Efficacy and safety of calcipotriene 0.005% foam for the treatment of plaque-type psoriasis: results of two multicenter, randomized, double-blind, vehicle-controlled, phase III clinical trials.

BACKGROUND

Topical calcipotriene is frequently prescribed for the treatment of plaque-type psoriasis. Calcipotriene is currently available in the US as an ointment, a solution, a cream, and in a fixed-dose combination ointment with betamethasone dipropionate. Calcipotriene 0.005% has recently been formulated as a foam using a novel aqueous-based formulation to provide a new topical treatment option for patients with psoriasis.

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of topical calcipotriene 0.005% foam for the treatment of mild to moderate plaque-type psoriasis.

DESIGN

Two identical, randomized, double-blind, vehicle-controlled, 8-week phase III clinical trials.

INTERVENTION

Subjects with plaque-type psoriasis affecting 2-20% of the body surface area, with an identifiable target lesion affecting the trunk or extremities, were randomized in a 2:1 ratio to calcipotriene foam (n = 437) or vehicle foam (n = 222). Study medication was applied twice daily for 8 weeks.

OUTCOME MEASURES

Treatment success was defined as a score of 0 or 1 (clear or almost clear) on the Investigator's Static Global Assessment (ISGA) psoriasis rating scale and a minimum improvement of ISGA score of at least 2 grades from baseline. Predefined target lesions were assessed for erythema, scaling, and plaque thickness. Primary endpoint was the proportion of subjects in each treatment group who achieved treatment success after 8 weeks, analyzed on an intent-to-treat (ITT) basis. In the primary endpoint analysis, subjects missing 8-week outcomes data were classified as treatment failures regardless of their outcomes at earlier evaluations. As part of the sensitivity analysis, a last-observation-carried-forward (LOCF) approach to impute missing 8-week efficacy outcomes also examined treatment. Secondary endpoints included treatment success as a function of baseline ISGA score (mild or moderate), ISGA score of 0 or 1 (clear or almost clear), and effects of treatment on target lesion. Adverse events (AEs) were recorded throughout the study.

RESULTS

In the ITT population of Study 1, treatment success after 8 weeks was achieved by 14% of subjects in the calcipotriene foam group versus 7% of subjects in the vehicle foam group (p = 0.058). In the LOCF analysis, treatment success was achieved by more subjects with calcipotriene foam than with vehicle foam (15% vs 7%; p = 0.034). In Study 2, treatment success was achieved by more subjects in the calcipotriene foam group for the primary endpoint (27% vs 16%; p = 0.016) and the LOCF analysis (28% vs 16%; p = 0.010). Subjects in the calcipotriene foam group exhibited better response rates than did the vehicle foam group for most of the secondary outcomes. Calcipotriene foam was safe with an overall incidence of AEs similar to those experienced in the vehicle foam group. Application-site reactions were noted in approximately 1-2% of subjects in each group. No AE was reported in more than 2% of subjects in the calcipotriene foam group. Treatment was discontinued because of AEs in approximately 2% of subjects in both groups.

CONCLUSIONS

In two identically designed, phase III clinical trials, calcipotriene 0.005% foam was safe and effective for the treatment of mild to moderate plaque-type psoriasis for up to 8 weeks.

CLINICAL TRIAL REGISTRATION

Registered at clinicaltrials.gov: NCT00688519 and NCT00689481.