Two New DPP-4 Inhibitor/Metformin Combination Therapies Approved in the US

In late January, the FDA granted approval to two new combination therapies for the treatment of type 2 diabetes – Merck’s Janumet XR and Eli Lilly/Boehringer Ingelheim’s Jentadueto. Both therapies combine a DPP-4 inhibitor and metformin (both already approved therapies for type 2 diabetes) into a single pill, increasing convenience over taking each drug separately. As background, DPP-4 inhibitors help prevent the destruction of the gut hormone GLP-1 in the body, which improves glucose control with minimal risk for hypoglycemia or weight gain. Meanwhile, metformin lowers blood glucose levels by decreasing glucose production by the liver. With the recent approval of Janumet XR and Jentadueto, there are now four different DPP-4 inhibitor and metformin combination therapies available in the US. Jentadueto is a combination of the DPP-4 inhibitor Tradjenta and metformin and is taken twice daily. Janumet (approved in 2007), and Janumet XR both contain the DPP-4 inhibitor Januvia, but differ in the formulation of metformin that is used. For this reason, Janumet is taken twice daily, whereas Janumet XR can be taken once a day. The only other currently approved once-daily DPP-4 inhibitor/metformin combination therapy in the US is Bristol-Myer Squibb/AstraZeneca’s Kombiglyze XR (saxagliptin plus metformin XR). We note that none of these combination therapies should be used in people with impaired kidney function because of increased risks for certain side effects (such as lactic acidosis). The manufacturers of both Janumet XR and Jentadueto have indicated that the drugs will be available at pharmacies shortly. –LR/BK