New urate-lowing therapies.

PURPOSE OF REVIEW: To discuss recent studies of lesinurad and arhalofenate.

RECENT FINDINGS: Lesinurad acts by blocking urate reabsorption channels URAT-1 and OAT-4. It has urate-lowering effect when used alone and in combination with xanthine oxidase inhibitors (XOIs). Its uricosuric activity depends on glomerular filtration, and its' efficacy is impaired at eGFR less than 30 ml/min. Lesinurad monotherapy (400 mg/day) associates with serum creatinine elevations. However, this risk is substantially attenuated with coprescription of a XOI and when prescribed at a dose of 200 mg/day. Given its' modest urate-lowering effect, and the risk of serum creatinine elevation when used alone, it is licenced for use in combination with XOI for people unable to achieve target serum uric acid with XOI alone. Lesinurad does not have the drug interactions associated with probenecid, however, it is metabolized by CYP2C9, and should be used with caution if CYP2C9 inhibitors are coprescribed. Arhalofenate also acts by blocking URAT-1; however, it also blocks the NALP-3 inflammasome providing gout-specific anti-inflammatory effect. Arhalofenate has a weaker urate-lowering effect than lesinurad and further phase III evaluation is planned.

SUMMARY: Lesinurad provides an additional option for people with gout unable to achieve target serum uric acid with XOI alone.