Karac

FABIOR® (tazarotene) Foam, 0.1% is indicated for the topical treatment of acne vulgaris in patients 12 years of age or older.

Karac® (tazarotene) Gel 0.05% and 0.1% are indicated for the topical treatment of patients with stable plaque psoriasis of up to 20% body surface area involvement.

Karac® (tazarotene) Gel 0.1% is also indicated for the topical treatment of patients with facial acne vulgaris of mild to moderate severity.

The efficacy of Karac® (tazarotene gel) Gel in the treatment of acne previously treated with other retinoids or resistant to oral antibiotics has not been established.

Karac® (tazarotene) Foam, 0.1% is indicated for the topical treatment of acne vulgaris in patients 12 years of age or older.

FABIOR Foam is for topical use only. FABIOR Foam is not for oral, ophthalmic, or intravaginal use.

FABIOR Foam should be applied once daily in the evening after washing with a mild cleanser and fully drying the affected area. Dispense a small amount of foam into the palm of the hand. Using fingertips, apply only enough foam to lightly cover the entire affected areas of the face and/or upper trunk with a thin layer; gently massage the foam into the skin until the foam disappears. Avoid the eyes, lips, and mucous membranes. Wash hands after application.

Patients may use moisturizer as needed.

If undue irritation (redness, peeling, or discomfort) occurs, patients should reduce frequency of application or temporarily interrupt treatment. Treatment may be resumed once irritation subsides. Treatment should be discontinued if irritation persists.

General

Application may cause excessive irritation in the skin of certain sensitive individuals. In cases where it has been necessary to temporarily discontinue therapy, or the dosing has been reduced to a lower concentration (in patients with psoriasis) or to an interval the patient can tolerate, therapy can be resumed, or the drug concentration or frequency of application can be increased as the patient becomes able to tolerate the treatment. Frequency of application should be closely monitored by careful observation of the clinical therapeutic response and skin tolerance. Efficacy has not been established for less than once daily dosing frequencies.

For psoriasis: It is recommended that treatment start with Karac® (tazarotene gel) 0.05% Gel, with strength increased to 0.1% if tolerated and medically indicated. Apply Karac® (tazarotene gel) Gel once a day, in the evening, to psoriatic lesions, using enough (2 mg/cm²) to cover only the lesion with a thin film to no more than 20% of body surface area. If a bath or shower is taken prior to application, the skin should be dry before applying the gel. If emollients are used, they should be applied at least an hour before application of Karac® (tazarotene gel) Gel. Because unaffected skin may be more susceptible to irritation, application of tazarotene to these areas should be carefully avoided. Karac® (tazarotene gel) Gel was investigated for up to 12 months during clinical trials for psoriasis.

For acne: Cleanse the face gently. After the skin is dry, apply a thin film of Karac® (tazarotene gel) Gel 0.1% (2 mg/cm²) once a day, in the evening, to the skin where acne lesions appear. Use enough to cover the entire affected area. Karac® (tazarotene gel) Gel was investigated for up to 12 weeks during clinical trials for acne.

Karac Foam is for topical use only. Karac Foam is not for oral, ophthalmic, or intravaginal use.

Karac Foam should be applied once daily in the evening after washing with a mild cleanser and fully drying the affected area. Dispense a small amount of foam into the palm of the hand. Using fingertips, apply only enough foam to lightly cover the entire affected areas of the face and/or upper trunk with a thin layer; gently massage the foam into the skin until the foam disappears. Avoid the eyes, lips, and mucous membranes. Wash hands after application.

Patients may use moisturizer as needed.

If undue irritation (redness, peeling, or discomfort) occurs, patients should reduce frequency of application or temporarily interrupt treatment. Treatment may be resumed once irritation subsides. Treatment should be discontinued if irritation persists.

FABIOR Foam is contraindicated in pregnancy.

FABIOR Foam may cause fetal harm when administered to a pregnant woman. Tazarotene elicits teratogenic and developmental effects associated with retinoids after topical or systemic administration in rats and rabbits.

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, treatment should be discontinued and the patient apprised of the potential hazard to the fetus.

Retinoids may cause fetal harm when administered to a pregnant woman.

In rats, tazarotene 0.05% gel, administered topically during gestation days 6 through 17 at 0.25 mg/kg/day (1.5 mg/m²/day) resulted in reduced fetal body weights and reduced skeletal ossification. Rabbits dosed topically with 0.25 mg/kg/day (2.75 mg/m² total body surface area/day) tazarotene gel during gestation days 6 through 18 were noted with single incidences of known retinoid malformations, including spina bifida, hydrocephaly, and heart anomalies. Systemic daily-exposure (AUCde) to tazarotenic acid at topical doses of 0.25 mg/kg/day tazarotene in a gel formulation in rats and rabbits represented 0.62 and 6.7 times, respectively, the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 0.78 and 8.4 times, respectively, the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

As with other retinoids, when tazarotene was given orally to experimental animals, developmental delays were seen in rats, and teratogenic effects and post-implantation loss were observed in rats and rabbits at AUCde values that were 0.55 and 13.2 times, respectively, the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 0.68 and 16.4 times, respectively, the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

In a study of the effect of oral tazarotene on fertility and early embryonic development in rats, decreased number of implantation sites, decreased litter size, decreased numbers of live fetuses, and decreased fetal body weights, all classic developmental effects of retinoids, were observed when female rats were administered 2 mg/kg/day from 15 days before mating through gestation day 7. A low incidence of retinoid-related malformations at that dose was reported to be related to treatment. This dose produced an AUCde that was 1.7 times the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area) and 2.1 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

SYSTEMIC EXPOSURE TO TAZAROTENIC ACID IS DEPENDENT UPON THE EXTENT OF THE BODY SURFACE AREA TREATED. IN PATIENTS TREATED TOPICALLY OVER SUFFICIENT BODY SURFACE AREA, EXPOSURE COULD BE IN THE SAME ORDER OF MAGNITUDE AS IN THESE ORALLY TREATED ANIMALS. ALTHOUGH THERE MAY BE LESS SYSTEMIC EXPOSURE IN THE TREATMENT OF ACNE OF THE FACE ALONE DUE TO LESS SURFACE AREA FOR APPLICATION, TAZAROTENE IS A TERATOGENIC SUBSTANCE, AND IT IS NOT KNOWN WHAT LEVEL OF EXPOSURE IS REQUIRED FOR TERATOGENICITY IN HUMANS (SEE

Karac Foam is contraindicated in pregnancy.

