- Study participant has a draining tunnel count of >20 at either the Screening or Baseline Visits. - Study participant has experienced primary failure (no response within 12 weeks) to 1 or more IL 17 biologic response modifiers (eg, brodalumab, ixekizumab, secukinumab) OR primary failure to more than 1 biologic response modifier other than an IL-17 biologic response modifier. - Study participant has previously participated in this study or has received previous therapy with bimekizumab. - Study participant has a history of IBD or symptoms suggestive of IBD. - History of active tuberculosis unless successfully treated, latent TB unless prophylactically treated - Study participant has an active infection or history of infections (such as serious infection, chronic infections, opportunistic infections, unusually severe infections) - Study participant has received drugs outside the specified timeframes relative to the Baseline Visit or receives prohibited concomitant treatments - Study participant has the presence of active suicidal ideation, or positive suicide behavior, - Study participant diagnosed with severe depression in the past 6 months prior to the Screening Visit. - Study participant has a history of psychiatric inpatient hospitalization within the past year before enrolling into the study.