Encouraging Results of Tesetaxel in Patients with Metastatic Breast Cancer

Release Date: 30-Nov-2020

The phase-3 study results of  tesetaxel in patients with metastatic breast cancer (MBC), were presented in an oral presentation at the 2020 San Antonio Breast Cancer Symposium (SABCS).  Odonate Therapeutics, Inc has initiated CONTESSA which is a multinational, multicenter randomized study of tesetaxel. The trial aims to evaluate tesetaxel dosed orally at 27 mg/m2 on the first day of each 21‑day cycle plus a reduced dose of capecitabine (1,650 mg/m2/day dosed orally for 14 days of each 21‑day cycle) to the approved dose of capecitabine alone (2,500 mg/m2/day dosed orally for 14 days of each 21‑day cycle) in 685 patients randomized 1:1 with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative MBC previously treated with a taxane in the neoadjuvant or adjuvant setting.

The study has met with the endpoint by significantly improving the median progression free survival time by 9.8 months and the risk of disease progression was also reduced by 28%. The ORR as assessed by the IRC was 57% for tesetaxel plus a reduced dose of capecitabine versus 41% for the approved dose of capecitabine alone. Further, the protocols for analyzing overall survival rate is expected to occur in 2022.

The clinical studies have found that tesetaxel has manageable side effects. Grade andge;3 treatment-emergent adverse events (TEAEs) that occurred in andge;5% of patients were: neutropenia (70.9% for tesetaxel plus capecitabine vs. 8.3% for capecitabine alone); diarrhea (13.1% for tesetaxel plus capecitabine vs. 8.9% for capecitabine alone); hand‑foot syndrome (6.8% for tesetaxel plus capecitabine vs. 12.2% for capecitabine alone); febrile neutropenia (13.1% for tesetaxel plus capecitabine vs. 1.2% for capecitabine alone); fatigue (8.6% for tesetaxel plus capecitabine vs. 4.5% for capecitabine alone); hypokalemia (8.6% for tesetaxel plus capecitabine vs. 2.7% for capecitabine alone); leukopenia (9.8% for tesetaxel plus capecitabine vs. 0.9% for capecitabine alone); and anemia (8.0% for tesetaxel plus capecitabine vs. 2.4% for capecitabine alone).

Further, adverse events which leads to treatment discontinuation in andge;1% of patients were: neutropenia or febrile neutropenia (4.2% for tesetaxel plus capecitabine vs. 1.5% for capecitabine alone); neuropathy (3.6% for tesetaxel plus capecitabine vs. 0.3% for capecitabine alone); sepsis or septic shock (1.8% for tesetaxel plus capecitabine vs. 0.6% for capecitabine alone); diarrhea (0.9% for tesetaxel plus capecitabine vs. 1.5% for capecitabine alone); and hand-foot syndrome (0.6% for tesetaxel plus capecitabine vs. 2.1% for capecitabine alone). Treatment discontinuation due to any adverse event occurred in 23.1% of patients treated with tesetaxel plus capecitabine versus 11.9% of patients treated with capecitabine alone.

Overall, tesetaxel has potential for patients with breast cancer. The PFS improvement observed in CONTESSA, along with once‑every‑three‑weeks oral dosing and low rates of clinically significant hair loss and neuropathy, could make tesetaxel an important new treatment option for patients with metastatic breast cancer. Further, there is still unmet need for thr development of novel therapies that can improve the quality of life of breast cancer patients.