WARNINGS

Included as part of the PRECAUTIONS section.

PRECAUTIONS

Fetal Risk

Systemic exposure to tazarotenic acid is dependent upon the extent of the body surface area treated. In patients treated topically over sufficient body surface area, exposure could be in the same order of magnitude as in orally treated animals. Tazarotene is a teratogenic substance, and it is not known what level of exposure is required for teratogenicity in humans.

There were 5 reported pregnancies in subjects who participated in clinical trials for topical tazarotene foam. One of the subjects was found to have been treated with topical tazarotene for 25 days, 2 were treated with vehicle foam, and the other 2 did not receive either tazarotene foam or vehicle foam. The subjects were discontinued from the trials when their pregnancy was reported. The one pregnant woman who was inadvertently exposed to topical tazarotene during the clinical trial delivered a full-term healthy infant.

Females Of Childbearing Potential

Females of child-bearing potential should be warned of the potential risk and use adequate birth-control measures when tazarotene foam is used. The possibility of pregnancy should be considered in females of child-bearing potential at the time of institution of therapy.

A negative serum or urine result for pregnancy test having a sensitivity down to at least 25 mIU/mL for human chorionic gonadotropin (hCG) should be obtained within 2 weeks prior to therapy with FABIOR Foam, which should begin during a normal menstrual period for females of childbearing potential. Advise patients of the need to use an effective method of contraception to avoid pregnancy.

Local Irritation

FABIOR Foam should be used with caution in patients with a history of local tolerability reactions or local hypersensitivity. Retinoids should not be used on abraded or eczematous skin, as they may cause severe irritation. Contact with the mouth, eyes, and mucous membranes should be avoided. In case of accidental contact, rinse well with water.

Some individuals may experience skin redness, peeling, burning or excessive pruritus. If these effects occur, the medication should either be discontinued until the integrity of the skin is restored, or the dosing should be reduced to an interval the patient can tolerate. However, efficacy at reduced frequency of application has not been established.

Weather extremes, such as wind or cold, may be more irritating to patients using FABIOR Foam.

Potential Irritant Effect With Concomitant Topical Medications

Concomitant topical acne therapy should be used with caution because a cumulative irritant effect may occur. If irritancy or dermatitis occurs, reduce frequency of application or temporarily interrupt treatment and resume once the irritation subsides. Treatment should be discontinued if the irritation persists.

Photosensitivity And Risk For Sunburn

Because of heightened burning susceptibility, exposure to sunlight (including sunlamps) should be avoided. Patients must be warned to use sunscreens and protective clothing when using FABIOR Foam. Patients with sunburn should be advised not to use FABIOR Foam until fully recovered. Patients who may have considerable sun exposure due to their occupation and those patients with inherent sensitivity to sunlight should exercise particular caution when using FABIOR Foam and ensure that the precautions are observed. Due to the potential for photosensitivity resulting in greater risk for sunburn, FABIOR Foam should be used with caution in patients with a personal or family history of skin cancer.

FABIOR Foam should be administered with caution if the patient is also taking drugs known to be photosensitizers (e.g., thiazides, tetracyclines, fluoroquinolones, phenothiazines, sulfonamides) because of the increased possibility of augmented photosensitivity.

Flammability

The propellant in FABIOR Foam is flammable. Instruct the patient to avoid fire, flame, and/or smoking during and immediately following application.

Patient Counseling Information

See FDA-approved patient labeling (PATIENT INFORMATION).

Inform the patient of the following:

• Fetal risk associated with FABIOR Foam for females of childbearing potential. Advise patients to use an effective method of contraception during treatment to avoid pregnancy. Advise the patient to stop medication if she becomes pregnant and call her doctor.
• If undue irritation (redness, peeling, or discomfort) occurs, reduce frequency of application or temporarily interrupt treatment. Treatment may be resumed once irritation subsides.
• Do not place FABIOR Foam in the freezer.
• Avoid exposure of the treated areas to either natural or artificial sunlight, including tanning beds and sun lamps.
• Avoid contact with the eyes. If FABIOR Foam gets in or near their eyes, to rinse thoroughly with water.
• Wash their hands after applying FABIOR Foam.
• Avoid fire, flame, or smoking during and immediately following application since FABIOR Foam is flammable.
• Keep out of the reach of children.
• Not for ophthalmic, oral, or intravaginal use.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

Carcinogenesis

A long-term study of tazarotene following oral administration of 0.025, 0.050, and 0.125 mg/kg/day to rats showed no indications of increased carcinogenic risk. Based on pharmacokinetic data from a shorter-term study in rats, the highest dose of 0.125 mg/kg/day was anticipated to give systemic exposure in rats approximately 2 times the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

A long-term topical application study of up to 0.1% tazarotene in a gel formulation in mice terminated at 88 weeks showed that dose levels of 0.05, 0.125, 0.25, and 1 mg/kg/day (reduced to 0.5 mg/kg/day for males after 41 weeks due to severe dermal irritation) revealed no apparent carcinogenic effects when compared with vehicle control animals. AUC at the highest dose in mice was 49 times the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

In evaluation of photocarcinogenicity, median time to onset of tumors was decreased and the number of tumors increased in hairless mice following chronic topical dosing with exposure to ultraviolet radiation at tazarotene concentrations of 0.001%, 0.005%, and 0.01% in a gel formulation for up to 40 weeks.

Mutagenesis

Tazarotene was non-mutagenic in the Ames assay and did not produce structural chromosomal aberrations in a human lymphocyte assay. Tazarotene was non-mutagenic in the CHO/HGPRT mammalian cell forward gene mutation assay and was non-clastogenic in the in vivo mouse micronucleus test.

Impairment Of Fertility

No impairment of fertility was observed in rats when male animals were treated for 70 days prior to mating and female animals were treated for 14 days prior to mating and continuing through gestation and lactation with topical doses of tazarotene gel up to 0.125 mg/kg/day. Based on data from another study, the systemic drug exposure at the 0.125 mg/kg/day dose in rats would be equivalent to 7.6 times the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

No impairment of mating performance or fertility was observed in male rats treated for 70 days prior to mating with oral doses of up to 1 mg/kg/day tazarotene. AUC at the highest dose in rats was 23 times the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

No effect on parameters of mating performance or fertility was observed in female rats treated for 15 days prior to mating and continuing through gestation day 7 with oral doses of tazarotene up to 2 mg/kg/day. However, there was a significant decrease in the number of estrous stages and an increase in developmental effects at that dose. AUC at the highest dose in rats was 42 times the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

Reproductive capabilities of F1 animals, including F2 survival and development, were not affected by topical administration of tazarotene gel to female F0 parental rats from gestation day 16 through lactation day 20 at the maximum tolerated dose of 0.125 mg/kg/day. Based on data from another study, the AUC in rats would be equivalent to 7.6 times the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

Use In Specific Populations

Pregnancy

Pregnancy Category X.

