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News
The FDA has granted fast track designation to opamtistomig, a PD-L1/4-1BB bispecific antibody, for first-line treatment of advanced or metastatic biliary tract cancer. The decision came just 9 days after submission and follows encouraging early data from a phase 2 trial showing good tolerability and preliminary tumor reduction. This is opamtistomig's second fast track designation in 2026.
The FDA has granted fast track designation to opamtistomig (LBL-024), a novel PD-L1/4-1BB bispecific antibody developed by Leads Biolabs, for the first-line treatment of advanced or metastatic biliary tract cancer (BTC). Notably, the designation was granted just 9 days after submission — a signal of the FDA's strong engagement with the program.
Opamtistomig works by simultaneously blocking PD-L1-mediated immune suppression and activating the 4-1BB costimulatory pathway, aiming to "warm up" immunologically cold tumors — a major hurdle in BTC treatment. Early data from a phase 2 trial's safety run-in cohort showed the drug combined with chemotherapy was well tolerated with no new safety signals, and demonstrated encouraging tumor reduction trends. The study has since completed enrollment of approximately 140 patients.
Key Takeaways:
Why it matters: Biliary tract cancer carries a poor prognosis and limited first-line options, making this fast track designation a meaningful step toward potentially expanding the immunotherapy toolkit for a disease that has historically resisted checkpoint blockade alone.
