Paricalcitol

ZEMPLAR is a vitamin D analog indicated in adults and pediatric patients 10 years and older for the prevention and treatment of secondary hyperparathyroidism associated with: Chronic kidney disease (CKD) Stages 3 and 4 ( 1.1 ). CKD Stage 5 in patients on hemodialysis or peritoneal dialysis ( 1.2 ).

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).

ZEMPLAR capsules are available as 1 mcg and 2 mcg soft gelatin capsules. 1 mcg: oval, gray capsule imprinted with “ZA” 1 mcg: oval, gray capsule imprinted with the “a” logo and “ZA” 2 mcg: oval, orange-brown capsule imprinted with “ZF” 2 mcg: oval, orange-brown capsule imprinted with the “a” logo and “ZF” Capsules: 1 mcg and 2 mcg ( 3 ).

ZEMPLAR capsules should not be given to patients with evidence of hypercalcemia or vitamin D toxicity [see Warnings and Precautions ( 5.1 )] . Evidence of hypercalcemia ( 4 ). Evidence of vitamin D toxicity ( 4 ).

Excessive administration of vitamin D compounds, including ZEMPLAR capsules, can cause over suppression of PTH, hypercalcemia, hypercalciuria, hyperphosphatemia, and adynamic bone disease. Hypercalcemia: Excessive administration of ZEMPLAR capsules can cause over suppression of PTH, hypercalcemia, hypercalciuria, hyperphosphatemia, and adynamic bone disease. Prescription-based doses of vitamin D and its derivatives should be withheld during ZEMPLAR treatment ( 5.1 ). Digitalis toxicity: Potentiated by hypercalcemia of any cause. Use caution when ZEMPLAR capsules are prescribed concomitantly with digitalis compounds ( 5.2 ). Laboratory tests: Monitor serum calcium, serum phosphorus, and serum or plasma iPTH during initial dosing or following any dose adjustment. ZEMPLAR capsules may increase serum creatinine and therefore decrease the estimated GFR (eGFR) ( 5.3 ). Aluminum overload and toxicity: Avoid excessive use of aluminum containing compounds ( 5.4 ).

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.

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. The most common adverse reactions (> 5% and more frequent than placebo) include diarrhea, nasopharyngitis, dizziness, vomiting, hypertension, hypersensitivity, nausea, and edema ( 6 ). To report SUSPECTED ADVERSE REACTIONS, contact AbbVie Inc. at 1-800-633-9110 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

