EXCLUSIVE: GT Biopharma Plans 2026 Trial For New Cancer Treatment

Core Viewpoint - GT Biopharma Inc. has submitted an investigational new drug (IND) application for GTB-5550 TriKE, targeting B7-H3-expressing solid tumors, marking a significant step in its clinical development pipeline [1][2]. Company Developments - The IND for GTB-5550 is the third NK cell engager the company plans to advance into clinical trials, with a Phase 1 basket trial scheduled for 2026 [2]. - The company is currently enrolling patients in a Phase 1 trial for GTB-3650, focusing on myeloid blood cancer, with data readout expected in the first half of 2026 [3]. Market Context - The global market for B7-H3 expressing solid tumor cancers is part of the estimated $362 billion global solid tumor cancers market, indicating substantial commercial potential [3]. Trial Design - The Phase 1a trial will include a dose escalation study to determine the maximum tolerated dose (MTD) across 7 dose levels [4]. - The Phase 1b trial will confirm the MTD identified in Phase 1a and evaluate tolerability across distinct metastatic disease cohorts [4]. Treatment Protocol - GTB-5550 will be administered via subcutaneous injection for 5 consecutive days during the first two weeks, followed by a treatment-free period, with a minimum of 2 treatment cycles planned [5]. - Patients will be monitored for 12 months to assess progression-free survival (PFS) and overall survival (OS) [6]. Stock Performance - Following the announcement, GTBP stock experienced a 12.92% increase, reaching $0.75 in premarket trading [6].