Talabostat mesylate

Talabostat mesylate is an orally active, selective inhibitor of dipeptidyl peptidases IV (DPP4, IC50: 0.18 nM), including tumor-associated fibroblast activation protein. This agent may also stimulate the production of colony stimulating factors, such as granulocyte colony-stimulating factor (G-CSF), resulting in the stimulation of hematopoiesis. (In Vitro) :By cleaving N-terminal Xaa-Pro or Xaa-Ala residues, Talabostat mesylate (Val-boroPro mesylate) inhibits dipeptidyl peptidases, such as FAP, resulting in the stimulation of cytokine and chemokine production and specific T-cell immunity and T-cell dependent activity.Talabostat mesylate (Val-boroPro mesylate) competitively inhibits the dipeptidyl peptidase (DPP) activity of FAP and CD26/DPP-IV, and there is a high-affinity interaction with the catalytic site. (In Vivo) :Talabostat mesylate (Val-boroPro mesylate) can stimulate immune responses against tumors involving both the innate and adaptive branches of the immune system.In WEHI 164 fibrosarcoma and EL4 and A20/2J lymphoma models, Talabostat mesylate (Val-boroPro mesylate) causes regression and rejection of tumors. The antitumor effect appears to involve tumor-specific CTL and protective immunological memory.Talabostat mesylate (Val-boroPro mesylate) treatment of WEHI 164-inoculated mice increases mRNA expression of cytokines and chemokines known to promote T-cell priming and chemoattraction of T cells and innate effector cells.