Long-term effectiveness of cinacalcet in non-dialysis patients with chronic kidney disease and seconday hyperparathyroidism

Abstract

Background: secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD). Cinacalcet use is controversial in non-dialysis patients. Methods: this retrospective observational study recruited patients receiving cinacalcet (off-label use) in 2010 and 2011. Patients were followed for three years from the beginning of treatment using an intention-to-treat approach. Results: forty-one patients were studied: 14 CKD stage 3 (34.1%), 21 CKD stage 4 (51.2%), and 6 CKD stage 5 (14.6%). Median baseline parathyroid hormone (PTH) was 396 (101-1,300) pg/mL. Upon cinacalcet treatment (22 ± 12 months), PTH levels decreased by ≥ 30% in 73.2% of patients (P < 0.001; 95% confidence interval [CI], 59-87%), with a mean time for response of 18.7 months (95% CI, 15.4-22.1). Sixteen patients were followed for 36 months and treated for 32 ± 9 months. Mean reduction in their PTH levels was 50.1% (P < 0.001; 95% CI, 33.8-66.4%) at 36 months, with 62.5% of patients (P < 0.001; 95% CI, 35.9-89.1%) presenting reductions of ≥ 30%. Serum calcium levels decreased from 9.95 ± 0.62 mg/dL to 9.21 ± 0.83 and 9.12 ± 0.78 mg/dL at 12 and 36 months, respectively (P < 0.001). Serum phosphorus levels increased from 3.59 ± 0.43 to 3.82 ± 0.84 at 12 months (P = 0.180), remaining so at 36 months (P = 0.324). At 12 and 36 months, 2 (12.5%) patients experienced hypocalcemia. Meanwhile, 1 (6.3%) and 4 (25.0%) patients reported hyperphosphatemia at 12 and 36 months, respectively. Conclusion: Cinacalcet remained effective for at least 36 months in non-dialysis patients with SHPT. Electrolytic disturbances were managed with concurrent use of vitamin D and its analogs or phosphate binders.