The purpose of this study is to confirm the clinical efficacy and the safety of P-3073 in patients affected by isolated psoriatic nail(s) and/or those with psoriatic nails and concomitant mild to moderate plaque psoriasis.

Inclusion Criteria:

• Written informed consent before starting any study related procedures
• Patients aged 18 to 80 years old of any race.
• Males or females.
• Patients with mild to moderate psoriastic fingernail(s) defined as fingernail/s with matrix psoriasis NAPSI score and/or bed psoriasis NAPSI score ≥ 1 and ≤ 3 at baseline.
• In case of skin involvement, patients with established clinical diagnosis of mild-to-moderate psoriasis (BSA involvement ≤ 8% or PASI ≤ 10)

Exclusion Criteria:

• Woman who is pregnant, nursing an infant, or planning a pregnancy during the study period.
• Use of any systemic treatment for psoriasis during the last six months before the screening visit.
• Use of photochemotherapy or other forms of radiotherapy during the last four weeks before the screening visit.
• Positive mycology findings
• Systemic use of immunosuppressives, chemotherapy and corticosteroids during last three months before the screening visit.
• Consumption of Vitamin D or its analogues during the last three months.
• History of hypercalcaemia or hypercalciuria.
• HIV infection or any other immunodeficiency.
• Alcohol or substance abuse.
• Patients with history of allergic reactions to calcipotriol or its excipients.