Long-term (52-78 weeks) treatment with colesevelam HCl added to metformin therapy in type 2 diabetes mellitus patients

Objective: To evaluate the long-term safety, tolerability, and efficacy of colesevelam HCl (colesevelam) in type 2 diabetes mellitus patients receiving metformin monotherapy or metformin combination therapy. Methods: This post-hoc subgroup analysis examined data from type 2 diabetes mellitus patients aged 18 to 75 years with a hemoglobin A(1c) of 7.5% to 9.5%, who received metformin as part of their treatment via their participation in one of three randomized, double-blind base studies wherein colesevelam (3.75 g/day) or a placebo was added to existing metformin-, insulin-, or sulfonylurea-based treatment. After completing the base studies, the subjects who initially received blinded colesevelam (n = 196) or the placebo (n = 166) entered a 52-week extension study wherein they received open-label colesevelam (3.75 g/day). Results: This analysis describes the 362 patients receiving background metformin therapy who also received open-label colesevelam (3.75 g/day) during a 1-year extension study. From a safety perspective, hypoglycemia was reported by 11 patients (3.0%; none severe). Drug-related adverse events (AEs) occurred in 38 patients (10.5%). At least one serious AE occurred in 35 patients (9.7%), with only one being assessed by investigators as drug related (exacerbation of diverticulitis). Twenty-four patients (6.6%) discontinued open-label treatment because of an AE (10 due to a drug-related AE). Compared with baseline values obtained prior to the start of both the base and extension studies, colesevelam improved and maintained improvement in hemoglobin A(1c) and various lipid parameters. Conclusion: This analysis found colesevelam to be generally safe and effective for long-term therapy in type 2 diabetes mellitus patients with inadequately controlled glucose while treated with metformin monotherapy or metformin combination therapy.