Abstract 2575
Background
Loss-of-function mutations in genes encoding components of the homologous recombination (HR) machinery are associated with tumor sensitivity to poly (ADP-ribose) polymerase (PARP) inhibitors. In ABRAZO, the PARP inhibitor talazoparib demonstrated encouraging efficacy in gBRCA-mutated ABC, both in pts whose cancer responded to prior platinum therapy (cohort 1) and in pts who had received ≥3 prior nonplatinum chemotherapy regimens for ABC (cohort 2).
Methods
Baseline tumor tissue (primary or metastatic sites) from enrolled pts was sequenced using the FoundationOne CDx NGS panel. 60/84 pts (71%) in the intent-to-treat population had available tumor tissue, which could be sequenced. Mutations summarized below were known or likely pathogenic single-nucleotide variants, insertions, deletions, or rearrangements. Additional exploratory computational analyses pertinent to HR deficiency were performed, including genomic loss of heterozygosity (gLOH) and somatic-germline-zygosity assessments.
Results
Tumor mutations in BRCA1 and BRCA2 were detected in 29 (48%) and 28 (47%) of 60 evaluable pts (no pts exhibited mutations in both BRCA1 and BRCA2). These mutations were most commonly single-nucleotide variants (BRCA1: 12 [20%] and BRCA2: 10 [17%]) or deletions (BRCA1: 11 [18%] and BRCA2: 12 [20%]). Mutations in other genes implicated in HR were comparatively rare, with mutations in CHEK2 (2 pts), ARID1A, ATR, BARD1, BRD4, BRIP1, FANCC, and STAG2 (each in single pts) detected. In addition to BRCA1/2, genes where mutations were detected in ≥ 10% of evaluable pts included TP53 (45%) and PIK3CA (12%). TP53 mutations were more commonly observed in BRCA1-mutated than in BRCA2-mutated tumors (22/29 [76%] compared with 4/28 [14%]). Associations of genetic/genomic events with progression-free survival will be presented.
Conclusions
NGS of tumors from the ABRAZO study of talazoparib in patients with gBRCA-mutated ABC revealed a complex mutational landscape. Exploratory correlative analyses are ongoing and will be reported.
Clinical trial identification
NCT02034916.
Editorial acknowledgement
Legal entity responsible for the study
Pfizer Inc.
Funding
Pfizer Inc.
Disclosure
N.C. Turner: Advisory / Consultancy, Research grant / Funding (institution): Pfizer Inc.; Advisory / Consultancy, Research grant / Funding (institution): BioMarin. A..D. Laird: Full / Part-time employment: Pfizer Inc. M.L. Telli: Advisory / Consultancy, Research grant / Funding (institution): Pfizer Inc.; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution): Tesaro; Advisory / Consultancy, Research grant / Funding (institution): PharmaMar; Advisory / Consultancy, Research grant / Funding (institution): Vertex; Research grant / Funding (institution): AbbVie; Research grant / Funding (institution): Biothera; Research grant / Funding (institution): Calithera Biosciences; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): Medivation; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): OncoSec; Research grant / Funding (institution): Sanofi. H.S. Rugo: Research grant / Funding (institution): Eisai; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): GSK; Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly; Research grant / Funding (institution): MacroGenics; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): OBI Pharma; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Plexxikon; Travel / Accommodation / Expenses: Mylan; Travel / Accommodation / Expenses: Puma; Research grant / Funding (institution): Eisai; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): GlaxoSmithKline; Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly; Research grant / Funding (institution): MacroGenics; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): OBI Pharma; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Plexxikon; Travel / Accommodation / Expenses: Mylan; Travel / Accommodation / Expenses: Puma. A. Mailliez: Honoraria (self), Advisory / Consultancy: AstraZeneca; Advisory / Consultancy: Tesaro; Advisory / Consultancy, Research grant / Funding (institution): PharmaMar; Advisory / Consultancy: Vertex; Research grant / Funding (institution): AbbVie; Research grant / Funding (institution): Biothera; Research grant / Funding (institution): Calithera Biosciences; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): Medivation; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): OncoSec; Research grant / Funding (institution): Pfizer Inc. J. Ettl: Honoraria (institution), Advisory / Consultancy: Lilly; Advisory / Consultancy, Travel / Accommodation / Expenses: Novartis; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Pfizer; Honoraria (institution), Advisory / Consultancy: Roche; Advisory / Consultancy: Tesaro; Advisory / Consultancy: Eisai; Research grant / Funding (institution), Travel / Accommodation / Expenses: Celgene; Honoraria (self): TEVA; Honoraria (self): AstraZeneca. J. Balmaña: Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZenca; Advisory / Consultancy: Clovis; Advisory / Consultancy: Tesaro; Advisory / Consultancy: BMS; Research grant / Funding (institution), Travel / Accommodation / Expenses: PharMar. P.A. Fasching: Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy: