Antitumor activity of ASP8273 300 mg in subjects with EGFR mutation-positive non-small cell lung cancer: Interim results from an ongoing phase 1 study.

Abstract

9050Background: ASP8273 is an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) that selectively and irreversibly inhibits EGFR mutations (eg, exon 19 deletions, L858R), including the secondary resistance mutation T790M. Prior analyses of an ongoing open-label study estimated the ASP8273 recommended Phase 2 dose (RP2D) as 300 mg orally QD. Described here are the preliminary antitumor effects of the RP2D in EGFR mutation-positive non-small cell lung cancer (NSCLC) previously treated with an EGFR TKI (most patients received ≥ 1 prior treatment) in 2 study populations: all subjects and subjects with T790M. Methods: Subjects ( ≥ 18 yr) were enrolled into a dose-escalation (25–500 mg), response-expansion (100–400 mg), RP2D (300 mg), or food effect (300 mg) cohort of an ongoing study (NCT02113813) conducted in the United States. Antitumor activity for all subjects was assessed based on RECIST 1.1. Response and progression-free survival (PFS) were determined for all subjects treated with ASP8...