6.1 Clinical Trials Experience CKD Stages 3 and 4 Adults The safety of ZEMPLAR capsules has been evaluated in three 24-week (approximately six-month), double-blind, placebo-controlled, multicenter clinical studies involving 220 CKD Stages 3 and 4 patients. Six percent (6%) of ZEMPLAR capsules treated patients and 4% of placebo treated patients discontinued from clinical studies due to an adverse event. Adverse events occurring in the ZEMPLAR capsules group at a frequency of 2% or greater and more frequently than in the placebo group are presented in Table 3: Table 3. Adverse Reactions by Body System Occurring in ≥ 2% of Subjects in the ZEMPLAR-Treated Group of Three, Double-Blind, Placebo-Controlled CKD Stages 3 and 4 Studies Number (%) of Subjects Adverse Event a ZEMPLAR Capsules (n = 107) Placebo (n = 113) Overall 88 (82%) 86 (76%) Ear and Labyrinth Disorders Vertigo 5 (5%) 0 (0%) Gastrointestinal Disorders Abdominal Discomfort 4 (4%) 1 (1%) Constipation 4 (4%) 4 (4%) Diarrhea 7 (7%) 5 (4%) Nausea 6 (6%) 4 (4%) Vomiting 5 (5%) 5 (4%) General Disorders and Administration Site Conditions Chest Pain 3 (3%) 1 (1%) Edema 6 (6%) 5 (4%) Pain 4 (4%) 4 (4%) Immune System Disorders Hypersensitivity 6 (6%) 2 (2%) Infections and Infestations Fungal Infection 3 (3%) 0 (0%) Gastroenteritis 3 (3%) 3 (3%) Infection 3 (3%) 3 (3%) Sinusitis 3 (3%) 1 (1%) Urinary Tract Infection 3 (3%) 1 (1%) Viral Infection 8 (7%) 8 (7%) Metabolism and Nutrition Disorders Dehydration 3 (3%) 1 (1%) Musculoskeletal and Connective Tissue Disorders Arthritis 5 (5%) 0 (0%) Back Pain 3 (3%) 1 (1%) Muscle Spasms 3 (3%) 0 (0%) Nervous System Disorders Dizziness 5 (5%) 5 (4%) Headache 5 (5%) 5 (4%) Syncope 3 (3%) 1 (1%) Psychiatric Disorders Depression 3 (3%) 0 (0%) Respiratory, Thoracic and Mediastinal Disorders Cough 3 (3%) 2 (2%) Oropharyngeal Pain 4 (4%) 0 (0%) Skin and Subcutaneous Tissue Disorders Pruritus 3 (3%) 3 (3%) Rash 4 (4%) 1 (1%) Skin Ulcer 3 (3%) 0 (0%) Vascular Disorders Hypertension 7 (7%) 4 (4%) Hypotension 5 (5%) 3 (3%) a. Includes only events more common in the ZEMPLAR treatment group. Additional Adverse Reactions The following additional adverse reactions occurred in <2% of the ZEMPLAR-treated patients in the above double-blind, placebo-controlled clinical trial. Gastrointestinal Disorders: Dry mouth Investigations: Hepatic enzyme abnormal Nervous System Disorders: Dysgeusia Skin and Subcutaneous Tissue Disorders: Urticaria Pediatric patients 10 to 16 years of age The safety of ZEMPLAR capsules has been evaluated in one multicenter clinical study involving CKD Stages 3 and 4 patients ages 10 to 16 years. A 12-week double-blind, placebo-controlled phase was followed by an open-label phase during which all patients received ZEMPLAR capsules. During the 12-week blinded phase, a total of 18 patients received ZEMPLAR capsules and 18 patients received placebo. Adverse events occurring more frequently in the ZEMPLAR capsules group than in the placebo group are presented in Table 4. Table 4. Adverse Reactions by Body System Occurring in the Double-Blind, Placebo-Controlled, CKD Stages 3 and 4 Study in Patients Ages 10 to 16 Years Number (%) of Subjects Adverse Event a ZEMPLAR Capsules (n = 18) Placebo (n = 18) Overall 7 (39%) 16 (89%) Gastrointestinal Disorders Nausea 1 (6%) 0 (0%) Infections and Infestations Conjunctivitis 1 (6%) 0 (0%) Rhinitis 3 (17%) 0 (0%) Renal and Urinary Disorders Micturition Urgency 1 (6%) 0 (0%) Respiratory, Thoracic and Mediastinal Disorders Asthma 1 (6%) 0 (0%) a. Includes only events more common in the ZEMPLAR treatment group. Additional Adverse Reactions The following adverse reactions have occurred in ZEMPLAR-treated patients: Gastrointestinal Disorders: Abdominal pain, constipation, vomiting Metabolism and Nutrition Disorders: Hypercalcemia and hyperphosphatemia Nervous System Disorders: Headache CKD Stage 5 Adults The safety of ZEMPLAR capsules has been evaluated in one 12-week, double-blind, placebo-controlled, multicenter clinical study involving 88 CKD Stage 5 patients. Sixty-one patients received ZEMPLAR capsules and 27 patients received placebo. The proportion of patients who terminated prematurely from the study due to adverse events was 7% for ZEMPLAR capsules treated patients and 7% for placebo patients. Adverse events occurring in the ZEMPLAR capsules group at a frequency of 2% or greater and more frequently than in the placebo group are as follows: Table 5. Adverse Reactions by Body System Occurring in ≥ 2% of Subjects in the ZEMPLAR-Treated Group, Double-Blind, Placebo-Controlled CKD Stage 5 Study Number (%) of Subjects Adverse Events a ZEMPLAR Capsules (n=61) Placebo (n = 27) Overall 43 (70%) 19 (70%) Gastrointestinal Disorders Constipation 3 (5%) 0 (0%) Diarrhea 7 (11%) 3 (11%) Vomiting 4 (7%) 0 (0%) General Disorders and Administration Site Conditions Fatigue 2 (3%) 0 (0%) Edema Peripheral 2 (3%) 0 (0%) Infections and Infestations Nasopharyngitis 5 (8%) 2 (7%) Peritonitis 3 (5%) 0 (0%) Sinusitis 2 (3%) 0 (0%) Urinary Tract Infection 2 (3%) 0 (0%) Metabolism and Nutrition Disorders Fluid Overload 3 (5%) 0 (0%) Hypoglycemia 2 (3%) 0 (0%) Nervous System Disorders Dizziness 4 (7%) 0 (0%) Headache 2 (3%) 0 (0%) Psychiatric Disorders Anxiety 2 (3%) 0 (0%) Insomnia 3 (5%) 0 (0%) Renal and Urinary Disorders Renal Failure Chronic 2 (3%) 0 (0%) a. Includes only events more common in the ZEMPLAR treatment group. Additional Adverse Reactions The following adverse reactions occurred in <2% of the ZEMPLAR-treated patients in the above double-blind, placebo-controlled clinical trial. Gastrointestinal Disorders: Gastroesophageal reflux disease Metabolism and Nutrition Disorders : Decreased appetite, hypercalcemia, hypocalcemia Reproductive System and Breast Disorders : Breast tenderness Skin and Subcutaneous Tissue Disorders : Acne Pediatric patients 10 to 16 years of age The safety of ZEMPLAR capsules has been evaluated in one 12-week, open-label, single-arm, multicenter clinical studies involving 13 CKD Stage 5 patients ages 10 to 16 years of age receiving peritoneal dialysis or hemodialysis. The following adverse reactions were reported: Gastrointestinal Disorders: Abdominal pain, diarrhea, nausea, vomiting Metabolism and Nutrition Disorders: Hypercalcemia, hyperphosphatemia Three of 13 patients (23%) had hypercalcemia defined as at least 2 consecutive serum calcium values >10.2 mg/dL (2.55 mmol/L).

