Multifunctional and potent roles of the 3-hydroxypropoxy group provide eldecalcitol's benefit in osteoporosis treatment.

Abstract

Eldecalcitol (1α,25-dihydroxy-2β-(3-hydroxypropoxy)vitamin D3, [developing code: ED-71]), a new osteoporosis treatment drug that was recently approved in Japan, is a best-in-class drug in the class of calcitriol (1α,25-dihydroxyvitamin D3) and its prodrug alfacalcidol (1α-hydroxyvitamin D3), which have been used to treat osteoporosis for 30 years. In a comparative Phase III clinical study with alfacalcidol in osteoporosis patients, eldecalcitol demonstrated superior efficacy in the endpoints of increment of bone mineral density and reduction of bone fracture with equivalent safety to alfacalcidol. Eldecalcitol was discovered by searching synthetic analogs of calcitriol and alfacalcidol, and its main structural characteristic is having the 3-hydroxypropoxy group at the 2β-position. This review discusses why introducing the group leads to excellent efficacy and safety in osteoporosis treatment and elucidates the functional roles of the 3-hydroxypropoxy group. Briefly, the functional roles of the group are, first, realizing the metabolism switching in which eldecalcitol shows resistance to CYP24A1 and is metabolized in the liver; second, increasing the affinity to the serum carrier protein and prolonging the half-life to 53h; and third, stabilizing the eldecalcitol-receptor complex. Taken together, these functional roles of the 3-hydroxypropoxy group are beneficial in osteoporosis treatment. This review attempts to give a detailed account of the mode of action of eldecalcitol by clarifying these multifunctional roles of the 3-hydroxypropoxy group from the medicinal chemist's perspective.

• Authors: Yoshiyuki Ono
• Journal: The Journal of steroid biochemistry and molecular biology (J Steroid Biochem Mol Biol) Vol. 139 Pg. 88-97 (Jan 2014) ISSN: 1879-1220 [Electronic] England
• PMID: 24139874 (Publication Type: Journal Article, Review)
• Copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemical References

• Bone Density Conservation Agents
• FGF23 protein, human
• Receptors, Calcitriol
• Vitamin D-Binding Protein
• Vitamin D
• Fibroblast Growth Factor-23
• eldecalcitol

Topics

• Animals
• Binding Sites
• Bone Density Conservation Agents (pharmacokinetics, pharmacology, therapeutic use)
• Clinical Trials as Topic
• Fibroblast Growth Factor-23
• Humans
• Models, Molecular
• Osteoporosis (drug therapy, metabolism)
• Protein Binding
• Receptors, Calcitriol (chemistry, metabolism)
• Structure-Activity Relationship
• Vitamin D (analogs & derivatives, pharmacokinetics, pharmacology, therapeutic use)
• Vitamin D-Binding Protein (chemistry, metabolism)