|The following article features coverage from the 2020 San Antonio Breast Cancer Symposium. Click here to read more of Cancer Therapy Advisor‘s conference coverage.|
Compared with capecitabine, treatment with oral chemotherapeutic tesetaxel plus a reduced dose of capecitabine led to delayed disease progression in previously treated patients with HER2-negative, hormone receptor–positive metastatic breast cancer, according to the results of the primary analysis of the phase 3 CONTESSA trial (ClinicalTrials.gov Identifier: NCT03326674).
The trial results were presented at the 2020 Virtual San Antonio Breast Cancer Symposium (SABCS).
A total of 685 patients were randomly assigned to receive treatment with capecitabine alone or tesetaxel plus a reduced dose of capecitabine. All patients were previously treated with a taxane.
At a median follow-up of 13.9 months, the chemotherapy combination arm saw a gain of nearly 3 months for median progression-free survival compared with the capecitabine-alone arm (9.8 months vs 6.9 months) and a reduced likelihood of disease progression or death (HR, 0.716; 95% CI, 0.573-0.895; P =.003). This benefit was consistent across subgroups.
The overall response rate was also higher for the chemotherapy combination arm compared with the capecitabine-alone arm (57% vs 41%; P =.0002), as was the disease control rate (67% vs 50%; P <.0001)
However, additional toxicity was seen with the oral chemotherapy combination — and whether there is an overall survival (OS) difference is unknown, as the OS data are immature, and a final analysis of OS is not anticipated until 2022.
Grade 3 or 4 neutropenia was the most common treatment-emergent adverse event in the chemotherapy combination arm, with grade 3 neutropenia affecting 32.6% of patients and grade 4 in 38.3%. In contrast, grade 3/4 neutropenia was seen in approximately 8% of patients in the capecitabine-alone arm.
Grade 3/4 neuropathy was also more frequent in the chemotherapy combination arm than the capecitabine-alone arm (5.9% vs 0.9%), as was grade 2 alopecia (8% vs 0.3%).
The chemotherapy combination arm had more treatment discontinuations due to adverse events than the capecitabine-alone arm (23.1% vs 11.9%). The most common reasons for treatment discontinuations in the chemotherapy combination arm were neutropenia or febrile neutropenia (4.2%) and neuropathy (3.6%).
Patients died from treatment more frequently in the chemotherapy combination arm compared with the capecitabine-alone arm (1.8% vs 0.9%).
Disclosures: Study presenter Joyce O’Shaughnessy, MD, Baylor University Medical Center, Texas Oncology, US Oncology, Dallas, reported receiving consulting fees from several pharmaceutical companies, including Odonate Therapeutics, the sponsor of the trial. For a full list of disclosures, please refer to the presentation abstract.
Read more of Cancer Therapy Advisor‘s coverage of the 2020 SABCS meeting by visiting the conference page.
O’Shaughnessy J, Schwartzberg L, Piccart M, et al. Results from CONTESSA: A phase 3 study of tesetaxel plus a reduced dose of capecitabine versus capecitabine alone in patients with HER2-, hormone receptor + (HR+) metastatic breast cancer (MBC) who have previously received a taxane. Presented at: 2020 Virtual San Antonio Breast Cancer Symposium; December 8-11, 2020. Abstract GS4-01.