Abstract
Inhibition of tissue-nonspecific alkaline phosphatase (TNAP) may prevent ectopic soft tissue calcification by increasing endogenous pyrophosphate (PPi). DS-1211 is a potent and selective novel small molecule TNAP inhibitor with well-characterized pharmacokinetics (PKs) in rodent and monkey. Herein, we report a comprehensive summary of studies establishing the pharmaceutical profile of DS-1211. In vitro studies characterized the mode of inhibition and inhibitory effects of DS-1211 on three human alkaline phosphatase (ALP) isozymes-TNAP, human intestinal ALP, human placental ALP-and on ALP activity across species in mouse, monkey, and human plasma. In vivo PK and pharmacodynamic (PD) effects of a single oral dose of DS-1211 in mice and monkeys were evaluated, including biomarker changes in PPi and pyridoxal 5'-phosphate (PLP). Oral bioavailability (BA) was determined through administration of DS-1211 at a 0.3-mg/kg dose in monkeys. In vitro experiments demonstrated DS-1211 inhibited ALP activity through an uncompetitive mode of action. DS-1211 exhibited TNAP selectivity and potent inhibition of TNAP across species. In vivo studies in mice and monkeys after single oral administration of DS-1211 showed linear PKs, with dose-dependent inhibition of ALP activity and increases in plasma PPi and PLP. Inhibitory effects of DS-1211 were consistent in both mouse and monkey. Mean absolute oral BA was 73.9%. Overall, in vitro and in vivo studies showed DS-1211 is a potent and selective TNAP inhibitor across species. Further in vivo pharmacology studies in ectopic calcification animal models and clinical investigations of DS-1211 in patient populations are warranted. © 2022 Daiichi Sankyo, Inc. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).