ORLANDO, Fla.—Cinacalcet appears to be a safe and effective agent in the long-term management of persistent post-renal transplant hyperparathyroidism. Researchers at the State University of New York-Stony Brook found that this therapy on a long-term basis produced no deleterious impact on renal function after a three-year follow-up.
Patrick Lynch, MD, and his colleagues evaluated the use of cinacalcet to optimize treatment of persistent hyperparathyroidism (HPT) over a 36-month period after successful kidney transplantation. In this study, 37 patients with persistent HPT three months following transplantation with stable graft function were given 30 mg daily of cinacalcet and titrated to a maximum of 120 mg a day.
Among these patients, 35 underwent induction therapy with alemtuzumab and methylprednisolone at the time of engraftment, followed by rapid steroid withdrawal. Maintenance immunotherapy consisted of standard suppression regimens with 33 of the 37 patients (89%) receiving a combination of calcineurin inhibitors and mycophenolate mofetil. Over the 36 months, investigators measured serial serum intact parathyroid hormone (iPTH), calcium, phosphorus, and alkaline phosphatase (AP) levels.
Serum iPTH decreased significantly from 230 pg/mL at the start of treatment to 128 pg/mL at 36 months, Dr. Lynch’s team reported here at the National Kidney Foundation’s 2010 Spring Clinical Meetings. Serum calcium decreased significantly from 10.26 to 9.58 mg/dL. Researchers observed a significant concomitant rise in serum phosphorus from 2.55 to 3.26 mg/dL. Serum alkaline phosphatase decreased significantly from 110 to 84.9 U/L.
Twenty-one patients remained on cinacalcet therapy for the duration of 36 months, with a mean dosage of 50 mg/day.
Factors contributing to the discontinuation of treatment included achieving appropriate iPTH level for the CKD stage, gastrointestinal side effects, and financial constraints. In addition, renal function remained stable, with no significant changes in serum creatinine or estimated glomerular filtration rate (eGFR). At baseline and 36 months, serum creatinine levels were 1.55 and 1.42 mg/dL, respectively. The eGFR was 53.3 mL/min/1.73 m2 at both time points.