Efficacy of benfluorex in combination with sulfonylurea in type 2 diabetic patients: An 18 to 34-week, open-label, extension period

Abstract Aim The aim of this trial was to obtain further data on the efficacy and safety of benfluorex as an add-on therapy in type 2 diabetic patients insufficiently controlled by sulfonylurea monotherapy who had a limitation for the use of metformin during a 4-month extension period following a 4-month double-blind trial. Methods Patients who completed the 18-week double-blind period entered the 16-week extension period. Patients in the benfluorex group during the double-blind period continued benfluorex 450 mg/day (B-B group), whilst patients in the placebo group switched to benfluorex 450 mg/day (P-B group). The main efficacy criterion was HbA1c , analyzed as the change from week 18 (W18) to the end of treatment using a two-sided Student paired t -test. Secondary criteria were fasting plasma glucose (FPG), insulin resistance and lipids. Results Between W18 and the end of treatment, HbA1c decreased in the P-B group from 8.53 ± 1.37% to 7.49 ± 1.04% ( P < 0.001) and remained stable in the B-B group from 7.52 ± 1.07% to 7.53 ± 1.14% (NS). In the P-B group, parameters of glycemic control showed improvements from W18 to week 34 (W34) which were similar to those observed from baseline to W18 in the B-B group. Overall, the target HbA1c (≤ 7%) was achieved in 36% (103 of 289) of patients and a decrease in HbA1c of at least 1% was seen in 44% (128 of 289) of patients. Digestive disorders were the most common adverse events and the incidence of diarrhoea was 4.9% in patients receiving benfluorex for 34 weeks. Conclusion The beneficial effect of benfluorex as add-on therapy in lowering HbA1c at W18 was maintained at W34 without evidence for a loss of efficacy or an increased incidence of side effects over a 34-week follow-up.