Taclonex Scalp

Dosage Forms And Strengths

Topical Suspension, 0.005%/0.064%

Each gram of Taclonex® Topical Suspension contains 52.18 mcg of calcipotriene hydrate (equivalent to 50 mcg of calcipotriene) and 0.643 mg of betamethasone dipropionate (equivalent to 0.5 mg of betamethasone). Taclonex® Topical Suspension is a viscous, nearly odorless, almost clear, colorless to slightly off-white suspension.

Applicator: After priming, each full actuation delivers a consistent amount of Taclonex® Topical Suspension.

Storage And Handling

Taclonex® Topical Suspension is a viscous, nearly odorless, almost clear, colorless to slightly off-white suspension. It is available as: 60 g bottle (NDC 50222-501-06)

60 g cartridge with applicator (NDC 50222-499-60)
120 g (2 bottles of 60 g) (NDC 50222-501-66)

Storage

Store between 20°C-25°C (68°F-77°F); excursions permitted between 15°C-30°C (59°F-86°F).

Do not refrigerate.

Bottle: Keep the bottle in the outer carton when not in use. Unused product should be discarded six months after the bottle has been opened.

Applicator: Unused product should be discarded six months after the cartridge has been opened.

Handling

Bottle: Shake before use. Applicator: Follow the enclosed “Instructions for Use”. Keep out of reach of children

Manufactured by: LEO Laboratories Ltd., 285 Cashel Road, Dublin 12, Ireland Distributed by: LEO Pharma Inc., 1 Sylvan Way, Parsippany, NJ 07054. Revised: June 2016

Taclonex® Topical Suspension is indicated for the topical treatment of:

• Plaque psoriasis of the scalp and body in patients 18 years and older
• Plaque psoriasis of the scalp in patients 12 to 17 years

Bottle: Instruct patients to shake bottle prior to using Taclonex® Topical Suspension and to wash their hands after applying the product.

Applicator: Instruct patients to wash their hands if they get Taclonex® Topical Suspension on their fingers.

Apply Taclonex® Topical Suspension to affected areas once daily for up to 8 weeks. Therapy should be discontinued when control is achieved.

Patients 18 years and older should not use more than 100 g per week and patients 12 to 17 years should not use more than 60 g per week.

Taclonex® Topical Suspension should not be used with occlusive dressings unless directed by a physician. Taclonex® Topical Suspension is not for oral, ophthalmic, or intravaginal use. Avoid use on the face, groin, or axillae, or if skin atrophy is present at the treatment site.

None.

WARNINGS

Included as part of the PRECAUTIONS section.

PRECAUTIONS

Hypercalcemia And Hypercalciuria

Hypercalcemia and hypercalciuria have been observed with use of Taclonex® Topical Suspension. If hypercalcemia or hypercalciuria develop, discontinue treatment until parameters of calcium metabolism have normalized. The incidence of hypercalcemia and hypercalciuria following Taclonex® Topical Suspension treatment of more than 8 weeks has not been evaluated.

Effects On Endocrine System

Taclonex® Topical Suspension can cause reversible hypothalamic-pituitary-adrenal (HPA) axis suppression with the potential for clinical glucocorticosteroid insufficiency. This may occur during treatment or upon withdrawal of treatment. Factors that predispose a patient to HPA axis suppression include the use of high-potency steroids, large treatment surface areas, prolonged use, use of occlusive dressings, altered skin barrier, liver failure, and young age. Evaluation for HPA axis suppression may be done by using the adrenocorticotropic hormone (ACTH) stimulation test.

In a trial evaluating the effects of Taclonex® Topical Suspension and Taclonex® Ointment on the HPA axis, 32 adult subjects were treated with both Taclonex® Topical Suspension on the scalp and Taclonex® Ointment on the body. Adrenal suppression was identified in 5 of 32 subjects (16%) after 4 weeks of treatment and in 2 of 11 subjects (18%) who continued treatment for 8 weeks. In another trial of 43 subjects treated with Taclonex® Topical Suspension on body (including the scalp in 36 out of 43 subjects) adrenal suppression was identified in 3 out of 43 subjects (7%) after 4 weeks of treatment and in none of the 36 subjects who continued treatment for 8 weeks.

In a trial evaluating the effects of Taclonex® Topical Suspension on the HPA axis, 31 subjects aged 12 to 17 years were treated with Taclonex® Topical Suspension on the scalp. Adrenal suppression was identified in 1 of 30 evaluable subjects (3.3%) after 4 weeks of treatment.

