1.1 Secondary Hyperparathyroidism

Sensipar is indicated for the treatment of secondary hyperparathyroidism (HPT) in patients with chronic kidney disease (CKD) on dialysis [see Clinical Studies (14.1)].

1.2 Parathyroid Carcinoma

Sensipar is indicated for the treatment of hypercalcemia in patients with Parathyroid Carcinoma [see Clinical Studies (14.2)].

1.3 Primary Hyperparathyroidism

Sensipar is indicated for the treatment of severe hypercalcemia in patients with primary HPT who are unable to undergo parathyroidectomy [see Clinical Studies (14.3)].

2.1 Secondary Hyperparathyroidism in Patients with Chronic Kidney Disease on Dialysis

The recommended starting oral dose of Sensipar is 30 mg once daily. Serum calcium and serum phosphorus should be measured within 1 week and intact parathyroid hormone (iPTH) should be measured 1 to 4 weeks after initiation or dose adjustment of Sensipar. Sensipar should be titrated no more frequently than every 2 to 4 weeks through sequential doses of 30, 60, 90, 120, and 180 mg once daily to target iPTH levels of 150 to 300 pg/mL. Serum iPTH levels should be assessed no earlier than 12 hours after dosing with Sensipar.

Sensipar can be used alone or in combination with vitamin D sterols and/or phosphate binders.

During dose titration, serum calcium levels should be monitored frequently and if levels decrease below the normal range, appropriate steps should be taken to increase serum calcium levels, such as by providing supplemental calcium, initiating or increasing the dose of calcium-based phosphate binder, initiating or increasing the dose of vitamin D sterols, or temporarily withholding treatment with Sensipar [see Warnings and Precautions (5.1,5.6)].

2.2 Parathyroid Carcinoma and Primary Hyperparathyroidism

The recommended starting oral dose of Sensipar is 30 mg twice daily.

The dose of Sensipar should be titrated every 2 to 4 weeks through sequential doses of 30 mg twice daily, 60 mg twice daily, and 90 mg twice daily, and 90 mg 3 or 4 times daily as necessary to normalize serum calcium levels [see Warnings and Precautions (5.6)].

5.1 Hypocalcemia

Sensipar lowers serum calcium and, therefore, patients should be carefully monitored for the occurrence of hypocalcemia. Potential manifestations of hypocalcemia include paresthesias, myalgias, muscle cramping, tetany, and convulsions.

Serum calcium should be measured within 1 week after initiation or dose adjustment of Sensipar. Once the maintenance dose has been established, serum calcium should be measured approximately monthly [see Dosage and Administration (2.1)].

If serum calcium falls below 8.4 mg/dL but remains above 7.5 mg/dL, or if symptoms of hypocalcemia occur, calcium-containing phosphate binders and/or vitamin D sterols can be used to raise serum calcium. If serum calcium falls below 7.5 mg/dL, or if symptoms of hypocalcemia persist and the dose of vitamin D cannot be increased, withhold administration of Sensipar until serum calcium levels reach 8.0 mg/dL and/or symptoms of hypocalcemia have resolved. Treatment should be reinitiated using the next lowest dose of Sensipar [see Dosage and Administration (2.1)].

In 26-week studies of patients with CKD on dialysis, 66% of patients receiving Sensipar compared with 25% of patients receiving placebo developed at least one serum calcium value < 8.4 mg/dL. Less than 1% of patients in each group permanently discontinued study drug due to hypocalcemia.

Sensipar is not indicated for patients with CKD not on dialysis. In patients with secondary HPT and CKD not on dialysis, the long term safety and efficacy of Sensipar have not been established. Clinical studies indicate that Sensipar-treated patients with CKD not on dialysis have an increased risk for hypocalcemia compared with Sensipar-treated patients with CKD on dialysis, which may be due to lower baseline calcium levels. In a phase 3 study of 32 weeks duration and including 404 patients with CKD not on dialysis (302 cinacalcet, 102 placebo), in which the median dose for cinacalcet was 60 mg per day at the completion of the study, 80% of Sensipar-treated patients experienced at least one serum calcium value < 8.4 mg/dL compared with 5% of patients receiving placebo.

5.2 Seizures

In clinical studies, seizures (primarily generalized or tonic-clonic) were observed in 1.4% (43/3049) of Sensipar-treated patients and 0.7% (5/687) of placebo-treated patients. While the basis for the reported difference in seizure rate is not clear, the threshold for seizures is lowered by significant reductions in serum calcium levels. Therefore, serum calcium levels should be closely monitored in patients receiving Sensipar, particularly in patients with a history of a seizure disorder [see Warnings and Precautions (5.1)].

5.3 Hypotension and/or Worsening Heart Failure

In postmarketing safety surveillance, isolated, idiosyncratic cases of hypotension, worsening heart failure, and/or arrhythmia have been reported in patients with impaired cardiac function, in which a causal relationship to Sensipar could not be completely excluded and which may be mediated by reductions in serum calcium levels [see Adverse Reactions (6.2)].

