Abstract CT052: A highly selective, brain-penetrant and overcoming G2032R resistance ROS1 inhibitor JYP0322 in NSCLC patients with ROS1 fusion

Abstract Background: JYP0322 is a potent, brain-penetrant and highly selective ROS1 inhibitor, demonstrating over 100-fold selectivity for ROS1 compared to TRKA and sub-nanomolar potency against the ROS1 G2032R resistance mutation. JYP0322 is designed to simultaneously address the key clinical challenges including ROS1 resistance mutations, tumor brain metastases while avoiding the off-target neurotoxicity associated with TRK inhibition. Method: The Phase I study (NCT06128148) was designed to evaluate safety, pharmacokinetics (PK), and preliminary clinical efficacy in patients with locally advanced or metastatic ROS1+NSCLC, including both ROS1 TKI pre-treated patients as well as TKI naïve patients. Response was assessed by investigators according to RECIST V1.1. Results: As of December 10, 2024, dose escalation study was conducted across 7 dose levels: 50mg qd, 100mg qd, 200mg qd, 100mg bid, 150mg bid, 200mg bid, 150mg tid and dose expansion stage is ongoing at doses of 100mg bid, 150mg bid and 150mg tid. A total of 73 NSCLC patients were enrolled. No dose-limiting toxicities were observed. The most frequently reported treatment related adverse events (TRAE) were low grade including weight gains (32.9%), hyperglyceridemia (31.5%), hypercholesteremia (26%), and AST elevation (21.9%). Grade 3-5 TRAE occurred in 12.3% patients. Only low grade neurotoxicities (6.8%) occurred. Among 58 efficacy evaluable patients, objective response rates (ORRs) were 85.7% (12/14) for ROS1 TKI naive, 54.5% (12/22) for patients previously received ≥2L systemic therapy and ≥1 prior ROS1 TKIs including 19 patients pre-treated with 2 to 4 ROS1 TKIs (Table). In ROS1 G2032R mutant cancers, ORR was 71.4% (5/7) with 3 patients pre-treated with Lorlatinib. In patients with measurable brain metastasis at baseline, intracranial ORR was 33.3% (2/6) and intracranial DCR was 83.3%. JYP0322 showed significantly brain penetration ability with the brain to plasma ration 1.20. Enrollment in the dose expansion stage is ongoing. Conclusions: JYP0322 had a favorable safety profile with a low incidence of neurotoxicities. It showed highly promising anti-tumor effects in patients with ROS1+NSCLC including both TKI-naïve and TKI pre-treated patients, as well as those with TKI-heavily treated, brain metastases, or harboring ROS1 G2032R mutation. Citation Format: Hongyun Zhao, Yanqiu Zhao, Yuxiang Ma, Yan Zhang, Zhangzhou Huang, Ying Cheng, Zhengbo Song, Yongzhong Luo, Juan Li, Wei Wei, Yaling Qi, Binyan Xia, Yuexia Zeng, Jing Lv, Li Zhang. A highly selective, brain-penetrant and overcoming G2032R resistance ROS1 inhibitor JYP0322 in NSCLC patients with ROS1 fusion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_2):Abstract nr CT052.