Phase 2/3 win in a rare cancer with no approved second-line standard, contingent on FDA accepting ORR-based accelerated approval without OS confirmation

Compass Therapeutics is a clinical-stage company developing a targeted cancer drug for second-line biliary tract cancer, a rare tumor type with no approved treatment options at that stage, and the drug is not yet approved.

Tovecimig beat both primary ORR and key secondary PFS endpoints in COMPANION-002 for second-line biliary tract cancer, a setting with no approved standard of care. The thesis resolves on whether FDA accepts the ORR and PFS data as sufficient for approval given the OS endpoint was not met, contaminated by 54% crossover. The path carries real approval-path risk: a single-arm-style ORR filing without OS confirmation invites scrutiny, and Replimune's RP2 in the same indication is an early but real competitive threat.