This is a Phase 2a, multicenter, randomized, double-blind, placebo-controlled, dose-ranging study to evaluate the efficacy, safety, and pharmacokinetics study of 6 different dose regimens of ABP-671 compared with placebo. The study will consist of three sequential groups with escalating total daily ABP-671 doses. Each group is further divided into two dose cohorts with either QD or BID dosing. Each dose group will have 3 stages following screening: Run-in, Dose Evaluation, and Follow-up.

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.