Leads Biolabs' opamtistomig posts 65% ORR in Phase 2 NSCLC study
Nanjing Leads Biolabs has published the Phase 2 abstract for opamtistomig (LBL-024), its PD-L1/4-1BB bispecific antibody, ahead of a full oral presentation at the World Conference on Lung Cancer in September. The data, cut as of March 2026 after a median follow-up of 3.6 months, showed an objective response rate of 65.0% and a disease control rate of 95.0% across 60 efficacy-evaluable patients with locally advanced or metastatic NSCLC receiving opamtistomig in combination with chemotherapy as first-line treatment.
Results were stronger in the squamous subgroup, where the ORR reached 77.4% and the DCR 96.8%, compared with 51.7% and 93.1% respectively in non-squamous disease. The company reported no new safety signals, describing the overall profile as manageable. Importantly, these figures are based on only 3.6 months of median follow-up; Leads Biolabs says that with longer treatment durations it has observed continued tumour shrinkage in some patients, alongside an upward trend in ORR.
September readout
Updated results from more than seven months of follow-up will be delivered in an oral presentation on 14 September at WCLC, which runs 12 to 15 September. That dataset is expected to include the updated ORR, a six-month progression-free survival rate, and subgroup analyses stratified by PD-L1 expression level in both squamous and non-squamous populations. Investors and clinicians will view those figures as the first meaningful durability signal for the combination.
Dr Charles Cai, chief medical officer of Leads Biolabs, said: "With extended follow-up, we have observed continued tumour shrinkage in some patients, accompanied by an upward trend in ORR. This encouraging signal suggests that, with additional treatment cycles and longer follow-up, the updated clinical data may further demonstrate the therapeutic potential of LBL-024."
Opamtistomig works by simultaneously blocking PD-1/PD-L1 immune suppression and conditionally activating the 4-1BB co-stimulatory receptor, a mechanism the company describes as releasing an immune brake while pressing an accelerator. The drug received Breakthrough Therapy Designation from China's National Medical Products Administration in October 2024 and FDA Fast Track Designation for extrapulmonary neuroendocrine carcinoma in January 2026, alongside Orphan Drug Designations from both the FDA and the European Commission for that indication.
Market context
Squamous NSCLC remains a particularly underserved segment. Driver gene mutations are rare in squamous disease, ruling out the targeted therapies that have transformed outcomes in EGFR- or ALK-altered non-squamous patients, and commonly used agents such as pemetrexed are generally unsuitable. PD-1/PD-L1 inhibitors combined with chemotherapy have become the standard of care, yet median PFS in squamous NSCLC sits at only five to eight months, leaving meaningful room for improvement.
The broader bispecific antibody space in oncology is crowded, with a number of PD-1-directed and 4-1BB-directed programmes from both large pharmaceutical companies and emerging biotechs competing for share. Leads Biolabs positions opamtistomig as the first 4-1BB-targeting bispecific to advance to a single-arm pivotal trial as a monotherapy, a clinical differentiation claim that, if supported by the WCLC durability data, could strengthen the asset's partnering or licensing prospects outside China. The company is listed in Hong Kong (9887.HK) and has not disclosed a regulatory filing timeline in Western markets beyond the EP-NEC orphan designations already in hand.