MO29-6 Safety and tolerability of lazertinib and in combination with amivantamab in advanced EGFR-mutated Japanese NSCLC

Abstract

Background:The phase 3 RELAY study (NCT02411448) showed a superior progression-free survival (PFS) time for ramucirumab (RAM)+erlotinib (ERL) vs placebo+ERL in 449 untreated patients (pts) with EGFR-mutated metastatic NSCLC (median PFS: 19.4 vs 12.4 months [mo]; stratified hazard ratio: 0.59, 95% CI: 0.46-0.76, p <0.0001; 1year [yr] PFS rate: 71.9% vs 50.7%). RELAY+ (an additional cohort of RELAY) is an exploratory study in East Asian pts evaluating RAM+gefitinib (GEF) followed by RAM+osimertinib (OSI) in T790M+ pts.Methods: Previously untreated metastatic NSCLC pts with an EGFR Ex19del or Ex21.L858R mutation and no CNS metastases received RAM (10mg/kg Q2W)+GEF (250mg/day) until disease progression or unacceptable toxicity. Pts with post-progression EGFR T790M mutation received RAM+OSI until second PFS event. Efficacy, safety and biomarkers were evaluated.Results: 82 pts were enrolled (Japan:68, Taiwan:8, Korea:6); 65.9% female, 65.9% never-smokers, 43.9% had Ex19del. At the time of ASCO2020 and with median followup of 13.8 mo (min-max: 2.6-20.2), the overall 1-yr PFS rate (95% CI) was 65.0% (52.4-75.1), 67.2% (48.6-80.3) in pts with Ex19del (n¼36), and 63.4% (45.0-77.1) in pts with Ex21.L858R (n¼46). The objective response rate(ORR) was 70.7% (95% CI: 59.6-80.3), disease control rate(DCR) was 98.8% (95% CI: 93.4-100.0), and duration of response was immature with 56.9% censoring rate where the median was 13.6 mo (95% CI: 11.1-18.2). Post-progression T790M was observed in 7 of 9 pts in whom an EGFR activating mutation was detected by NGS. Grade 3 treatment-emergent adverse events reported in >5% of pts were ALT increased (23.2%), hypertension (22.0%), and AST increased (12.2%). Conclusions:In RELAY+, RAM+GEF showed a 1-yr PFS rate of 65.0%; which was consistent with that of RAM+ERL (71.9%). ORR/DCR were also comparable with RAM+ERL. The safety profile was consistent with that of each regimen. We will present updated outcomes with an additional 12 mo of follow up.