Leads Biolabs wins NMPA priority review for first-ever EP-NEC treatment opamtistomig

Edited by Robert McTiernan··3 min read

China-based Nanjing Leads Biolabs Co., Ltd. (HKEX: 09887) announced that China’s National Medical Products Administration (NMPA) has accepted its biologics license application (BLA) for opamtistomig (LBL-024), a PD-L1/4-1BB bispecific antibody, under the priority review and approval procedure for the treatment of advanced extrapulmonary neuroendocrine carcinoma (EP-NEC) as monotherapy. The BLA covers patients whose disease has progressed following two or more prior lines of systemic therapy — a population for which no drug has received regulatory approval anywhere in the world.

Under NMPA regulations, priority review reduces the standard BLA review timeline from 200 to 130 working days. The designation follows a series of earlier regulatory milestones for opamtistomig in EP-NEC: NMPA Breakthrough Therapy Designation in October 2024, US FDA Orphan Drug Designation for neuroendocrine carcinoma in November 2024, and both US FDA Fast Track Designation and EU Orphan Drug Designation for EP-NEC in January 2026.

Opamtistomig combines PD-L1 blockade with conditional 4-1BB agonism, activating immune cells only within the tumor microenvironment. The approach is intended to avoid the systemic hepatotoxicity that limited earlier 4-1BB agonists. The BLA is based on a pivotal single-arm registrational study (CTR20213023) led by Professor Shen Lin of Peking University Cancer Hospital, evaluating opamtistomig monotherapy in patients with advanced EP-NEC who had failed at least two prior lines of chemotherapy. Leads Biolabs completed enrollment in that trial in August 2025, ahead of schedule. The current announcement contains no new efficacy or safety figures from the pivotal study.

The most detailed public data come from a Phase Ib/II combination study presented at ASCO 2025, where opamtistomig plus platinum-based chemotherapy achieved a 75.0% objective response rate and 92.3% disease control rate. Although separate from the monotherapy registrational study supporting the BLA, these data established the clinical activity underpinning broader EP-NEC development.

The AllSci BriefSystematic R&D and deal news. Daily.

The context for these response rates is material. In the third-line or later EP-NEC setting targeted by the BLA, published historical data show ORRs of 0% to 10% and a median overall survival of three to four months. First-line platinum-based chemotherapy — the only widely used treatment for EP-NEC — produces ORRs of 30% to 50% and a median overall survival of approximately one year. No checkpoint inhibitor, targeted agent, or any other drug carries a label specifically for EP-NEC; use of atezolizumab or durvalumab in this setting is entirely off-label, extrapolated from small cell lung cancer trial data.

Outlook

The pivotal Phase III approval Leads Biolabs received in May 2026 to initiate a randomized, double-blind, first-line combination study in EP-NEC — running in parallel with the current BLA review — reflects a deliberate strategy to pursue both near-term approval in heavily pretreated patients and longer-term label expansion into the front line. The company has indicated it plans to present full Phase Ib/II proof-of-concept data from the first-line combination program at the 2026 ESMO Congress.

The investigational EP-NEC pipeline outside Leads Biolabs remains early-stage. Boehringer Ingelheim’s BI 764532, a DLL3 × CD3 bispecific T-cell engager, is in Phase I/II development for EP-NEC and extensive-stage small cell lung cancer. Zymeworks and Zai Lab’s zocilurtatug pelitecan, a DLL3-targeting antibody-drug conjugate, is also in Phase I/II for later-line EP-NEC. Both are in early clinical stages. Opamtistomig is the only molecule to have completed enrollment in a registrational EP-NEC trial and to have a BLA under review.

This article was generated with AI assistance and reviewed and edited by the AllSci editorial team Explore more at AllSci News: https://allsci.com/news/