A Study to Evaluate the Safety and Tolerability of the Covalent Phosphoinositide-3-Kinase (PI3K)-Alpha Inhibitor, TOS-358, in Adult Subjects With Select Solid Tumors
Totus Medicines
Summary
The goal of this clinical trial is to evaluate the safety and efficacy of TOS-358 in women with HR+ HER2- metastatic breast cancer whose tumors have a mutation in PIK3CA and who meet all other study enrollment criteria. The main questions it aims to answer are: 1. Phase 1a: what is the maximum tolerated dose and recommended dose for phase 2? 2. Phase 1a: how safe and tolerable is TOS-358 at different dose levels when taken orally once or twice per day? 3. Phase 1b: how safe and effective is TOS-358 when given with standard of care medicines for HR+HER2- metastatic breast cancer (fulvestrant and CDK4/6i)
Description
This study will be conducted in two parts: a dose finding portion to determine the maximum tolerated dose and recommended phase 2 dose (RP2D) of TOS-358 administered orally on once a day (QD) and twice daily (BID) schedules, and a dose expansion portion to evaluate safety and tolerability in tumor-specific cohorts administered TOS-358 at the recommended phase 2 dose and schedule. Women with histologically confirmed diagnosis of hormone receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2) negative breast cancer with known PIK3CA mutations or amplifications and who meet all…