5.4 Adynamic Bone Disease

Adynamic bone disease may develop if iPTH levels are suppressed below 100 pg/mL. One clinical study eva luated bone histomorphometry in patients treated with Sensipar for 1 year. Three patients with mild hyperparathyroid bone disease at the beginning of the study developed adynamic bone disease during treatment with Sensipar. Two of these patients had iPTH levels below 100 pg/mL at multiple time points during the study. In three 6-month, phase 3 studies conducted in patients with CKD on dialysis, 11% of patients treated with Sensipar had mean iPTH values below 100 pg/mL during the efficacy-assessment phase. If iPTH levels decrease below 150 pg/mL in patients treated with Sensipar, the dose of Sensipar and/or vitamin D sterols should be reduced or therapy discontinued.

5.5 Hepatic Impairment

Cinacalcet exposure, as defined by the Area Under the Curve (AUC0-inf), is increased by 2.4 and 4.2 fold in patients with moderate and severe hepatic impairment, respectively. These patients should be monitored throughout treatment with Sensipar [see Use in Specific Populations (8.7) and Clinical Pharmacology (12.3)].

5.6 Laboratory Tests

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

6.2 Postmarketing Experience with Sensipar

The following adverse reactions have been identified during postapproval use of Sensipar. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Rash, hypersensitivity reactions (including angioedema and urticaria), diarrhea, and myalgia have been identified as adverse reactions during postapproval use of Sensipar. Isolated, idiosyncratic cases of hypotension, worsening heart failure, and/or arrhythmia have been reported in Sensipar-treated patients with impaired cardiac function in postmarketing safety surveillance.

7.1 Strong CYP3A4 Inhibitors

Cinacalcet is partially metabolized by CYP3A4. Dose adjustment of Sensipar may be required if a patient initiates or discontinues therapy with a strong CYP3A4 inhibitor (e.g., ketoconazole, itraconazole). The iPTH and serum calcium concentrations should be closely monitored in these patients [see Clinical Pharmacology (12.3)].

7.2 CYP2D6 Substrates

Cinacalcet is a strong inhibitor of CYP2D6. Dose adjustments may be required for concomitant medications that are predominantly metabolized by CYP2D6 (e.g., desipramine, metoprolol, and carvedilol) and particularly those with a narrow therapeutic index (e.g., flecainide and most tricyclic antidepressants) [see Clinical Pharmacology (12.3)].

8.1 Pregnancy: Category C

In pregnant female rats given oral gavage doses of 2, 25, 50 mg/kg/day cinacalcet during gestation, no teratogenicity was observed at doses up to 50 mg/kg/day (exposure 4 times those resulting with a human oral dose of 180 mg/day based on Area Under the Curve [AUC] comparison). Decreased fetal body weights were observed at all doses (less than 1 to 4 times a human oral dose of 180 mg/day based on AUC comparison) in conjunction with maternal toxicity (decreased food consumption and body weight gain).

In pregnant female rabbits given oral gavage doses of 2, 12, 25 mg/kg/day cinacalcet during gestation, no adverse fetal effects were observed (exposures less than with a human oral dose of 180 mg/day based on AUC comparisons). Reductions in maternal food consumption and body weight gain were seen at doses of 12 and 25 mg/kg/day. Sensipar has been shown to cross the placental barrier in rabbits.

In pregnant rats given oral gavage doses of 5, 15, 25 mg/kg/day cinacalcet during gestation through lactation, no adverse fetal or pup (post-weaning) effects were observed at 5 mg/kg/day (exposures less than with a human therapeutic dose of 180 mg/day based on AUC comparisons). Higher doses of 15 and 25 mg/kg/day cinacalcet (exposures 2 to 3 times a human oral dose of 180 mg/day based on AUC comparisons) were accompanied by maternal signs of hypocalcemia (periparturient mortality and early postnatal pup loss), and reductions in postnatal maternal and pup body-weight gain.

There are no adequate and well-controlled studies of Sensipar in pregnant women. Sensipar should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Women who become pregnant during Sensipar treatment are encouraged to enroll in Amgen’s Pregnancy Surveillance Program. Patients or their physicians should call 1-800-77-AMGEN (1-800-772-6436) to enroll.

8.3 Nursing Mothers

Studies in rats have shown that Sensipar is excreted in the milk with a high milk-to-plasma ratio. It is not known whether this drug is excreted in human milk. Considering these data in rats, and because many drugs are excreted in human milk and there is a potential for clinically significant adverse reactions in infants who ingest Sensipar, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the lactating woman.

8.4 Pediatric Use

The safety and efficacy of Sensipar in pediatric patients have not been established.

8.5 Geriatric Use

Of the 1136 patients enrolled in the Sensipar phase 3 clinical program in patients with CKD on dialysis, 26% were ≥ 65 years old, and 9% were ≥ 75 years old. No differences in the safety and efficacy of Sensipar were observed in patients greater or less than 65 years of age. No dosage adjustment is required for geriatric patients [see Clinical Pharmacology (12.3)].

8.6 Renal Impairment

No dosage adjustment is necessary for renal impairment [see Clinical Pharmacology (12.3)].

8.7 Hepatic Impairment

Patients with moderate and severe hepatic impairment should have serum calcium, serum phosphorus, and iPTH levels monitored closely throughout treatment with Sensipar because cinacalcet exposure (AUC0-inf) is increased by 2.4 and 4.2 fold, respectively, in these patients [see Warnings and Precautions (5.5) and Clinical Pharmacology (12.3)].