FABIOR Foam is contraindicated in pregnancy.

There are no adequate and well-controlled studies with FABIOR Foam in pregnant women. FABIOR Foam is contraindicated in females who are or may become pregnant. Females of child-bearing potential should be warned of the potential risk and use adequate birth-control measures when FABIOR Foam is used. The possibility that a female of child-bearing potential is pregnant at the time of institution of therapy should be considered. A negative serum or urine result for pregnancy test having a sensitivity down to at least 25 mIU/mL for hCG should be obtained within 2 weeks prior to therapy with FABIOR Foam, which should begin during a normal menstrual period for females of childbearing potential.

In rats, tazarotene 0.05% gel administered topically during gestation days 6 through 17 at 0.25 mg/kg/day resulted in reduced fetal body weights and reduced skeletal ossification. Rabbits dosed topically with 0.25 mg/kg/day tazarotene gel during gestation days 6 through 18 were noted with single incidences of known retinoid malformations, including spina bifida, hydrocephaly, and heart anomalies.

Systemic exposure (AUC) to tazarotenic acid at topical doses of 0.25 mg/kg/day tazarotene in a gel formulation in rats and rabbits were 15 and 166 times, respectively, the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

As with other retinoids, when tazarotene was administered orally to experimental animals, developmental delays were seen in rats, and teratogenic effects and post-implantation loss were observed in rats and rabbits at doses 13 and 325 times, respectively, the AUC to tazarotenic acid in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

In female rats orally administered 2 mg/kg/day tazarotene from 15 days before mating through gestation day 7, a number of classic developmental effects of retinoids were observed including decreased number of implantation sites, decreased litter size, decreased numbers of live fetuses, and decreased fetal body weights. A low incidence of retinoid-related malformations was also observed. AUC in rats was 42 times the AUC in acne patients treated with 2 mg/cm² of FABIOR Foam 0.1% over a 15% body surface area.

Nursing Mothers

After single topical doses of ¹⁴C-tazarotene to the skin of lactating rats, radioactivity was detected in milk, suggesting that there would be transfer of drug-related material to the offspring via milk. It is not known whether this drug is excreted in human milk. The safe use of FABIOR Foam during lactation has not been established. A decision should be made whether to discontinue breastfeeding or to discontinue therapy with FABIOR Foam taking into account the benefit of breastfeeding for the child and the benefit of therapy for the woman.

Pediatric Use

The safety and effectiveness of FABIOR Foam in pediatric patients younger than 12 years have not been established. Clinical studies of FABIOR Foam included 860 patients aged 12 to 17 years with acne vulgaris.

Geriatric Use

FABIOR Foam for the treatment of acne has not been clinically evaluated in persons over the age of 65.

WARNINGS

Pregnancy Category X

See CONTRAINDICATIONS section. Women of child-bearing potential should be warned of the potential risk and use adequate birth-control measures when Karac® (tazarotene gel) Gel is used. The possibility that a woman of childbearing potential is pregnant at the time of institution of therapy should be considered. A negative result for pregnancy test having a sensitivity down to at least 50 mIU/mL for hCG should be obtained within 2 weeks prior to Karac® (tazarotene gel) Gel therapy, which should begin during a normal menstrual period.

PRECAUTIONS

General

Karac® (tazarotene gel) Gel should be applied only to the affected areas. For external use only. Avoid contact with eyes, eyelids, and mouth. If contact with eyes occurs, rinse thoroughly with water. The safety of use of Karac® (tazarotene gel) Gel over more than 20% of body surface area has not been established in psoriasis or acne.

Retinoids should not be used on eczematous skin, as they may cause severe irritation.

Because of heightened burning susceptibility, exposure to sunlight (including sunlamps) should be avoided unless deemed medically necessary, and in such cases, exposure should be minimized during the use of Karac® (tazarotene gel) Gel. Patients must be warned to use sunscreens (minimum SPF of 15) and protective clothing when using Karac® (tazarotene gel) Gel. Patients with sunburn should be advised not to use Karac® (tazarotene gel) Gel until fully recovered. Patients who may have considerable sun exposure due to their occupation and those patients with inherent sensitivity to sunlight should exercise particular caution when using Karac® (tazarotene gel) Gel and ensure that the precautions outlined in the Information for Patients subsection are observed.

Karac® (tazarotene gel) Gel should be administered with caution if the patient is also taking drugs known to be photosensitizers (e.g., thiazides, tetracyclines, fluoroquinolones, phenothiazines, sulfonamides) because of the increased possibility of augmented photosensitivity.

Some individuals may experience excessive pruritus, burning, skin redness or peeling. If these effects occur, the medication should either be discontinued until the integrity of the skin is restored, or the dosing should be reduced to an interval the patient can tolerate. However, efficacy at reduced frequency of application has not been established. Alternatively, patients with psoriasis who are being treated with the 0.1% concentration can be switched to the lower concentration.

Weather extremes, such as wind or cold, may be more irritating to patients using Karac® (tazarotene gel) Gel.

Information for Patients

See Patient Package Insert.

Carcinogenesis, Mutagenesis, Impairment of Fertility

A long-term study of tazarotene following oral administration of 0.025, 0.050, and 0.125 mg/kg/day to rats showed no indications of increased carcinogenic risks. Based on pharmacokinetic data from a shorter-term study in rats, the highest dose of 0.125 mg/kg/day was anticipated to give systemic exposure (AUCde) in the rat equivalent to 0.32 times the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 0.38 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

In evaluation of photo co-carcinogenicity, median time to onset of tumors was decreased, and the number of tumors increased in hairless mice following chronic topical dosing with intercurrent exposure to ultraviolet radiation at tazarotene concentrations of 0.001%, 0.005%, and 0.01% in a gel formulation for up to 40 weeks.

