1.1 Primary Hyperlipidemia

1.2 Homozygous Familial Hypercholesterolemia (HoFH)

The combination of ZETIA and atorvastatin or simvastatin is indicated for the reduction of elevated total-C and LDL-C levels in patients with HoFH, as an adjunct to other lipid-lowering treatments (e.g., LDL apheresis) or if such treatments are unavailable.

1.3 Homozygous Sitosterolemia

ZETIA is indicated as adjunctive therapy to diet for the reduction of elevated sitosterol and campesterol levels in patients with homozygous familial sitosterolemia.

1.4 Limitations of Use

The effect of ZETIA on cardiovascular morbidity and mortality has not been determined.

ZETIA has not been studied in Fredrickson Type I, III, IV, and V dyslipidemias.

2.1 General Dosing Information

The recommended dose of ZETIA is 10 mg once daily.

ZETIA can be administered with or without food.

2.2 Concomitant Lipid-Lowering Therapy

ZETIA may be administered with a statin (in patients with primary hyperlipidemia) or with fenofibrate (in patients with mixed hyperlipidemia) for incremental effect. For convenience, the daily dose of ZETIA may be taken at the same time as the statin or fenofibrate, according to the dosing recommendations for the respective medications.

2.3 Coadministration with Bile Acid Sequestrants

Dosing of ZETIA should occur either ≥2 hours before or ≥4 hours after administration of a bile acid sequestrant [see Drug Interactions (7.4)].

2.4 Patients with Hepatic Impairment

No dosage adjustment is necessary in patients with mild hepatic impairment [see Warnings and Precautions (5.4)].

2.5 Patients with Renal Impairment

No dosage adjustment is necessary in patients with renal impairment [see Clinical Pharmacology (12.3)]. When given with simvastatin in patients with moderate to severe renal impairment (estimated glomerular filtration rate <60 mL/min/1.73 m2), doses of simvastatin exceeding 20 mg should be used with caution and close monitoring [see Use in Specific Populations (8.6)].

2.6 Geriatric Patients

No dosage adjustment is necessary in geriatric patients [see Clinical Pharmacology (12.3)].

5.1 Use with Statins or Fenofibrate

Concurrent administration of ZETIA with a specific statin or fenofibrate should be in accordance with the product labeling for that medication.

5.2 Liver Enzymes

In controlled clinical monotherapy studies, the incidence of consecutive elevations (≥3 × the upper limit of normal [ULN]) in hepatic transaminase levels was similar between ZETIA (0.5%) and placebo (0.3%).

In controlled clinical combination studies of ZETIA initiated concurrently with a statin, the incidence of consecutive elevations (≥3 × ULN) in hepatic transaminase levels was 1.3% for patients treated with ZETIA administered with statins and 0.4% for patients treated with statins alone. These elevations in transaminases were generally asymptomatic, not associated with cholestasis, and returned to baseline after discontinuation of therapy or with continued treatment. When ZETIA is coadministered with a statin, liver tests should be performed at initiation of therapy and according to the recommendations of the statin. Should an increase in ALT or AST ≥3 × ULN persist, consider withdrawal of ZETIA and/or the statin.

5.3 Myopathy/Rhabdomyolysis

In clinical trials, there was no excess of myopathy or rhabdomyolysis associated with ZETIA compared with the relevant control arm (placebo or statin alone). However, myopathy and rhabdomyolysis are known adverse reactions to statins and other lipid-lowering drugs. In clinical trials, the incidence of creatine phosphokinase (CPK) >10 × ULN was 0.2% for ZETIA vs. 0.1% for placebo, and 0.1% for ZETIA coadministered with a statin vs. 0.4% for statins alone. Risk for skeletal muscle toxicity increases with higher doses of statin, advanced age (>65), hypothyroidism, renal impairment, and depending on the statin used, concomitant use of other drugs.

