ASCO 2021: Neoadjuvant Talazoparib Active in Germline BRCA1/2-Mutated HER2-Negative Breast Cancer
Posted: Friday, July 2, 2021
Jennifer Keating Litton, MD, of The University of Texas MD Anderson Cancer Center, Houston, and colleagues presented their phase II study findings on the efficacy and safety of neoadjuvant talazoparib in a subset of patients with locally advance or metastatic breast cancer, during the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 505). The investigators found that this therapy was active, demonstrating rates of pathologic complete response consistent with those of combination anthracycline and taxane-based chemotherapy.
“This study built upon our previous single-institution study but enrolled patients at multiple sites with germline BRCA mutations and early-stage triple-negative breast cancer. It continued to demonstrate that a daily oral PARP inhibitor, talazoparib, did demonstrate pathologic complete response in almost half of the patients on the study,” mentioned Dr. Litton in an MD Anderson press release.
This study enrolled 61 patients with stage I to III germline BRCA1/2-mutated HER2-negative breast cancer who were administered talazoparib 24 weeks prior to breast surgery. Patients who were evaluable received at least 80% of the talazoparib dose, underwent breast surgery, and were assessed for pathologic complete response, as well as those who experienced disease progression before assessment.
With a mean patient age of 44.6 years, the intent-to-treat population included all 61 participants, and the evaluable population included 48. All individuals had triple-negative breast cancer of stage I (n = 20), II (n = 27), or III (n = 14); 60 had adenocarcinoma; and 1 had squamous cell histology. The mean duration of treatment was 23.3 weeks, with a mean of 4.5 weeks since the onset of disease. The mean overall relative dose intensity for the intent-to-treat population was 84.5%. A pathologic complete response was achieved in 49.2% of the intent-to-treat population and 45.8% of evaluable patients.
Treatment-emergent adverse events were observed in 98.4% of individuals, the most common being fatigue, nausea, and alopecia. Due to progressive disease and adverse events, 10 and 3 patients discontinued treatment, respectively.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.