Extended release calcifediol and paricalcitol in the treatment of secondary hyperparathyroidism: a network meta-analysis of indirect comparison

Introduction: Secondary hyperparathyroidism (SHPT) is a common and major complication of chronic kidney disease (CKD) among patients on dialysis and in patients with CKD stage G3 to G5. SHPT in CKD is caused by disturbances in metabolic parameters. Paricalcitol (PCT), other active vitamin D analogous (doxercalciferol and alfacalcidol), and active vitamin D (calcitriol) have been commonly used to treat SHPT in non-dialysis CKD (ND-CKD) for several years. However, recent studies indicate that these therapies adversely increase serum calcium, phosphate, and fibroblast growth factor 23 (FGF-23) levels. Extended release calcifediol (ERC) has been developed as an alternative treatment for SHPT in ND-CKD. The present meta-analysis compares the effect of ERC against PCT in the control of PTH and calcium levels. Methods: A systematic literature review was conducted, according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines to identify studies for inclusion in the Network Meta-Analysis (NMA). Results: 18 publications were eligible for inclusion in the network meta-analysis and 9 articles were included in the final NMA. The estimated PTH reduction from PCT (-59.5 pg/ml) was larger than the PTH reduction from ERC (-45.3 pg/ml), but the difference in treatment effects did not show statistical significance. Treatment with PCT caused statistically significant increases in calcium vs. placebo (increase: 0.31 mg/dl), while the marginal increase in calcium from treatment with ERC (increase: 0.10 mg/dl) did not reach statistical significance. Conclusions: The evidence suggests that both PCT and ERC are effective in reducing levels of PTH, whereas calcium levels tended to increase from treatment with PCT. Therefore, ERC may be an equally effective, but more tolerable treatment alternative to PCT.