13 NONCLINICAL TOXICOLOGY

13.1 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 (9, 30, and 90 mcg/m2/day, respectively), no significant changes in tumor incidence were observed when compared to control.

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 (6, 30, and 90 mcg/m2/day, respectively). Beginning week 71, the dosage for high-dose animals of both genders was reduced to 10 mcg/kg/day (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 (up to 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 (120, 360, and 1200 mcg/m2/day, respectively), 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.

14 CLINICAL STUDIES

Clinical Trials Conducted in Subjects 18 Years and Older with Psoriasis of the Scalp

Two multicenter, randomized, double-blind trials were conducted in adult subjects with moderate to very severe psoriasis of the scalp.

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In Trial One, 1,407 subjects were randomized to 1 of 4 treatment groups: calcipotriene and betamethasone dipropionate topical suspension, betamethasone dipropionate in the same vehicle, calcipotriene in the same vehicle, or the vehicle alone. 

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In Trial Two, 1,280 subjects were randomized to 1 of 3 treatment groups: calcipotriene and betamethasone dipropionate topical suspension, betamethasone dipropionate in the same vehicle, or calcipotriene in the same vehicle. 

Both trials enrolled subjects with moderate to very severe psoriasis of the scalp. The majority of subjects had disease of moderate severity at baseline. Subjects were treated once daily for 8 weeks. Efficacy was assessed as the proportion of subjects at Week 8 with absent or very mild disease according to the Investigator’s Global Assessment of Disease Severity. “Clear” was defined as no evidence of redness, thickness or scaling. “Almost clear” was defined as an overall clinical picture of lesions with the presence of minimal erythema. Table 2 contains the response rates in each of these 2 trials.

Clinical Trials Conducted in Subjects 18 Years and Older with Psoriasis of the Body

One multicenter, randomized, double-blind trial was conducted in subjects with mild to moderate plaque psoriasis on non-scalp areas, excluding face, axillae, and groin. In this trial, 1152 subjects were randomized to 1 of 4 treatment groups: calcipotriene and betamethasone dipropionate topical suspension, betamethasone dipropionate in the same vehicle, calcipotriene in the same vehicle, or the vehicle alone. Seventy eight percent (78%) of subjects had disease of moderate severity at baseline. Subjects were treated once daily for 8 weeks. Efficacy was assessed at Week 4 and Week 8 as the proportion of subjects who were “Clear” or “Almost clear” according to the Investigator’s Global Assessment of Disease Severity. Subjects with mild disease at baseline were required to be “Clear” to be considered a success. Table 3 contains the response rates in this trial.

*Subjects with mild disease at baseline were required to be “Clear” to be considered a success.