In post-marketing experience with ZETIA, cases of myopathy and rhabdomyolysis have been reported. Most patients who developed rhabdomyolysis were taking a statin prior to initiating ZETIA. However, rhabdomyolysis has been reported with ZETIA monotherapy and with the addition of ZETIA to agents known to be associated with increased risk of rhabdomyolysis, such as fibrates. ZETIA and any statin or fibrate that the patient is taking concomitantly should be immediately discontinued if myopathy is diagnosed or suspected. The presence of muscle symptoms and a CPK level >10 × the ULN indicates myopathy.

5.4 Hepatic Impairment

Due to the unknown effects of the increased exposure to ezetimibe in patients with moderate to severe hepatic impairment, ZETIA is not recommended in these patients. [See Clinical Pharmacology (12.3).]

Monotherapy Studies: In the ZETIA controlled clinical trials database (placebo-controlled) of 2396 patients with a median treatment duration of 12 weeks (range 0 to 39 weeks), 3.3% of patients on ZETIA and 2.9% of patients on placebo discontinued due to adverse reactions. The most common adverse reactions in the group of patients treated with ZETIA that led to treatment discontinuation and occurred at a rate greater than placebo were:

• Arthralgia (0.3%)
• Dizziness (0.2%)
• Gamma-glutamyltransferase increased (0.2%)

The most commonly reported adverse reactions (incidence ≥2% and greater than placebo) in the ZETIA monotherapy controlled clinical trial database of 2396 patients were: upper respiratory tract infection (4.3%), diarrhea (4.1%), arthralgia (3.0%), sinusitis (2.8%), and pain in extremity (2.7%).

Statin Coadministration Studies: In the ZETIA + statin controlled clinical trials database of 11,308 patients with a median treatment duration of 8 weeks (range 0 to 112 weeks), 4.0% of patients on ZETIA + statin and 3.3% of patients on statin alone discontinued due to adverse reactions. The most common adverse reactions in the group of patients treated with ZETIA + statin that led to treatment discontinuation and occurred at a rate greater than statin alone were:

• Alanine aminotransferase increased (0.6%)
• Myalgia (0.5%)
• Fatigue, aspartate aminotransferase increased, headache, and pain in extremity (each at 0.2%)

The most commonly reported adverse reactions (incidence ≥2% and greater than statin alone) in the ZETIA + statin controlled clinical trial database of 11,308 patients were: nasopharyngitis (3.7%), myalgia (3.2%), upper respiratory tract infection (2.9%), arthralgia (2.6%) and diarrhea (2.5%).

6.1 Clinical Trials Experience

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 clinical practice.

6.2 Post-Marketing Experience

Because the reactions below are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

The following additional adverse reactions have been identified during post-approval use of ZETIA:

Hypersensitivity reactions, including anaphylaxis, angioedema, rash, and urticaria; erythema multiforme; arthralgia; myalgia; elevated creatine phosphokinase; myopathy/rhabdomyolysis [see Warnings and Precautions (5.3)]; elevations in liver transaminases; hepatitis; abdominal pain; thrombocytopenia; pancreatitis; nausea; dizziness; paresthesia; depression; headache; cholelithiasis; cholecystitis.

7.1 Cyclosporine

Caution should be exercised when using ZETIA and cyclosporine concomitantly due to increased exposure to both ezetimibe and cyclosporine. Cyclosporine concentrations should be monitored in patients receiving ZETIA and cyclosporine.

The degree of increase in ezetimibe exposure may be greater in patients with severe renal insufficiency. In patients treated with cyclosporine, the potential effects of the increased exposure to ezetimibe from concomitant use should be carefully weighed against the benefits of alterations in lipid levels provided by ezetimibe.

7.2 Fibrates

The efficacy and safety of coadministration of ezetimibe with fibrates other than fenofibrate have not been studied.

Fibrates may increase cholesterol excretion into the bile, leading to cholelithiasis. In a preclinical study in dogs, ezetimibe increased cholesterol in the gallbladder bile [see Nonclinical Toxicology (13.2)]. Coadministration of ZETIA with fibrates other than fenofibrate is not recommended until use in patients is adequately studied.

