Effectiveness of evocalcet for hypercalcemia in patients with primary hyperparathyroidism

Patients with primary hyperparathyroidism (PHPT) ineligible for surgery require medical management for hypercalcemia and osteoporosis. The aim of this retrospective study was to determine the long-term effects of evocalcet on serum corrected calcium (cCa) levels and bone mineral density (BMD) in PHPT. The study included 26 patients with PHPT and hypercalcemia treated with evocalcet (7 switched from cinacalcet) for at least 24 months. Their mean age was 75.5 years. At baseline, cCa, phosphorus, and median intact parathyroid hormone levels were 10.76 mg/dL, 2.91 mg/dL, and 99.0 pg/mL, respectively. Osteoporosis was observed in 18 (69%), and 16 (62%) patients were on treatment for osteoporosis. Twenty-four months of evocalcet treatment significantly decreased cCa level to 9.77 mg/dL (mean change: -0.98 ± 0.91 mg/dL). Patients who switched from cinacalcet had a smaller reduction in cCa levels (-0.31 ± 0.72 mg/dL) than did those who were evocalcet-naïve (-1.23 ± 0.87 mg/dL, p = 0.019). By 24 months, 84.6% of patients had achieved a cCa level ≤10.3 mg/dL. Multivariate analysis identified baseline calcium levels as determinants of calcium level changes at 24 months. For patients not receiving osteoporosis treatment, lumbar spine BMD remained largely unchanged, whereas femoral neck BMD showed a decreasing trend. No other serious side effects requiring dose-lowering or withdrawal were noted. Evocalcet maintained its calcium-lowering effect for over 24 months in patients with PHPT, suggesting its potential as a medical treatment for surgery-ineligible patients. Careful monitoring of BMD is necessary during long-term evocalcet treatment to prevent worsening of osteoporosis.