Merck ($MRK), building on the success of its diabetes blockbuster Januvia, won a first global approval for a long-acting form of the drug, convincing Japanese regulators to approve its new weekly product. Called omarigliptin, Merck's treatment works by blocking a protein called DPP-4 to lower blood glucose levels. In Phase III trials, the new drug measured up to Januvia, a daily DPP-4 treatment that brought in about $3.9 billion for Merck last year. The company expects to launch omarigliptin in Japan under the trade name Marizev. Merck has said it's on track to submit the drug in the U.S. by the end of this year. Release