Excess of uric acid crystals in a joint causes gout. It is a form of arthritis that causes burning pain, stiffness, and swelling in a joint, usually a big toe. 

The new drug application (NDA) for lesinurad/allopurinol fixed-dose combination for the treatment of hyperuricemia in patients with uncontrolled gout has been accepted for review by the Food and Drug Administration (FDA).

The data from the lesinurad clinical trial program and a pharmacokinetic study gave way to the NDA submission for this drug inspecting the bioequivalence of the fixed-dose combination compared to lesinurad and allopurinol co-administered separately.

The results of this study revealed that the addition of lesinurad to a xanthine oxidase inhibitor (XOI) almost doubled the number of patients who accomplished target serum uric acid (sUA) levels of <6mg/dL at month 6. Also, the fixed-dose combination reduced the mean sUA to <6mg/dL by month 1 and sustained that level through month 12. 

Recently, Lesinurad- a URAT1 inhibitor, was approved in combination with a XOI for the treatment of hyperuricemia associated with gout in patients. These did not achieve target serum uric acid levels with a XOI alone. It's increases the renal excretion of uric acid through the selective inhibition of URAT1- the transporter responsible for the majority of renal uric acid reabsorption. Allopurinol is a XOI which decreases the production of uric acid. As a combination product, it will excercise dual-mechanism which can address the issues of uric acid.

The FDA is anticipating the Prescription Drug User Fee Act (PDUFA) target action date to occur  in the second half of 2017. This drug would become the first gout treatment in a daily fixed-dose combination possessing dual mechanism of action, if approved.