7.3 Fenofibrate

If cholelithiasis is suspected in a patient receiving ZETIA and fenofibrate, gallbladder studies are indicated and alternative lipid-lowering therapy should be considered [see Adverse Reactions (6.1) and the product labeling for fenofibrate].

7.4 Cholestyramine

Concomitant cholestyramine administration decreased the mean area under the curve (AUC) of total ezetimibe approximately 55%. The incremental LDL-C reduction due to adding ezetimibe to cholestyramine may be reduced by this interaction.

7.5 Coumarin Anticoagulants

If ezetimibe is added to warfarin, a coumarin anticoagulant, the International Normalized Ratio (INR) should be appropriately monitored.

8.1 Pregnancy

8.3 Nursing Mothers

It is not known whether ezetimibe is excreted into human breast milk. In rat studies, exposure to total ezetimibe in nursing pups was up to half of that observed in maternal plasma. Because many drugs are excreted in human milk, caution should be exercised when ZETIA is administered to a nursing woman. ZETIA should not be used in nursing mothers unless the potential benefit justifies the potential risk to the infant.

8.4 Pediatric Use

The effects of ZETIA coadministered with simvastatin (n=126) compared to simvastatin monotherapy (n=122) have been evaluated in adolescent boys and girls with heterozygous familial hypercholesterolemia (HeFH). In a multicenter, double-blind, controlled study followed by an open-label phase, 142 boys and 106 postmenarchal girls, 10 to 17 years of age (mean age 14.2 years, 43% females, 82% Caucasians, 4% Asian, 2% Blacks, 13% multi-racial) with HeFH were randomized to receive either ZETIA coadministered with simvastatin or simvastatin monotherapy. Inclusion in the study required 1) a baseline LDL-C level between 160 and 400 mg/dL and 2) a medical history and clinical presentation consistent with HeFH. The mean baseline LDL-C value was 225 mg/dL (range: 161–351 mg/dL) in the ZETIA coadministered with simvastatin group compared to 219 mg/dL (range: 149–336 mg/dL) in the simvastatin monotherapy group. The patients received coadministered ZETIA and simvastatin (10 mg, 20 mg, or 40 mg) or simvastatin monotherapy (10 mg, 20 mg, or 40 mg) for 6 weeks, coadministered ZETIA and 40-mg simvastatin or 40-mg simvastatin monotherapy for the next 27 weeks, and open-label coadministered ZETIA and simvastatin (10 mg, 20 mg, or 40 mg) for 20 weeks thereafter.

The results of the study at Week 6 are summarized in Table 3. Results at Week 33 were consistent with those at Week 6.

From the start of the trial to the end of Week 33, discontinuations due to an adverse reaction occurred in 7 (6%) patients in the ZETIA coadministered with simvastatin group and in 2 (2%) patients in the simvastatin monotherapy group.

During the trial, hepatic transaminase elevations (two consecutive measurements for ALT and/or AST ≥3 × ULN) occurred in four (3%) individuals in the ZETIA coadministered with simvastatin group and in two (2%) individuals in the simvastatin monotherapy group. Elevations of CPK (≥10 × ULN) occurred in two (2%) individuals in the ZETIA coadministered with simvastatin group and in zero individuals in the simvastatin monotherapy group.

In this limited controlled study, there was no significant effect on growth or sexual maturation in the adolescent boys or girls, or on menstrual cycle length in girls.

Coadministration of ZETIA with simvastatin at doses greater than 40 mg/day has not been studied in adolescents. Also, ZETIA has not been studied in patients younger than 10 years of age or in pre-menarchal girls.

Based on total ezetimibe (ezetimibe + ezetimibe-glucuronide), there are no pharmacokinetic differences between adolescents and adults. Pharmacokinetic data in the pediatric population <10 years of age are not available.

8.5 Geriatric Use

8.6 Renal Impairment

When used as monotherapy, no dosage adjustment of ZETIA is necessary.

