%) and the 2-mg dose demonstrated near-maximal efficacy (HbA_1c −1.1 ± 0.12%), which was not statistically different from the efficacy of 45 mg pioglitazone (HbA_1c −0.9 ± 0.12%; P < 0.01 for noninferiority). With the 1-mg dose, INT131 provided significant improvements in glycemic control (HbA_1c 0.8 ± 0.12; P < 0.001 vs. placebo) but with less edema, weight gain, and hemodilution than observed with 45 mg pioglitazone.

INT131 demonstrated dose-dependent reductions in HbA_1c, equivalent to 45 mg pioglitazone, but with less fluid accumulation and weight gain, consistent with its SPPARM design.