A Study of Dotinurad Versus Allopurinol in Tophaceous Gout

The primary objective of this study is to evaluate the efficacy of dotinurad in lowering serum uric acid (sUA) at Week 24 compared with allopurinol in adult participants with tophaceous gout.

Inclusion Criteria 1. Between 18 and 75 years of age (inclusive) at the time of signing informed consent. 2. Diagnosis of gout based on 2015 American College of Rheumatology-European Union League Against Rheumatism (ACR-EULAR) criteria for at least 1 year. 3. Has ≥1 measurable tophus on the hands/wrists and/or feet/ankles between Screening and Day 1. A measurable tophus is defined as ≥5 mm and ≤30 mm in the longest diameter. 4. sUA level ≥5.0 mg/dL at Screening Visit 1 (Day -35 Visit) and Screening Visit 2 (Day -7 Visit). 5. Female participants of childbearing potential must have a negative serum pregnancy test at Screening Visit 1 (Day -35 Visit) and Screening Visit 2 (Day -7 Visit), a negative urine pregnancy test on Day 1, and must not be breastfeeding. 6. Fertile male participants and female participants of childbearing potential must be willing to completely abstain from heterosexual sex or agree to use acceptable contraception from the time of signing informed consent through 30 days after the last dose of study drug. Exclusion Criteria 1. History of or presence of kidney stones within 1 year prior to Screening. 2. History of or presence of malignancy in the last 5 years other than treated cutaneous basal or squamous cell carcinoma. 3. Hypersensitivity or intolerance to dotinurad or to colchicine and nonsteroidal anti-inflammatory drugs (NSAIDs). 4. Known or suspected history of drug abuse, a positive drug test at Screening Visit 1, or a recent history of alcohol abuse. 5. Known history of or positive results for human immunodeficiency virus (HIV), Hepatitis B Surface Antigen (HBsAg), or Hepatitis C antibodies (HCV) during Screening.