China’s NMPA accepted the NDA for opamtistomig (LBL-024) for previously treated advanced extrapulmonary neuroendocrine carcinoma. The Center for Drug Evaluation granted priority review, with regulatory input supported by a registrational study across 96 patients in 34 sites. Opamtistomig is a PD-L1/4-1BB–directed bispecific antibody developed using the X-Body platform. The program aims to combine PD-L1 blockade with conditional 4-1BB agonism to reactivate exhausted T cells in tumors described as immunologically “cold,” where options are limited. An application of this design—and regulatory willingness to prioritize it—signals active competition for next-generation checkpoint agonists in aggressive solid tumors.