Adrenal Suppression and Absorption Study of Halobetasol Propionate Foam in Subjects 12-17 With Plaque Psoriasis

Adrenal Suppression and Absorption Study of Halobetasol Propionate Foam in Subjects 12-17 With Plaque Psoriasis

Open Label Evaluation of the Adrenal Suppression Potential and Pharmacokinetic Properties of Twice Daily Halobetasol Propionate Foam, 0.05% in Subjects 12 to Less Than 18 Years of Age With Plaque Psoriasis Receiving Two Weeks of Treatment

The purpose of this study is to evaluate Halobetasol Propionate (HBP) foam, 0.05% in subjects aged 12 through less than 18 years with plaque psoriasis in order to check the safety, the potential to suppress the adrenal glands and the degree to which the drug is absorbed into the bloodstream.

This is a Phase 4 (for US site only, Phase 2 for non-US sites), open label, multicenter study of halobetasol propionate (HBP) Foam, 0.05% in male and female subjects who are 12 to less than 18 years of age with stable plaque psoriasis. Twenty-four subjects with stable plaque psoriasis on at least 10% of their body surface area (BSA) (excluding the face, scalp, groin, axillae, and other intertriginous areas), who fulfill the inclusion/exclusion criteria will be enrolled at multiple study sites in the US and Europe. All subjects are to have a Cosyntropin Stimulation Test (CST) to assess their (hypothalmic pituitary adrenal) HPA axis response at Visit 1/Screening initiated between 7 and 9 AM. Enrollment into the treatment phase of the study will be timed such that the Screening CST is performed a minimum of 20 days before Visit 2/Baseline. At Visit 2/Baseline, eligible subjects with normal adrenal function will be eligible to participate in the study. The primary objective of the study is to assess safety, not efficacy. Safety will be determined by assessing the adrenal suppression potential and the PK properties of HBP Foam, 0.05% applied twice daily in male and female subjects who were 12 to less than 18 years of age with stable plaque psoriasis. Other safety endpoints include plasma levels of HBP. Trough HBP concentrations in plasma on day 8 and 15 will be calculated and summarized. Efficacy will also be noted utilizing the Investigator's Global Assessment (IGA) scale and percent BSA treated and affected with disease to assess and document any changes observed with regard to IGA and percent BSA.

A subject is considered to have adrenal suppression evidence if post cosyntropin stimulation lab draw result is less than or equal to 18.0 mcg/100 mL. HPA axis responses to cosyntropin were dichotomized to normal and abnormal. Cosyntropin stimulation testing was performed at Screening and Day 15 and approximately 4 weeks post-treatment if a subject's laboratory results at Day 15 showed an abnormal hypothalamic pituitary adrenal (HPA) axis response (HPA axis suppression). An abnormal HPA axis response was defined as a 30-minute post-stimulation serum cortisol level of ≤18 μg/dL at end of study (EOS).

Morning trough concentrations of HBP in plasma at Screening, Day 8, and Day 15 were summarized for the PK population using geometric mean, coefficient of variation in addition to n, mean, median, standard deviation (SD), minimum, and maximum.

Key Inclusion Criteria: Subject is male or non-pregnant female and is 12 to less than 18 years of age Subject has provided written informed assent and was accompanied by the parent or legal guardian at the time of assent/consent signing Subject has a clinical diagnosis of stable plaque psoriasis involving a minimum of 10% Body Surface Area (BSA) Subject has an Investigator's Global Assessment (IGA) score of at least three (3 = moderate) at the Baseline Visit Key Exclusion Criteria: Subject has spontaneously improving or rapidly deteriorating plaque psoriasis Subject has guttate, pustular, erythrodermic or other non-plaque forms of psoriasis Subject has a physical condition which, in the investigator's opinion, might impair evaluation of plaque psoriasis, adrenal axis function or which exposes the subject to an unacceptable risk by study participation Subject has had prolonged exposure to natural or artificial sources of ultraviolet radiation Subject is pregnant, lactating, or is planning to become pregnant during the study Subject is currently enrolled in an investigational drug or device study