Nucleotide pyrophosphatase/phosphodiesterases (NPPs) including NPP1 and NPP2/ ATX as important drug targets: A patent review (2015-2020)

Ectobucleotidases are a broad class of extracellular nucleotide and nucleoside hydrolyzing enzymes. Since they play a crucial role in mediating purinergic cell signalling, they are promising therapeutic targets for treatment of a range of disorders, including fibrosis, tumor metastasis, inflammation, multiple sclerosis, and autoimmune diseases. Hence selective inhibtors of ectonulceotidases are of great interest for therapeutic intervention.Many compounds have demonstrated promising inhibitory potential against ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs). The chemistry and clinical applications of NPP inhibitors patented between 2015 and 2020 are discussed in this review.In recent years, there has been a lot of effort towards finding effective and selective inhibitors of NPPs. Even though a number of inhibitors are known, only a few in vivo investigations have been published. In addition to IOA-289, which has passed Phase Ia clinical trials, potent NPP2/ATX inhibitor compounds such as BLD-0409, IPF and BBT-877 have been placed in phase I clinical studies. Some of the most promising NPP2/ATX inhibitors in recent years are closely related analogs of previously known inhibitors, such as PF-8380. Knowledge of the structure activity relationship of such promising inhibitors can potentially translate into the discovery of more potent and effective inhibitors of NPP.