A Proof-of-concept Study to Evaluate the Efficacy and Safety of Rozanolixizumab to Treat Adult Study Participants With Severe Fibromyalgia Syndrome

The purpose of the study is to evaluate efficacy and safety of rozanolixizumab to treat adult study participants with severe fibromyalgia syndrome (FMS).

Inclusion Criteria:Study participant must be ≥18 years and ≤70 years of age at the time of signing the informed consent form (ICF)Study participant with a diagnosis of fibromyalgia as defined by the 2016 Revisions to the 2010/2011 fibromyalgia diagnostic criteria (American College of Rheumatology PreliminaryDiagnostic Criteria) plus the following characteristics during the Screening Period:Brief Pain Inventory-short form (BPI-SF) interference score ≥6.Revised Fibromyalgia Impact Questionnaire (FIQR) score ≥64.Fatigue numeric rating scale (NRS) score ≥5.Study participant has completed pain management program of at least 36 hours duration, completion must have been >6 months from study entry dateStudy participant has been diagnosed with fibromyalgia syndrome (FMS) for at least 6 months.Study participant has been having FMS symptomatology for at least 2 years before enrollment - Capable of giving signed informed consent as described in the Protocol which includes compliance with the requirements and restrictions listed in the ICF and in the Study ProtocolExclusion Criteria:Study participant has been diagnosed with fibromyalgia syndrome (FMS) for >15 yearsStudy participant has any systemic autoimmune inflammatory diseaseStudy 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 painStudy 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 visitStudy participant has a clinically relevant active infection or has had a serious infection within 6 weeks prior to the first dose of investigational medicinal product (IMP)Study participant has chronic inflammatory demyelinating polyneuropathyStudy participant has a current or medical history of primary immunodeficiencyStudy participant has positive tuberculosis (TB) test at the Screening VisitStudy participant is pregnant or lactatingStudy participant has a current or medical history of immunglobulin A (IgA) deficiency, or a measurement of IgA <50 mg/dL at the Screening VisitStudy participant has a suicide attempt in the past 5 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 in the Protocol