Abstract CT055: Efficacy of YK-029A, a novel EGFR TKI, in advanced NSCLC patients with acquired T790M mutation

Abstract In the multicenter, dose-escalation and dose-expansion phase 1 clinical trial (NCT05767866), we evaluated safety and tolerability of YK-029A in various EGFR mutated non-small-cell lung cancer (NSCLC). We have reported efficacy of YK-029A in untreated NSCLC with EGFR ex20ins mutation[1]. This time we report efficacy of YK-029A in patients with acquired EGFR T790M mutation after failure of first or second generation EGFR tyrosine kinase inhibitors (TKIs). Method: This dose-escalation and dose-expansion phase 1 trial recruited previously treated NSCLC patients with EGFR T790M mutation or patients with EGFR ex20ins or EGFR rare mutations. In dose-escalation phase, patients with EGFR T790M mutation were enrolled. YK-029A was given at doses of 50, 100, 150, 200 to 250 mg/day (3+3 design). In dose-expansion phase, patients with EGFR T790M, EGFR ex20ins, or EGFR rare mutations were enrolled. The primary objective was safety. Dose-limiting toxicity (DLT) and maximum tolerated dose (MTD) were explored. Efficacy of YK-029A in EGFR T790M mutated NSCLC was assessed by the investigators. Results: A total of 114 patients were recruited into the study. Safety profile of the first 108 patients was reported previously[1]. By the cut-off date on Sep 12, 2023, 38 patients harbored EGFR T790M mutation were included in efficacy analysis. All these patients were previously treated with first or second generation EGFR-TKIs. The objective response rate (ORR; RECIST 1.1) was 65.8% (95%CI: 48.6%-80.4%) and disease control rate (DCR) was 84.2% (95%CI: 68.7%-94.0%). With a median follow-up time of 8.2 months,the median progression free survival (PFS) was 11.0 months (95%CI: 7.75-NR). The median overall survival (OS) was not reached. Among the 8 patients with measurable brain metastases, intracranial ORR was 75% (95%CI: 35.6%-95.6%) . Conclusions: YK-029A has promising activity in previously treated NSCLC patients harboring EGFR T790M mutation. Reference[1] DUAN J, WU L, YANG K, et al. Safety, Tolerability, Pharmacokinetics, and Preliminary Efficacy of YK-029A in Treatment-Naive Patients With Advanced NSCLC Harboring EGFR Exon 20 Insertion Mutations: A Phase 1 Trial [J]. J Thorac Oncol, 2023. Citation Format: Rui Wan, Yi Fung Chau, Jun Zhao, Zhe Liu, Mingfang Zhao, Yanqiu Zhao, Xiumei Dai, Yueyin Pan, Zhihong Zhang, Yu Yao, Kunyu Yang, Lin Wu, Yanyan Xie, Bi Chen, Yixuan Yang, Yongqi Guo, Jie Wang, Jianchun Duan. Efficacy of YK-029A, a novel EGFR TKI, in advanced NSCLC patients with acquired T790M mutation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT055.