19 Real-world Patient Characteristics, Treatment Patterns, and Clinical Outcomes Among Talazoparib-Treated Patients With HER2-Negative, Locally Advanced or Metastatic Breast Cancer and Germline BRCA Mutations

Background

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.

Methods

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.

Results

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%.

Conclusion

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

Author Affiliations:

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
*Presenting author