Cinacalcet Plus Low-Dose Vitamin D Improves SHPT Treatment

PHILADELPHIA— Cinacalcet plus low-dose vitamin D provides a more effective approach to treating secondary hyperparathyroidism (SHPT) in hemodialysis (HD) patients, according to findings presented at Kidney Week 2011 .

In a randomized, open-label trial, Pablo A. Ure?±a, MD, of Clinique du Landy in Saint-Ouen, France, and colleagues evaluated the efficacy of combined treatment with cinacalcet and low-dose vitamin D in 309 HD patients with parathyroid hormone (PTH) levels above 300 pg/mL. Investigators randomized subjects to receive either cinacalcet plus low-dose vitamin D (20 mcg IV paricalcitol or equivalent per dialysis session if prescribed) or flexible dosing of vitamin D (if prescribed) alone (Flex-D).

The mean dialysis vintage was 7.2 months. Fifty-four percent of subjects were not on vitamin D at study enrollment.

Study results showed that 63% of the cinacalcet arm achieved a 30% reduction in PTH at six months (the primary endpoint) compared with only 38% of the Flex-D group. Results favored the cinacalcet arm across all PTH strata . The magnitude of the reductions in PTH in the combination group did not differ according to prior vitamin D use at enrollment, according to the researchers. Additionally, a significantly greater proportion of cinacalcet plus low-dose vitamin D patients than the Flex-D group achieved a PTH level of 300 or below at six months (57% vs. 35%).

Patients new to dialysis have a high prevalence of SHPT and initial therapy typically includes vitamin D, calcium supplements, and phosphate binders, Dr. Ure?±a's group noted. Treatment with cinacalcet commonly is used later in the course of disease in patients whose SHPT is not adequately controlled with vitamin D.