Promega’s OncoMate Microsatellite Instability (MSI) Detection Kit received National Medical Products Administration (NMPA) approval in China as a Class III in vitro diagnostic and was cleared for use as a companion diagnostic to identify MSI‑high tumors for pembrolizumab (Keytruda). The PCR-based assay will be marketed to guide checkpoint inhibitor selection in solid tumors. The approval, supported by a collaboration with Merck, is Promega’s first companion diagnostic clearance from the NMPA and follows the company’s prior regulatory wins in the U.S. and EU. Promega highlighted that the assay will support precision oncology workflows in China, expanding patient identification for immunotherapy. Regulatory alignment on companion diagnostics remains an industry focus as pharma and diagnostics firms co-develop linked therapeutic and testing strategies to expedite patient selection in targeted therapies.