Overview of the clinical efficacy and safety of eldecalcitol for the treatment of osteoporosis

Eldecalcitol (ELD) is a new oral analog of the active form of vitamin D with anti-resorptive properties. We conducted a meta-analysis to investigate the efficacy and safety of ELD in osteoporosis. Compared with alfacalcidol, ELD significantly lowered vertebral facture risk, increased bone mineral density, but also had a higher risk of hypercalciuria.

PURPOSE

This study aimed to investigate the efficacy and safety of eldecalcitol (ELD) in osteoporosis by examining fracture rates, bone mineral density (BMD), bone turnover markers, and adverse events as outcomes.

METHODS

PubMed, EMBASE, and Cochrane Library were searched up to July 20, 2020, to identify eligible randomized controlled trials. The odds ratio (OR) or weighted mean difference (WMD) with 95% confidence interval was calculated by the random-effects model.

RESULTS

ELD significantly increased lumbar BMD (WMD: 2.80; 95% CI: 1.60, 4.00; P < 0.001, 2 studies involved), total hip BMD (WMD: 2.11; 95% CI: 0.68, 3.55; P = 0.004, 2 studies involved), and femoral neck BMD (WMD: 1.78; 95% CI: 0.76, 2.79; P = 0.001, 1 study involved) compared with alfacalcidol. Moreover, ELD caused a significantly lower rate of vertebral fracture (OR: 0.52; 95% CI: 0.29-0.95; P = 0.034, 2 studies involved) than alfacalcidol, but did not lower the rate of non-vertebral facture (OR: 0.44; 95% CI: 0.06-3.05; P = 0.405, 2 studies involved) compared with alfacalcidol. ELD significantly reduced the percentage change in bone-specific alkaline phosphatase (WMD: - 15.40; 95% CI: - 20.30, - 10.60; P < 0.001, 1 study involved) and serum type I collagen C-telopeptide (WMD: - 38.50; 95% CI: - 50.00, - 27.10; P < 0.001, 1 study involved) as compared with alfacalcidol. ELD was also associated with higher risk of hypercalciuria compared with alfacalcidol (OR: 1.64; 95% CI: 1.22, 2.20; P = 0.001, 2 studies involved).

CONCLUSIONS

This systematic review indicated that ELD was superior than alfacalcidol for improving vertebral fracture risk and BMD. Further large-scale trials should be conducted to verify the long-term effects and safety of ELD in osteoporosis.

PROSPERO REGISTRATION NUMBER

CRD42020147518.

A Novel Vitamin D Receptor Agonist, VS-105, Improves Bone Mineral Density without Affecting Serum Calcium in a Postmenopausal Osteoporosis Rat Model

BACKGROUND AND OBJECTIVES

VS-105, a novel vitamin D receptor agonist with significantly less hypercalcemic side effects than calcitriol, is a useful tool to investigate whether or not a vitamin D receptor agonist at non-hypercalcemic doses could improve bone mineral density (BMD).

METHODS

VS-105 and calcitriol were evaluated in an ovariectomized (OVX) osteoporosis rat model and in calvariae bone organ culture.

RESULTS

Treatment of OVX rats by VS-105 (0.1, 0.2 or 0.5 μg/kg, intraperitoneal, 3×/week, for 90 days) significantly improved BMD in the L3 lumbar vertebra in a dose-dependent manner (sham vs. OVX/vehicle: 324 ± 14 vs. 279 ± 10 mg/cm²; VS-105 at 0.1, 0.2 and 0.5 μg/kg: 306 ± 9, 329 ± 12, and 327 ± 10 mg/cm², respectively) without affecting serum calcium (Ca). Calcitriol at 0.1 μg/kg significantly increased BMD but it also increased serum Ca. VS-105 and calcitriol at the test doses significantly suppressed serum parathyroid hormone and promoted tibia bone growth. With respect to biomarkers of bone remodeling, calcitriol and VS-105 both significantly elevated serum osteocalcin. In the calvariae bone organ culture, net Ca release was significantly less in VS-105-treated groups (vs. calcitriol).

CONCLUSIONS

VS-105 is efficacious in improving BMD in a dose range that does not affect serum Ca in OVX rats; the improvement in BMD by VS-105 is attributable to increased osteoblastic activity and reduced osteoclastic bone resorption.

How vitamin D works on bone

Vitamin D is important for the normal development and maintenance of bone. The elucidation of the vitamin D activation pathway and the cloning of the vitamin D receptor have advanced our understanding of the actions of vitamin D on bone. The preponderance of evidence indicates that 1,25(OH)₂D₃ enhances bone mineralization through its effects to promote calcium and phosphate absorption. Although 1,25(OH)₂D₃ stimulates bone resorption in vitro, treatment in vivo can prevent bone loss and fracture through several potential mechanisms. The development of vitamin D analogues has provided new therapeutic options for increasing bone mineral density and reducing fractures.