Activity Of Tesetaxel, An Oral Taxane, Given As A Single-Agent In Patients (Pts) With Her2-, Hormone Receptor Plus (Hr Plus ) Locally Advanced Or Metastatic Breast Cancer (Mbc) In A Phase 2 Study

1042Background: Chemotherapy treatments that offer improved quality of life are needed. Tesetaxel (T) is a novel, oral taxane that has potential advantages over currently available taxanes, including: oral administration with a low pill burden and Q3W dosing; no history of hypersensitivity reactions (HSRs); and improved activity against chemotherapy-resistant tumors (Shionoya 2003; Chan 2006). 555 pts have been treated with T in clinical studies. In MBC, T was shown to have robust single-agent activity in 2 multicenter, Phase 2 studies. In TOB203, 46 pts with HER2- MBC received single-agent T Q3W, including 38 pts with HR+ MBC, the population being enrolled in CONTESSA, an ongoing Phase 3 study. Methods: Pts eligible for TOB203 had HER2- MBC, ECOG PS 0-1, measurable disease and adequate organ function. Adjuvant chemotherapy (including taxanes) was allowed. T was administered orally as first-line chemotherapy at 27 mg/m2 on Day 1 of a 21-day cycle, with escalation to 35 mg/m2 in subsequent cycles depending...