Lesinurad and Allopurinol Combination Extension Study in Gout

Inclusion Criteria: * Subject is able to understand the study procedures and the risks involved and is willing to provide written informed consent before the first study related activity. * Subject completed the double-blind treatment period in either Study RDEA594-301 or RDEA594-302 and was actively receiving and tolerating study medication (lesinurad or placebo) and allopurinol at the Month 12 visit. * Subject is male or female; female subjects of childbearing potential must agree to use an effective non-hormonal method of birth Exclusion Criteria: * Subject has any medical or psychological condition, which in the opinion of the Investigator and/or the Medical Monitor, might create undue risk to the subject or interfere with the subject's ability to comply with the protocol requirements, or to complete the study.