ASCO20: Adding Veliparib to Cisplatin for Select Metastatic Triple-Negative Breast Cancers
Posted: Friday, June 12, 2020
According to Priyanka Sharma, MD, of the University of Kansas Medical Center, Westwood, and colleagues, the addition of the PARP inhibitor veliparib to standard cisplatin chemotherapy appears to improve progression-free survival in patients with BRCA-associated advanced triple-negative breast cancer. In fact, a trend toward improved overall survival was noted with this combination therapy as well. The findings of the phase II SWOG S1416 trial were presented during the ASCO20 Virtual Scientific Program (Abstract 1001).
“Approximately one-half of BRCA wild-type triple-negative breast cancers demonstrate homologous recombination deficiency resulting in a BRCA-like phenotype, which might render them sensitive to PARP [inhibitors],” the investigators commented. “Integral biomarkers used in this study identified a subgroup of [patients with] BRCA wild-type triple-negative breast cancer who benefited from [the] addition of PARP [inhibitors] to cisplatin.”
Based on the results of a biomarker panel, a total of 323 patients with metastatic triple-negative breast cancer or germline BRCA1/2-associated metastatic breast cancer were stratified into four groups: germline BRCA-positive (n = 37), BRCA-like (n = 101), non-BRCA–like (n = 110), and unclassified (n = 75). Each patient was randomly assigned to undergo standard cisplatin chemotherapy with the addition of either veliparib or a placebo.
In the germline BRCA-positive group, progression-free survival seemed to improve in the experimental arm versus the placebo arm. However, there was no statistically significant difference between the arms (P = .26). In the BRCA-like group, the median progression-free survival appeared to be significantly longer in the experimental arm than in the placebo arm (5.7 vs. 4.3 months, P = .023). The median length of overall survival in the experimental and placebo arms was 13.7 versus 12.1 months, respectively. The objective response rate was 45% in the experimental arm and 35% in the placebo arm. Patients in the unclassified and non-BRCA–like groups did not seem to derive a progression-free survival benefit from the experimental treatment.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
