Sensipar Shows Benefit in Dialysis Patients
By Kristina Fiore, Staff Writer, MedPage Today
Published: April 05, 2013
Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania
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Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
In this analysis of data from the randomized EVOLVE trial, the need for parathyroidectomy was reduced by the use of cinacalcet.
ORLANDO -- Taking cinacalcet (Sensipar) may lessen the need for parathyroidectomy among patients with hyperparathyroidism who are on dialysis, researchers reported
here.
In a post-hoc analysis of the EVOLVE trial, the time to first parathyroidectomy was significantly longer among patients on cinacalcet compared with placebo (HR 0.44, 95% CI 0.36 to 0.54, P<0.001), Ricardo Correa-Rotter, MD, of the National Institute of Medical Sciences & Nutrition in Mexico City, and colleagues reported at the National Kidney Foundation meeting here.
"The group on cinacalcet had half of the parathyroidectomy events as the group on placebo," he said. "It's expected because cinacalcet is effective in reducing parathyroid hormone, which has previously been demonstrated in EVOLVE and many other studies."
Cinacalcet "without doubt was protective" in the trial, Correa-Rotter added, and that it is "fairly clear" that the drug is "useful" for these patients.
Secondary hyperparathyroidism often progresses in patients on dialysis, despite medical therapy, and refractory cases often need surgery. In that setting it was speculated that cinacalcet, which acts to diminish serum calcium levels, could improve outcomes for this population.
But the results of the 3,883-patient EVOLVE trial -- which were reported simultaneously at Kidney Week and in the New England Journal of Medicine last November -- suggested otherwise. Researchers found that the drug didn't reduce the risk of death or major cardiovascular events in chronic kidney disease patients who have secondary hyperparathyroidism, compared with placebo.
The FDA also stopped all pediatric trials of the drug in February after the death of a 14-year-old patient in one of the trials.
In order to assess the impact of cinacalcet specifically on rates of parathyroidectomy, as well as risk factors for needing the surgery, Correa-Rotter and colleagues conducted this post-hoc analysis of EVOLVE data.
The study had also recorded parathyroidectomy rate, with an overall rate of 10.7% -- although the rate was far higher for patients on placebo than for those on cinacalcet (14% versus 7%), they reported.
In further analyses, Correa-Rotter and colleagues found that the time to first parathyroidectomy was significantly lower among those on cinacalcet (HR 0.44, 95% CI 0.36 to 0.54, P<0.001).
But Correa-Rotter was cautious in interpreting the clinical significance of the findings of this post-hoc analysis: "I wouldn't say the results of this post-hoc analysis can guide our decisions at all," he warned. "I don't think there's anything we can take from this study for clinical decisions."
The analysis also showed that certain characteristics were associated with risk of parathyroidectomy. Significant predictors of a lower risk of parathyroidectomy included older age (HR 0.98, 95% CI 0.97 to 0.99, P=0.002) and male sex (HR 0.66, 95% CI 0.52 to 0.85, P=0.001).
Parathyroidectomy was also significantly associated with geographic region, with higher risk for the procedure in Latin America (HR 2.59, 95% CI 1.69 to 3.98, P<0.001) and Russia (HR 3.74, 95% CI 2.18 to 6.41, P<0.001), they found.
Correa-Rotter explained that these findings are probably due to the fact that patients enrolled in the trial from these countries were younger than those in other countries.
"The patients are younger in these regions," he said, "because the population on dialysis is younger in those parts of the world."
The EVOLVE trial was supported by Amgen.
Correa-Rotter reported no conflicts of interest.
Primary source: National Kidney Foundation
Source reference:
Parfrey P, et al "Disease progression and surgical parathyroidectomy in the EVOLVE trial" NKF 2013; Abstract 72.
http://www.medpagetoday.com/MeetingCoverage/NKF/38267
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