P2.13-12 The deNovo T790M Mutation Recovered by ddPCR is Associated with a Poor Response to 1st and 2nd Generation EGFR-TKI in Lung Adenocarcinoma.

Abstract

clinical trials. Increased AXL expression is associated with innate immune suppression and the appearance of resistance to targeted therapies in models of NSCLC and pt samples. AXL inhibition via bemcentinib prevents the appearance of such resistance in vivo and has shown immunomodulatory effect in AML patients. Method: This study was designed to confirm the safety and tolerability of bemcentinib as a monotherapy and when administered in combination with erlotinib (arm A). Pts with activating EGFR mutation driven NSCLC who had progressed on an approved EGFR inhibitor (arm B) or were receiving erlotinib in the first line setting (arm C) were treated with bemcentinib at RP2D in combination with full dose erlotinib to evaluate the potential of bemcentinib to reverse or prevent resistance to EGFR targeted therapy, respectively. Plasma protein biomarker levels were measured using the DiscoveryMap v3.3 panel (Myriad RBM) at C1D1 and C2D1. Result: 2 out of 8 pts (25%) with stage IV disease who received bemcentinib monotherapy achieved SD for close to 1 year including evidence of tumour shrinkage of 19% in 1 pt. 1 pt who had progressed on previous erlotinib monotherapy (12.5%) achieved a PR receiving bemcentinib in combination with erlotinib and remains on treatment well beyond 2 years later (arm A). A further 3 pts had SD at 6 wks. 11 patients (4 female, median age 58; 38-67) were enrolled in arm B and had received a median of 2 (1 -4) previous lines of cytotoxic chemotherapy and a median of 2 previous EGFR inhibitors. 2 of these 11 pts (18%) including 1 pt who was refractory to erlotinib therapy at the onset of combination therapy remain on treatment more than 6 months into therapy at the time of writing with best responses of PR and SD, respectively. 1 further pt had SD at 6 weeks. The most common treatment-related AEs have been gastrointestinal and rash.There was no evidence of any impact of bemcentinib on erlotinib pharmacokinetics. Protein biomarkers predictive of pt benefit following bemcentinib treatment were identified. Conclusion: Bemcentinib can be safely administered in combination with erlotinib to pts with NSCLC and achieves additional benefit in a proportion of patients who do not have T790M and have progressed on EGFR inhibition or are maintained on erlotinib alone. Clinical trial information: NCT02424617.Background: Tumor heterogeneity causes different EGFR mutation abundances, and is believed to be responsible for varied progressionfree survival (PFS) in lung adenocarcinoma (ADC) patients receiving EGFR-TKI treatment. EGFR amplification and its common presence in EGFR mutant allele might be determined by the EGFR copy number variation. Examination of EGFR amplification status in EGFR mutant patients could predict the efficacy of EGFR-TKI treatment Method: 72 lung ADC patients, who harbored EGFR activating mutations and received erlotinib as first line treatment, were examined for EGFR amplification by FISH. We analyzed the relationship between the EGFR mutational status and copy number profile with clin...