Zemplar

1.1 Chronic Kidney Disease Stages 3 and 4

ZEMPLAR capsules are indicated in adults and pediatric patients 10 years of age and older for the prevention and treatment of secondary hyperparathyroidism associated with Chronic Kidney Disease (CKD) Stages 3 and 4.

1.2 Chronic Kidney Disease Stage 5

ZEMPLAR capsules are indicated in adults and pediatric patients 10 years of age and older for the prevention and treatment of secondary hyperparathyroidism associated with CKD Stage 5 in patients on hemodialysis (HD) or peritoneal dialysis (PD).

2.1 Chronic Kidney Disease Stages 3 and 4 in Adults

Administer ZEMPLAR capsules orally once daily or three times a week [see Clinical Studies ( 14.1)]. When dosing three times weekly, do not administer more frequently than every other day.

Initial Dose

Dose Titration

If a patient is taking the lowest dose, 1 mcg, on the daily regimen and a dose reduction is needed, the dose can be decreased to 1 mcg three times a week. If a further dose reduction is required, the drug should be withheld as needed and restarted at a lower dosing frequency.

2.2 Chronic Kidney Disease Stage 5 in Adults

Initial Dose

Administer the dose of ZEMPLAR capsules orally three times a week, no more frequently than every other day based upon the following formula:

   Dose (micrograms) = baseline iPTH (pg/mL) divided by 80

Treat patients only after their baseline serum calcium has been adjusted to 9.5 mg/dL or lower to minimize the risk of hypercalcemia [see Clinical Pharmacology ( 12.2) and Clinical Studies ( 14.2)].

Dose Titration

Individualize the dose of ZEMPLAR based on iPTH, serum calcium and phosphorus levels. Titrate ZEMPLAR dose based on the following formula:

   Dose (micrograms) = most recent iPTH level (pg/ml) divided by 80

If serum calcium is elevated, the dose should be decreased by 2 to 4 micrograms.

As iPTH approaches the target range, small, individualized dose adjustments may be necessary in order to achieve a stable iPTH. In situations where monitoring of iPTH, Ca or P occurs less frequently than once per week, a more modest initial and dose titration ratio (e.g., iPTH divided by 100) may be warranted.

2.3 Pediatric Patients (Ages 10 to 16 Years)

CKD Stages 3 and 4

Initial Dose

Administer ZEMPLAR 1 mcg capsule orally three times a week, no more frequently than every other day.

Dose Titration

Individualize and titrate ZEMPLAR dose based on iPTH, serum calcium and phosphorus levels to maintain an iPTH level within target range.

Every 4 weeks, each administered ZEMPLAR dose may be increased in 1 mcg increments, maintaining the three times per week regimen (e.g., increase from 1 mcg three times per week to 2 mcg three times per week). At any time, each administered dose may be decreased by 1 mcg. ZEMPLAR may be stopped if the patient requires reduction while receiving 1 mcg three times per week, resuming when appropriate.

CKD Stage 5

Initial Dose

Administer the dose of ZEMPLAR capsules orally three times a week, no more frequently than every other day based upon the following formula:

    Dose* (micrograms) = baseline iPTH (pg/mL) divided by 120

    * Round down to the nearest whole number

Dose Titration

Subsequent dosing should be individualized and based on iPTH, serum calcium and phosphorus levels to maintain an iPTH level within target range.

Every 4 weeks, each administered ZEMPLAR dose may be increased in 1 mcg increments, maintaining the three times per week regimen (e.g., increase from 1 mcg three times per week to 2 mcg three times per week). At any time, each administered dose may be decreased by 2 mcg. ZEMPLAR may be stopped if the patient requires reduction while receiving 2 mcg three times per week or 1 mcg three times per week, resuming when appropriate.

2.4 Monitoring

Monitor serum calcium and phosphorus levels closely after initiation of ZEMPLAR, during dose titration periods and during co-administration with strong CYP3A inhibitors [see Warnings and Precautions ( 5.3), Drug Interactions ( 7), and Clinical Pharmacology ( 12.3)].

If hypercalcemia is observed, the dose of ZEMPLAR should be reduced or withheld until these parameters are normalized.

2.5 Administration

ZEMPLAR capsules may be taken without regard to food.

8.1 Pregnancy

Risk Summary

Limited data with ZEMPLAR capsules in pregnant women are insufficient to inform a drug-associated risk for major birth defects and miscarriage. There are risks to the mother and fetus associated with chronic kidney disease in pregnancy [see Clinical Considerations].

In animal reproduction studies, slightly increased embryofetal loss was observed in pregnant rats and rabbits administered paricalcitol intravenously during the period of organogenesis at doses 2 and 0.5 times, respectively, the maximum recommended human dose (MRHD). Adverse reproductive outcomes were observed at doses that caused maternal toxicity [see Data].

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Clinical Considerations

Disease-associated maternal and/or embryo/fetal risk

Chronic kidney disease in pregnancy increases the maternal risk for hypertension, spontaneous abortion, preterm labor, and preeclampsia. Chronic kidney disease increases the fetal risk for intrauterine growth restriction (IUGR), prematurity, polyhydramnios, still birth, and low birth weight.