If HPA axis suppression is documented, gradually withdraw the drug, reduce the frequency of application, or substitute with a less potent corticosteroid.

Cushing's syndrome and hyperglycemia may also occur due to the systemic effects of the topical corticosteroid. These complications are rare and generally occur after prolonged exposure to excessively large doses, especially of high-potency topical corticosteroids.

Pediatric patients may be more susceptible to systemic toxicity due to their larger skin surface to body mass ratios.

Use of more than one corticosteroid-containing product at the same time may increase the total systemic corticosteroid exposure.

Allergic Contact Dermatitis With Topical Corticosteroids

Allergic contact dermatitis to a topical corticosteroid is usually diagnosed by observing a failure to heal rather than a clinical exacerbation. Such an observation should be corroborated with appropriate diagnostic patch testing.

Allergic Contact Dermatitis With Topical Calcipotriene

Allergic contact dermatitis has been observed with use of topical calcipotriene. Such an observation should be corroborated with appropriate diagnostic patch testing.

Eye Irritation

Avoid eye exposures. Taclonex® Topical Suspension may cause eye irritation.

Risks Of Ultraviolet Light Exposures

Patients who apply Taclonex® Topical Suspension to exposed skin should avoid excessive exposure to either natural or artificial sunlight, including tanning booths, sun lamps, etc. Physicians may wish to limit or avoid use of phototherapy in patients who use Taclonex® Topical Suspension.

Patient Counseling Information

See FDA-approved patient labeling (PATIENT INFORMATION and Instructions for Use)

Inform patients of the following:

• Instruct adult patients (18 years and older) not to use more than 100 g per week.
• Instruct pediatric patients (12 to 17 years) not to use more than 60 g per week.
• Discontinue therapy when control is achieved unless directed otherwise by the physician.
• Do not apply Taclonex® Topical Suspension to the scalp in the 12 hours before or after any chemical treatments to the hair. Since hair treatments may involve strong chemicals, talk with physician first.
• If applied to the scalp, do not wash hair or take a bath or shower right after application.
• Avoid use of Taclonex® Topical Suspension on the face, underarms, groin or eyes. If this medicine gets on face or in eyes, wash area right away.
• Do not occlude the treatment area with a bandage or other covering unless directed by the physician.
• Note that local reactions and skin atrophy are more likely to occur with occlusive use, prolonged use or use of higher potency corticosteroids.
• Bottle: Instruct patients to shake bottle prior to using Taclonex® Topical Suspension and to wash hands after application.
• Applicator: Instruct patients to wash hands if Taclonex® Topical Suspension gets on the fingers Instruct patients not to use other products containing calcipotriene or a corticosteroid with Taclonex® Topical Suspension without first talking to the physician.
• Instruct patients who use Taclonex® Topical Suspension to avoid excessive exposure to either natural or artificial sunlight (including tanning booths, sun lamps, etc.).

Nonclinical Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

When calcipotriene was applied topically to mice for up to 24 months at dosages of 3, 10, and 30 mcg/kg/day (corresponding to 9, 30, and 90 mcg/m²/day), no significant changes in tumor incidence were observed when compared to control.

In a study in which albino hairless mice were exposed to both ultra-violet radiation (UVR) and topically applied calcipotriene, a reduction in the time required for UVR to induce the formation of skin tumors was observed (statistically significant in males only), suggesting that calcipotriene may enhance the effect of UVR to induce skin tumors.

A 104-week oral carcinogenicity study was conducted with calcipotriene in male and female rats at doses of 1, 5 and 15 mcg/kg/day (corresponding to dosages of approximately 6, 30, and 90 mcg/m²/day). Beginning week 71, the dosage for high-dose animals of both genders was reduced to 10 mcg/kg/day (corresponding to a dosage of approximately 60 mcg/m²/day). A treatment-related increase in benign C-cell adenomas was observed in the thyroid of females that received 15 mcg/kg/day. A treatment-related increase in benign pheochromocytomas was observed in the adrenal glands of males that received 15 mcg/kg/day. No other statistically significant differences in tumor incidence were observed when compared to control. The relevance of these findings to patients is unknown.

When betamethasone dipropionate was applied topically to CD-1 mice for up to 24 months at dosages approximating 1.3, 4.2, and 8.5 mcg/kg/day in females, and 1.3, 4.2, and 12.9 mcg/kg/day in males (corresponding to dosages of up to approximately 26 mcg/m²/day and 39 mcg/m²/day, in females and males, respectively), no significant changes in tumor incidence were observed when compared to control.

