Baricitinib in Relapsing Giant Cell Arteritis

Inclusion Criteria

• Diagnosis of Giant Cell Arteritis (GCA) defined by the following Revised GCA Diagnosis Criteria:
• Age ≥50 years.
• History of Erythrocyte Sedimentation Rate (ESR) ≥ 50 mm/hour or C-Reactive Protein (CRP) ≥ 10 mg/L.
• Presence of at least one of the following:
• Unequivocal cranial symptoms of GCA (new onset localized headache, scalp or temporal artery tenderness, otherwise unexplained mouth or jaw pain upon mastication).
• Unequivocal symptoms of Polymyalgia Rheumatica (PMR), defined as shoulder and/or hip girdle pain associated with inflammatory stiffness.
• Systemic inflammatory disease in which the presence of the fever (>38 degrees Celsius for ≥ 7 days), weight loss (> 5 pounds or 10% premorbid weight), and/or night sweats were attributable to GCA and no other cause was identified.
• Presence of at least one of the following:
• Temporal artery biopsy revealing features of GCA.
• Evidence of large-vessel vasculitis by angiography or cross-sectional imaging, including but not limited to magnetic resonance angiography (MRA), computed tomography angiography (CTA), positron emission tomography-computed tomography (PET-CT) or evidence of large-vessel or temporal artery vasculitis by ultrasound (US).
• Relapse with active GCA within 6 weeks of study entry where active disease is defined by an ESR ≥30 mm/hr or CRP ≥10 mg/L AND the presence of at least one of the following:
• Unequivocal cranial symptoms of GCA (new onset or recurrent localized headache, scalp or temporal artery tenderness, otherwise unexplained mouth or jaw pain upon mastication [i.e., jaw claudication]).
• Unequivocal symptoms of PMR, defined as shoulder and/or hip girdle pain associated with inflammatory stiffness.
• Other feature(s) judged by the clinician investigator to be consistent with GCA or PMR flares (e.g. fever of unknown origin, weight loss, fatigue/malaise, etc.)
• Clinically stable at baseline visit (study drug initiation) such that the subject is able to safely participate in the standardized taper regimen in the opinion of the investigator.

Exclusion Criteria

• Presence of any other autoimmune disease (such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory arthritis, other vasculitides, scleroderma, polymyositis, dermatomyositis, or other similar systemic connective tissue diseases).
• Subjects demonstrating symptoms of visual loss (transient or permanent blindness) or diplopia attributable to GCA.
• Subjects with history of aortic dissection, myocardial infarction, or cerebrovascular attack attributable to GCA.
• Has received, or is expected to receive, any live virus vaccinations (with the exception of herpes zoster vaccination) within 3 months before the first dose of study drug, during the study, or within 3 months after the last administration of the study drug. All patients who have not received the herpes zoster vaccine at screening will be encouraged (per local guidelines) to do so prior to randomization; vaccination must occur >4 weeks prior to randomization and start of investigational product. Patients will be excluded if they were exposed to herpes zoster vaccination within 4 weeks of planned randomization.
• Organ transplant recipients.
• Have had a major surgery within 8 weeks prior to screening or will require major surgery during the study that, in the opinion of the investigator would pose an unacceptable risk to the patient.
• Have experienced any of the following within 12 weeks of screening: myocardial infarction (MI), unstable ischemic heart disease, stroke, or New York Heart Association Stage IV heart failure
• Have a history or presence of cardiovascular (including but not limited to uncontrolled hypertension), respiratory, hepatic, gastrointestinal, endocrine, hematological, neurological, or neuropsychiatric disorders, or any other serious and/or unstable illness that, in the opinion of the investigator, could constitute an unacceptable risk when taking investigatio