Data

Animal Data

Pregnant rats and rabbits were treated with paricalcitol by once-daily intravenous (IV) injection during the period of organogenesis (in rats, from gestation day (GD) 6 to 17; in rabbits, from GD 6 to 18). Rats were dosed at 0, 0.3, 1.0 or 3.0 mcg/kg/day and rabbits at 0, 0.03, 0.1 or 0.3 mcg/kg/day, representing up to 2 or 0.5 times, respectively, the maximum recommended human dose (MRHD) of 0.24 mcg/kg, based on body surface area (mcg/m2). Slightly decreased fetal viability was observed in both studies at the highest doses representing 2 and 0.5 times, respectively, the MRHD in the presence of maternal toxicity (decreased body weight and food consumption). Pregnant rats were administered paricalcitol by IV injection three times per week at doses of 0, 0.3, 3.0 or 20.0 mcg/kg/day throughout gestation, parturition and lactation (GD 6 to lactation day (LD) 20) representing exposures up to 13 times the MHRD. A small increase in stillbirths and pup deaths from parturition to LD 4 were observed at the high dose when compared to the control group (9.2% versus 3.3% in controls) at 13 times the MRHD, which occurred at a maternally toxic dose known to cause hypercalcemia in rats. Surviving pups were not adversely affected; body weight gains, developmental landmarks, reflex ontogeny, learning indices, and locomotor activity were all within normal parameters. F1 reproductive capacity was unaffected.

8.2 Lactation

Risk Summary

There is no information available on the presence of paricalcitol in human milk, the effects of the drug on the breastfed infant or the effects of the drug on milk production. Studies in rats have shown that paricalcitol and/or its metabolites are present in the milk of lactating rats; however, due to specifies-specific differences in lactation physiology, animal data may not reliably predict drug levels in human milk [see Data]. Because of the potential for serious adverse reactions, including hypercalcemia in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with ZEMPLAR.

Data

Following a single oral administration of 20 mcg/kg of radioactive [3H] paricalcitol to lactating rats, the concentrations of total radioactivity was determined. Lower levels of total radioactivity were present in the milk compared to that in the plasma of the dams indicating that low levels of [3H] paricalcitol and/or its metabolites are secreted into milk. Exposure of the pups to [3H] paricalcitol through milk was confirmed by the presence of radioactive material in the pups’ stomachs.

8.4 Pediatric Use

The safety and effectiveness of ZEMPLAR capsules have been established in pediatric patients 10 to 16 years of age for the prevention and treatment of secondary hyperparathyroidism associated with Stage 3, 4, and 5 CKD.

Use of ZEMPLAR capsules in this age group is supported by evidence from adequate and well controlled studies in adults with CKD, a 12-week double-blind placebo-controlled randomized multicenter study in 36 pediatric patients 10 to 16 years of age with CKD Stages 3 and 4, and safety data from a 12-week open-label single-arm multicenter study in 13 pediatric patients 10 to 16 years of age with CKD Stage 5 receiving peritoneal dialysis or hemodialysis. The pharmacokinetics of paricalcitol in Stage 5 CKD pediatric patients appear to be similar to those observed in Stage 3 and 4 pediatric patients [see Clinical Pharmacology ( 12.3) and Clinical Studies ( 14.1)].

Adverse reactions reported in these pediatric studies are consistent with the known safety profile of ZEMPLAR capsules and with what has been reported in adult clinical studies [see Adverse Reactions ( 6.1)].

Safety and effectiveness of ZEMPLAR capsules in pediatric patients under the age of 10 years have not been established.

8.5 Geriatric Use

Of the total number (n = 220) of CKD Stages 3 and 4 patients in clinical studies of ZEMPLAR capsules, 49% were age 65 and over, while 17% were age 75 and over. Of the total number (n = 88) of CKD Stage 5 patients in the pivotal study of ZEMPLAR capsules, 28% were age 65 and over, while 6% were age 75 and over. No overall differences in safety and effectiveness were observed between these patients and younger patients, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

5.1 Hypercalcemia

Progressive hypercalcemia due to overdosage of vitamin D and its metabolites may be so severe as to require emergency attention [see Overdosage ( 10)]. Acute hypercalcemia may exacerbate tendencies for cardiac arrhythmias and seizures and may potentiate the action of digitalis. Chronic hypercalcemia can lead to generalized vascular calcification and other soft-tissue calcification. Concomitant administration of high doses of calcium-containing preparations or thiazide diuretics with ZEMPLAR may increase the risk of hypercalcemia. High intake of calcium and phosphate concomitant with vitamin D compounds may lead to serum abnormalities requiring more frequent patient monitoring and individualized dose titration. Patients also should be informed about the symptoms of elevated calcium, which include feeling tired, difficulty thinking clearly, loss of appetite, nausea, vomiting, constipation, increased thirst, increased urination and weight loss.

Prescription-based doses of vitamin D and its derivatives should be withheld during ZEMPLAR treatment to avoid hypercalcemia.

5.2 Digitalis Toxicity

Digitalis toxicity is potentiated by hypercalcemia of any cause. Use caution when ZEMPLAR capsules are prescribed concomitantly with digitalis compounds.

5.3 Laboratory Tests

During the initial dosing or following any dose adjustment of medication, serum calcium, serum phosphorus, and serum or plasma iPTH should be monitored at least every two weeks for 3 months, then monthly for 3 months, and every 3 months thereafter.

In pre-dialysis patients, ZEMPLAR capsules may increase serum creatinine and therefore decrease the estimated GFR (eGFR). Similar effects have also been seen with calcitriol.

5.4 Aluminum Overload and Toxicity

Aluminum-containing preparations (e.g., antacids, phosphate binders) should not be administered chronically with ZEMPLAR, as increased blood levels of aluminum and aluminum bone toxicity may occur.