Cinacalcet hydrochloride maintains long-term normocalcemia in patients with primary hyperparathyroidism.
Calcimimetics increase the sensitivity of parathyroid calcium-sensing receptors to extracellular calcium, thereby reducing PTH secretion. This multicenter, randomized, double-blind, placebo-controlled study assessed the ability of the oral calcimimetic cinacalcet HCl to achieve long-term reductions in serum calcium and PTH concentrations in patients with primary hyperparathyroidism (HPT). Patients (n = 78) were randomized to cinacalcet or placebo. Cinacalcet was titrated from 30-50 mg twice daily during a 12-wk dose-titration phase. Efficacy was assessed during 12-wk maintenance and 28-wk follow-up phases. The primary endpoint was the achievement of normocalcemia [serum calcium </= 10.3 mg/dl (2.57 mmol/liter)] with at least 0.5 mg/dl (0.12-mmol/liter) reduction from baseline. Plasma PTH, serum and urine biochemistry, biochemical measures of bone turnover, bone mineral density, and safety were also assessed. Seventy-three percent of cinacalcet-treated patients vs. only 5% of placebo-treated patients achieved the primary endpoint (P < 0.001). Fasting predose plasma PTH decreased 7.6% in cinacalcet patients but increased 7.7% in placebo patients (P < 0.01). Bone mineral density was unchanged by cinacalcet, but bone resorption and formation markers increased (P < 0.05). Adverse events were mild and similar between treatment groups. Cinacalcet rapidly normalizes serum calcium and reduces PTH in patients with primary HPT, and these effects are maintained with long-term treatment. Cinacalcet may be an effective, nonsurgical approach for management of primary HPT.
Peacock
Munro
M
Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA. mpeacock@iupui.edu
Bilezikian
John P
JP
Klassen
Preston S
PS
Guo
Matthew D
MD
Turner
Stewart A
SA
Shoback
Dolores
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D002118:Calcium / Q000097:blood*; D000069449:Cinacalcet; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009281:Naphthalenes / Q000627:therapeutic use*; D010281:Parathyroid Hormone / Q000097:blood
D009281:Naphthalenes; D010281:Parathyroid Hormone; D002118:Calcium; D000069449:Cinacalcet