When betamethasone dipropionate was administered via oral gavage to male and female Sprague Dawley rats for up to 24 months at dosages of 20, 60, and 200 mcg/kg/day (corresponding to dosages of approximately 120, 260, and 1200 mcg/m²/day), no significant changes in tumor incidence were observed when compared to control.

Calcipotriene did not elicit any genotoxic effects in the Ames mutagenicity assay, the mouse lymphoma TK locus assay, the human lymphocyte chromosome aberration test, or the mouse micronucleus test. Betamethasone dipropionate did not elicit any genotoxic effects in the Ames mutagenicity assay, the mouse lymphoma TK locus assay, or in the rat micronucleus test.

Studies in rats with oral doses of up to 54 mcg/kg/day (324 mcg/m²/day) of calcipotriene indicated no impairment of fertility or general reproductive performance. Studies in male rats at oral doses of up to 200 mcg/kg/day (1200 mcg/m²/day), and in female rats at oral doses of up to 1000 mcg/kg/day (6000 mcg/m²/day), of betamethasone dipropionate indicated no impairment of fertility.

Use In Specific Populations

Pregnancy

Teratogenic Effects

Pregnancy Category C

Animal reproduction studies have not been conducted with Taclonex® Topical Suspension. Taclonex® Topical Suspension contains calcipotriene that has been shown to be fetotoxic and betamethasone dipropionate that has been shown to be teratogenic in animals when given systemically. There are no adequate and well-controlled studies in pregnant women. Taclonex® Topical Suspension should be used during pregnancy only if the potential benefit to the patient justifies the potential risk to the fetus. Teratogenicity studies with calcipotriene were performed by the oral route in rats and rabbits. In rabbits, increased maternal and fetal toxicity were noted at a dosage of 12 mcg/kg/day (144 mcg/m²/day); a dosage of 36 mcg/kg/day (432 mcg/m²/day) resulted in a significant increase in the incidence of incomplete ossification of the pubic bones and forelimb phalanges of fetuses. In a rat study, a dosage of 54 mcg/kg/day (324 mcg/m²/day) resulted in a significantly increased incidence of skeletal abnormalities (enlarged fontanelles and extra ribs). The enlarged fontanelles were most likely due to the effect of calcipotriene upon calcium metabolism. The estimated maternal and fetal no-adverse effect levels (NOAEL) in the rat (108 mcg/m²/day) and rabbit (48 mcg/m²/day) derived from oral studies are lower than the maximum topical dose of calcipotriene in man (460 mcg/m²/day). Corticosteroids have been shown to be teratogenic in laboratory animals when administered systemically at relatively low dosage levels. Betamethasone dipropionate has been shown to be teratogenic in mice and rabbits when given by the subcutaneous route at dosages of 156 mcg/kg/day (468 mcg/m²/day) and 2.5 mcg/kg/day (30 mcg/m²/day), respectively. Those dose levels are lower than the maximum topical dose in man (about 5,950 mcg/m²/day). The abnormalities observed included umbilical hernia, exencephaly and cleft palate.

Nursing Mothers

Systemically administered corticosteroids appear in human milk and can suppress growth, interfere with endogenous corticosteroid production, or cause other untoward effects. It is not known whether topically administered calcipotriene or corticosteroids could result in sufficient systemic absorption to produce detectable quantities in human milk. Because many drugs are excreted in human milk, caution should be exercised when Taclonex® Topical Suspension is administered to a nursing woman.

The patient should be instructed not to use Taclonex® Topical Suspension on the breast when nursing.

Pediatric Use

Safety and effectiveness of the use of Taclonex® Topical Suspension in pediatric patients under the age of 12 years have not been established.

The safety and effectiveness of Taclonex® Topical Suspension for the treatment of plaque psoriasis of the scalp have been established in the age group 12 to 17 years. Two prospective, uncontrolled trials (N=109) were conducted in pediatric subjects age 12 to 17 years with scalp psoriasis, including assessment of HPA axis suppression in 30 subjects..

Because of a higher ratio of skin surface area to body mass, pediatric patients are at a greater risk than adults of systemic toxicity when treated with topical drugs. They are, therefore, also at greater risk of HPA axis suppression and adrenal insufficiency upon the use of topical corticosteroids. Rare systemic toxicities such as Cushing's syndrome, linear growth retardation, delayed weight gain, and intracranial hypertension have been reported in pediatric patients, especially those with prolonged exposure to large doses of high potency topical corticosteroids.

