China’s NMPA accepted the new drug application for opamtistomig (LBL-024), a PD-L1/4-1BB–directed bispecific antibody, as monotherapy for previously treated advanced extrapulmonary neuroendocrine carcinoma (EP-NEC). The agency granted priority review, with the CDE setting the application review in motion as the registrational study data continue to mature. Opamtistomig is reported to be the first agent directly targeting 4-1BB to reach the market if approved, and also the first approved agonistic antibody for that target. The NDA is supported by a registrational study led by Lin Shen, MD, of Peking University Cancer Hospital, with enrollment completed for 96 patients across 34 sites in August 2025. The program is positioned for immunologically “cold” EP-NEC, where there are currently no approved therapies worldwide, and where PD-1/PD-L1 resistance is common. Expected next steps include international meeting data presentations and the outcome of NMPA’s priority review.