Neoadjuvant Talazoparib in BRCA-Positive Breast Cancer
Posted: Tuesday, July 10, 2018
Prior to definitive surgery in women with early-stage BRCA-positive breast cancer, the use of single-agent talazoparib exceeded the expectations of study authors, according to the early results of a pilot trial, presented at the 2018 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 508). Jennifer Keating Litton, MD, of The University of Texas MD Anderson Cancer Center, and colleagues believe these early results warrant further investigation in a larger study of this patient population.
“To my knowledge, this study is the first time that a single-agent targeted therapy has shown a pathologic complete response in women with BRCA mutations, including those with triple-negative breast cancer,” stated Dr. Litton in a press release.
In this single-institution phase II trial, 20 women with stages I to III BRCA-positive breast cancer (17 of whom had triple-negative disease) took part. They received the oral PARP inhibitor talazoparib (once daily) and then underwent definitive surgery. All but 1 patient completed 6 months of therapy.
The researchers found that at the time of surgery, more than half of the women had achieved pathologic complete response (a score of RCB0), with a few also receiving a score of RCB1. (The same positive outcome is expected with both scores.) Ten of the women with RCB0 or RCB1 had triple-negative disease.
As for toxicity, one case of grade 4 thrombocytopenia was reported, and grade 3 side effects included anemia (eight patients) as well as neutropenia (three patients). The most common grade 1 or 2 toxicities were nausea, fatigue, alopecia, dizziness, and dyspnea. Nine patients required dose reductions as a result of toxicities.
