This is a drug-drug interaction study in healthy volunteers to evaluate the potential pharmacokinetic (PK) effects of ranitidine on lesinurad.

This study will evaluate the potential effect of ranitidine on the pharmacokinetics of lesinurad. An earlier study demonstrated an effect on lesinurad PK in the presence of both calcium-containing and magnesium- and aluminum-containing antacids. The current study will assess whether raising gastric pH, without the presence of these cations, affects lesinurad PK and PD under the fasted state. If an impact is seen, then the optional second cohort will be conducted under the fed state.

Inclusion Criteria:

• body weight ≥ 50 kg (110 lbs) and body mass index ≥ 18 and ≤ 30 kg/m2.
• Screening sUA value ≤ 7.0 mg/dL.
• free of any clinically significant disease that requires a physician's care and/or would interfere with study evaluations or procedures.
• Subject has no clinically relevant abnormalties in vital signs, ECG, physical examination or safety laboratory values per the Investigator's judgment.

Exclusion Criteria:

• history or clinical manifestations of significant metabolic, hematological, pulmonary, cardiovascular, gastrointestinal, neurologic, hepatic renal,urological, or psychiatric disorders.
• history or suspicion of kidney stones.
• undergone major surgery within 3 months prior to Day 1.
• donated blood or experienced significant blood loss (> 450 mL) within 12 weeks prior to Day 1 or gave a plasma donation within 4 weeks prior to the Screening visit.
• inadequate venous access or unsuitable veins for repeated venipuncture.