A long-term topical application study of up to 0.1% tazarotene in a gel formulation in mice terminated at 88 weeks showed that dose levels of 0.05, 0.125, 0.25, and 1 mg/kg/day (reduced to 0.5 mg/kg/day for males after 41 weeks due to severe dermal irritation) revealed no apparent carcinogenic effects when compared to vehicle control animals; untreated control animals were not completely evaluated. Systemic exposure (AUC0-12h) at the highest dose was 2 times the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 2.5 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

Tazarotene was found to be non-mutagenic in the Ames assay using Salmonella and E. coli and did not produce structural chromosomal aberrations in a human lymphocyte assay. Tazarotene was also non-mutagenic in the CHO/HGPRT mammalian cell forward gene mutation assay and was non-clastogenic in the in vivo mouse micronucleus test.

No impairment of fertility occurred in rats when male animals were treated for 70 days prior to mating and female animals were treated for 14 days prior to mating and continuing through gestation and lactation with topical doses of tazarotene gel up to 0.125 mg/kg/day. Based on data from another study, the systemic drug exposure (AUCde) in the rat would be equivalent to 0.31 times the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 0.38 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

No impairment of mating performance or fertility was observed in male rats treated for 70 days prior to mating with oral doses of up to 1 mg/kg/day tazarotene, which produced an AUCde that was 0.95 times the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 1.2 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

No effect on parameters of mating performance or fertility was observed in female rats treated for 15 days prior to mating and continuing through day 7 of gestation with oral doses of tazarotene up to 2 mg/kg/day. However, there was a significant decrease in the number of estrous stages and an increase in developmental effects at 2 mg/kg/day (see CONTRAINDICATIONS). This dose produced an AUC0-24h which was 1.7 times that observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 2.1 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

Reproductive capabilities of F1 animals, including F2 survival and development, were not affected by topical administration of tazarotene gel to female F0 parental rats from gestation day 16 through lactation day 20 at the maximum tolerated dose of 0.125 mg/kg/day. Based on data from another study, the systemic drug exposure (AUCde) in the rat would be equivalent to 0.31 times the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 0.38 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

Pregnancy

Teratogenic Effects - Pregnancy Category X

See CONTRAINDICATIONS section. Women of childbearing potential should use adequate birth-control measures when Karac® (tazarotene gel) Gel is used. The possibility that a woman of childbearing potential is pregnant at the time of institution of therapy should be considered. A negative result for pregnancy test having a sensitivity down to at least 50 mIU/mL for hCG should be obtained within 2 weeks prior to Karac® (tazarotene gel) Gel therapy, which should begin during a normal menstrual period. There are no adequate, well-controlled studies in pregnant women. Although there may be less systemic exposure in the treatment of acne of the face alone due to less surface area for application, tazarotene is a teratogenic substance, and it is not known what level of exposure is required for teratogenicity in humans (see CLINICAL PHARMACOLOGY: Pharmacokinetics).

Nursing Mothers

After single topical doses of ¹⁴C-tazarotene to the skin of lactating rats, radioactivity was detected in milk, suggesting that there would be transfer of drug-related material to the offspring via milk. It is not known whether this drug is excreted in human milk. Caution should be exercised when tazarotene is administered to a nursing woman.

Pediatric Use

The safety and efficacy of tazarotene have not been established in pediatric patients under the age of 12 years.

Geriatric Use

Of the total number of subjects in clinical studies of tazarotene gels, 0.05% and 0.1% for plaque psoriasis, 163 were over the age of 65. Subjects over 65 years of age experienced more adverse events and lower treatment success rates after 12 weeks of use of Karac® (tazarotene gel) Gel compared with those 65 years of age and younger. Currently there is no other reliable clinical experience on the differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals can not be ruled out. Tazarotene gel for the treatment of acne has not been clinically evaluated in persons over the age of 65.

WARNINGS

Included as part of the PRECAUTIONS section.

PRECAUTIONS

Fetal Risk

Systemic exposure to tazarotenic acid is dependent upon the extent of the body surface area treated. In patients treated topically over sufficient body surface area, exposure could be in the same order of magnitude as in orally treated animals. Tazarotene is a teratogenic substance, and it is not known what level of exposure is required for teratogenicity in humans.

There were 5 reported pregnancies in subjects who participated in clinical trials for topical tazarotene foam. One of the subjects was found to have been treated with topical tazarotene for 25 days, 2 were treated with vehicle foam, and the other 2 did not receive either tazarotene foam or vehicle foam. The subjects were discontinued from the trials when their pregnancy was reported. The one pregnant woman who was inadvertently exposed to topical tazarotene during the clinical trial delivered a full-term healthy infant.

Females Of Childbearing Potential

Females of child-bearing potential should be warned of the potential risk and use adequate birth-control measures when tazarotene foam is used. The possibility of pregnancy should be considered in females of child-bearing potential at the time of institution of therapy.

A negative serum or urine result for pregnancy test having a sensitivity down to at least 25 mIU/mL for human chorionic gonadotropin (hCG) should be obtained within 2 weeks prior to therapy with Karac Foam, which should begin during a normal menstrual period for females of childbearing potential. Advise patients of the need to use an effective method of contraception to avoid pregnancy.

Local Irritation

Karac Foam should be used with caution in patients with a history of local tolerability reactions or local hypersensitivity. Retinoids should not be used on abraded or eczematous skin, as they may cause severe irritation. Contact with the mouth, eyes, and mucous membranes should be avoided. In case of accidental contact, rinse well with water.

Some individuals may experience skin redness, peeling, burning or excessive pruritus. If these effects occur, the medication should either be discontinued until the integrity of the skin is restored, or the dosing should be reduced to an interval the patient can tolerate. However, efficacy at reduced frequency of application has not been established.

Weather extremes, such as wind or cold, may be more irritating to patients using Karac Foam.

Potential Irritant Effect With Concomitant Topical Medications

Concomitant topical acne therapy should be used with caution because a cumulative irritant effect may occur. If irritancy or dermatitis occurs, reduce frequency of application or temporarily interrupt treatment and resume once the irritation subsides. Treatment should be discontinued if the irritation persists.

Photosensitivity And Risk For Sunburn

Because of heightened burning susceptibility, exposure to sunlight (including sunlamps) should be avoided. Patients must be warned to use sunscreens and protective clothing when using Karac Foam. Patients with sunburn should be advised not to use Karac Foam until fully recovered. Patients who may have considerable sun exposure due to their occupation and those patients with inherent sensitivity to sunlight should exercise particular caution when using Karac Foam and ensure that the precautions are observed. Due to the potential for photosensitivity resulting in greater risk for sunburn, Karac Foam should be used with caution in patients with a personal or family history of skin cancer.

