Using Cinacalcet to Treat the Hypophosphatemia of Early Kidney Transplant

Montefiore Medicine Academic Health System

Status: Terminated

Conditions: Hypophosphatemia; Renal Transplant

Treatments: Drug: Placebo; Drug: Cinacalcet

Study type: Interventional

Funder types: Other

Identifiers

NCT01011114

09-07-203

Details and patient eligibility

About

The purpose of the study is to determine whether cinacalcet, used in patients with secondary hyperparathyroidism to control excessive parathyroid hormone, can normalize low blood phosphorus that is commonly seen in patients who have had a kidney transplant.

Full description

Secondary hyperparathyroidism (SHPT), common in ESRD, persists following renal transplantation resulting in profound hypophosphatemia. This can lead to hemolysis, congestive heart failure, rhabdomyolysis. Phosphate repletion is difficult in view of the persistent SHPT: oral phosphate supplementation can lead to hypocalcemia, reduced 1,25-OH Vitamin D production, hypercalcemia and further hyperparathyroidism. In addition, phospho-soda has been associated with phosphate nephropathy and renal failure.

Cinacalcet HCl is a calcimimetic agent that has recently become a standard therapy in the treatment of SHPT in ESRD. It suppresses PTH secretion by acting as a modulator of the Calcium-sensing receptor on the PTH cell, causing the PTH cell to decrease production of parathyroid hormone. It is a very effective agent, producing significant reduction of PTH as well as improvement in calcium and phosphate metabolism in the dialysis patient. The drug is well-tolerated with minimal adverse effects. Cinacalcet has also been used to control hypercalcemia in renal transplant patients with persistent hyperparathyroidism. Short-term cinacalcet given for 2 to 4 weeks has normalized serum phosphorus and decreased urinary phosphate wasting in renal transplant recipients with stable graft function.

We hypothesize that Cinacalcet HCl will normalize the hypophosphatemia of early renal transplant by reducing the effects of PTH on the proximal renal tubular transport of phosphorus, thereby allowing phosphate reabsorption and decreasing urinary phosphate wasting.

Enrollment: 40 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• renal transplant within last 3 months
• serum phosphorus less than 2.0 mg/dl
• serum creatinine less than 2.0 mg/dl

Exclusion criteria

• sensitivity to cinacalcet
• use of amitryptiline, desipramine, itraconazole, ketoconazole
• pregnancy

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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40 participants in 2 patient groups, including a placebo group

Cincalcet

Active Comparator group

Description:

cinacalcet will be titrated as needed to achieve serum phosphorus of \> 2.5 mg/dl randomized, placebo-controlled trial comparing the effect of cinacalcet to placebo in controlling serum phosphorus. All subjects will receive oral phosphorus supplementation and Vitamin D as needed to maintain baseline Phosphorus at \~ 2.5 mg/l.

Treatment:

Drug: Cinacalcet

Control

Placebo Comparator group

Description:

subjects will receive placebo pill titrated as needed to achieve phosphorus \> 2.5 mg/dl. randomized, placebo-controlled trial comparing the effect of cinacalcet to placebo in controlling serum phosphorus. All subjects will receive oral phosphorus supplementation and Vitamin D as needed to maintain baseline Phosphorus at \~ 2.5 mEq/l.

Treatment:

Drug: Placebo