Tomivosertib

Tomivosertib (eFT508) is a potent, highly selective, and orally active MNK1 and MNK2 inhibitor, with IC₅₀s of 1-2 nM against both isoforms. Tomivosertib (eFT508) treatment leads to a dose-dependent reduction in eIF4E phosphorylation at serine 209 (IC₅₀=2-16 nM) in tumor cell lines^[1]. Tomivosertib (eFT508) also dramatically downregulates PD-L1 protein abundance^[2]. IC50 & Target: IC50: 1-2 nM (MNK1), 1-2 nM (MNK2)^[1] In Vitro: Tomivosertib (eFT508) reduces eIF4E phosphorylation dose-dependently at serine 209 (IC₅₀=2-16 nM) in tumor cell lines. In a panel of appr 50 hematological cancers, Tomivosertib shows anti-proliferative activity against multiple DLBCL cell lines. Sensitivity to Tomivosertib in TMD8, OCI-Ly3 and HBL1 DLBCL cell lines is associated with dose-dependent decreases in production of pro-inflammatory cytokines including TNFα, IL-6, IL-10 and CXCL10. Further evaluation Tomivosertib mechanism of action demonstrates that decreased TNFα production correlates with a 2-fold decrease in TNFα mRNA half-life^[1]. In Vivo: Tomivosertib (eFT508) shows significant anti-tumor activity in the TMD8 and HBL-1 ABC-DLBCL models, both of which harbor activating MyD88 mutations. Besides, Tomivosertib combines effectively with components of R-CHOP and with novel targeted agents, including PCI-32765 and Venetoclax, in human lymphoma models^[1].