Germline BRCA (gBRCA) mutations are detected in less than 5% of unselected patients with metastatic breast cancer (mBC). Talazoparib (Talzenna) is a PARP inhibitor approved by the FDA on October 16, 2018, for the treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm), HER2-negative locally advanced or metastatic breast cancer (LA/mBC). The objective of this retrospective chart review study is to describe the demographic and clinical characteristics, treatment patterns, and clinical outcomes among adult patients with gBRCAm, HER2-negative LA/mBC treated with talazoparib in the real-world setting in the United States.
A subset of physicians from the Cardinal Health Oncology Provider Extended Network abstracted data from the medical records of US adult patients with gBRCAm, HER2-negative LA/mBC who initiated talazoparib monotherapy on or after October 16, 2018. Demographic and clinical characteristics, treatment patterns, and clinical outcomes were reported using descriptive statistics. The Kaplan-Meier method was used to describe time-to-event outcomes.
Eighty-four patients treated by 9 community practice physicians met eligibility criteria and were included in this study. Among eligible patients, 98% were female, median age at initiation of talazoparib was 62 years, and 71% were White. Hormone receptor–positive status was reported for 36% of patients, while triple-negative breast cancer classification was reported for 64% of patients. At the time of talazoparib initiation, all patients had stage IV disease, 30% had an ECOG performance status ≥2, 19% had brain metastases, and 96% had visceral metastases. A gBRCA1 mutation was detected among 64% of patients, while a mutation in gBRCA2 was detected among 36%. Talazoparib was given as first-line therapy for LA/mBC in 14% of patients, as second-line in 41%, and as third- or fourth-line in 45%. Patients had a median of 8.2 months duration of follow-up from initiation of talazoparib. Median time to talazoparib treatment discontinuation for any reason was 8.6 months (95% CI, 8.0-9.7). Median progression-free survival for talazoparib was 8.7 months (95% CI, 8.0-9.9). The overall tumor response rate during talazoparib treatment was 63%.
Findings from this study show the clinical benefits of talazoparib treatment in gBRCAm, HER2-negative LA/mBC in real-world practice in the United States. Clinical outcomes in this real-world population were consistent with those reported in the phase 3 EMBRACA randomized clinical trial (NCT01945775).
Funding: Pfizer, Inc
Reshma L. Mahtani,1* Jasmina Ivanova,2 Angelica Falkenstein,3 Alexander Niyazov,2 Joanne C. Ryan,2 Jonathan Kish,3 Ajeet Gajra,3 Kristin M. Zimmerman Savill3
1Miami Cancer Institute, Miami, FL
2Pfizer Inc, New York, NY
3Cardinal Health Specialty Solutions, Cardinal Health, Dublin, OH