Chemical. CAS 150080-09-4. Formula C9H19BN2O3 . CH4O3S. MW 310.2. Talabostat is an orally bioavailable non-selective inhibitor of dipeptidyl-peptidases DPPs, including DPP-4, DPP-7/QPP, DPP-8, DPP-9, fibroblast activation protein FAP and prolyl endopeptidase PREP PEP IC50s = >4, 310, 4, 11, 560 and 390 nM, respectively. Talabostat induces powerful anti-tumor immune responses in cancer models. Talabostat is a NLRP1 and caspase recruitment domain family member 8 CARD8 inflammasome activator. Talabostat triggers an immunostimulatory form of programmed cell death known as pyroptosis selectively in monocytes and macrophages. DPP8/9 inhibition by Talabostat activates the inflammasome sensor protein Nlrp1b, which in turn activates pro-caspase-1 to mediate pyroptosis, suggesting that DPP8/9 serve as an intracellular checkpoint to restrain Nlrp1b and the innate immune system.