A Study to Assess the Adverse Events and How Oral ABBV-1606 Moves Through the Body of Healthy Adult Participants.

Inclusion Criteria:

• BMI is ≥ 18.0 to ≤ 32.0 kg/m2 after rounding to the tenths decimal at Screening. BMI is calculated as weight in kg divided by the square of height measured in meters.
• Total body weight > 50.0 kg at Screening.
• A condition of general good health, based upon the results of a medical history, physical examination, neurological examination, vital signs, laboratory profile, and a 12-lead ECG.

Exclusion Criteria:

• History of any clinically significant cardiac, respiratory (except mild asthma as a child), renal, hepatic, gastrointestinal, hematologic, immunological, neurological, pulmonary, metabolic, endocrine or psychiatric disease or disorder, active or chronic infectious diseases or any uncontrolled medical illness.
• History of any vasculitis-related conditions, or any confirmed autoimmune or connective tissue diseases (e.g., Systemic Lupus Erythematosus, Sjogren's Syndrome, inflammatory bowel disease, etc.) as per the Investigator judgement.
• History of unexplained purpura or skin rash, or unexplained signs or symptoms suggestive of vasculitis (including, but not limited to, fever, weight loss, arthralgia or arthritis, myalgia, hematuria, abdominal pain, gastrointestinal bleeding, etc.) that is not resolved for at least 30 days prior to dosing.
• History of any abnormal result for Antinuclear antibody (ANA) or Antineutrophil cytoplasmic antibody (ANCA) at Screening
• Abnormal result for C-Reactive Protein (CRP) or Erythrocyte Sedimentation Rate (ESR), or fibrinogen > the Upper limit of normal (ULN) at Screening.