A Cancer Antigen Long Thought Untouchable Is Suddenly the Hottest Target in Oncology

GT Biopharma announced on May 14, 2026, that the first patient has been dosed in a Phase 1 dose-escalation trial of GTB-5550, a B7-H3-targeted natural killer cell engager for solid tumors, marking entry into the clinic of the third TriKE molecule from the company and the first to use subcutaneous dosing.