In the Study of Heart and Renal Protection (SHARP) trial of 9270 patients with moderate to severe renal impairment (6247 non-dialysis patients with median serum creatinine 2.5 mg/dL and median estimated glomerular filtration rate 25.6 mL/min/1.73 m2, and 3023 dialysis patients), the incidence of serious adverse events, adverse events leading to discontinuation of study treatment, or adverse events of special interest (musculoskeletal adverse events, liver enzyme abnormalities, incident cancer) was similar between patients ever assigned to ezetimibe 10 mg plus simvastatin 20 mg (n=4650) or placebo (n=4620) during a median follow-up of 4.9 years. However, because renal impairment is a risk factor for statin-associated myopathy, doses of simvastatin exceeding 20 mg should be used with caution and close monitoring when administered concomitantly with ZETIA in patients with moderate to severe renal impairment.

8.7 Hepatic Impairment

ZETIA is not recommended in patients with moderate to severe hepatic impairment [see Warnings and Precautions (5.4) and Clinical Pharmacology (12.3)].

ZETIA given concomitantly with a statin is contraindicated in patients with active liver disease or unexplained persistent elevations of hepatic transaminase levels [see Contraindications (4); Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].

12.1 Mechanism of Action

Ezetimibe reduces blood cholesterol by inhibiting the absorption of cholesterol by the small intestine. In a 2-week clinical study in 18 hypercholesterolemic patients, ZETIA inhibited intestinal cholesterol absorption by 54%, compared with placebo. ZETIA had no clinically meaningful effect on the plasma concentrations of the fat-soluble vitamins A, D, and E (in a study of 113 patients), and did not impair adrenocortical steroid hormone production (in a study of 118 patients).

The cholesterol content of the liver is derived predominantly from three sources. The liver can synthesize cholesterol, take up cholesterol from the blood from circulating lipoproteins, or take up cholesterol absorbed by the small intestine. Intestinal cholesterol is derived primarily from cholesterol secreted in the bile and from dietary cholesterol.

Ezetimibe has a mechanism of action that differs from those of other classes of cholesterol-reducing compounds (statins, bile acid sequestrants [resins], fibric acid derivatives, and plant stanols). The molecular target of ezetimibe has been shown to be the sterol transporter, Niemann-Pick C1-Like 1 (NPC1L1), which is involved in the intestinal uptake of cholesterol and phytosterols.

Ezetimibe does not inhibit cholesterol synthesis in the liver, or increase bile acid excretion. Instead, ezetimibe localizes at the brush border of the small intestine and inhibits the absorption of cholesterol, leading to a decrease in the delivery of intestinal cholesterol to the liver. This causes a reduction of hepatic cholesterol stores and an increase in clearance of cholesterol from the blood; this distinct mechanism is complementary to that of statins and of fenofibrate [see Clinical Studies (14.1)].

12.2 Pharmacodynamics

Clinical studies have demonstrated that elevated levels of total-C, LDL-C and Apo B, the major protein constituent of LDL, promote human atherosclerosis. In addition, decreased levels of HDL-C are associated with the development of atherosclerosis. Epidemiologic studies have established that cardiovascular morbidity and mortality vary directly with the level of total-C and LDL-C and inversely with the level of HDL-C. Like LDL, cholesterol-enriched triglyceride-rich lipoproteins, including very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), and remnants, can also promote atherosclerosis. The independent effect of raising HDL-C or lowering TG on the risk of coronary and cardiovascular morbidity and mortality has not been determined.

ZETIA reduces total-C, LDL-C, Apo B, non-HDL-C, and TG, and increases HDL-C in patients with hyperlipidemia. Administration of ZETIA with a statin is effective in improving serum total-C, LDL-C, Apo B, non-HDL-C, TG, and HDL-C beyond either treatment alone. Administration of ZETIA with fenofibrate is effective in improving serum total-C, LDL-C, Apo B, and non-HDL-C in patients with mixed hyperlipidemia as compared to either treatment alone. The effects of ezetimibe given either alone or in addition to a statin or fenofibrate on cardiovascular morbidity and mortality have not been established.

