Abstract 406: Targeting NSD2 aberrations in hematological malignancies with a potent and selective NSD2 PROTAC degrader

Abstract Nuclear receptor-binding SET domain-containing 2 (NSD2) is a methyltransferase that predominantly catalyzes the dimethylation of lysine 36 on histone 3 (H3K36me2). It has been implicated as an oncogene, with a hotspot gain-of-function mutation frequently identified in B-cell acute lymphoblastic leukemia (B-ALL) and chromosomal translocations involving NSD2 reported in approximately 20% of multiple myeloma cases. Despite its clinical significance, existing NSD2 inhibitors suffer from low activity or inferior selectivity, and none can simultaneously remove the methyltransferase activity and chromatin binding function of NSD2. To address these limitations, we developed LLC0424, a novel NSD2 degrader engineered using proteolysis-targeting chimera (PROTAC) technology based on a PWWP1 domain binder. LLC0424 demonstrated potent degradation of NSD2 protein in acute lymphoblastic leukemia (ALL) RPMI-8402 cells, with a DC50 value of 20 nM and a Dmax value of 96%. TMT quantitative proteomics confirmed LLC0424’s high selectivity for NSD2, underscoring its specificity. Intravenous or intraperitoneal administration of LLC0424 achieved robust NSD2 degradation in vivo, validating its systemic effectiveness. In B-ALL cells harboring the NSD2 point mutation, LLC0424 treatment led to sustained downregulation of H3K36me2, a critical epigenetic mark associated with NSD2 activity. Additionally, LLC0424 exhibited cytotoxicity in ALL cell lines with NSD2 mutations, inhibiting cell growth and reducing colony formation capacity. Overall, these findings highlight the therapeutic potential of NSD2 degradation as a novel strategy to target cancers driven by NSD2 aberrations. Citation Format: Yihan Liu, Abhijit Parolia, Lianchao Liu, Tongchen He, Yuanyuan Qiao, Sanjana Eyunni, Jie Luo, Zhen Wang, Arul Chinnaiyan, Ke Ding. Targeting NSD2 aberrations in hematological malignancies with a potent and selective NSD2 PROTAC degrader [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 406.