AACR 2020: Talazoparib Versus Chemotherapy in HER2-Negative Advanced Breast Cancer
Posted: Tuesday, May 12, 2020
For patients with germline BRCA1/2-mutated HER2-negative advanced breast cancer, talazoparib did not significantly improve overall survival compared with chemotherapy, according to the final results of the randomized phase III EMBRACA trial, presented as part of the 2020 American Association for Cancer Research (AACR) Virtual Annual Meeting (Abstract CT071). However, patient-reported outcomes seemed to favor the PARP inhibitor. Before this final analysis, talazoparib had prolonged progression-free survival when compared with chemotherapy, noted Jennifer K. Litton, MD, of The University of Texas MD Anderson Cancer Center, Houston, and colleagues.
The authors randomly assigned 421 patients with HER2-negative advanced breast cancer to receive talazoparib (286 patients) or chemotherapy (126 patients). The hazard ratio for overall survival was based on a stratified Cox regression model.
As of September 2019, 216 patients treated with talazoparib had died (75.3%) and 108 patients in the chemotherapy cohort had died (75.0%), after a median follow-up of 44.9 months and 36.8 months, respectively. The hazard ratio for overall survival was 0.85, and the survival probability for patients who received talazoparib was higher than for those given chemotherapy at 24 months (0.42), 36 months (0.27), and 48 months (0.19). The results for overall survival were consistent across patient subgroups, including by prior platinum or hormone receptor status.
Grade 3 to 4 adverse events occurred in 69.6% of patients treated with talazoparib and in 64.3% of those treated with chemotherapy. Adverse events that led to permanent treatment discontinuation (excluding progressive disease) were observed in 5.9% and 8.7% of the patient groups, respectively. Extended follow-up demonstrated a statistically significant overall improvement and delays in the time to clinically meaningful deterioration for patients who received talazoparib, which was consistent with an initial patient-reported outcomes analysis.
Disclosure: For a full list of the authors’ disclosures, visit aacr.org.