Tesetaxel Plus 3 Different PD-(L)1 Inhibitors in Patients With Triple-Negative MBC and Tesetaxel Monotherapy in Patients With HER2-Negative MBC

CONTESSA TRIO is a multi-cohort, multicenter, Phase 2 study of tesetaxel, an investigational, orally administered taxane, in patients with MBC. Cohort 1: Approximately 200 patients with triple-negative MBC who have not received prior chemotherapy for advanced disease will be randomized 1:1:1 to receive tesetaxel dosed orally at 27 mg/m2 once every three weeks (Q3W) plus either: * Nivolumab at 360 mg by intravenous infusion Q3W; * Pembrolizumab at 200 mg by intravenous infusion Q3W; or * Atezolizumab at 1,200 mg by intravenous infusion Q3W. Nivolumab and pembrolizumab (programmed cell death protein 1 \[PD-1\] inhibitors) and atezolizumab (a programmed death-ligand 1 \[PD-L1\] inhibitor) are immuno-oncology (IO) agents approved for the treatment of multiple types of cancer. Two of these agents, atezolizumab and pembrolizumab, have been approved by the U.S. Food and Drug Administration (FDA) as a first-line treatment for patients with triple-negative MBC. The primary efficacy endpoints for Cohort 1 are ORR and PFS in patients with PD-L1 positive status. The secondary efficacy endpoints are ORR and PFS in all patients, duration of response (DoR) and overall survival (OS). Cohort 2: Approximately 60 elderly patients with HER2-negative MBC who have not received prior chemotherapy for advanced disease will receive tesetaxel monotherapy dosed orally at 27 mg/m2 Q3W. The primary efficacy endpoints for Cohort 2 are ORR and PFS in patients with HR-positive, HER2-negative disease. The secondary efficacy endpoints are ORR and PFS in patients with triple-negative disease, DoR and OS. Cohort 3: Approximately 60 non-elderly adult patients with HER2-negative MBC who have not received prior chemotherapy for advanced disease will receive tesetaxel monotherapy dosed orally at 27 mg/m2 Q3W. The primary efficacy endpoints for Cohort 3 are ORR and PFS in patients with HR positive, HER2-negative disease. The secondary efficacy endpoints are ORR and PFS in patients with triple negative disease, DoR and OS.