2021Background: Microtubule inhibitors, including taxanes, are active in preclinical models of glioblastoma (GBM), however, clinical benefit is hampered by poor blood-brain barrier (BBB) accumulation. TPI 287, a third-generation taxane designed to evade P-glycoprotein mediated efflux, readily penetrates the BBB and overcomes this limitation. CB-017 is a multi-center phase 1/2 trial designed to determine the optimal dose of TPI 287 and potential efficacy in patients treated with this drug plus bevacizumab (BEV) for treatment of recurrent GBM. Final results of the dose escalation Phase 1 stage of this trial are reported. Methods: GBM patients at first or second relapse after standard therapy and without prior exposure to anti-angiogenic agents were eligible for enrollment. BEV was administered at 10 mg/kg every 2 weeks and TPI 287 every 3 weeks via IV infusion. MRIs were obtained every six weeks with response assessed via RANO criteria. TPI 287 dose escalation was based on a traditional 3+3 design. Results:...