TAS-117 in Patients With Advanced Solid Tumors Harboring Germline PTEN Mutations

Study TAS-117-201 is an open-label, single-arm Phase 2 study evaluating the efficacy, safety, tolerability, pharmacokinetics, and pharmacodynamics of TAS-117 in patients with advanced or metastatic solid tumors harboring germline PTEN inactivating mutations. The study will be conducted in two parts: * Part A: Safety lead-in (Dose Escalation and Dose Regimen Confirmation) * Part B: Single-arm Phase 2 study Patients will receive TAS-117 orally every day or intermittently on a 21-day cycle * Part A (Dose Escalation): up to 36 adult patients with advanced or metastatic solid tumors (excluding primary brain tumors) irrespective of gene alterations. The Dose Escalation consists of 2 cohorts: Daily Dose Regimen and Intermittent Dose Regimen. * Part A (Dose Regimen Confirmation): approximately 6 adult or adolescent patients with advanced or metastatic solid tumors (excluding primary brain tumors) harboring germline PTEN inactivating mutations * Part B (Phase 2): approximately 54 adult or adolescent patients with advanced or metastatic solid tumors (excluding primary brain tumors) harboring germline PTEN inactivating mutations Treatment will continue until disease progression, unacceptable toxicity, or any other of the criteria for treatment discontinuation is met. For patients who discontinue treatment for reasons other than disease progression, tumor assessments should be continued until radiologic disease progression is documented or until initiation of subsequent new anticancer therapy (whichever occurs first). Patients will be followed for survival every 12 weeks (±2 weeks) until survival events (deaths) have been reported for 75% of enrolled patients or the study is terminated early by the Sponsor.