A phase I study to assess the safety, pharmacokinetics (PK), pharmacodynamics (PD) and antitumor activities of daily oral BAL101553, a novel tumor checkpoint controller (TCC) in adult patients with progressive or recurrent glioblastoma (GBM) or high-grade glioma

TPS2601Background: BAL101553 (prodrug of BAL27862) is a novel TCC that promotes tumor cell death by modulating the spindle assembly checkpoint. BAL27862 is a lipophilic, small molecule (MW 387) shown in rats to penetrate the brain (1:1 plasma ratio) and has shown promising antitumor activity in orthotopic preclinical models of GBM as monotherapy or in combination with radiotherapy (RT) with/without chemotherapy. In a completed Phase 1 study with 2-h IV infusions (Days 1, 8, 15, q28d, NCT01397929, CDI-CS-001, Lopez et al. J Clin Oncol 34, 2016 suppl; 2525), dose-limiting vascular effects were observed and appeared Cmax related. Preclinical data suggest that antiproliferative effects of BAL101553/27862 are driven by exposure (AUC); thus vascular toxicity and antitumor activity are mediated by different PK drivers. In this ongoing study (NCT02490800, CDI-CS-002), daily oral BAL101553 was initially examined in solid-tumor patients; no vascular toxicities were observed at doses up to the MAD of 30 mg QD. Given...