China's NMPA Accepts Leads Biolabs' PD-L1/4-1BB Bispecific Opamtistomig for Review in Neuroendocrine Carcinoma

A 96-patient study that has not been shown

The filing draws on a single-arm registrational trial run at 34 Chinese sites under Professor Shen Lin of Peking University Cancer Hospital. Enrollment of 96 EP-NEC patients closed in August 2025, and Leads says detailed results are "planned for presentation at a leading international medical congress." The Aug. 21 release gives no response rate, duration or survival figure for that study, only the regulatory trail of a CDE Breakthrough Therapy Designation in October 2024 and priority review on July 10, 2026. By the company's account EP-NEC has no approved therapy anywhere. It cites a first-line platinum response rate of about 30% to 50% with median survival near one year, and second-line regimens such as FOLFOX, FOLFIRI, CAPTEM or temozolomide at roughly 10% to 25% with median survival around eight months.

Behind the "world's first 4-1BB" claim

Leads Biolabs calls opamtistomig the first PD-L1/4-1BB bispecific globally to enter NDA review and says an approval would make it the first approved antibody directly targeting 4-1BB and the first approved agonistic antibody, with 4-1BB becoming the fourth immuno-oncology target to carry an approved drug after PD-1/PD-L1, CTLA-4 and LAG-3. Those are the company's claims. APO|APE News has not surveyed every 4-1BB program in registration. The molecule, built on the company's X-Body platform, is designed to block PD-L1 while conditionally activating 4-1BB, and Leads says it has been studied in 13 solid tumor indications in China with a safety profile the company describes as comparable to PD-1/PD-L1 inhibitors.

"Since our founding, we have deliberately moved beyond the highly competitive PD-1/PD-L1 space to pursue differentiated mechanisms and address areas of significant unmet medical needs, with 4-1BB representing one of the most promising frontiers in immuno-oncology," said Dr. Xiaoqiang Kang, founder, chairman and CEO of Leads Biolabs.

In the United States the drug holds orphan designation for neuroendocrine carcinoma (November 2024) and fast track for EP-NEC (January 2026), the European Commission granted orphan status the same month, and no US submission has been announced.

The lung cancer abstract at WCLC

On Aug. 19 Leads said the full abstract of its Phase 2 study of LBL-024 plus chemotherapy as first-line NSCLC treatment had been posted on the World Conference on Lung Cancer website. Among 60 efficacy-evaluable patients with locally advanced or metastatic disease, ORR was 65.0% and disease control 95.0%; squamous patients responded at 77.4% (DCR 96.8%) and non-squamous at 51.7% (DCR 93.1%). Median follow-up at the March 6 cutoff was 3.6 months, and the company reported no new safety signal. A May 28 release had described the WCLC dataset as an expansion beyond a previously reported 18-patient cohort.

"With extended follow-up, we have observed continued tumor shrinkage in some patients, accompanied by an upward trend in ORR," said Dr. Charles Cai, the company's chief medical officer, who added that the Sept. 14 oral will include "the updated ORR, 6-month PFS rate, and subgroup analyses by PD-L1 expression levels in both squamous and non-squamous NSCLC."

Why This Matters to the APO|APE Reader

The PD-L1 subgroup cut promised for Sept. 14 will be the first public look at whether adding a conditional 4-1BB agonist loosens the link between PD-L1 expression and response in first-line NSCLC, which goes directly to how the assay result would be used in treatment selection if the drug advances. On the EP-NEC side, the CDE becomes the first agency to weigh a 4-1BB antibody on a single-arm dataset in a tumor type that, by the company's own description, arises across lung, gastrointestinal and bladder sites and reaches pathology as a high-grade diagnosis with no approved targeted pathway. Whether the 96-patient results surface at ESMO or a later meeting will set expectations for any FDA package built on the designations already in hand.