6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of ZEMPLAR capsules. 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. Immune System Disorders: Angioedema (including laryngeal edema) Investigations: Blood creatinine increased

Table 6 shows the clinically significant drug interactions with ZEMPLAR capsules. Table 6: Clinically Significant Drug Interactions with Paricalcitol CYP3A Inhibitors Clinical Impact Paricalcitol is partially metabolized by CYP3A. Hence, exposure of paricalcitol will increase upon coadministration with strong CYP3A inhibitors such as but not limited to: boceprevir, clarithromycin, conivaptan, grapefruit juice, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, mibefradil, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telaprevir, telithromycin, voriconazole. Intervention Dose adjustment of ZEMPLAR capsules may be necessary. Monitor closely for iPTH and serum calcium concentrations, if a patient initiates or discontinues therapy with a strong CYP3A4 inhibitor. Cholestyramine Clinical Impact Drugs that impair intestinal absorption of fat-soluble vitamins, such as cholestyramine, may interfere with the absorption of paricalcitol. Intervention Recommend to take ZEMPLAR capsules at least 1 hour before or 4 to 6 hours after taking cholestyramine (or at as great an interval as possible) to avoid impeding absorption of paricalcitol. Mineral Oil Clinical Impact Mineral oil or other substances that may affect absorption of fat may influence the absorption of paricalcitol. Intervention Recommend to take ZEMPLAR capsules at least 1 hour before or 4 to 6 hours after taking mineral oil (or at as great an interval as possible) to avoid affecting absorption of paricalcitol. Strong CYP3A inhibitors (e.g. ketoconazole) will increase the exposure of paricalcitol. Use with caution ( 7 ). Cholestyramine, Mineral Oil: Intestinal absorption of paricalcitol may be reduced if administered simultaneously with cholestyramine or mineral oil. Take ZEMPLAR Capsules at least 1 hour before or 4 to 6 hours after taking cholestyramine or mineral oil ( 7 ).

Lactation: Breastfeeding not recommended ( 8.2 ).

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/m 2 ). 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 [ 3 H] 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 [ 3 H] paricalcitol and/or its metabolites are secreted into milk. Exposure of the pups to [ 3 H] 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.

Paricalcitol is a synthetic, biologically active vitamin D 2 analog of calcitriol. Preclinical and in vitro studies have demonstrated that paricalcitol's biological actions are mediated through binding of the VDR, which results in the selective activation of vitamin D responsive pathways. Vitamin D and paricalcitol have been shown to reduce parathyroid hormone levels by inhibiting PTH synthesis and secretion.