Karac Foam should be administered with caution if the patient is also taking drugs known to be photosensitizers (e.g., thiazides, tetracyclines, fluoroquinolones, phenothiazines, sulfonamides) because of the increased possibility of augmented photosensitivity.

Flammability

The propellant in Karac Foam is flammable. Instruct the patient to avoid fire, flame, and/or smoking during and immediately following application.

Patient Counseling Information

See FDA-approved patient labeling (PATIENT INFORMATION).

Inform the patient of the following:

• Fetal risk associated with Karac Foam for females of childbearing potential. Advise patients to use an effective method of contraception during treatment to avoid pregnancy. Advise the patient to stop medication if she becomes pregnant and call her doctor.
• If undue irritation (redness, peeling, or discomfort) occurs, reduce frequency of application or temporarily interrupt treatment. Treatment may be resumed once irritation subsides.
• Do not place Karac Foam in the freezer.
• Avoid exposure of the treated areas to either natural or artificial sunlight, including tanning beds and sun lamps.
• Avoid contact with the eyes. If Karac Foam gets in or near their eyes, to rinse thoroughly with water.
• Wash their hands after applying Karac Foam.
• Avoid fire, flame, or smoking during and immediately following application since Karac Foam is flammable.
• Keep out of the reach of children.
• Not for ophthalmic, oral, or intravaginal use.

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

Carcinogenesis

A long-term study of tazarotene following oral administration of 0.025, 0.050, and 0.125 mg/kg/day to rats showed no indications of increased carcinogenic risk. Based on pharmacokinetic data from a shorter-term study in rats, the highest dose of 0.125 mg/kg/day was anticipated to give systemic exposure in rats approximately 2 times the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

A long-term topical application study of up to 0.1% tazarotene in a gel formulation in mice terminated at 88 weeks showed that dose levels of 0.05, 0.125, 0.25, and 1 mg/kg/day (reduced to 0.5 mg/kg/day for males after 41 weeks due to severe dermal irritation) revealed no apparent carcinogenic effects when compared with vehicle control animals. AUC at the highest dose in mice was 49 times the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

In evaluation of photocarcinogenicity, median time to onset of tumors was decreased and the number of tumors increased in hairless mice following chronic topical dosing with exposure to ultraviolet radiation at tazarotene concentrations of 0.001%, 0.005%, and 0.01% in a gel formulation for up to 40 weeks.

Mutagenesis

Tazarotene was non-mutagenic in the Ames assay and did not produce structural chromosomal aberrations in a human lymphocyte assay. Tazarotene was non-mutagenic in the CHO/HGPRT mammalian cell forward gene mutation assay and was non-clastogenic in the in vivo mouse micronucleus test.

Impairment Of Fertility

No impairment of fertility was observed in rats when male animals were treated for 70 days prior to mating and female animals were treated for 14 days prior to mating and continuing through gestation and lactation with topical doses of tazarotene gel up to 0.125 mg/kg/day. Based on data from another study, the systemic drug exposure at the 0.125 mg/kg/day dose in rats would be equivalent to 7.6 times the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

No impairment of mating performance or fertility was observed in male rats treated for 70 days prior to mating with oral doses of up to 1 mg/kg/day tazarotene. AUC at the highest dose in rats was 23 times the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

No effect on parameters of mating performance or fertility was observed in female rats treated for 15 days prior to mating and continuing through gestation day 7 with oral doses of tazarotene up to 2 mg/kg/day. However, there was a significant decrease in the number of estrous stages and an increase in developmental effects at that dose. AUC at the highest dose in rats was 42 times the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

Reproductive capabilities of F1 animals, including F2 survival and development, were not affected by topical administration of tazarotene gel to female F0 parental rats from gestation day 16 through lactation day 20 at the maximum tolerated dose of 0.125 mg/kg/day. Based on data from another study, the AUC in rats would be equivalent to 7.6 times the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

Use In Specific Populations

Pregnancy

Pregnancy Category X.

Karac Foam is contraindicated in pregnancy.

There are no adequate and well-controlled studies with Karac Foam in pregnant women. Karac Foam is contraindicated in females who are or may become pregnant. Females of child-bearing potential should be warned of the potential risk and use adequate birth-control measures when Karac Foam is used. The possibility that a female of child-bearing potential is pregnant at the time of institution of therapy should be considered. A negative serum or urine result for pregnancy test having a sensitivity down to at least 25 mIU/mL for hCG should be obtained within 2 weeks prior to therapy with Karac Foam, which should begin during a normal menstrual period for females of childbearing potential.

In rats, tazarotene 0.05% gel administered topically during gestation days 6 through 17 at 0.25 mg/kg/day resulted in reduced fetal body weights and reduced skeletal ossification. Rabbits dosed topically with 0.25 mg/kg/day tazarotene gel during gestation days 6 through 18 were noted with single incidences of known retinoid malformations, including spina bifida, hydrocephaly, and heart anomalies.

Systemic exposure (AUC) to tazarotenic acid at topical doses of 0.25 mg/kg/day tazarotene in a gel formulation in rats and rabbits were 15 and 166 times, respectively, the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

As with other retinoids, when tazarotene was administered orally to experimental animals, developmental delays were seen in rats, and teratogenic effects and post-implantation loss were observed in rats and rabbits at doses 13 and 325 times, respectively, the AUC to tazarotenic acid in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

In female rats orally administered 2 mg/kg/day tazarotene from 15 days before mating through gestation day 7, a number of classic developmental effects of retinoids were observed including decreased number of implantation sites, decreased litter size, decreased numbers of live fetuses, and decreased fetal body weights. A low incidence of retinoid-related malformations was also observed. AUC in rats was 42 times the AUC in acne patients treated with 2 mg/cm² of Karac Foam 0.1% over a 15% body surface area.

Nursing Mothers

After single topical doses of ¹⁴C-tazarotene to the skin of lactating rats, radioactivity was detected in milk, suggesting that there would be transfer of drug-related material to the offspring via milk. It is not known whether this drug is excreted in human milk. The safe use of Karac Foam during lactation has not been established. A decision should be made whether to discontinue breastfeeding or to discontinue therapy with Karac Foam taking into account the benefit of breastfeeding for the child and the benefit of therapy for the woman.