Local adverse reactions including striae have also been reported with use of topical corticosteroids in pediatric patients.

Geriatric Use

Clinical studies of Taclonex® Topical Suspension in plaque psoriasis on non-scalp areas included 124 subjects who were 65 years of age or over, and 36 were 75 years of age or over. Clinical studies of Taclonex® Topical Suspension in scalp psoriasis included 334 subjects who were 65 years or over and 84 subjects who were 75 years or over.

No overall differences in safety or effectiveness of Taclonex® Topical Suspension were observed between these subjects and younger subjects, and other reported clinical experience has not identified any differences in response between elderly and younger patients. However, greater sensitivity of some older individuals cannot be ruled out.

SIDE EFFECTS

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 directed compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Clinical Trials Conducted In Subjects 18 Years And Older With Scalp Psoriasis

The rates of adverse reactions given below were derived from randomized, multicenter, prospective vehicle- and/or active controlled clinical trials in adult subjects with scalp psoriasis. Subjects applied study product once daily for 8 weeks, and the median weekly dose was 12.6 g.

Adverse reactions that occurred in ≥ 1% of subjects treated with Taclonex® Topical Suspension and at a rate higher than in subjects treated with vehicle are presented in Table 1:

Table 1: Number and Percentage with Adverse Reactions in Scalp Psoriasis Trials (Events Reported by ≥ 1% of Subjects and for Which a Relationship is Possible)

Other less common adverse reactions ( < 1% but > 0.1%) were, in decreasing order of incidence: acne, exacerbation of psoriasis, eye irritation, and pustular rash.

In a 52-week trial, adverse reactions that were reported by > 1% of subjects treated with Taclonex® Topical Suspension were pruritus (3.6%), psoriasis (2.4%), erythema (2.1%), skin irritation (1.4%), and folliculitis (1.2%).

Clinical Trials Conducted In Subjects 18 Years And Older With Psoriasis On The Body

In randomized, multicenter, prospective vehicle- and/or active controlled clinical trials in adult subjects with plaque psoriasis on non-scalp areas, subjects applied study product once daily for 8 weeks. A total of 824 subjects were treated with Taclonex® Topical Suspension and the median weekly dose was 22.6 g. There were no adverse reactions that occurred in ≥ 1% of subjects treated with Taclonex® Topical Suspension and at a rate higher than in subjects treated with vehicle.

Other less common adverse reactions ( < 1% but > 0.1%) were, in decreasing order of incidence: rash and folliculitis.

Clinical Trials Conducted In Subjects 12 To 17 Years With Scalp Psoriasis

In two uncontrolled prospective clinical trials, a total of 109 subjects aged 12-17 years with plaque psoriasis of the scalp were treated with Taclonex® Topical Suspension once daily for up to 8 weeks. The median weekly dose was 40 g. Adverse reactions included acne, acneiform dermatitis and application site pruritus (0.9% each).

Postmarketing Experience

Because adverse 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.

Postmarketing reports for local adverse reactions to topical corticosteroids may also include: atrophy, striae, telangiectasias, itching, dryness, hypopigmentation, perioral dermatitis, secondary infection, and miliaria.

DRUG INTERACTIONS

No information provided.

Teratogenic Effects

Pregnancy Category C

Animal reproduction studies have not been conducted with Taclonex® Topical Suspension. Taclonex® Topical Suspension contains calcipotriene that has been shown to be fetotoxic and betamethasone dipropionate that has been shown to be teratogenic in animals when given systemically. There are no adequate and well-controlled studies in pregnant women. Taclonex® Topical Suspension should be used during pregnancy only if the potential benefit to the patient justifies the potential risk to the fetus. Teratogenicity studies with calcipotriene were performed by the oral route in rats and rabbits. In rabbits, increased maternal and fetal toxicity were noted at a dosage of 12 mcg/kg/day (144 mcg/m²/day); a dosage of 36 mcg/kg/day (432 mcg/m²/day) resulted in a significant increase in the incidence of incomplete ossification of the pubic bones and forelimb phalanges of fetuses. In a rat study, a dosage of 54 mcg/kg/day (324 mcg/m²/day) resulted in a significantly increased incidence of skeletal abnormalities (enlarged fontanelles and extra ribs). The enlarged fontanelles were most likely due to the effect of calcipotriene upon calcium metabolism. The estimated maternal and fetal no-adverse effect levels (NOAEL) in the rat (108 mcg/m²/day) and rabbit (48 mcg/m²/day) derived from oral studies are lower than the maximum topical dose of calcipotriene in man (460 mcg/m²/day). Corticosteroids have been shown to be teratogenic in laboratory animals when administered systemically at relatively low dosage levels. Betamethasone dipropionate has been shown to be teratogenic in mice and rabbits when given by the subcutaneous route at dosages of 156 mcg/kg/day (468 mcg/m²/day) and 2.5 mcg/kg/day (30 mcg/m²/day), respectively. Those dose levels are lower than the maximum topical dose in man (about 5,950 mcg/m²/day). The abnormalities observed included umbilical hernia, exencephaly and cleft palate.

