A Study to Assess the Efficacy, Safety, and Pharmacokinetics of ABP-671 in Patients With Gout or Hyperuricemia

Inclusion Criteria: * Subject is able to understand the study procedures, the risks involved and willing to provide written informed consent before the first study related activity. * Subject meets the diagnosis of gout as per the American College of Rheumatism/ European League Against Rheumatism (EULAR) Gout Classification Criteria or diagnosis of hyperuricemia. * Subject has an sUA level ≥ 7.0 mg/dL at baseline. * Subject must be willing to discontinue any other UA-lowering medication (e.g., allopurinol, febuxostat, and probenecid) and take gout prophylaxis medication during the study. * Body mass index (BMI) ≤ 40 kg/m2. Exclusion Criteria: * Subject with a documented history of rheumatoid arthritis or other autoimmune disease. * Subject with any clinically significant hepatic, cardiovascular, renal, neoplastic, psychiatric illness, or hematological disorders such as polycythemia vera, sickle cell disease, or myelodysplastic disorder. * Subject with a history of alcohol or drug abuse within the past 1 year prior to screening, or current evidence of substance dependence or abuse. * Subject with a positive test for active hepatitis B, hepatitis C infection or human immunodeficiency virus (HIV) infection. * Subject with active liver disease, or hepatic dysfunction. * Subject with an inadequate renal function with estimated serum creatinine \> 1.5 mg/dL (\> 0.133 mmol/L) or creatinine clearance \< 60 mL/min (by Cockcroft-Gault formula). * Subject with a history of malignancy within the previous 5 years with the exception of non-melanoma skin cancer that has been treated with no evidence of recurrence, treated cervical dysplasia or treated in situ Grade 1 cervical cancer. * Subject with unstable angina, New York Heart Association class III or IV heart failure, myocardial infarction, stroke, or deep venous thrombosis within the last 12 months; or subjects currently receiving anticoagulants. * Subject with QT interval corrected for heart rate according to Fridericia's formula \> 470 msec (females) and \> 450 msec (males) during the Screening Period, confirmed by a repeat assessment. * Subject with uncontrolled hypertension * Subject receiving chronic treatment with more than 325 mg aspirin per day. * Subject that requires or may require systemic immunosuppressive or immunomodulatory treatment. * Subject who received any investigational therapy within 30 days or 5 half-lives (whichever is longer) prior to screening. * Subject who is pregnant or breastfeeding.