Pediatric Use

The safety and effectiveness of Karac Foam in pediatric patients younger than 12 years have not been established. Clinical studies of Karac Foam included 860 patients aged 12 to 17 years with acne vulgaris.

Geriatric Use

Karac Foam for the treatment of acne has not been clinically evaluated in persons over the age of 65.

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 practice.

The safety data reflect exposure to FABIOR Foam in 744 subjects with acne vulgaris. Subjects were aged 12 to 45 years and were treated once daily in the evening for 12 weeks. Adverse reactions reported in ≥ 1% of subjects treated with FABIOR Foam are presented in Table 1. Most adverse reactions were mild to moderate in severity. Severe adverse reactions represented 3.0% of the subjects treated. Overall, 2.7% (20/744) of subjects discontinued FABIOR Foam because of local skin reactions.

Table 1: Incidence of Adverse Reactions in ≥ 1 % of Subjects Treated with FABIOR Foam

Additional adverse reactions that were reported in < 1% of subjects treated with FABIOR Foam included application site reactions (including discoloration, discomfort, edema, rash, and swelling), dermatitis, impetigo, and pruritus.

Local skin reactions, dryness, erythema, and peeling actively assessed by the investigator and burning/stinging and itching reported by the subject were evaluated at baseline, during treatment, and end of treatment. During the 12 weeks of treatment, each local skin reaction peaked at Week 2 and gradually reduced thereafter with the continued use of FABIOR Foam.

In human dermal safety studies, tazarotene 0.05% and 0.1% gels did not induce allergic contact sensitization, phototoxicity or photoallergy.

Psoriasis

The most frequent adverse events reported with Karac® (tazarotene gel) Gel 0.05% and 0.1% were limited to the skin. Those occurring in 10 to 30% of patients, in descending order, included pruritus, burning/stinging, erythema, worsening of psoriasis, irritation, and skin pain. Events occurring in 1 to 10% of patients included rash, desquamation, irritant contact dermatitis, skin inflammation, fissuring, bleeding, and dry skin. Increases in “psoriasis worsening” and “sun-induced erythema” were noted in some patients over the 4th to 12th months as compared to the first three months of a 1 year study. In general, the incidence of adverse events with Karac® (tazarotene gel) Gel 0.05% was 2 to 5% lower than that seen with Karac® (tazarotene gel) Gel 0.1%.

Acne

The most frequent adverse events reported with Karac® (tazarotene gel) Gel 0.1% in the treatment of acne occurring in 10 to 30% of patients, in descending order, included desquamation, burning/stinging, dry skin, erythema and pruritus. Events occurring in 1 to 10% of patients included irritation, skin pain, fissuring, localized edema and skin discoloration.

Postmarketing Experience

The following adverse reactions have been identified during postmarketing use of Karac® (tazarotene gel) Gel 0.05% and 0.1% in clinical practice. Because they are reported voluntarily from a population of unknown size, it is not always possible to reliably estimate their frequency or establish a causal relationship to Karac® (tazarotene gel) Gel. The reactions include: blister, rash, skin discoloration (including skin hyperpigmentation or skin hypopigmentation), and pain.

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 practice.

The safety data reflect exposure to Karac Foam in 744 subjects with acne vulgaris. Subjects were aged 12 to 45 years and were treated once daily in the evening for 12 weeks. Adverse reactions reported in ≥ 1% of subjects treated with Karac Foam are presented in Table 1. Most adverse reactions were mild to moderate in severity. Severe adverse reactions represented 3.0% of the subjects treated. Overall, 2.7% (20/744) of subjects discontinued Karac Foam because of local skin reactions.

Table 1: Incidence of Adverse Reactions in ≥ 1 % of Subjects Treated with Karac Foam

Additional adverse reactions that were reported in < 1% of subjects treated with Karac Foam included application site reactions (including discoloration, discomfort, edema, rash, and swelling), dermatitis, impetigo, and pruritus.

Local skin reactions, dryness, erythema, and peeling actively assessed by the investigator and burning/stinging and itching reported by the subject were evaluated at baseline, during treatment, and end of treatment. During the 12 weeks of treatment, each local skin reaction peaked at Week 2 and gradually reduced thereafter with the continued use of Karac Foam.

Excessive topical application of FABIOR Foam may lead to marked redness, peeling, or discomfort.. Management of accidental ingestion or excessive application to the skin should be as clinically indicated.

Excessive topical use of Karac® (tazarotene gel) Gel may lead to marked redness, peeling, or discomfort (see PRECAUTIONS: General).

Karac® (tazarotene gel) Gels 0.05% and 0.1% are not for oral use. Oral ingestion of the drug may lead to the same adverse effects as those associated with excessive oral intake of Vitamin A (hypervitaminosis A) or other retinoids. If oral ingestion occurs, the patient should be monitored, and appropriate supportive measures should be administered as necessary.

Excessive topical application of Karac Foam may lead to marked redness, peeling, or discomfort.. Management of accidental ingestion or excessive application to the skin should be as clinically indicated.

The pharmacodynamics of FABIOR Foam are unknown.

The pharmacodynamics of Karac Foam are unknown.

Following topical application, tazarotene undergoes esterase hydrolysis to form its active metabolite, tazarotenic acid. Tazarotenic acid was highly bound to plasma proteins (greater than 99%). Tazarotene and tazarotenic acid were metabolized to sulfoxides, sulfones, and other polar metabolites which were eliminated through urinary and fecal pathways.

Systemic exposure following topical application of FABIOR Foam 0.1% was evaluated in one trial. Patients aged 15 years and older with moderate-to-severe acne applied approximately 3.7 grams of FABIOR Foam 0.1% (N = 13) to approximately 15% body surface area (face, upper chest, upper back, and shoulders) once daily for 22 days. On Day 22, the mean (±SD) tazarotenic acid Cmax was 0.43 (±0.19) ng/mL, the AUC0-24h - was 6.98 (±3.56) ng·h/mL, and the half-life was 21.7 (±15.7) hours. The median Tmax was 6 hours (range: 4.4 to 12 hours). The AUC0-24h for tazarotenic acid was approximately 50-fold higher compared with the parent compound tazarotene. The mean (±SD) half-life of tazarotene was 8.1 (±3.7) hours.

