Three 16 week, randomized, double-blind, placebo-controlled clinical trials were conducted to evaluate the effects of pioglitazone (15 mg and/or 30 mg) on glycemic control in patients with type 2 diabetes who were inadequately controlled (HbA1c ≥ 8%) despite current therapy with a sulfonylurea, metformin, or insulin. In addition, three 24 week randomized, double-blind clinical trials were conducted to evaluate the effects of pioglitazone 30 mg vs. pioglitazone 45 mg on glycemic control in patients with type 2 diabetes who were inadequately controlled (HbA1c ≥ 8%) despite current therapy with a sulfonylurea, metformin, or insulin. Previous diabetes treatment may have been monotherapy or combination therapy. 

Add-on to Sulfonylurea Trials

Two clinical trials were conducted with pioglitazone hydrochloride in combination with a sulfonylurea. Both studies included patients with type 2 diabetes on any dose of a sulfonylurea, either alone or in combination with another antidiabetic agent. All other antidiabetic agents were withdrawn at least three weeks prior to starting study treatment. 

In the first study, 560 patients were randomized to receive 15 mg or 30 mg of pioglitazone or placebo once daily for 16 weeks in addition to their current sulfonylurea regimen. Treatment with pioglitazone hydrochloride as add-on to sulfonylurea produced statistically significant improvements in HbA1c and FPG at endpoint compared to placebo add-on to sulfonylurea (see Table 20). 

In the second trial, 702 patients were randomized to receive 30 mg or 45 mg of pioglitazone once daily for 24 weeks in addition to their current sulfonylurea regimen. The mean reduction from baseline at Week 24 in HbA1c was 1.6% for the 30 mg dose and 1.7% for the 45 mg dose (see Table 21). The mean reduction from baseline at Week 24 in FPG was 52 mg/dL for the 30 mg dose and 56 mg/dL for the 45 mg dose. 

The therapeutic effect of pioglitazone hydrochloride in combination with sulfonylurea was observed in patients regardless of the sulfonylurea dose. 

95% CI = 95% confidence interval

Add-on to Metformin Trials 

Two clinical trials were conducted with pioglitazone hydrochloride in combination with metformin. Both trials included patients with type 2 diabetes on any dose of metformin, either alone or in combination with another antidiabetic agent. All other antidiabetic agents were withdrawn at least three weeks prior to starting study treatment. 

In the first trial, 328 patients were randomized to receive either 30 mg of pioglitazone or placebo once daily for 16 weeks in addition to their current metformin regimen. Treatment with pioglitazone hydrochloride as add-on to metformin produced statistically significant improvements in HbA1c and FPG at endpoint compared to placebo add-on to metformin (see Table 22). 

In the second trial, 827 patients were randomized to receive either 30 mg or 45 mg of pioglitazone once daily for 24 weeks in addition to their current metformin regimen. The mean reduction from baseline at Week 24 in HbA1c was 0.8% for the 30 mg dose and 1.0% for the 45 mg dose (see Table 23). The mean reduction from baseline at Week 24 in FPG was 38 mg/dL for the 30 mg dose and 51 mg/dL for the 45 mg dose. 

95% CI = 95% confidence interval

The therapeutic effect of pioglitazone hydrochloride in combination with metformin was observed in patients regardless of the metformin dose. 

Add-on to Insulin Trials

Two clinical trials were conducted with pioglitazone hydrochloride in combination with insulin. Both trials included patients with type 2 diabetes on insulin, either alone or in combination with another antidiabetic agent. All other antidiabetic agents were withdrawn prior to starting study treatment. In the first trial, 566 patients were randomized to receive either 15 mg or 30 mg of pioglitazone or placebo once daily for 16 weeks in addition to their insulin regimen. Treatment with pioglitazone hydrochloride as add-on to insulin produced statistically significant improvements in HbA1c and FPG at endpoint compared to placebo add-on to insulin (see Table 24). The mean daily insulin dose at baseline in each treatment group was approximately 70 units. The majority of patients (75% overall, 86% treated with placebo, 77% treated with pioglitazone 15 mg, and 61% treated with pioglitazone 30 mg) had no change in their daily insulin dose from baseline to the final study visit. The mean change from baseline in daily dose of insulin (including patients with no insulin dose modifications) was -3 units in the patients treated with pioglitazone 15 mg, -8 units in the patients treated with pioglitazone 30 mg, and -1 unit in patients treated with placebo.

In the second trial, 690 patients receiving a median of 60 units per day of insulin were randomized to receive either 30 mg or 45 mg of pioglitazone once daily for 24 weeks in addition to their current insulin regimen. The mean reduction from baseline at Week 24 in HbA1c was 1.2% for the 30 mg dose and 1.5% for the 45 mg dose. The mean reduction from baseline at Week 24 in FPG was 32 mg/dL for the 30 mg dose and 46 mg/dL for the 45 mg dose (see Table 25). The mean daily insulin dose at baseline in both treatment groups was approximately 70 units. The majority of patients (55% overall, 58% treated with pioglitazone 30 mg, and 52% treated with pioglitazone 45 mg) had no change in their daily insulin dose from baseline to the final study visit. The mean change from baseline in daily dose of insulin (including patients with no insulin dose modifications) was -5 units in the patients treated with pioglitazone 30 mg and -8 units in the patients treated with pioglitazone 45 mg. 

The therapeutic effect of pioglitazone hydrochloride in combination with insulin was observed in patients regardless of the insulin dose. 

95% CI = 95% confidence interval