 REDWOOD CITY, Calif., Sept. 09, 2021 GLOBE NEWSWIRE -- Codexis, Inc. Nasdaq: CDXS, a leading enzyme engineering company enabling the promise of synthetic biology, announced the amendment and extension of its agreement with Merck, known as MSD outside the United States and Canada, to license and supply a proprietary enzyme used in the manufacturing process for sitagliptin, the active pharmaceutical ingredient API in Mercks JANUVIA and one of the active ingredients in Mercks JANUMET. 