Amgen; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Honoraria (self), Advisory / Consultancy: Pfizer; Honoraria (self), Advisory / Consultancy: Celgene; Honoraria (self), Advisory / Consultancy: Puma; Honoraria (self), Advisory / Consultancy: Daiichi Sankyo; Honoraria (self), Advisory / Consultancy: Eisai; Honoraria (self), Advisory / Consultancy: Merck; Honoraria (self), Advisory / Consultancy: AstraZeneca; Honoraria (self), Advisory / Consultancy: Teva; Honoraria (self), Advisory / Consultancy: Hexal; Honoraria (institution), Speaker Bureau / Expert testimony: Myelo; Research grant / Funding (institution): BioNTech. S.A. Hurvitz: Research grant / Funding (institution): Ambryx; Research grant / Funding (institution): Amgen; Research grant / Funding (institution): Bayer; Research grant / Funding (institution): BI Pharma; Research grant / Funding (institution): Biomarin; Research grant / Funding (institution): Cascadian; Research grant / Funding (institution): Daiichi Sankyo; Research grant / Funding (institution): Dignitana; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): GSK; Research grant / Funding (institution), Travel / Accommodation / Expenses: Lilly; Research grant / Funding (institution): Macrogenics; Research grant / Funding (institution): Medivation; Research grant / Funding (institution): Merrimack; Research grant / Funding (institution), Travel / Accommodation / Expenses: Novartis; Research grant / Funding (institution), Travel / Accommodation / Expenses: OBI Pharma; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Pieris; Research grant / Funding (institution): PUMA; Research grant / Funding (institution): Roche. L.A. Albacker: Full / Part-time employment: Foundation Medicine Inc. G.M. Frampton: Full / Part-time employment: Foundation Medicine Inc. J. Chelliserry: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. P. Bycott: Research grant / Funding (self), Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. U. Conte: Shareholder / Stockholder / Stock options, Full / Part-time employment: Pfizer Inc. A.M. Wardley: Honoraria (self), Advisory / Consultancy: AstraZeneca; Honoraria (self), Advisory / Consultancy: Lilly; Honoraria (self), Advisory / Consultancy: Novartis; Honoraria (self), Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Roche. M.E. Robson: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy: McKesson; Research grant / Funding (institution): AbbVie; Research grant / Funding (institution): BioMarin; Research grant / Funding (institution): Medivation; Research grant / Funding (institution): Myriad Genetics; Research grant / Funding (institution): Tesaro. All other authors have declared no conflicts of interest.
Resources from the same session
4250 - Phase II study of avelumab in combination with cetuximab as a rechallenge strategy in pre-treated RAS wild type metastatic colorectal cancer patients: CAVE (cetuximab-avelumab) Colon.
Presenter: Erika Martinelli
Session: Poster Display session 2
Resources:
Abstract
5234 - The ORCHESTRA trial; A phase III trial of adding tumor debulking to systemic therapy versus systemic therapy alone in multi-organ metastatic colorectal cancer (mCRC).
Presenter: Lotte Bakkerus
Session: Poster Display session 2
Resources:
Abstract
5294 - EMERGE: Epigenetic Modulation of the Immune Response in Gastrointestinal cancers
Presenter: Elizabeth Cartwright
Session: Poster Display session 2
Resources:
Abstract
913 - Phase III, international, multicenter, randomized, open-label trial of adjuvant nab-paclitaxel plus gemcitabine (nab-P/G) vs gemcitabine (G) alone for surgically resected pancreatic adenocarcinoma (APACT): subgroup analyses
Presenter: Margaret Tempero
Session: Poster Display session 2
Resources:
Abstract
1668 - FOLFIRINOX in locally advanced (LA) and borderline resectable (BR) pancreatic adenocarcinoma : update of the AGEO cohort.
Presenter: Edouard Auclin
Session: Poster Display session 2
Resources:
Abstract
2559 - Impact of adjuvant treatment with nab-paclitaxel and gemcitabine (nab-P+GEM) vs gemcitabine alone (GEM) on health-related quality of life (QoL) in patients (pts) with surgically resected pancreatic adenocarcinoma (PA) in the Adjuvant Pancreatic Adenocarcinoma Clinical Trial (APACT)
Presenter: Hanno Riess
Session: Poster Display session 2
Resources:
Abstract
4897 - Early detection of pancreatic ductal adenocarcinoma using methylation signatures in circulating tumor DNA
Presenter: Xiao-ding Liu
Session: Poster Display session 2
Resources:
Abstract
1755 - Evaluation of minimal important difference (MID) for the European Organisation for Research and Treatment of Cancer (EORTC) Pancreatic Cancer Module (PAN26) in patients with surgically resected pancreatic adenocarcinoma
Presenter: Michele Reni
Session: Poster Display session 2
Resources:
Abstract
2876 - Multispectral analysis of lymphocyte complexity in periampullary adenocarcinoma
Presenter: Sebastian Lundgren
Session: Poster Display session 2
Resources:
Abstract
1902 - Phase II trial of preoperative modified FOLFIRINOX (mFOLFIRINOX) followed by postoperative gemcitabine (GEM) in patients (pts) with borderline resectable (BR) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC)
Presenter: Jae Ho Jeong
Session: Poster Display session 2
Resources:
Abstract