Study to Evaluate Apo805K1 in Subjects With Moderate to Severe Chronic Plaque Psoriasis

A) To evaluate the safety and tolerability of 12 weeks of treatment with Apo805K1

B) To evaluate the pharmacokinetics of Apo805K1 following daily administration for 14 days

C) To evaluate the efficacy and pharmacodynamics of Apo805K1

Main Inclusion Criteria:

- A clinical diagnosis of moderate to severe chronic plaque psoriasis for at least 6
months (before Baseline assessment) with current body surface area (BSA) involvement
≥10% and Psoriasis Area Severity Index (PASI) ≥10.

- Male and female subjects 18 to 65 years of age, inclusive.

- At least one psoriatic plaque ≥6 mm in diameter (in a location suitable for biopsy).

- Signed and witnessed written informed consent form obtained prior to the first study
intervention, as well as the ability to adhere to study restrictions, appointments
and evaluation schedule.

Main Exclusion Criteria:

- Treatment of psoriasis with biologic agents within 90 days prior to Baseline
assessment and during the study.

- Treatment with methotrexate, cyclosporine, retinoids, hydroxyurea or other systemic
agents within 30 days prior to Baseline assessment and during the study.

- Phototherapy within 30 days prior to Baseline assessment and during the study.

- Psoriasis topical therapy within 14 days prior to Baseline assessment and during the
study (exception: non-medicated emollients and tar shampoo will be allowed).

- History of liver disease or abnormal liver enzymes

- Serum creatinine ≥1.5 times the upper limit of normal for age and sex-matched
controls.

- Previous treatment with Apo805K1or Thymodepressin or other immunosuppressant drugs.

- Evidence of skin conditions other than psoriasis (e.g., eczema) that could interfere
with psoriasis assessments.

- History of chronic infection or malignancy