SPL-707 is a potent, selective and orally available signal peptide peptidase-like 2a (SPPL2a) inhibitor with an IC50 of 80 nM.
SPL-707 shows 25-fold selectivity over SPP with an IC50 of 3.7 μM and some preference for SPPL2a over SPPL2b with a 3-fold selectivity, comparing IC50 values generated with comparable assay formats for the different proteases[1].
SPL-707 significantly inhibits processing of the SPPL2a substrate CD74/p8 fragment in rodents at doses ≤10 mg/kg b.i.d. po. Oral dosing of SPL-707 for 11 days at ≥10 mg/kg b.i.d. recapitulates the phenotype seen in Sppl2a knockout (ko) and ENU mutant mice (reduced number of specific B cells and myeloid dendritic cells)[1].
[1]. Velcicky J, et al. Discovery of the First Potent, Selective, and Orally Bioavailable Signal Peptide Peptidase-Like 2a (SPPL2a) Inhibitor Displaying Pronounced Immunomodulatory Effects In Vivo. J Med Chem. 2018 Feb 8;61(3):865-880.
















