Single Rising Dose Study of BI 655066 in Patients With Moderate and Severe Psoriasis

Inclusion criteria: 1. Male or female patients aged 18-75 years (inclusive) 2. Chronic moderate to severe plaque psoriasis lasting =\>6 months with involvement of Body Surface Area (BSA) =\>10%, Psoriasis Area and Severity Index (PASI) =\>12 and Static Physician Global Assessment (sPGA) score of moderate and above 3. Body Mass Index (BMI) =\>18.5 and \<40 kg/m2 4. Signed and dated written informed consent prior to admission to the study in accordance with Good Clinical Practice (GCP) and the local legislation 5. Female patients must not be of childbearing potential (i.e., must be postmenopausal or surgically sterilized) and must have a negative pregnancy test at screening. Exclusion criteria: 1. Evidence of current or previous clinically significant disease, medical condition other than psoriasis, or finding of the medical examination (including vital signs and Electrocardiogram (ECG)), that in the opinion of the Investigator, would compromise the safety of the patient or the quality of the data. This criterion provides an opportunity for the investigator to exclude patients based on clinical judgment, even if other eligibility criteria are satisfied (Psoriatic arthritis is not considered an exclusion.) 2. Gastrointestinal, hepatic, renal, respiratory, cardiovascular, metabolic, immunological or hormonal disorders, diseases of the central nervous system (such as epilepsy) or psychiatric disorders or neurological disorders, chronic or relevant acute infections including hepatitis and tuberculosis (or a positive interferon-gamma release assay at screening) or history of orthostatic hypotension, fainting spells or blackouts, that in the investigator's judgement, could jeopardize the safe conduct of the study 3. History of allergy/hypersensitivity to a systemically administered biologic agent or its excipients 4. Use of biologic agents or psoralen and ultraviolet A (PUVA) within 12 weeks prior to Visit 2, ultraviolet B (UVB) phototherapy and oral anti-psoriatic medications within 4 weeks prior to Visit 2, or topical anti-psoriasis medications (except emollients) within 2 weeks prior to Visit 2 5. Use of ustekinumab within 24 weeks prior to Visit 2 6. Had a prior treatment of psoriasis with biologics with inadequate clinical response to therapy as assessed by a dermatologist or the investigator 7. Intake of restricted medications or drugs considered likely to interfere with the safe conduct of the study 8. Use of drugs which might reasonably influence the results of the trial or that prolong the QT/QTc interval within 10 days prior to administration or during the trial 9. Participation in another trial with an investigational drug within 4 weeks or 5 half-lives (whichever is greater) preceding Visit 2 10. History of alcohol abuse within last 12 months (intake of more than 30 g/day) 11. History of drug abuse within last 12 months or positive drug screen at screening or Visit 2 12. Any blood donation or significant blood loss within 4 weeks prior to Visit 2 13. Unwilling or not capable to abstain from alcoholic beverages one day prior and two days after Visit 2 14. Excessive physical activities (within 1 week prior to Visit 2) 15. Any laboratory value at the screening visit outside the reference range that is of clinical relevance based on physician investigator judgement