Abstract 543: Preclinical characteristic of HMPL-306, a CNS-penetrable dual inhibitor of mutant IDH1 and IDH2

作者：Na Yang, Jia Hu, Tingwen Li, Juntao Yu, Dongxia Shi, Min Cheng, Zeyu Zhong, Jian Wang, Yang Sai, Weiguo Qing, Guangxiu Dai, Yongxin Ren, Michael Shi, Weiguo Su · 发表于：Cancer Research · 年份：2023 · DOI：10.1158/1538-7445.am2023-543 · 被引用次数：4 · 研究领域：Biochemical and Molecular Research、Colorectal Cancer Treatments and Studies、Cancer Genomics and Diagnostics

Abstract Background: Mutations in isocitrate dehydrogenase (IDH) 1/2 are frequently identified in various cancers, such as AML, cholangiocarcinoma, chondrosarcoma and glioma. Mutant IDHs (mIDHs) cause accumulated 2-HG, leading to blockage of cell differentiation, thereby inducing malignant transformation. Rare cases were identified carrying co-existing mutations in IDH1 and IDH2. mIDH isoform switching, from mutant IDH1 to mutant IDH2 and vice versa, have been reported as a mechanism of acquired resistance to IDH inhibition in AML and cholangiocarcinoma. Thus, simultaneous inhibition on both mIDH1 and mIDH2 may be a promising strategy to overcome resistance and improve clinical efficacy. HMPL-306, a dual inhibitor of mIDH1/mIDH2, developed by HUTCHMED, is being evaluated in clinical trials. Methods: The inhibition of HMPL-306 on IDH enzymes, including mutant and wild type, was determined by fluorescence-based assay. The selectivity of HMPL-306 was evaluated in 322 kinases (SelectScreenTM) and 88 proteins (Cerep). For cellular activities of HMPL-306, 2-HG production and differentiation were detected in cells harboring mIDH. Human tumor xenograft models carrying IDH1 or 2 mutations were established for evaluating mIDH inhibition by detecting 2-HG in plasma and tumor, and anti-tumor efficacies. Results: HMPL-306 inhibited mutant IDH enzyme activities including IDH1R132H, IDH2R140Q and IDH2R172K, while showed weaker inhibition on IDH1/2 wild type enzymes. HMPL-306 had a superior ...