Conditions: Psoriasis Plaque Psoriasis
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 24
Healthy volunteers: no

Brief summary:
This is a within-participant comparison study to investigate the efficacy of a 28-day regimen of MK-0873 2% cream twice a day (b.i.d.) compared to MK-0873 vehicle (matching placebo) b.i.d. as well as to a positive control comparator calcitriol 0.0003% (3 µg/g) in participants with plaque psoriasis. In order to be enrolled in the study, patients need to have at least two pairs (lesions AB and CD) of approximately similar plaque lesions in severity and size of surface area involved and located in approximately symmetric regions such as the trunk or limbs of the body. Participants will be randomly assigned to apply either MK-0873 or MK-0873 vehicle to plaque A or B and will be randomly assigned to apply MK-0873 or calcitriol to plaque C or D. It is hypothesized that MK-0873 cream formulation administered to participants with psoriasis by the topical route will result in a statistically greater percent target lesion severity (TLS) reduction in plaque lesion than will MK-0873 Vehicle on Day 29.

Detailed description:

Arms:
arm 1: Participants were randomized to receive MK-0873 on upper lesion A and vehicle on upper lesion B, and MK-0873 on lower lesion C and calcitriol on lower lesion D. arm 2: Participants were randomized to received MK-0873 on lower lesion A and vehicle on lower lesion B, and MK-0873 on upper lesion C and calcitriol on upper lesion D. arm 3: Participants were randomized to receive MK-0873 on upper lesion A and vehicle on upper lesion B, and calcitriol on lower lesion C and MK-0873 on lower lesion D. arm 4: Participants were randomized to receive MK-0873 on lower lesion A and vehicle on lower lesion B, and calcitriol on upper lesion C and MK-0873 on upper lesion D. arm 5: Participants were randomized to receive vehicle on upper lesion A and MK-0873 on upper lesion B, and MK-0873 on lower lesion C and calcitriol on lower lesion D. arm 6: Participants were randomized to receive vehicle on lower lesion A and MK-0873 on lower lesion B, and MK-0873 on upper lesion C and calcitriol on upper lesion D. arm 7: Participants were randomized to receive vehicle on upper lesion A and MK-0873 on upper lesion B, and calcitriol on lower lesion C and MK-0873 on lower lesion D. arm 8: Participants were randomized to receive vehicle on lower lesion A and MK-0873 on lower lesion B, and calcitriol on upper lesion C and MK-0873 on upper lesion D.

Interventions: intervention 1: MK-0873 2% Cream intervention 2: MK-0873 vehicle (placebo) Cream intervention 3: Calcitriol Cream
Intervention descriptions: intervention 1: Approximately 3 to 5 mg of MK-0873 2% cream per cm\^2 of body area in 2 divided applications per day for 28 days. The maximum area for one treatment will be approximately 5% of body surface area. intervention 2: Approximately 3 to 5 mg matching placebo to MK-0873 2% cream per cm\^2 of body area in 2 divided applications per day for 28 days. The maximum area for one treatment will be approximately 5% of body surface area. intervention 3: Approximately 3 to 5 mg of Calcitriol 0.0003% (3 µg/g) per cm\^2 of body area once daily for 28 days. The maximum area for one treatment will be approximately 5% of body surface area

Protocol document: