Abstract: TH-PO1035

Incidence, Predictors, and Therapeutic Consequences of Hypocalcemia in Patients Treated with Cinacalcet: The EVOLVE Trial

Session Information

Category: Mineral Disease

  • 1201 Mineral Disease: Ca/Mg/PO4

Authors

  • Floege, Jürgen, RWTH University of Aachen, Aachen, Germany
  • Tsirtsonis, Kate, Amgen ltd, Uxbridge, United Kingdom
  • Iles, Jan, Amgen Inc, Thousand Oaks, Colorado, United States
  • Drueke, Tilman B., CESP, Université Paris-Sud, France
  • Chertow, Glenn Matthew, Stanford University School of Medicine, Palo Alto, California, United States
  • Parfrey, Patrick S., Memorial University, St. John's, Newfoundland, Canada
Background

The calcimimetic cinacalcet is used to treat secondary hyperparathyroidism in patients receiving dialysis. Asymptomatic hypocalcemia is often observed following its initiation. Here we investigated the incidence, predictors and therapeutic consequences of hypocalcemia.

Methods

This was a post-hoc analysis of the randomized, double-blind, placebo-controlled EValuation Of Cinacalcet Hydrochloride Therapy to Lower CardioVascular Events (EVOLVE) trial. Hypocalcemia was classified as mild (total serum calcium 8.0 – 8.39 mg/dL), moderate (7.5 – 7.99 mg/dL) or severe (<7.5 mg/dL).

Results

At least one episode of hypocalcemia developed within 16 weeks after the first administered dose among 58.3% (1130/1938) patients randomized to cinacalcet versus 14.9% (286/1923) with placebo. Hypocalcemia in the cinacalcet group was severe in 18.4% of the patients versus 4.4% in the placebo group. Severe hypocalcemia following administration of cinacalcet was associated with geographic region (patients with Latin America and Russia had a higher risk relative to US), higher body mass index, higher baseline plasma PTH, lower corrected total serum calcium and higher serum alkaline phosphatase. Median cinacalcet dose immediately prior to the first hypocalcemia episode was 54-58 mg/day and similar in the three hypocalcemia categories. In the majority of patients, hypocalcemia resolved spontaneously within 14 days without modification of background therapy. Among patients who received an intervention, the most common was an increase in active vitamin D sterol dose.

Conclusion

The occurrence of hypocalcemia is a frequent effect following initiation of cinacalcet. The likelihood of developing hypocalcemia was related to the severity of secondary hyperparathyroidism. Hypocalcemia was generally asymptomatic and self-limited.

Funding

  • Commercial Support