Cinacalcet, a calcimimetic, is safe and effective for Chinese hemodialysis (HD) patients with severe secondary hyperparathyroidism (SHPT), according to a new study.
In a double-blind phase 3 trial, investigators led by Nan Chen, MD, of Ruijin Hospital in Shanghai, China, studied 238 HD patients with SHPT from 12 centers in China. The researchers randomly assigned 121 patients to receive cinacalcet (up to 100 mg daily) and 117 to receive placebo. They kept the administration and dosage of vitamin D sterols, phosphate binders, and dialysate calcium concentration the same. The primary efficacy endpoint was the percentage of patients achieving a serum parathyroid hormone (PTH) level of 250 pg/mL or less.
At baseline, patients had high intact PTH (iPTH) levels: median 1,102 pg/mL in the cinacalcet group and 960.5 pg/mL for the placebo group). After 14 weeks of treatment, 25.4% of patients treated with cinacalcet and 3.5% of those receiving placebo attained PTH levels at or below 250 pg/mL, an efficacy rate of 21.9%, the researchers reported online in Hemodialysis International. Calcium and phosphorus levels and calcium-phosphorus product were lower in the cinacalcet group.
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The findings are consistent with a 2009 study by Pablo Urena, MD, and colleagues published in Nephrology Dialysis Transplantation showing that 28% of patients with a median baseline iPTH of 721 pg/mL reached the target with cinacalcet. The percentage of patients achieving the goal in the current study, however, is much lower that researchers have found in U.S. and Japanese studies. According to Dr Chen and colleagues, this is likely due to the selection of patients with higher levels of parathyroid hormone to start.
Eleven serious adverse events were reported overall, but none were linked with the medication. Hypocalcemia and reduced serum calcium occurred in more patients taking cinacalcet. The most frequent drug-related adverse event was QT interval prolongation. Gastrointestinal disorders, such as nausea and vomiting, were also reported by 5% or more of patients.
Overall, cinacalcet appears to be safe and effective for SHPT, even in patients with high baseline iPTH levels, Dr Chen and colleagues concluded, adding that the availability of the drug in China will assist in the treatment and management of SHPT patients.
The study was funded by Kyowa Hakko Kirin China Pharmaceutical Co., a manufacturer of cinacalcet.