12.3 Pharmacokinetics

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

A 104-week dietary carcinogenicity study with ezetimibe was conducted in rats at doses up to 1500 mg/kg/day (males) and 500 mg/kg/day (females) (~20 × the human exposure at 10 mg daily based on AUC0–24hr for total ezetimibe). A 104-week dietary carcinogenicity study with ezetimibe was also conducted in mice at doses up to 500 mg/kg/day (>150 × the human exposure at 10 mg daily based on AUC0–24hr for total ezetimibe). There were no statistically significant increases in tumor incidences in drug-treated rats or mice.

No evidence of mutagenicity was observed in vitro in a microbial mutagenicity (Ames) test with Salmonella typhimurium and Escherichia coli with or without metabolic activation. No evidence of clastogenicity was observed in vitro in a chromosomal aberration assay in human peripheral blood lymphocytes with or without metabolic activation. In addition, there was no evidence of genotoxicity in the in vivo mouse micronucleus test.

In oral (gavage) fertility studies of ezetimibe conducted in rats, there was no evidence of reproductive toxicity at doses up to 1000 mg/kg/day in male or female rats (~7 × the human exposure at 10 mg daily based on AUC0–24hr for total ezetimibe).

13.2 Animal Toxicology and/or Pharmacology

The hypocholesterolemic effect of ezetimibe was evaluated in cholesterol-fed Rhesus monkeys, dogs, rats, and mouse models of human cholesterol metabolism. Ezetimibe was found to have an ED50 value of 0.5 µg/kg/day for inhibiting the rise in plasma cholesterol levels in monkeys. The ED50 values in dogs, rats, and mice were 7, 30, and 700 µg/kg/day, respectively. These results are consistent with ZETIA being a potent cholesterol absorption inhibitor.

In a rat model, where the glucuronide metabolite of ezetimibe (SCH 60663) was administered intraduodenally, the metabolite was as potent as the parent compound (SCH 58235) in inhibiting the absorption of cholesterol, suggesting that the glucuronide metabolite had activity similar to the parent drug.

In 1-month studies in dogs given ezetimibe (0.03 to 300 mg/kg/day), the concentration of cholesterol in gallbladder bile increased ~2- to 4-fold. However, a dose of 300 mg/kg/day administered to dogs for one year did not result in gallstone formation or any other adverse hepatobiliary effects. In a 14-day study in mice given ezetimibe (0.3 to 5 mg/kg/day) and fed a low-fat or cholesterol-rich diet, the concentration of cholesterol in gallbladder bile was either unaffected or reduced to normal levels, respectively.

A series of acute preclinical studies was performed to determine the selectivity of ZETIA for inhibiting cholesterol absorption. Ezetimibe inhibited the absorption of 14C-cholesterol with no effect on the absorption of triglycerides, fatty acids, bile acids, progesterone, ethinyl estradiol, or the fat-soluble vitamins A and D.

In 4- to 12-week toxicity studies in mice, ezetimibe did not induce cytochrome P450 drug metabolizing enzymes. In toxicity studies, a pharmacokinetic interaction of ezetimibe with statins (parents or their active hydroxy acid metabolites) was seen in rats, dogs, and rabbits.

14.1 Primary Hyperlipidemia

ZETIA reduces total-C, LDL-C, Apo B, non-HDL-C, and TG, and increases HDL-C in patients with hyperlipidemia. Maximal to near maximal response is generally achieved within 2 weeks and maintained during chronic therapy.

