Clinical Study Results of Desoximetasone Spray, 0.25% in Moderate to Severe Plaque Psoriasis

December 2013 | Volume 12 | Issue 12 | Original Article | 1404 | Copyright © December 2013

Leon Kircik MD,a,b,c Mark G. Lebwohl MD,c James Q. Del Rosso DO,d
Jerry Bagel MD,eLinda Stein Gold MD,f Jonathan S. Weiss MDg

aDepartment of Dermatology, Indiana University School of Medicine, Indianapolis, IN
bPhysicians Skin Care, PLLC, Louisville, KY
cDepartment of Dermatology, Mount Sinai School of Medicine, New York, New York
dDepartment of Dermatology, Touro University College of Osteopathic Medicine, Henderson, NV
ePsoriasis Treatment Center of Central New Jersey, East Windsor, NJ
fDirector of Dermatology, Clinical Research and Division Head of Dermatology, Henry Ford Health System, Detroit and West Bloomfield, Michigan
gGwinnett Clinical Research Center, Snellville, Georgia

table 2
A Phase 2 dose-finding study of desoximetasone spray in adult subjects with moderate to severe plaque psoriasis involving ≤10% body surface area (BSA) resulted in the selection of 0.25% twice daily as the concentration and frequency of application. A total of 151 subjects were enrolled in the fivearm phase 2 dose-finding study, and a total of 240 subjects collectively in the two Phase 3 trials. Table 1 depicts the three pivotal trials, one Phase 2 trial and two Phase 3 trials, used as the basis of submission for FDA approval.

Desoximetasone Spray 0.25% Phase 3 Pivotal Study Overview

Two Phase 3 double-blind, randomized, vehicle-controlled parallel studies evaluated the efficacy and safety of desoximetasone spray 0.25% twice daily versus vehicle spray twice daily for 28 days in adult patients with moderate to severe plaque psoriasis. Demographic characteristics for the subjects entering both Phase 3 studies are presented in Table 2. Appropriate candidates for inclusion in the study had to be at least 18 years of age with a definite clinical diagnosis of stable plaque psoriasis involving >=10% of BSA using the “Rules of Nine” and were graded in severity as moderate to severe by both overall assessment and with evaluation of a designated target lesion. The mean age of the subjects was similar across studies, ranging from 48-54 years. There was a male prevalence and most subjects were white.
At baseline and throughout the study, the severity of disease for the psoriatic lesions was assessed using the Physician Global Assessment (PGA) score and a target lesion was assessed using the Total Lesion Severity Score (TLSS), a sum of the scores assigned by the investigator on three measures used to determine target plaque severity, scaling, erythema, and plaque elevation (induration), with each of these criteria on a 6-point scale. A designated psoriatic plaque lesion was selected as the target lesion upon enrollment and evaluated throughout the study to determine the TLSS. To qualify for study entry, the subject needed to exhibit a PGA score of 3 (moderate) or 4 (severe) for overall disease severity, and a target lesion with an area of at least 5 cm2 that achieved a combined score TLSS of >=7, with a plaque elevation score of >=3 (at least moderate). The mean % BSA affected by psoriasis ranged from 15%-18% at baseline. This and the other key disease characteristics at baseline, the mean PGA, TLSS, and target lesion size, are presented in Table 3. There were no clinically meaningful differences in any of the assessment values among the treatment groups
Subjects who were eligible to participate in the study based on the inclusion and exclusion criteria and who consented to proceed were enrolled at baseline (Day 1) and returned to the study center at Day 7, Day 14, and Day 28 (end of study). Education was given by study staff to subjects on proper use of study medication with instructions to spray the study medication directly to all affected areas and rub in gently and completely twice-daily for 28 days. Study medication was to be applied in the morning and evening approximately 12 hours apart. Subjects returned to the clinic for assessment of signs and symptoms of psoriasis, adverse events, update all concomitant medications, and to evaluate compliance with the subject and their dosing diary.

Desoximetasone Spray 0.25% Phase 3 Study Assessments and Analyses

The primary endpoint based on PGA score was the proportion of subjects in each treatment group who were considered a