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 directed compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Clinical Trials Conducted In Subjects 18 Years And Older With Scalp Psoriasis

The rates of adverse reactions given below were derived from randomized, multicenter, prospective vehicle- and/or active controlled clinical trials in adult subjects with scalp psoriasis. Subjects applied study product once daily for 8 weeks, and the median weekly dose was 12.6 g.

Adverse reactions that occurred in ≥ 1% of subjects treated with Taclonex® Topical Suspension and at a rate higher than in subjects treated with vehicle are presented in Table 1:

Table 1: Number and Percentage with Adverse Reactions in Scalp Psoriasis Trials (Events Reported by ≥ 1% of Subjects and for Which a Relationship is Possible)

Other less common adverse reactions ( < 1% but > 0.1%) were, in decreasing order of incidence: acne, exacerbation of psoriasis, eye irritation, and pustular rash.

In a 52-week trial, adverse reactions that were reported by > 1% of subjects treated with Taclonex® Topical Suspension were pruritus (3.6%), psoriasis (2.4%), erythema (2.1%), skin irritation (1.4%), and folliculitis (1.2%).

Clinical Trials Conducted In Subjects 18 Years And Older With Psoriasis On The Body

In randomized, multicenter, prospective vehicle- and/or active controlled clinical trials in adult subjects with plaque psoriasis on non-scalp areas, subjects applied study product once daily for 8 weeks. A total of 824 subjects were treated with Taclonex® Topical Suspension and the median weekly dose was 22.6 g. There were no adverse reactions that occurred in ≥ 1% of subjects treated with Taclonex® Topical Suspension and at a rate higher than in subjects treated with vehicle.

Other less common adverse reactions ( < 1% but > 0.1%) were, in decreasing order of incidence: rash and folliculitis.

Clinical Trials Conducted In Subjects 12 To 17 Years With Scalp Psoriasis

In two uncontrolled prospective clinical trials, a total of 109 subjects aged 12-17 years with plaque psoriasis of the scalp were treated with Taclonex® Topical Suspension once daily for up to 8 weeks. The median weekly dose was 40 g. Adverse reactions included acne, acneiform dermatitis and application site pruritus (0.9% each).

Postmarketing Experience

Because adverse 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.

Postmarketing reports for local adverse reactions to topical corticosteroids may also include: atrophy, striae, telangiectasias, itching, dryness, hypopigmentation, perioral dermatitis, secondary infection, and miliaria.

No information provided.

Hypothalamic-Pituitary-Adrenal (HPA) Axis Suppression

HPA axis suppression was evaluated in three trials (Trial A, B, and C) following the application of Taclonex® Topical Suspension. In Trial A, HPA axis suppression was evaluated in adult subjects (N=32) with extensive psoriasis involving at least 30% of the scalp and, in total, 15-30% of the body surface area. Treatment consisted of once daily application of Taclonex® Topical Suspension on the scalp in combination with Taclonex® Ointment on the body for 4 to 8 weeks. Adrenal suppression as indicated by a 30-minute post-stimulation cortisol level ≤ ;18 mcg/dL was observed in 5 of 32 subjects (15.6%) after 4 weeks of treatment and in 2 of 11 subjects (18.2%) who continued treatment for 8 weeks.

In Trial B, HPA axis suppression was evaluated in adult subjects (N=43) with extensive psoriasis involving 15-30% of the body surface area (including the scalp). Treatment consisted of once daily application of Taclonex® Topical Suspension to the body (including the scalp in 36 out of 43 subjects) for 4 to 8 weeks. Adrenal suppression as indicated by a 30-minute post-stimulation cortisol level ≤ ;18 mcg/dL was observed in 3 out of 43 subjects (7.0%) after 4 weeks of treatment and in none of the 36 subjects who continued treatment for 8 weeks.

