Abstract 3022
Background
MET amplification (amp) is rare in untreated metastatic colorectal cancer (mCRC), but cell-free DNA (cfDNA) analysis identifies it in ∼20% with anti-EGFR monoclonal antibody (mAb)-refractory disease. CfDNA analysis reveals both focal gene amp and gene copy number gain due to chromosomal aneuploidy (non-focal MET amp). We analyzed cfDNA from Japanese (JPN) and United States (US) patients (pts) with anti-EGFR mAb-refractory mCRC to investigate the prevalence of focal and non-focal MET amp.
Methods
We studied MET amp in pts with mCRC in the Nationwide Cancer Genome Screening Project in JPN (GOZILA; UMIN000029315; JPN cohort) and in a phase I/II trial of cabozantinib (C) +/- panitumumab (P) in pts with RAS wild-type mCRC (NCT02008383; US cohort). MET amp was detected with the Guardant360 assay. Focal MET amp was defined as either the only amp on chromosome (chr) 7q or MET copy number ³4. Non-focal MET amp was defined as co-amp with ³1 other genes (CDK6 or BRAF) located on chr 7q and MET copy number <4.
Results
244 JPN cohort pts were analyzed from 2/2018-12/2018, and 81 pts in the US cohort, from 8/2014-2/2018. In pts with prior anti-EGFR mAb (JPN: n = 184; US: n = 70), focal and non-focal MET amp were detected in 8 (4.3%) and 30 (16.3%) pts in the JPN cohort, and in 9 (12.9%) and 4 (5.7%) US pts. Without prior anti-EGFR mAb (JPN: n = 60; US: n = 11), focal and non-focal MET amp were detected in 1 (1.7%) and 4 (6.7%) pts in the JPN cohort, and 0 (0%) and 1 (9.1%) US pts. The focal MET amp rate combined was 6.7% (17/254) with prior anti-EGFR mAb. In the US cohort, 4/6 pts with focal MET amp treated with C or C+P had a reduction in RECIST lesions as best response, with one PR, while 2 pts with non-focal MET amp had tumor growth as best response.
Conclusions
The prevalence of focal MET amp detected by cfDNA analysis in mCRC pts was similar in the JPN and US cohorts. Given preliminary efficacy results from the US trial, focal MET amp may be a [A1] predictor of benefit from a MET inhibitor. A clinical trial evaluating a MET inhibitor in mCRC pts with focal MET amp is underway.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
A. Kawazoe: Honoraria (self), Research grant / Funding (institution): Ono Oharmaceutical; Honoraria (self), Research grant / Funding (institution): Taiho Pharmaceutical; Research grant / Funding (institution): Dainippon Sumitomo Pharma; Research grant / Funding (institution): Takeda Pharmaceutical; Research grant / Funding (institution): Astellas Pharmaceutical; Research grant / Funding (institution): MSD. Y. Nakamura: Research grant / Funding (institution): Ono Pharmaceutical; Research grant / Funding (institution): Taiho Pharmaceutical. J.I. Odegaard: Full / Part-time employment: Guardant Health. M.I. Lefterova: Full / Part-time employment: Guardant Health. R. Lanman: Full / Part-time employment: Guardant Health. T. Yoshino: Research grant / Funding (institution): Novartis Pharma K.K.; Research grant / Funding (institution): MSD.K.K.; Research grant / Funding (institution): Sumitomo Dainippon Pharma Co., Ltd.; Research grant / Funding (institution): CHUGAI PHARMACEUTICAL CO., LTD.; Research grant / Funding (institution): Sanofi K.K.; Research grant / Funding (institution): DAIICHI SANKYO COMPANY, LIMITED; Research grant / Funding (institution): PAREXEL International Inc.; Research grant / Funding (institution): ONO PHARMACEUTICAL CO., LTD.. J.H. Strickler: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Amgen; Honoraria (self), Advisory / Consultancy: Bayer; Honoraria (self): Chugai; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Seattle Genetics; Advisory / Consultancy, Research grant / Funding (institution): Genentech/Roche; Advisory / Consultancy: AstraZeneca; Advisory / Consultancy, Leadership role, Research grant / Funding (institution): OncoMed; Advisory / Consultancy: Celgene; Advisory / Consultancy: Proteus Digital Health; Advisory / Consultancy: Chengdu Kanghong Biotechnology Co., Ltd; Research grant / Funding (institution): Exelixis; Research grant / Funding (institution): Sanofi; Research grant / Funding (institution): Nektar; Research grant / Funding (institution): Abbvie; Research grant / Funding (institution): Gilead Sciences; Research grant / Funding (institution): Macrogenics; Research grant / Funding (institution): Leap Therapeutics; Research grant / Funding (institution): MedImmune. All other authors have declared no conflicts of interest.
Resources from the same session
2655 - The K-BASKET trial: A prospective phase II biomarker-driven multiple basket trial in Korean solid cancer patients.
Presenter: Seul Kim
Session: Poster Display session 3
Resources:
Abstract
5938 - Cambridge Liquid biopsy “CALIBRATION” study: Can changes in circulating tumour DNA (ctDNA) predict durable tumour responses in patients with advanced oesophageal cancer receiving MEDI4736?
Presenter: Constanza Linossi
Session: Poster Display session 3
Resources:
Abstract
3799 - Validation of a tumour mutational burden workflow on routine histological samples of colorectal cancer and assessment of a cohort with synchronous hepatic metastases
Presenter: Andrea Mafficini
Session: Poster Display session 3
Resources:
Abstract
4647 - Microsatellite Instability Testing and Lynch Syndrome Screening For Colorectal Cancer Patients Through Tumor Sequencing
Presenter: Li Liu
Session: Poster Display session 3
Resources:
Abstract
3231 - "Liquid Withdarw" technique in CT-guided cutting needle lung biopsy: decreased incidence of complications and increased tissue amount for lung cancer molecular testing.
Presenter: Xue Wang
Session: Poster Display session 3
Resources:
Abstract
3282 - WGS Implementation in standard cancer Diagnostics for Every cancer patient (WIDE)
Presenter: Paul Roepman
Session: Poster Display session 3
Resources:
Abstract
5905 - Known and unknown gene fusion detection capabilities of solid tumor laboratories conducting next generation sequencing in 6 countries
Presenter: Steph Finucane
Session: Poster Display session 3
Resources:
Abstract
4238 - Clinical and Analytical Accuracy of a 523 Gene Panel Next-Generation Sequencing (NGS) Assay on Formalin-Fixed Paraffin-Embedded (FFPE) Solid Tumor Samples
Presenter: Ina Deras
Session: Poster Display session 3
Resources:
Abstract
2493 - Methylation analysis of MLH1 using droplet digital PCR and methylation sensitive restriction enzyme.
Presenter: Celine De Rop
Session: Poster Display session 3
Resources:
Abstract
2963 - Analytical performance of the Resolution-HRD plasma assay used to identify mCRPC patients with biallelic disruption of DNA repair genes for treatment with niraparib
Presenter: Ira Pekker
Session: Poster Display session 3
Resources:
Abstract