- Study participant has been diagnosed with fibromyalgia syndrome (FMS) for >15 years - Study participant has any systemic autoimmune inflammatory disease - Study participant has any medical or psychiatric or separate chronic pain condition that, in the opinion of the investigator, could jeopardize or would compromise the study participant’s ability to participate in this study or the ability to assess FMS-related pain - Study participant has severe renal impairment, defined as estimated glomerular filtration rate <30 mL/min/1.73 m^2, (calculated using Modification of Diet in Renal Disease [MDRD] study equation), at Screening visit - Study participant has a clinically important active infection (including unresolved or not adequately treated infection) as assessed by the investigator - Study participant has chronic inflammatory demyelinating polyneuropathy - Study participant has a current or medical history of primary immunodeficiency - Study participant is pregnant or lactating - Study participant • Has suicide attempt in the past 2 years (including an active attempt, interrupted attempt, or aborted attempt), • OR had suicidal ideation with at least some intent to act in the past 6 months as indicated by a positive response (Yes) to either Question 4 or Question 5 of the Columbia Suicide Severity Rating Scale (C-SSRS) at Screening or Baseline (Visit 3); • OR is otherwise judged clinically to be at a serious suicidal risk based on the investigator’s judgment