China-based biotechnology company Nanjing Leads Biolabs Co., Ltd. (HKG: 9887) said on Friday that the Centre for Drug Evaluation of the National Medical Products Administration has accepted its New Drug Application for Opamtistomig (LBL-024) as a monotherapy for previously treated advanced extrapulmonary neuroendocrine carcinoma.

Opamtistomig is the first PD-L1/4-1BB bispecific antibody globally to reach NDA review and received Priority Review on 10 July 2026. If approved, Leads Biolabs says it would be the first authorised antibody directly targeting 4-1BB and the first approved agonistic antibody, making 4-1BB the fourth immuno-oncology target with an approved therapy after PD-1/PD-L1, CTLA-4 and LAG-3.

The filing is supported by a registrational study led by Peking University Cancer Hospital and conducted at 34 sites, which enrolled 96 patients with extrapulmonary neuroendocrine carcinoma in August 2025.

Neuroendocrine carcinoma accounts for 10% to 20% of neuroendocrine neoplasms and is highly aggressive, with extrapulmonary forms progressing rapidly and often diagnosed at an advanced stage. First-line treatment relies on platinum-based chemotherapy, which delivers an objective response rate of 30% to 50% and median overall survival of about one year, while second-line options show limited efficacy with response rates of 10% to 25% and median overall survival of roughly eight months.

Opamtistomig is designed to block PD-1/L1 immune suppression and conditionally activate 4-1BB, aiming to generate a synergistic anti-tumour response. It has been evaluated across 13 solid tumour indications in China, and has received Breakthrough Therapy Designation, Orphan Drug Designation, and Fast Track Designation from regulators in China, the US and Europe.