Marengo Therapeutics said the FDA expanded fast track designation for invikafusp alfa (STAR0602) across pan-tumor TMB-H solid tumors that progressed after prior therapy, including checkpoint inhibitors. The updated label includes unresectable, locally advanced, or metastatic cases with no satisfactory alternatives. The company pointed to earlier Phase 1/2 data presented at ESMO, where invikafusp alfa generated an objective response rate of 20.5% and disease control rate of 79.5% across a TMB-H population. Marengo highlighted stronger subgroup performance in TMB-H gastrointestinal cancers and in TMB-H metastatic colorectal cancer. The move extends fast track momentum from earlier TMB-H colorectal indications to a broader biomarker-defined setting, signaling regulatory support for continued clinical development.