ABSTRACT
Background: The value of increased HER2 gene copy number (GCN) in NSCLC is unclear. In this study we defined its frequency and characterized a cohort of patients harboring it. Methods: Patients with stage IIIB/IV NSCLC enrolled in the Gustave Roussy MSN study (NCT02105168) between Oct. 2009 and Feb. 2016 were screened by FISH (positivity defined as HER2 GCN to centromeres ratio ≥ 2) and tested for other molecular alterations. Descriptive analyses of clinical-pathological data were performed, progression-free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier method. Results: HER2 FISH tested positive in 22 of 250 screened patients (9%). Median age was 60 years (range 47-80), 68% (n=15) were male, 91% (n=20) were current or former tobacco smokers (median exposure 47 pack-year), 64% (n=14) had adenocarcinoma, 18% (n=4) squamous cell and 18% (n=4) large cell carcinoma. 91% (n=20) had an ECOG PS of 0 or 1. Stage IV with extra-thoracic involvement was the most common clinical presentation (64%, n=14). Overall, 95% of patients (n=21) had 1 or 2 metastatic sites at diagnosis (bone 32%, lung 27%, nodes 18%, liver 18%, brain 18%). In 9 patients (41%) 12 concurrent molecular alterations were detected: 5 KRAS mutation (3 G12C, 1 G12D, 1 G61H), 2 HER2 exon 20 insertion, 1 EGFR exon 19 deletion, 1 BRAF V600E mutation, 1 ALK rearrangement, 1 FGFR1 and 1 MET amplification. 18 patients received first-line platinum-based chemotherapy, with 33% (95% CI 16-56) objective response rate and 83% (95% CI 61-94) disease control rate. After a median follow-up of 28 months (95% CI 23-45), median PFS and OS were 5.9 (95% CI 3.4-11.0) and 15.3 (95% CI 10.3-NR) months, respectively. Median PFS was longer in patients with higher GCN. As further line of treatment, 5 patients received trastuzumab: 4 in combination with chemotherapy and 1 as monotherapy, with 1 stabilization of disease as best response. 3 patients received nivolumab (1 partial response and 1 stable disease) and 3 a targeted therapy (anti ALK, EGFR, BRAF). Conclusions: Increased HER2 GCN was found in 9% of patients with unresectable NSCLC, was not correlated to particular clinical characteristics, but frequently occurred with other molecular alterations. Its clinical actionability and the correlation with protein expression deserve further characterization. Clinical trial identification: NCT02105168. Legal entity responsible for the study: Gustave Roussy. Funding: Has not received any funding. Disclosure: M. Tagliamento: Other, Personal, Other, Travel grants: Roche, Bristol-Myers Squibb, AstraZeneca, Takeda, Eli Lilly;Other, Personal, Writing Engagements, Honoraria as medical writer: Novartis, Amgen. E. Auclin: Financial Interests, Personal, Advisory Board: Amgen, Sanofi. E. Rouleau: Financial Interests, Institutional, Advisory Board: AstraZeneca, Roche, Amgen, GSK;Financial Interests, Institutional, Invited Speaker: Clovis, BMS;Financial Interests, Institutional, Funding, Data base: AstraZeneca. A. Bayle: Non-Financial Interests, Institutional, Other, Principal/Sub-Investigator of Clinical Trials: AbbVie, Adaptimmune, Adlai Nortye USA Inc, Aduro Biotech, Agios Pharmaceuticals, Amgen, Argen-X Bvba, Astex Pharmaceuticals, AstraZeneca Ab, Aveo, Basilea Pharmaceutica International Ltd, Bayer Healthcare Ag, Bbb Technologies Bv, BeiGene, BicycleTx Ltd, Non-Financial Interests, Institutional, Research Grant: AstraZeneca, BMS, Boehringer Ingelheim, GSK, INCA, Janssen Cilag, Merck, Novartis, Pfizer, Roche, Sanofi;Financial Interests, Institutional, Other, drug supplied: AstraZeneca, Bayer, BMS, Boehringer Ingelheim, GSK, MedImmune, Merck, NH TherAGuiX, Pfizer, Roche. F. Barlesi: Financial Interests, Personal, Advisory Board: AstraZeneca, Bayer, Bristol Myers Squibb, Boehringer Ingelheim, Eli Lilly Oncology, F. Hoffmann–La Roche Ltd, Novartis, Merck, Mirati, MSD, Pierre Fabre, Pfizer, Sanofi-Aventis, Seattle Genetics, Takeda;Non-Financial Interests, Principal Investigator: AstraZeneca, BMS, Merck, Pierre Fabre, F. Hoffmann-La Roche Ltd. D. Planchard: Financial I terests, Personal, Advisory Board: AstraZeneca, BMS, Merck, Novartis, Pfizer, Roche, Samsung, Celgene, AbbVie, Daiichi Sankyo, Janssen;Financial Interests, Personal, Invited Speaker: AstraZeneca, Novartis, Pfizer, priME Oncology, Peer CME, Samsung, AbbVie, Janssen;Non-Financial Interests, Principal Investigator, Institutional financial interests: AstraZeneca, BMS, Merck, Novartis, Pfizer, Roche, Daiichi Sankyo, Sanofi-Aventis, Pierre Fabre;Non-Financial Interests, Principal Investigator: AbbVie, Sanofi, Janssen. B. Besse: Financial Interests, Institutional, Funding: 4D Pharma, AbbVie, Amgen, Aptitude Health, AstraZeneca, BeiGene, Blueprint Medicines, Boehringer Ingelheim, Celgene, Cergentis, Cristal Therapeutics, Daiichi Sankyo, Eli Lilly, GSK, Janssen, Onxeo, Ose Immunotherapeutics, Pfizer, Roche-Genentech, Sanofi, Takeda, Tolero Pharmaceuticals;Financial Interests, Institutional, Research Grant: Chugai Pharmaceutical, EISAI, Genzyme Corporation, Inivata, Ipsen, Turning Point Therapeutics. L. Mezquita: Financial Interests, Personal, Advisory Board: Takeda, AstraZeneca, Roche;Financial Interests, Personal, Invited Speaker: Roche, BMS, AstraZeneca, Takeda;Financial Interests, Personal, Research Grant, SEOM Beca Retorno 2019: BI;Financial Interests, Personal, Research Grant, ESMO TR Research Fellowship 2019: BMS;Financial Interests, Institutional, Research Grant, COVID research Grant: Amgen;Financial Interests, Institutional, Invited Speaker: Inivata, Stilla. All other authors have declared no conflicts of interest.