A phase II evaluation of the potent, highly selective PARP inhibitor veliparib in the treatment of persistent or recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer in patients who carry a germline BRCA1 or BRCA2 mutation - An NRG Oncology/Gynecologic Oncology Group study.

Abstract

BACKGROUND:

Veliparib is a potent small molecule inhibitor of PARP-1/2, which is cytotoxic in tumor cells with deficiencies in BRCA1 or BRCA2. We studied the clinical activity and toxicity of veliparib in ovarian cancer patients carrying a germline BRCA1 or BRCA2 mutation (gBRCA).

METHODS:

Eligibility included three or fewer prior chemotherapy regimens, measurable disease and no prior use of a PARP inhibitor. Veliparib was administered at 400mg orally BID with one cycle being 28days. The two-stage Simon design was capable of detecting a 25% response probability with 90% power while controlling alpha=10% (at a 10% assumed null response probability).

RESULTS:

The median age of the 50 eligible patients was 57years (range 37-94) and 14, 18, and 18 patients had 1, 2, and 3 prior therapies respectively. Thirty patients (60%) were platinum-resistant. The median number of cycles administered was 6 (1-27). There was one grade 4 thrombocytopenia. Grade 3 adverse events were: fatigue (n=3), nausea (2), leukopenia (1), neutropenia (1), dehydration (1), and ALT (1). Grade 2 events >10% were: nausea (46%), fatigue (26%), vomiting (18%), and anemia (14%). The proportion responding was 26% (90% CI: 16%-38%, CR: 2, PR: 11); for platinum-resistant and platinum-sensitive patients the proportion responding was 20% and 35%, respectively. The most common reason for treatment discontinuation was progression (62%). Twenty-nine patients are alive; two with SD remain on veliparib. The median PFS is 8.18months.

CONCLUSIONS:

The single agent efficacy and tolerability of veliparib for BRCA mutation-associated recurrent ovarian cancer warrants further investigation.

• Authors: Robert L Coleman, Michael W Sill, Katherine Bell-McGuinn, Carol Aghajanian, Heidi J Gray, Krishnansu S Tewari, Steven C Rubin, Thomas J Rutherford, John K Chan, Alice Chen, Elizabeth M Swisher
• Journal: Gynecologic oncology (Gynecol Oncol) Vol. 137 Issue 3 Pg. 386-91 (Jun 2015) ISSN: 1095-6859 [Electronic] United States
• PMID: 25818403 (Publication Type: Clinical Trial, Phase II, Journal Article, Multicenter Study, Research Support, N.I.H., Extramural)
• Copyright: Copyright © 2015 Elsevier Inc. All rights reserved.

Chemical References

• BRCA1 Protein
• BRCA1 protein, human
• BRCA2 Protein
• BRCA2 protein, human
• Benzimidazoles
• veliparib

Topics

• Adult
• Aged
• Aged, 80 and over
• BRCA1 Protein (genetics)
• BRCA2 Protein (genetics)
• Benzimidazoles (adverse effects, therapeutic use)
• Carcinoma, Ovarian Epithelial
• Fallopian Tube Neoplasms (drug therapy, genetics)
• Female
• Genes, BRCA1
• Genes, BRCA2
• Germ-Line Mutation
• Humans
• Middle Aged
• Neoplasm Recurrence, Local (drug therapy, genetics)
• Neoplasms, Glandular and Epithelial (drug therapy, genetics)
• Ovarian Neoplasms (drug therapy, genetics)
• Peritoneal Neoplasms (drug therapy, genetics)