Real-world assessment: effectiveness and safety of extended-release calcifediol and other vitamin D therapies for secondary hyperparathyroidism in CKD patients.

INTRODUCTION: Extended-release calcifediol (ERC), active vitamin D hormones and analogs (AVD) and nutritional vitamin D (NVD) are commonly used therapies for treating secondary hyperparathyroidism (SHPT) in adults with stage 3-4 chronic kidney disease (CKD) and vitamin D insufficiency (VDI). Their effectiveness for increasing serum total 25-hydroxyvitamin D (25D) and reducing elevated plasma parathyroid hormone (PTH), the latter of which is associated with increased morbidity and mortality, has varied across controlled clinical trials. This study aimed to assess real-world experience of ERC and other vitamin D therapies in reducing PTH and increasing 25D. METHODS: Medical records of 376 adult patients with stage 3-4 CKD and a history of SHPT and VDI from 15 United States (US) nephrology clinics were reviewed for up to 1 year pre- and post-ERC, NVD or AVD initiation. Key study variables included patient demographics, concomitant usage of medications and laboratory data. The mean age of the study population was 69.5 years, with gender and racial distributions representative of the US CKD population. Enrolled patients were grouped by treatment into three cohorts: ERC (n = 174), AVD (n = 55) and NVD (n = 147), and mean baseline levels were similar for serum 25D (18.8-23.5 ng/mL), calcium (Ca: 9.1-9.3 mg/dL), phosphorus (P: 3.7-3.8 mg/dL) and estimated glomerular filtration rate (eGFR: 30.3-35.7 mL/min/1.73m2). Mean baseline PTH was 181.4 pg/mL for the ERC cohort versus 156.9 for the AVD cohort and 134.8 pg/mL (p < 0.001) for the NVD cohort. Mean follow-up during treatment ranged from 20.0 to 28.8 weeks. RESULTS: Serum 25D rose in all cohorts (p < 0.001) during treatment. ERC yielded the highest increase (p < 0.001) of 23.7 ± 1.6 ng/mL versus 9.7 ± 1.5 and 5.5 ± 1.3 ng/mL for NVD and AVD, respectively. PTH declined with ERC treatment by 34.1 ± 6.6 pg/mL (p < 0.001) but remained unchanged in the other two cohorts. Serum Ca increased 0.2 ± 0.1 pg/mL (p < 0.001) with AVD but remained otherwise stable. Serum alkaline phosphatase remained unchanged. CONCLUSIONS: Real-world clinical effectiveness and safety varied across the therapies under investigation, but only ERC effectively raised mean 25D (to well above 30 ng/mL) and reduced mean PTH levels without causing hypercalcemia.

Real-World Assessment: Clinical Effectiveness and Safety of Extended-Release Calcifediol.

INTRODUCTION: The safety and efficacy of extended-release calcifediol (ERC) as a treatment for secondary hyperparathyroidism (SHPT) in adults with stage 3 or 4 chronic kidney disease (CKD) and vitamin D insufficiency (VDI) has been demonstrated in prospective randomized clinical trials (RCTs). ERC (Rayaldee®) was approved by the Food and Drug Administration in 2016 on the basis of these prospective RCTs. The current retrospective study assessed the postlaunch data available with respect to ERC's efficacy and safety in increasing serum 25-hydroxyvitamin D (25D) and reducing parathyroid hormone (PTH) in the indicated population. MATERIALS AND METHODS: Medical records of 174 patients who met study criteria from 15 geographically representative United States nephrology clinics were reviewed for 1 year before and after initiation of ERC treatment. Enrolled subjects had ages ≥18 years, stage 3 or 4 CKD, and a history of SHPT and VDI. Key study variables included patient demographics, medication usage, and laboratory results, including serial 25D and PTH determinations. RESULTS: The enrolled subjects had a mean age of 69.0 years, gender and racial distributions representative of the indicated population, and were balanced for CKD stage. Most (98%) received 30 mcg of ERC/day during the course of treatment (mean follow-up: 24 weeks). Baseline 25D and PTH levels averaged 20.3 ± 0.7 (standard error) ng/mL and 181 ± 7.4 pg/mL, respectively. ERC treatment raised 25D by 23.7 ± 1.6 ng/mL (p < 0.001) and decreased PTH by 34.1 ± 6.6 pg/mL (p < 0.001) with nominal changes of 0.1 mg/dL (p > 0.05) in serum calcium (Ca) and phosphorus (P) levels. DISCUSSION/CONCLUSION: Analysis of postlaunch data confirmed ERC's effectiveness in increasing serum 25D and reducing PTH levels without statistically significant or notable impact on serum Ca and P levels. A significant percentage of these subjects achieved 25D levels ≥30 mg/mL and PTH levels which decreased by at least 30% from baseline. Dose titration to 60 mcgs was rarely prescribed. Closer patient monitoring and appropriate dose titration may have led to a higher percentage of subjects achieving an increase in 25D levels to at least 50 ng/mL and a reduction in PTH levels of at least 30%.