In Trial C, HPA axis suppression was evaluated in subjects 12 to 17 years (N=30) with plaque psoriasis of the scalp involving at least 20% of the scalp area. Treatment consisted of once daily application of Taclonex® Topical Suspension to the affected area on the scalp for up to 8 weeks. Adrenal suppression as indicated by a 30-minute post-stimulation cortisol level ≤ ;18 mcg/dL was observed in 1 of 30 evaluable subjects (3.3%) after 4 weeks of treatment and in no subjects who continued treatment for 8 weeks.

Effects On Calcium Metabolism

In Trial A described above, the effects of once daily application of Taclonex® Topical Suspension on the scalp in combination with Taclonex® Ointment on the body for 4 to 8 weeks on calcium metabolism were also examined. Following once daily application of Taclonex® Topical Suspension on the scalp in combination with Taclonex® Ointment on the body, elevated urinary calcium levels outside the normal range were observed in two subjects (one at 4 weeks and one at 8 weeks).

In Trial B, the effects on calcium metabolism of once daily application of Taclonex® Topical Suspension to 15-30% of the body surface area (including the scalp) for 4 to 8 weeks were also examined. There was no change in mean serum or urinary calcium levels. Elevated urinary calcium levels outside the normal range were observed in two subjects (one at 4 weeks and one at 8 weeks).

In addition, calcium metabolism was evaluated in a total of 109 subjects aged 12 to 17 years with plaque psoriasis of the scalp involving at least 10% of the scalp area undergoing once daily application of Taclonex® Topical Suspension to the scalp for up to 8 weeks. No cases of hypercalcemia and no clinically relevant changes in urinary calcium were reported.

Absorption

Taclonex® Topical Suspension

The systemic effect of Taclonex® Topical Suspension in psoriasis was investigated in Trials A and B described above. In Trial A, the serum levels of calcipotriene and betamethasone dipropionate and their major metabolites were measured after 4 and 8 weeks of once daily application of Taclonex® Topical Suspension on the scalp in combination with Taclonex® Ointment on the body. Calcipotriene and betamethasone dipropionate were below the lower limit of quantification in all serum samples of the 34 subjects evaluated.

However, one major metabolite of calcipotriene (MC1080) was quantifiable in 10 of 34 (29.4%) subjects at week 4 and in 5 of 12 (41.7%) subjects at week 8. The major metabolite of betamethasone dipropionate, betamethasone 17-propionate (B17P) was also quantifiable in 19 of 34 (55.9%) subjects at week 4 and 7 of 12 (58.3%) subjects at week 8. The serum concentrations for MC1080 ranged from 20-75 pg/mL. The clinical significance of this finding is unknown.

In Trial B, the plasma levels of calcipotriene and betamethasone dipropionate and their major metabolites were measured after 4 weeks of once daily application of Taclonex® Topical Suspension to 15-30% of the body surface area (scalp and non-scalp areas). Calcipotriene and its metabolite MC1080 were below the lower limit of quantification in all plasma samples. Betamethasone dipropionate was quantifiable in 1 sample each taken from 4 of 43 (9.3%) subjects. The metabolite of betamethasone dipropionate (B17P) was quantifiable in 16 of 43 (37.2%) subjects. The plasma concentrations of betamethasone dipropionate ranged from 30.9

63.5 pg/mL and that of its metabolite betamethasone 17-propionate ranged from 30.5-257 pg/mL. The clinical significance of this finding is unknown.

Metabolism

Calcipotriene

Calcipotriene metabolism following systemic uptake is rapid and occurs in the liver. The primary metabolites of calcipotriene are less potent than the parent compound.

Calcipotriene is metabolized to MC1046 (the α,ß-unsaturated ketone analog of calcipotriene),which is metabolized further to MC1080 (a saturated ketone analog). MC1080 is the major metabolite in plasma. MC1080 is slowly metabolized to calcitroic acid.

Betamethasone Dipropionate

Betamethasone dipropionate is metabolized to betamethasone 17-propionate and betamethasone, including the 6ß-hydroxy derivatives of those compounds by hydrolysis. Betamethasone 17-propionate (B17P) is the primary metabolite.