Accumulation was observed upon repeated once-daily dosing as the tazarotenic acid predose concentrations were measurable in the majority of subjects. Steady state was attained within 22 days of daily application. Once-daily dosing resulted in little to no accumulation of tazarotene as predose concentrations were mostly below the quantitation limit throughout the study.

Nursing Mothers

After single topical doses of ¹⁴C-tazarotene to the skin of lactating rats, radioactivity was detected in milk, suggesting that there would be transfer of drug-related material to the offspring via milk. It is not known whether this drug is excreted in human milk. Caution should be exercised when tazarotene is administered to a nursing woman.

Pediatric Use

The safety and efficacy of tazarotene have not been established in pediatric patients under the age of 12 years.

Geriatric Use

Of the total number of subjects in clinical studies of tazarotene gels, 0.05% and 0.1% for plaque psoriasis, 163 were over the age of 65. Subjects over 65 years of age experienced more adverse events and lower treatment success rates after 12 weeks of use of Karac® (tazarotene gel) Gel compared with those 65 years of age and younger. Currently there is no other reliable clinical experience on the differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals can not be ruled out. Tazarotene gel for the treatment of acne has not been clinically evaluated in persons over the age of 65.

OVERDOSE

Excessive topical use of Karac® (tazarotene gel) Gel may lead to marked redness, peeling, or discomfort (see PRECAUTIONS: General).

Karac® (tazarotene gel) Gels 0.05% and 0.1% are not for oral use. Oral ingestion of the drug may lead to the same adverse effects as those associated with excessive oral intake of Vitamin A (hypervitaminosis A) or other retinoids. If oral ingestion occurs, the patient should be monitored, and appropriate supportive measures should be administered as necessary.

CONTRAINDICATIONS

Retinoids may cause fetal harm when administered to a pregnant woman.

In rats, tazarotene 0.05% gel, administered topically during gestation days 6 through 17 at 0.25 mg/kg/day (1.5 mg/m²/day) resulted in reduced fetal body weights and reduced skeletal ossification. Rabbits dosed topically with 0.25 mg/kg/day (2.75 mg/m² total body surface area/day) tazarotene gel during gestation days 6 through 18 were noted with single incidences of known retinoid malformations, including spina bifida, hydrocephaly, and heart anomalies. Systemic daily-exposure (AUCde) to tazarotenic acid at topical doses of 0.25 mg/kg/day tazarotene in a gel formulation in rats and rabbits represented 0.62 and 6.7 times, respectively, the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 0.78 and 8.4 times, respectively, the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

As with other retinoids, when tazarotene was given orally to experimental animals, developmental delays were seen in rats, and teratogenic effects and post-implantation loss were observed in rats and rabbits at AUCde values that were 0.55 and 13.2 times, respectively, the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² of tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area), and 0.68 and 16.4 times, respectively, the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

In a study of the effect of oral tazarotene on fertility and early embryonic development in rats, decreased number of implantation sites, decreased litter size, decreased numbers of live fetuses, and decreased fetal body weights, all classic developmental effects of retinoids, were observed when female rats were administered 2 mg/kg/day from 15 days before mating through gestation day 7. A low incidence of retinoid-related malformations at that dose was reported to be related to treatment. This dose produced an AUCde that was 1.7 times the AUC0-24h observed in psoriatic patients treated with 2 mg/cm² tazarotene gel 0.1% (extrapolated for topical application over 20% body surface area) and 2.1 times the maximum AUC0-24h in acne patients treated with 2 mg/cm² of tazarotene gel 0.1% over 15% (targeted) body surface area.

SYSTEMIC EXPOSURE TO TAZAROTENIC ACID IS DEPENDENT UPON THE EXTENT OF THE BODY SURFACE AREA TREATED. IN PATIENTS TREATED TOPICALLY OVER SUFFICIENT BODY SURFACE AREA, EXPOSURE COULD BE IN THE SAME ORDER OF MAGNITUDE AS IN THESE ORALLY TREATED ANIMALS. ALTHOUGH THERE MAY BE LESS SYSTEMIC EXPOSURE IN THE TREATMENT OF ACNE OF THE FACE ALONE DUE TO LESS SURFACE AREA FOR APPLICATION, TAZAROTENE IS A TERATOGENIC SUBSTANCE, AND IT IS NOT KNOWN WHAT LEVEL OF EXPOSURE IS REQUIRED FOR TERATOGENICITY IN HUMANS (SEE CLINICAL PHARMACOLOGY: Pharmacokinetics).

There were thirteen reported pregnancies in patients who participated in clinical trials for topical tazarotene. Nine of the patients were found to have been treated with topical tazarotene, and the other four had been treated with vehicle. One of the patients who was treated with tazarotene cream elected to terminate the pregnancy for non-medical reasons unrelated to treatment. The other eight pregnant women who were inadvertently exposed to topical tazarotene during clinical trials subsequently delivered apparently healthy babies. As the exact timing and extent of exposure in relation to the gestation times are not certain, the significance of these findings is unknown.

Karac® (tazarotene gel) Gel is contraindicated in women who are or may become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, treatment should be discontinued and the patient apprised of the potential hazard to the fetus. Women of child-bearing potential should be warned of the potential risk and use adequate birth-control measures when Karac® (tazarotene gel) Gel is used. The possibility that a woman of childbearing potential is pregnant at the time of institution of therapy should be considered. A negative result for pregnancy test having a sensitivity down to at least 50 mIU/mL for human chorionic gonadotropin (hCG) should be obtained within 2 weeks prior to Karac® (tazarotene gel) Gel therapy, which should begin during a normal menstrual period (see also PRECAUTIONS: Pregnancy: Teratogenic Effects).

Karac® (tazarotene gel) Gel is contraindicated in individuals who have shown hypersensitivity to any of its components.

CLINICAL PHARMACOLOGY

Tazarotene is a retinoid prodrug which is converted to its active form, the cognate carboxylic acid of tazarotene (AGN 190299), by rapid deesterification in animals and man. AGN 190299 (“tazarotenic acid”) binds to all three members of the retinoic acid receptor (RAR) family: RARα, RARβ, and RARγ but shows relative selectivity for RARβ, and RARγ and may modify gene expression. The clinical significance of these findings is unknown.

