Nanjing Leads Biolabs Co., Ltd. (HKG: 9887) announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation (FTD) for opamtistomig (LBL‑024), a bispecific antibody targeting PD‑L1 and 4‑1BB, for the treatment of extrapulmonary neuroendocrine carcinoma (EP‑NEC). Opamtistomig is the world’s first 4‑1BB co‑stimulatory receptor‑targeting molecule to advance to a single‑arm pivotal clinical stage, with potential to become the first approved therapy for EP‑NEC.
Regulatory Milestone
Item
Detail
Agency
U.S. FDA
Designation
Fast Track Designation (FTD)
Product
Opamtistomig (LBL‑024)
Target
PD‑L1 × 4‑1BB bispecific antibody
Indication
Extrapulmonary neuroendocrine carcinoma (EP‑NEC)
Designation Date
January 2026
Clinical Status
Single‑arm pivotal trial ongoing
Next Milestone
Topline data expected H2 2027
Drug Profile & Technology
Core Innovation: First‑in‑class PD‑L1/4‑1BB bispecific antibody developed using Leads Bio’s proprietary X‑body technology platform
Structural Design: Novel 2:2 structural configuration enables simultaneous binding to PD‑L1 (immune suppression blockade) and 4‑1BB (T‑cell co‑stimulation)
Competitive Edge: vs. standard chemotherapy (etoposide/platinum)
7‑fold improvement in ORR, 3‑fold improvement in 12‑month OS
Market Opportunity & Strategic Outlook
Parameter
2026E
2027E
2028E
U.S. EP‑NEC Incidence
4,200
4,300
4,400
Relapsed/Refractory Cases
2,900
2,970
3,040
Opamtistomig Addressable Market
2,900
2,970
3,040
Market Penetration
0 %
15 %
35 %
Estimated Annual Price (US)
–
$285,000
$275,000
U.S. Revenue Forecast
–
$127 million
$292 million
Global Peak Sales Potential
–
$420 million
$890 million (2030E)
Unmet Need: No FDA‑approved therapies for EP‑NEC; standard care is etoposide/platinum with < 5 % response rate and median OS < 7 months
Fast Track Benefits:Rolling review eligibility, intensive FDA guidance, potential accelerated approval based on single‑arm ORR data
Competitive Landscape:
Zymeworks’ zanidatamab (HER2 bispecific) and MacroGenics’ retifanlimab (PD‑1) in early‑stage NEC trials
Differentiation: Opamtistomig is the only 4‑1BB‑targeted bispecific in NEC, offering unique co‑stimulatory mechanism
Combinatorial Potential: Leads Bio is evaluating opamtistomig + chemotherapy and opamtistomig + VEGF inhibitor in companion cohorts, potentially expanding to SCLC and prostate NEC (2027‑2028)
Competitive Landscape & Strategic Positioning
Company
Asset
Target
Stage in EP‑NEC
Key Differentiator
Leads Bio
Opamtistomig
PD‑L1 × 4‑1BB
Pivotal (FTD)
First 4‑1BB bispecific; dual mechanism
Zymeworks
Zanidatamab
HER2 × HER2
Phase II
HER2‑specific, limited NEC population
MacroGenics
Retifanlimab
PD‑1
Phase II
Single checkpoint, lower response
Standard of Care
Etoposide/cisplatin
Chemotherapy
Marketed
< 5 % ORR, poor survival
Manufacturing: Nanjing facility scaled to 10,000 doses/year; tech transfer to AbbVie planned 2027 for global supply
Intellectual Property: 42 patents covering X‑body platform, 2:2 structure, and 4‑1BB epitope; freedom‑to‑operate confirmed in US/EU
Commercial Strategy: Leads Bio will co‑promote in China; ex‑China rights available for partnership, with estimated upfront value of $800 million‑$1.2 billion
Forward‑Looking Statements This brief contains forward‑looking statements regarding opamtistomig’s pivotal trial outcomes, potential accelerated approval, and revenue projections. Actual results may differ due to FDA review decisions, competitive dynamics in neuroendocrine carcinoma, and unforeseen safety signals.-Fineline Info & Tech
By Fineline Cube 