14.2 Homozygous Familial Hypercholesterolemia (HoFH)

A study was conducted to assess the efficacy of ZETIA in the treatment of HoFH. This double-blind, randomized, 12-week study enrolled 50 patients with a clinical and/or genotypic diagnosis of HoFH, with or without concomitant LDL apheresis, already receiving atorvastatin or simvastatin (40 mg). Patients were randomized to one of three treatment groups, atorvastatin or simvastatin (80 mg), ZETIA administered with atorvastatin or simvastatin (40 mg), or ZETIA administered with atorvastatin or simvastatin (80 mg). Due to decreased bioavailability of ezetimibe in patients concomitantly receiving cholestyramine [see Drug Interactions (7.4)], ezetimibe was dosed at least 4 hours before or after administration of resins. Mean baseline LDL-C was 341 mg/dL in those patients randomized to atorvastatin 80 mg or simvastatin 80 mg alone and 316 mg/dL in the group randomized to ZETIA plus atorvastatin 40 or 80 mg or simvastatin 40 or 80 mg. ZETIA, administered with atorvastatin or simvastatin (40- and 80-mg statin groups, pooled), significantly reduced LDL-C (21%) compared with increasing the dose of simvastatin or atorvastatin monotherapy from 40 to 80 mg (7%). In those treated with ZETIA plus 80-mg atorvastatin or with ZETIA plus 80-mg simvastatin, LDL-C was reduced by 27%.

14.3 Homozygous Sitosterolemia (Phytosterolemia)

A study was conducted to assess the efficacy of ZETIA in the treatment of homozygous sitosterolemia. In this multicenter, double-blind, placebo-controlled, 8-week trial, 37 patients with homozygous sitosterolemia with elevated plasma sitosterol levels (>5 mg/dL) on their current therapeutic regimen (diet, bile-acid-binding resins, statins, ileal bypass surgery and/or LDL apheresis), were randomized to receive ZETIA (n=30) or placebo (n=7). Due to decreased bioavailability of ezetimibe in patients concomitantly receiving cholestyramine [see Drug Interactions (7.4)], ezetimibe was dosed at least 2 hours before or 4 hours after resins were administered. Excluding the one subject receiving LDL apheresis, ZETIA significantly lowered plasma sitosterol and campesterol, by 21% and 24% from baseline, respectively. In contrast, patients who received placebo had increases in sitosterol and campesterol of 4% and 3% from baseline, respectively. For patients treated with ZETIA, mean plasma levels of plant sterols were reduced progressively over the course of the study. The effects of reducing plasma sitosterol and campesterol on reducing the risks of cardiovascular morbidity and mortality have not been established.

Reductions in sitosterol and campesterol were consistent between patients taking ZETIA concomitantly with bile acid sequestrants (n=8) and patients not on concomitant bile acid sequestrant therapy (n=21).

Storage

Store at 25°C (77°F); excursions permitted to 15–30°C (59–86°F). [See USP Controlled Room Temperature.] Protect from moisture.

17.1 Muscle Pain

All patients starting therapy with ezetimibe should be advised of the risk of myopathy and told to report promptly any unexplained muscle pain, tenderness or weakness. The risk of this occurring is increased when taking certain types of medication. Patients should discuss all medication, both prescription and over-the-counter, with their physician.

17.2 Liver Enzymes

Liver tests should be performed when ZETIA is added to statin therapy and according to statin recommendations.

17.3 Pregnancy

Women of childbearing age should be advised to use an effective method of birth control to prevent pregnancy while using ZETIA added to statin therapy. Discuss future pregnancy plans with your patients, and discuss when to stop combination ZETIA and statin therapy if they are trying to conceive. Patients should be advised that if they become pregnant they should stop taking combination ZETIA and statin therapy and call their healthcare professional.

17.4 Breastfeeding

Women who are breastfeeding should be advised to not use ZETIA added to statin therapy. Patients who have a lipid disorder and are breastfeeding should be advised to discuss the options with their healthcare professionals.

Merck Sharp & Dohme Corp., a subsidiary of
MERCK & CO., INC., Whitehouse Station, NJ 08889, USA

For patent information: www.merck.com/product/patent/home.html

Copyright © 2001-2012 MSD International GmbH, a subsidiary of Merck & Co., Inc.
All rights reserved.

uspi-mk0653-t-1308r026

Merck Sharp & Dohme Corp., a subsidiary of
MERCK & CO., INC., Whitehouse Station, NJ 08889, USA

For patent information: www.merck.com/product/patent/home.html

Copyright © 2001-2012 MSD International GmbH, a subsidiary of Merck & Co., Inc.
All rights reserved.

Revised: 08/2013

usppi-mk0653-t-1308r026