A 12-Day Randomized, Blinded, Vehicle and Active Comparator-Controlled Study to Determine the Efficacy and Safety of Six Concentrations of Topical E6201 Gel in Subjects With Psoriasis Vulgaris

The purpose of this study is to investigate the efficacy, safety, tolerability and the concentration/response relationship of E6201 in subjects with psoriasis vulgaris.

This is a single center, randomized, blinded, intra-individual comparison in two sequential cohorts of 15 subjects each (30 subjects in total) in an outpatient setting, in which each subject simultaneously receives five topical treatments (3 active, 1 vehicle, and 1 positive control) within one or two psoriatic plaques. Treatments consisted of 3 concentrations of E6201 gel, a negative control (gel vehicle), and a positive control (0.005% calcipotriene cream). The different concentrations of E6201 gel and vehicle control were double-blinded, while the calciprotriene cream was single-blinded. Cohort 2 participants were not dosed until all participants in Cohort 1 completed treatment and safety data were collected and evaluated.

Eligibility Criteria:
Inclusion:

* Chronic stable plaque psoriasis with one or two stable psoriatic plaques(s) suitable in size and location for five separate treatment fields to be assessed within it.
* Males and females aged between 18 and 75 years of age
* The general physical examination should be normal (excluding the skin examination for psoriasis) unless the Investigator considers an abnormality not to be clinically significant with regard to the study
* Females of childbearing potential must have a negative serum beta-human chorionic gonadotropin at Visit 1 (Screening) and a negative urine pregnancy test prior to starting study drug(s) (Visit 2). Female subjects of childbearing potential must agree to be abstinent or to use a highly effective method of contraception throughout the study period and for 30 days after the last dose of study drug.
* Provide written informed consent
* Willing and able to comply with all aspects of the protocol

Exclusion:

* Any clinically significant skin diseases other then chronic stable plaque psoriasis
* Other types of psoriasis than chronic stable plaque variant eg, guttate, pustular, erythodermic, etc
* An unstable course of the disease defined as flare(s) in the previous month
* Subjects who used any concommitant topical treatment for the psoriatic plaque(s) to be studied (other than emollients or salicylic acid) within 8 weeks before the Baseline visit eg corticosteroids or topical immunomodulators, anthralin (dithranil), vitamin D derivatives, ultraviolet-light therapy including sunbathing , or retinoids.
* Subjects who used any of the following systemic treatments within 12 weeks before the Baseline visit eg: corticosteroids or adrenocorticotrophic hormone analogs, retinoids such as acitretin or isotretinoin, cyclosporin, interferon, methotrexate, other immuno-suppressive/immunomodulating drugs, psoralen and ultraviolet A therapy, or biologics
* Subjects planning on significant exposure to sun (sun-bathing)
* Treatment with systemic or locally acting medications which might counter or influence the study aim (eg monoamine oxidase inhibitors, anti-epileptic drugs, anti-psychotic drugs) or medications which are known to provoke or aggravate psoriasis, eg Beta-blockers, antimalarial drugs, and lithium within two weeks before the Baseline visit
* Subject is a dependent person, ie, a relative/family member of the Investigator and/or is a member of the Investigator's staff
* Clinical study participation with any investigational drug less than 30 days prior to study entry or planning to receive an investigational drug during the study period