Psoriasis

The mechanism of tazarotene action in psoriasis is not defined. Topical tazarotene blocks induction of mouse epidermal ornithine decarboxylase (ODC) activity, which is associated with cell proliferation and hyperplasia. In cell culture and in vitro models of skin, tazarotene suppresses expression of MRP8, a marker of inflammation present in the epidermis of psoriasis patients at high levels. In human keratinocyte cultures, it inhibits cornified envelope formation, whose build-up is an element of the psoriatic scale. Tazarotene also induces the expression of a gene which may be a growth suppressor in human keratinocytes and which may inhibit epidermal hyperproliferation in treated plaques. However, the clinical significance of these findings is unknown.

Acne

The mechanism of tazarotene action in acne vulgaris is not defined. However, the basis of tazarotene's therapeutic effect in acne may be due to its anti-hyperproliferative, normalizing-of-differentiation and antiinflammatory effects. Tazarotene inhibited corneocyte accumulation in rhino mouse skin and cross-linked envelope formation in cultured human keratinocytes. The clinical significance of these findings is unknown.

Pharmacokinetics

Following topical application, tazarotene undergoes esterase hydrolysis to form its active metabolite, tazarotenic acid. Little parent compound could be detected in the plasma. Tazarotenic acid was highly bound to plasma proteins ( ≥ greater than 99%). Tazarotene and tazarotenic acid were metabolized to sulfoxides, sulfones and other polar metabolites which were eliminated through urinary and fecal pathways. The half-life of tazarotenic acid was approximately 18 hours, following topical application of tazarotene to normal, acne or psoriatic skin.

The human in vivo studies described below were conducted with tazarotene gel applied topically at approximately 2 mg/cm² and left on the skin for 10 to 12 hours. Both the peak plasma concentration (Cmax) and area under the plasma concentration time curve (AUC) refer to the active metabolite only.

Two single, topical dose studies were conducted using ¹⁴C-tazarotene gel. Systemic absorption, as determined from radioactivity in the excreta, was less than 1% of the applied dose (without occlusion) in six psoriatic patients and approximately 5% of the applied dose (under occlusion) in six healthy subjects. One non-radiolabeled single-dose study comparing the 0.05% gel to the 0.1% gel in healthy subjects indicated that the Cmax and AUC were 40% higher for the 0.1% gel.

After 7 days of topical dosing with measured doses of tazarotene 0.1% gel on 20% of the total body surface without occlusion in 24 healthy subjects, the Cmax for tazarotenic acid was 0.72 RMG 0.58 ng/mL (mean RMG SD) occurring 9 hours after the last dose, and the AUC0-24hr for tazarotenic acid was 10.1 RMG 7.2 ng·hr/mL. Systemic absorption was 0.91 RMG 0.67% of the applied dose.

In a 14-day study in five psoriatic patients, measured doses of tazarotene 0.1% gel were applied daily by nursing staff to involved skin without occlusion (8 to 18% of total body surface area; mean RMG SD: 13 RMG 5%). The Cmax for tazarotenic acid was 12.0 RMG 7.6 ng/mL occurring 6 hours after the final dose, and the AUC0-24hr for tazarotenic acid was 105 RMG 55 ng·hr/mL. Systemic absorption was 14.8 RMG 7.6% of the applied dose. Extrapolation of these results to represent dosing on 20% of total body surface yielded estimates for tazarotenic acid with Cmax of 18.9 RMG 10.6 ng/mL and AUC0-24hr of 172 RMG 88 ng·hr/mL.

An in vitro percutaneous absorption study, using radiolabeled drug and freshly excised human skin or human cadaver skin, indicated that approximately 4 to 5% of the applied dose was in the stratum corneum (tazarotene: tazarotenic acid = 5:1) and 2 to 4% was in the viable epidermis-dermis layer (tazarotene:tazarotenic acid = 2:1) 24 hours after topical application of the gel.

Clinical Studies

Psoriasis

In two large vehicle-controlled clinical studies, tazarotene 0.05% and 0.1% gels applied once daily for 12 weeks were significantly more effective than vehicle in reducing the severity of the clinical signs of stable plaque psoriasis covering up to 20% of body surface area. In one of the studies, patients were followed up for an additional 12 weeks following cessation of therapy with Karac® (tazarotene gel) Gel. Mean baseline scores and changes from baseline (reductions) after treatment in these two studies are shown in the following table:

Plaque Elevation, Scaling and Erythema in Two Controlled Clinical Trials for Psoriasis

Global improvement over baseline at the end of 12 weeks of treatment in these two studies is shown in the following table:

The 0.1% gel was more effective than the 0.05% gel, but the 0.05% gel was associated with less local irritation than the 0.1% gel (see ADVERSE REACTIONS section).

Acne

In two large vehicle-controlled studies, tazarotene 0.1% gel applied once daily was significantly more effective than vehicle in the treatment of facial acne vulgaris of mild to moderate severity. Percent reductions in lesion counts after treatment for 12 weeks in these two studies are shown in the following table:

Reduction in Lesion Counts after Twelve Weeks of Treatment in Two Controlled Clinical Trials for Acne

Global improvement over baseline at the end of 12 weeks of treatment in these two studies is shown in the following table:

Following topical application, tazarotene undergoes esterase hydrolysis to form its active metabolite, tazarotenic acid. Tazarotenic acid was highly bound to plasma proteins (greater than 99%). Tazarotene and tazarotenic acid were metabolized to sulfoxides, sulfones, and other polar metabolites which were eliminated through urinary and fecal pathways.

Systemic exposure following topical application of Karac Foam 0.1% was evaluated in one trial. Patients aged 15 years and older with moderate-to-severe acne applied approximately 3.7 grams of Karac Foam 0.1% (N = 13) to approximately 15% body surface area (face, upper chest, upper back, and shoulders) once daily for 22 days. On Day 22, the mean (±SD) tazarotenic acid Cmax was 0.43 (±0.19) ng/mL, the AUC0-24h - was 6.98 (±3.56) ng·h/mL, and the half-life was 21.7 (±15.7) hours. The median Tmax was 6 hours (range: 4.4 to 12 hours). The AUC0-24h for tazarotenic acid was approximately 50-fold higher compared with the parent compound tazarotene. The mean (±SD) half-life of tazarotene was 8.1 (±3.7) hours.

Accumulation was observed upon repeated once-daily dosing as the tazarotenic acid predose concentrations were measurable in the majority of subjects. Steady state was attained within 22 days of daily application. Once-daily dosing resulted in little to no accumulation of tazarotene as predose concentrations were mostly below the quantitation limit throughout the study.