Predicting Improvement in Signs and Symptoms of Plaque Psoriasis After 1 Week of Treatment With Clobetasol Propionate 0.05% Spray

December 2013 | Volume 12 | Issue 12 | Original Article | 1456 | Copyright © December 2013

Steven R. Feldman MD PhD,a Warren Winkelman MD PhD,b Eric Baum MD,c Norman Preston PhDb

aWake Forest University School of Medicine, Winston-Salem, NC
bGalderma Laboratories, LP, Fort Worth, TX
cDepartment of Dermatology, University of Alabama, Birmingham, AL

Abstract
One of the hurdles to effectively managing plaque psoriasis is lack of adherence to prescribed treatments. Up to 40% of subjects report they do not adhere to their medication for a variety of reasons. Earlier response to treatment may be a motivator for subjects to better adhere to treatment. Clobetasol propionate 0.05% spray (CPS) is a highly potent topical corticosteroid indicated for the treatment of moderate to severe plaque psoriasis that has efficacy as early as 1 week after initiating therapy. Using data from the 2 CPS pivotal trials, a post hoc analysis was performed to determine the relationship between week 1 improvements and week 4 treatment success (defined as a score of 0 [clear] or 1 [almost clear] in overall disease severity [ODS]). Improvements in week 1 ODS and pruritus were predictive of week 4 treatment success. Subjects who had ODS or pruritus scores of moderate or better at week 1 tended to be treatment successes at week 4 whereas no relationship between week 1 scores and week 4 treatment success was observed for those treated with vehicle spray. The results of this post hoc analysis indicate that early improvement correlates to treatment success.

J Drugs Dermatol. 2013;12(12):1456-1460.

INTRODUCTION

One of the biggest challenges in managing plaque psoriasis is lack of adherence to treatments by patients, which negatively affects treatment outcomes.1 Forty percent of surveyed subjects with plaque psoriasis reported nonadherence to their medication, which included under use and over use.2 Frequently reported reasons for under use included a lack of efficacy, staining of clothes or surfaces by the medication, and time consuming application. Reasons for over use included a desire for more rapid clearing of lesions, lack of effectiveness, and perceived increase in efficacy. Therefore, treatments with rapid efficacy that are easy to apply may help improve patient adherence and, thereby, treatment outcomes.
Topical corticosteroids are the mainstay of treating plaque psoriasis.3 Clobetasol propionate is a highly potent topical corticosteroid available in a spray formulation that is indicated to treat moderate to severe plaque psoriasis, and is the only class 1 topical steroid FDA-approved for up to 4 weeks of use.4-7 Multiple studies, comprising over 2,200 subjects, have demonstrated that clobetasol propionate 0.05% spray (CPS) is a safe and effective regimen for treating moderate to severe plaque psoriasis as a monotherapy or in combination therapy.8-10 Over 78% of subjects achieved treatment success (defined as a score of clear or almost clear for overall disease severity [ODS] or target plaque severity) at the end of the 4 week treatment period and subjects also reported improvements in QoL.4-7 CPS has been highly rated by subjects who felt it was easy to apply, was easily absorbed into the skin, and did not stain clothing or skin.11
A post hoc analysis of week 1 data from the 2 pivotal CPS trials demonstrated that a significant number of subjects experienced improvements in the signs and symptoms of plaque psoriasis (ODS, pruritus, plaque elevation, scaling, and erythema) as early as 1 week after initiation of treatment.12 Early improvement in signs and symptoms of plaque psoriasis after 1 week of treatment with CPS could improve patient adherence and treatment outcomes.
While the previous analysis indicated that a patient is likely to see improvements within a week of initiating treatment with CPS, it is unknown how these improvements at week 1 relate to improvements at week 4. Data from the 2 pivotal CPS trials was modeled using a generalized linear model in an effort to understand how improvements at week 1 affected treatment success at week 4. The purpose of this present post hoc analysis is to explore the predictive relationship between the response of ODS or pruritus to CPS after 1 week of treatment and treatment success of ODS after 4 weeks of treatment.

METHODS

Clobetasol Propionate 0.05% Spray Pivotal Studies

Two identical multicenter, randomized, double-blind, vehicle controlled, parallel group, phase 3 studies investigated the efficacy and safety of CPS compared to vehicle spray for the treatment of moderate to severe plaque psoriasis.5,7,13 Both studies were conducted in accordance with the Declaration of Helsinki, Good Clinical Practices, and all other applicable regulations.