A Study to Evaluate the Pharmacokinetics (PK), Pharmacodynamics (PD), and Safety of Bimekizumab in Patients With Chronic Plaque Psoriasis

Inclusion Criteria: * Male or female at least 18 years of age and less than or equal to 70 * Chronic plaque psoriasis for at least 6 months prior to Screening * Psoriasis Area and Severity Index (PASI) \>=12 and body surface area (BSA) \>=10% and Investigator's Global Assessment (IGA) score \>=3 on a 5-point scale * Candidates for systemic psoriasis therapy and/or phototherapy and/or chemophototherapy * Female subjects must be postmenopausal, permanently sterilized or, if of childbearing potential, must be willing to use a highly effective method of contraception up till 20 weeks after last administration of study drug, and have a negative pregnancy test at Visit 1 (Screening) and immediately prior to first dose * Male subjects with a partner of childbearing potential must be willing to use a condom when sexually active, up till 20 weeks after the last administration of study medication (anticipated 5 half-lives) Exclusion Criteria: * Subjects previously participating in a bimekizumab study * Subjects with erythrodermic, guttate, pustular form of psoriasis, or drug-induced psoriasis * History of chronic or recurrent infections, or a serious or life-threatening infection within the 6 months prior to the Baseline Visit (including herpes zoster) * High risk of infection in the Investigator's opinion * Current sign or symptom that may indicate an active infection * Concurrent acute or chronic viral hepatitis B or C or human immunodeficiency virus (HIV) infection * Live (includ…