Abstract 2246
Background
Niraparib is a selective oral poly(ADP-ribose) polymerase 1/2 inhibitor (PARPi) approved as maintenance treatment of recurrent ovarian cancer. Previous studies revealed unique pharmacological properties of niraparib, including a large volume of distribution, suggesting higher tissue penetration of this drug. Preclinical studies have consistently demonstrated that niraparib tumor exposure is higher than plasma exposure, whereas another PARPi, olaparib, has demonstrated lower tumor exposure than plasma exposure in tumor xenograft models. In a clinical study, tumor concentrations of olaparib were on average 41% of plasma concentrations in patients with breast cancer (BC)1. Here we report for the first time the intra-tumoral concentration of niraparib in clinical samples.
Methods
Tumor biopsies and plasma samples were collected from patients enrolled in a pilot study (NCT03329937) evaluating the antitumor activity and safety of niraparib as neoadjuvant treatment for HER2-negative, BRCA-mutated localized BC. Patients (N = 9) received oral niraparib 200 mg once daily over two 28-day cycles; 2 patients in the analysis had dose reduction to 100 mg. Biopsies and plasma were obtained at the end of Cycle 2. Additional plasma samples were collected on Cycle 2/Day 1 at 0, 2, and 4 hours post dose to determine steady-state maximum concentration (Cmax). Niraparib concentrations in plasma and tumor samples for each patient were quantified using a qualified liquid chromatography–tandem mass spectrometry method.
Results
Niraparib concentrations in plasma from patients with BC (N = 5) were within the reference range previously reported for solid tumors (steady state Cmax 3160+/-2799 nM, Ctrough 1753+/-1707 nM). In the same cohort of BC patients, niraparib concentrations in tumors ranged from approximately 4–131-fold higher than those in corresponding plasma samples after 2 months of niraparib treatment. Data for all patients will be presented at the meeting.
Conclusions
These results provide the first clinical data of at least 4-fold higher intra-tumor concentration of niraparib compared with plasma concentration in patients with BC. Reference: Bundred N et al. Invest New Drugs 2013; 31: 949-58.
Clinical trial identification
NCT03329937.
Editorial acknowledgement
Legal entity responsible for the study
Tesaro: A Gsk Company.
Funding
Tesaro: A Gsk Company.
Disclosure
M. Shan: Shareholder / Stockholder / Stock options, Full / Part-time employment: Tesaro: A GSK Company. E. Hamilton: Travel / Accommodation / Expenses: Amgen; Travel / Accommodation / Expenses: Bayer; Travel / Accommodation / Expenses: BMS; Travel / Accommodation / Expenses: Genzyme; Travel / Accommodation / Expenses: Helsinn Therapeutics; Travel / Accommodation / Expenses: HERON; Travel / Accommodation / Expenses: Lexicon; Travel / Accommodation / Expenses: Medivation; Travel / Accommodation / Expenses: Merck; Travel / Accommodation / Expenses: Novartis; Travel / Accommodation / Expenses: Roche; Travel / Accommodation / Expenses: Sysmex; Travel / Accommodation / Expenses: Guardant Health; Travel / Accommodation / Expenses: Foundation Medicine. C. Santa-Maria: Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Medimmune. S. Isakoff: Advisory / Consultancy, Research grant / Funding (institution): Abbvie; Advisory / Consultancy: Genentech/Roche; Advisory / Consultancy: PharmaMar; Research grant / Funding (institution): AstraZeneca/MedImmune; Research grant / Funding (institution): Genentech; Research grant / Funding (institution): Merck; Research grant / Funding (institution): OncoPep; Research grant / Funding (institution), Travel / Accommodation / Expenses: PharmaMar. D.B. Page: Honoraria (self): Novartis; Advisory / Consultancy: Merck Sharp & Dohme; Advisory / Consultancy: Syndax; Advisory / Consultancy: Nektar; Research grant / Funding (self): NanoString Technologies; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: Bristol-Myers Squibb; Advisory / Consultancy: Puma Biotechnology; Speaker Bureau / Expert testimony: Genentech/Roche; Research grant / Funding (institution), Travel / Accommodation / Expenses: MedImmune; Research grant / Funding (institution): Merck; Speaker Bureau / Expert testimony: Philips Healthcare. P. Pan: Shareholder / Stockholder / Stock options, Full / Part-time employment: Tesaro: A GSK Company. K. Sun: Shareholder / Stockholder / Stock options, Full / Part-time employment: Tesaro: A GSK Company. J.R. Graham: Shareholder / Stockholder / Stock options, Full / Part-time employment: Tesaro: A GSK Company. H.S. Han: Research grant / Funding (institution): Tesaro, Inc.; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): BMS; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Prescient; Research grant / Funding (institution): Horizon; Research grant / Funding (institution): Karyopharm; Research grant / Funding (institution): Abbvie; Research grant / Funding (institution): TapImmune; Research grant / Funding (institution): Ipsen; Research grant / Funding (institution): Seattle Genetics; Research grant / Funding (institution): Department of Defense. All other authors have declared no conflicts of interest.
Resources from the same session
4331 - STING Agonist, ADU-S100, Yields Potent Antitumor Activity and Therapeutically Favorable Immune Profile in an Esophageal Adenocarcinoma Model
Presenter: Ali Zaidi
Session: Poster Display session 2
Resources:
Abstract
1770 - Increased assessment of HER2 in metastatic gastroesophageal cancer patients: a nationwide population-based cohort study
Presenter: Willemieke Dijksterhuis
Session: Poster Display session 2
Resources:
Abstract
3755 - A new docetaxel (DOC)-based triplet regimen does not improve the outcome of metastatic (M) or locally advanced (LA) gastric cancer (GC) as compared with an epirubicin (EPI) standard triplet regimen: a GISCAD trial.
Presenter: Roberto Labianca
Session: Poster Display session 2
Resources:
Abstract
2439 - The analysis of T cell subsets and clinical efficacy of immune checkpoint blockades in patients with advanced gastric cancer using multiplex immunohistochemistry
Presenter: Tae-yong Kim
Session: Poster Display session 2
Resources:
Abstract
2211 - First-line pembrolizumab (P), trastuzumab (T), capecitabine (C) and oxaliplatin (O) in HER2-positive metastatic esophagogastric adenocarcinoma.
Presenter: Yelena Janjigian
Session: Poster Display session 2
Resources:
Abstract
3046 - Monitoring patient-specific mutation in ctDNA and CTC for tumor response evaluation after neoadjuvant chemotherapy in locally advanced gastric cancer (NCT03425058)
Presenter: Tao Fu
Session: Poster Display session 2
Resources:
Abstract
4628 - Gastric cancer screening in BRCA 2 gene mutation carriers: should it be recommended?
Presenter: Inês Oliveira
Session: Poster Display session 2
Resources:
Abstract
2127 - Interim analysis of an observational/translational study for nivolumab treatment in advanced gastric cancer: JACCRO GC-08 (DELIVER trial)
Presenter: Yu Sunakawa
Session: Poster Display session 2
Resources:
Abstract
2264 - Prediction of S-1 adjuvant chemotherapy efficacy in Stage II/III gastric cancer treatment based on comprehensive gene expression analysis
Presenter: Masanori Terashima
Session: Poster Display session 2
Resources:
Abstract
2444 - Assessing the clinical utility of circulating tumour DNA through longitudinal liquid biopsy sampling in Oesophageal adenocarcinoma
Presenter: Emma Ococks
Session: Poster Display session 2
Resources:
Abstract