Study to Evaluate the Efficacy and Safety of P-3073 Nail Solution in the Treatment of Mild to Moderate Psoriatic Fingernail/s

This phase III study versus vehicle will be conducted to confirm the clinical efficacy and
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.

The evaluation of the primary endpoint will be made using the Nail Psoriasis Severity Index
(NAPSI).

The secondary objectives will be:

- To assess if the topical treatment with P-3073 is able to improve the quality of life
and discomfort in patients with psoriatic fingernail.

- To assess the safety and tolerability of topical P-3073 in the treatment of psoriatic
fingernail.

The study consists of two arms comparing P-3073 (calcipotriene 0.005%) and vehicle. Eligible
patients will be randomized to either P-3073 or placebo in a 1:1 ratio, stratified by their
target nail NAPSI severity at screening.

The study population will include at least 470 patients (235 for each group) with nail
psoriasis (fingernails) of the matrix and/or of the nail bed in at least one fingernail.

The total duration of the trial for each patient will be approximately 29 weeks (from
Screening to Follow-up). During the 24 weeks of the treatment period, patients will apply the
assigned treatment to all affected psoriatic fingernails once daily.

Inclusion Criteria:

- Written informed consent before starting any study related procedure.

- Patients ages ≥ 18 and ≤ 80 years old.

- Men or women.

- Outpatients.

- Patients with mild to moderate psoriatic fingernail/s, defined as fingernail/s with
matrix psoriasis NAPSI score and/or bed psoriasis NAPSI score ≥ 1 and ≤ 3 at baseline.
The sum of the scores for each nail should range between 1 and 6.

- In case of skin involvement, patients with established clinical diagnosis of mild to
moderate psoriasis (BSA involvement ≤ 8% or Psoriasis Area Severity Index (PASI) ≤
10).

Exclusion Criteria:

- Use of any systemic treatment for psoriasis and/or nail psoriasis during the last six
months before the screening visit.

- Use of any topical treatment for nail psoriasis on fingernails during the last six
months before the screening visit.

- Use of photochemotherapy (phototherapy is allowed) or other forms of radiotherapy
during the last four weeks before the screening visit.

- Positive mycology findings (KOH evaluation or culture) obtained in the three months
before the screening visit or positive KOH evaluated at the screening visit.

- Patients using nail polish or other nail cosmetic products during last 72 hours prior
to study drug application.

- Systemic use of the following therapies for any reason during last three months before
the screening visit: immunosuppressives, chemotherapy and corticosteroids (topical use
for plaque psoriasis is allowed).

- Consumption of oral Vitamin D or its analogues for any reason during the last three
months before the screening visit (Calcipotriene topical use for plaque psoriasis is
allowed).

- Patients with a clinically significant history of cardiovascular, renal, neurologic,
liver, immunologic or endocrine dysfunction. A clinically significant disease is
defined as one that in the opinion of the investigator may either put the patient at
risk because of participation in the study or a disease that may influence the results
of the study or the patient's ability to participate in the study.

- Patients with a recent history (< 1 year) of myocardial infarction and/or (< 3 years)
of heart failure or patients with any cardiac arrhythmia requiring drug therapy.

- History of hypercalcaemia or hypercalciuria.

- History of previous or current malignancy in particular lymphoma, melanoma and/or
basal cell carcinoma.

- History of allergic reactions to Calcipotriene or P-3073 excipients.

- Patients unable to understand the procedures and purposes of the study.

- Patients unable or unwilling to accept and meet study requirements.

- Use of an investigational drug or participation in an investigational study within 30
days, or 6 half lives whichever is longer, prior to application of study medication.

- Alcohol or substance abuse.

- AIDS symptoms or any other immunodeficiency.

Additional exclusion criteria for females only:

- Breast-feeding patients.

- Positive urine pregnancy test at screening (performed for all females of child bearing
potential or for those in non-surgical post-menopause for less than 1 year).

- Female of childbearing potential having unprotected sexual intercourse with any
non-sterile male partner (i.e., a male who has not been sterilized by vasectomy at
least 6 months prior to drug application) within 14 days prior to study drug
application. Acceptable methods of contraception are the following: condom, diaphragm,
intrauterine contraceptive device (placed at least 4 weeks prior to study drug
application), pill + condom.