Leads Biolabs secures ESMO 2026 LBA slot for EP-NEC pivotal data
Leads Biolabs has announced that its pivotal Phase IIb study of opamtistomig (LBL-024) in advanced extrapulmonary neuroendocrine carcinoma has been selected as a Late-Breaking Abstract and Proffered Paper presentation at the ESMO Congress 2026, scheduled for 26 October. The results will form the centrepiece of the Hong Kong-listed company's conference presence, with a total of three Leads Biolabs studies earning Proffered Paper slots, a level of representation unusual for a single China-originated clinical-stage biotech at ESMO.
Opamtistomig is a PD-L1/4-1BB bispecific antibody developed on the company's proprietary X-Body platform. Unlike conventional PD-1/PD-L1 checkpoint inhibitors, it is designed to simultaneously block immune suppression through the PD-L1 axis and conditionally activate 4-1BB, a co-stimulatory receptor that can reactivate exhausted T cells. The company says this dual mechanism offers particular promise in immunologically "cold" tumours, those poorly infiltrated by immune cells, a category that includes EP-NEC.
Regulatory backdrop
The ESMO presentation carries direct regulatory significance. The pivotal Phase IIb data being presented are the same results underpinning an NDA submission to China's National Medical Products Administration that received priority review in July 2026 and formal acceptance in August 2026. If approved, opamtistomig would be the first therapy specifically approved for EP-NEC anywhere in the world, an indication where, Leads Biolabs notes, second-line options deliver an objective response rate of only 10–25% and a median overall survival of around eight months.
Beyond the headline EP-NEC study, the two additional Proffered Paper presentations cover a Phase Ib/II combination chemotherapy study in first-line EP-NEC and a Phase I study of LBL-034 in relapsed/refractory multiple myeloma. Four further studies will appear as posters, covering biliary tract cancer, microsatellite-stable colorectal cancer and meta-analyses, giving the company seven data disclosures in total at the congress.
Chief Medical Officer Charles Cai described opamtistomig as "a cornerstone of our IO 2.0 strategy," adding that the ESMO selection reflected the "significant unmet need faced by patients with advanced EP-NEC."
Market context
The 4-1BB agonist space has had a turbulent history. Early monospecific 4-1BB antibodies, including urelumab and utomilumab, were hampered by either liver toxicity or insufficient efficacy in pivotal studies. The field has since pivoted towards bispecific formats that aim to localise 4-1BB activation to the tumour microenvironment, thereby reducing systemic toxicity. Leads Biolabs' claims of a safety profile comparable to standard PD-1/PD-L1 inhibitors, if borne out by the ESMO dataset, would be a meaningful differentiation point. The company is not alone in this structural approach: several other bispecific 4-1BB programmes from larger multinationals are in mid-to-late-stage development, meaning that even if the NMPA approves opamtistomig for EP-NEC, Leads Biolabs will face competition in adjacent indications as the broader IO 2.0 wave advances.
EP-NEC itself remains a niche but acutely under-served indication. Approximately 10–20% of neuroendocrine neoplasms are classified as carcinomas; the extrapulmonary subset lacks any approved dedicated therapy. Opamtistomig also holds FDA Orphan Drug Designation and Fast Track Designation obtained in late 2024 and early 2026 respectively, which could smooth a potential future US regulatory filing should the NMPA approval and ESMO data support that pathway.
The full pivotal results, including efficacy endpoints and safety data, will be presented publicly on 26 October, at which point investors and clinicians will be able to assess whether the dataset supports the regulatory optimism currently priced into the programme.