Abstract LB388: Super potent and efficacious ALK/ROS1/TRK inhibitor that overcomes multiple drug-resistant mutations

Abstract Abnormal activation of ALK, ROS1 and TRK is implicated in tumorigenesis, progression, invasion, and metastasis of malignancies through various mechanisms. The first generation TRK inhibitors including larotrectinib and entrectinib have limited applications due to acquired resistance in clinical settings. Multiple on-target mutations occur at the solvent-front, gatekeeper, and xDFG motif inside the ATP binding pocket of the TRK kinase domain. While some candidates under current clinical development aim to address the solvent-front mutation, they are ineffective against the xDFG mutations (e. g. NTRK1. G667X). There is strong unmet medical needs for next generation TRK inhibitors that can address resistance mutations. We employ the synergistic advantages of domain expertise and modern technology to accelerate early stage drug discovery. On our deep learning (DL) centric AI platform, extensive scientific computing supports large scale virtual screening, generative design, drug property prediction and multi-objective lead optimization. Only the optimized candidate compounds are passed along for synthesis and testing to save time and cost. In Ba/F3-TPM3 cellular assays, LB-2159 showed superior potencies that are hundreds to thousands of fold higher than larotrectinib and/or entrectinib, with IC50 values of 0. 02 nM for NTRK1. WT, 0. 3 nM for NTRK1. G595R and 0. 88 nM for NTRK1. G667C. Similar cellular potencies were demonstrated for ALK and ROS1. In xenograft models LB-2159 at 10 mg/kg bid resulted in complete tumor regression in Ba/F3-TPM3-NTRK1-WT tumors, 96% TGI in Ba/F3-TPM3-NTRK1-G595R tumors, 84% TGI and 100% survival in mice bearing Ba/F3-TPM3-NTRK1-G667C tumors. The pharmacokinetic profiles of LB-2159 are overall favorable, demonstrating extended stability and half life. In vitro safety screens yielded clean profiles without any DDI signal or hERG liability. Preclinical safety evaluations exhibited good tolerance in rats. In multiple dose escalation studies LB-2159 was well tolerated at 50 mg/kg/day and beyond. Empowered by our proprietary AI platform, we have discovered the novel ALK/ROS1/TRK inhibitors that overcome clinically known resistance mutations. Our drug candidate exhibited good tolerance in animals in preclinical safety evaluations. In xenograft models that are resistant to current treatments the compound demonstrates strong tumor suppression efficacy. LB-2159 is advancing through IND enabling studies, and its preclinical profiles support the potential for best-in-class treatment for NTRK fusion-positive solid tumors. Citation Format: Li Xing, Jingbing Wang, Wei Zhu. Super potent and efficacious ALK/ROS1/TRK inhibitor that overcomes multiple drug-resistant mutations 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 (7Suppl): Abstract nr LB388.