A Phase III Randomized, Double-blind, Parallel-group Study to Evaluate the Efficacy and Safety of Acarmet (Metformin HCl 500 mg Plus Acarbose 50 mg Tablets) Versus Acarbose Alone in Subjects With Type 2 Diabetes Mellitus

Type 2 diabetes mellitus is a chronic metabolic disorder which is caused by both insulin secretion deficiency and insulin action defect. In this type of subjects, fasting hyperglycemia is the result of the elevated rate of basal hepatic glucose production, and it is coexisting with hyperinsulinemia.After a meal, the impaired control of hepatic glucose production by insulin and decreased insulin-mediated glucose uptake by muscle contributed nearly equally to postprandial hyperglycemia(Scheen, 1997). Type 2 diabetic subjects experience significant morbidity and mortality from microvascular (retinopathy, nephropathy, and neuropathy) and macrovascular (cardiovascular disease, stroke, and peripheral vascular disease) complications. The appropriate treatment and good glycemic control of diabetes is therefore important and necessary (Vaag, 2006). Evidences suggest that combination therapy using oral antidiabetic agents with different mechanisms of action may be more effective in achieving and maintaining target blood glucose level (Turner et al., 2005).There are five classes of oral antihyperglycemic agents (sulfonylureas, biguanides, α- ucosidase inhibitors, thiazolidinediones and meglitinides) currently available to improve glycemic control in subjects with type 2 diabetes, each of which works through a different mechanism of action. Metformin, a biguanide which has insulin-sensitizing properties, can be used alone or in combination with other classes of agents. Metformin is the currently the first-choice treatment in subjects with diagnosed type 2 diabetic subjects and obesity, characterized by insulin-resistance. Metformin also provides reduction of body weight and ameliorates lipid abnormalities and is thought to be related to a reduction in hepatic gluconeogenesis (Hundal \& Inzucchi, 2003).Acarbose, the α-glucosidase inhibitor, is approved for the treatment of type 2 diabetes, and first approved for prediabetes treatment (Chiasson et al., 1994; Breuer, 2003; Chiasson et al., 2002). The drug was launched worldwide as a type 2 diabetes monotherapy and combination therapy in 1990 which has proven efficacious as first-line therapy (Coniff et al., 1995) and in combination with sulfonylureas or insulin (Kelley et al., 1998). Acarbose and metformin are both associated with beneficial effects on hyperglycemia, hyperinsulinemia, body weight, and, in some studies,triglyceride levels (Krentz et al., 1994). Because these factors are part of a cluster of risk factors for cardiovascular disease, combining the two drugs may be useful. In long-term clinical studies, acarbose has shown a favorable safety profile (Hasche et al., 1999).In combination with metformin, acarbose has been shown to improve long-term glycemic control (Rosenstock et al., 1998; Halimi et al., 2000). This study was conducted as a further vestigation into the efficacy and safety of concurrent use of acarbose and metformin in type 2 diabetes mellitus subjects.Lotus Pharmaceutical Co., Ltd. intends to initiate Phase III program to investigate assess the efficacy and safety of metformin in combination with acarbose for type 2 diabetes mellitus subjects considered inadequately blood glucose control. Since combination tablet of acarbose and metformin has not yet been approved by the Taiwan DOH, this study is conducted to evaluate the efficacy and safety of combination tablet of acarbose and metformin in the treatment of type 2 diabetes mellitus subjects in Taiwan. Acarbose is chosen as an active-comparator.