Efficacy of Crizotinib After Entrectinib Resistance Due to MET Polysomy in ROS1-Rearranged NSCLC: A Case Report

Resistance to ROS1 tyrosine kinase inhibitors is inevitable, but it has been unclear whether crizotinib might be effective after the development of entrectinib resistance. We here present a case of ROS1-rearranged NSCLC that responded to crizotinib after tumor progression due to MET polysomy during entrectinib treatment. This case suggests that crizotinib is an effective option for patients with MET polysomy, even after disease progression on entrectinib

High Incidence of C797S Mutation in Patients With Long Treatment History of EGFR Tyrosine Kinase Inhibitors Including Osimertinib

Introduction: Although treatment with osimertinib confers survival benefits in patients with lung cancer with the EGFR T790M mutation, the mechanism of acquired resistance to osimertinib remains poorly understood. We conducted a prospective observational study to identify the mechanism on the basis of repeated tissue biopsies. Methods: Patients with EGFR-mutated advanced lung cancer with a T790M mutation detected on a tissue biopsy underwent a rebiopsy after developing acquired resistance to osimertinib. Nucleic acids extracted from the biopsy samples were subjected to targeted resequencing (Oncomine Comprehensive Assay), and circulating cell-free DNA (ccfDNA) was analyzed by CAncer Personalized Profiling by deep Sequencing (AVENIO ctDNA Surveillance Kit). Results: Between November 2016 and March 2020, a total of 87 patients were screened. Among them, 44 developed acquired resistance. Of these, 19 samples from rebiopsies and 12 from preosimertinib biopsies were able to be analyzed by an Oncomine Comprehensive Assay. A ccfDNA analysis was performed in 16 patients. Regarding the mechanisms of acquired resistance, structural change in EGFR, namely, C797S, G796S, or L792V, was the most frequent alteration, being observed in 57.9% of the cases. MET gain was observed in 31.6% of the cases, and gains in cell cycle genes were observed in 26.3% of the cases. In addition, we identified GAS6 gain and an ATM mutation in a patient with small-cell transformation and a BRAF V600E mutation in a patient with oligoprogressive disease. Conclusions: A repeated tissue biopsy and a ccfDNA analysis were useful in analyzing the mechanisms underlying acquired resistance. A long treatment history of EGFR TKIs may result in a high percentage of EGFR structural change

Ramucirumab Plus Erlotinib Versus Placebo Plus Erlotinib in Patients With Untreated Metastatic EGFR-Mutated NSCLC: RELAY Japanese Subset

Introduction: The phase 3 RELAY global study (NCT02411448) revealed significant improvement in progression-free survival (PFS) with ramucirumab plus erlotinib (RAM + ERL) compared with placebo plus ERL (PL + ERL) in untreated EGFR-mutated metastatic NSCLC (hazard ratio [HR] = 0.59 [95% confidence interval (CI): 0.46–0.76, p < 0.0001]). This prespecified analysis evaluates efficacy, safety, and postprogression EGFR T790M rates of RELAY patients enrolled in Japan. Methods: Patients were randomized (1:1) to oral ERL (150 mg/d) plus intravenous RAM (10 mg/kg) or PL every 2 weeks. End points included PFS (primary), safety (secondary), and biomarker analyses (exploratory). Plasma samples collected at baseline and poststudy treatment discontinuation were evaluated for EGFR T790M mutations by next-generation sequencing. Results: The Japanese subset included 211 of 449 (47.0%) RELAY patients (RAM + ERL, n = 106; PL + ERL, n = 105). Median PFS was 19.4 versus 11.2 months for RAM + ERL versus PL + ERL treatment (HR = 0.610 [0.431–0.864]) in the Japanese intent-to-treat population, 16.6 versus 12.5 months (HR = 0.701 [0.424–1.159]) in the EGFR exon 19 deletion subgroup, and 19.4 versus 10.9 months (HR = 0.514 [0.317–0.835]) in the EGFR exon 21 L858R subgroup, respectively. Adverse events of grade 3 or above with RAM + ERL included hypertension (24.8%, all grade 3) and dermatitis acneiform (23.8%). Postprogression treatment-emergent T790M rates were similar between arms (RAM + ERL: 47%, 9 of 19 patients; PL + ERL: 50%, 20 of 40 patients). Conclusions: Clinically meaningful efficacy was observed with RAM + ERL versus PL + ERL in the RELAY Japanese subset, with no new safety concerns. Postprogression T790M rates were similar across treatment arms, indicating the addition of RAM did not affect the ERL-associated EGFR T790M rates at disease progression