The aim of this study is to determine the efficacy and safety of topical application of the gel compared to placebo in nail psoriasis.

Inclusion Criteria:

• Key inclusion criteria:
• Mild to moderate nail psoriasis on at least one fingernail

Exclusion Criteria:

Key exclusion criteria:

• any other skin condition, with a potential to affect the nails or to interfere with evaluation of the disease;
• history of hypersensitivity to retinoids or to other components of the trial medication
• topical treatment of nails with antipsoriatics in the 4 weeks preceding the treatment phase;
• systemic treatment of psoriasis within the three months before the treatment phase of the trial or during the trial
• intralesional steroid injection before the treatment phase of the trial
• phototherapy before the treatment phase of the trial;
• any chronic infection or condition capable of interfering with the conduct of the trial;
• evidence of drug or alcohol abuse;
• symptoms of a clinically significant illness that may influence the outcome of the trial in the four weeks preceding the treatment phase of the trial;
• participation in another clinical trial within the last 4 weeks prior to first treatment in this clinical trial;
• pregnancy or nursing;