AstraZeneca, a global, innovation-driven biopharmaceutical business, announced that the US Food and Drug Administration’s (FDA) Arthritis Advisory Committee (AAC) voted 10 to 4 to recommend the approval of lesinurad 200mg tablets for the treatment of hyperuricemia associated with gout, in combination with a xanthine oxidase inhibitor (XOI). The AAC reviewed safety and efficacy data from the pivotal phase III combination therapy programme trials, representing the largest clinical trial data set of gout patients treated with combination urate lowering therapy.

The FDA is not bound by the Advisory Committee’s recommendation but takes its advice into consideration when reviewing the application for a potential medicine. The Prescription Drug User Fee Act (PDUFA) target goal date for lesinurad is December 29, 2015.

If approved, lesinurad will be the first selective uric acid reabsorption inhibitor, or SURI, in the US. It inhibits the urate transporter, URAT1, which is responsible for the majority of the renal reabsorption of uric acid.

Sean Bohen, executive vice president of global medicines development and chief medical officer, AstraZeneca, said, “The Committee’s positive recommendation for lesinurad is an encouraging step for patients suffering from the debilitating effects of gout. We look forward to the outcome of the FDA’s review and the opportunity to provide a new treatment option that, when combined with a xanthine oxidase inhibitor, addresses both the under-excretion and over-production of uric acid, the underlying causes of gout.”

Gout is a serious and debilitating form of inflammatory arthritis caused by hyperuricemia (elevated serum uric acid (sUA)). Gout affects millions of Americans, many of whom do not reach recommended sUA treatment goals on the current standard of care (XOIs), which decrease production of uric acid. For those inadequately controlled patients, the addition of a urate lowering therapy to increase excretion of uric acid, may help them achieve treatment goals.

Lesinurad is also under regulatory review in the European Union and other territories.

If approved, lesinurad will be the first selective uric acid reabsorption inhibitor, or SURI, in the US. It inhibits the urate transporter, URAT1, which is responsible for the majority of the renal reabsorption of uric acid. By inhibiting URAT1, lesinurad increases uric acid excretion and thereby lowers serum uric acid (sUA). Lesinurad also inhibits organic anion transporter (OAT4), a uric acid transporter involved in diuretic-induced hyperuricemia. In addition, in patients, lesinurad does not inhibit OAT1 and OAT3, which are drug transporters in the kidney associated with drug-drug interactions.

If approved, lesinurad in combination with an XOI would provide a dual mechanism of action to increase excretion and decrease production of uric acid enabling more patients with inadequately controlled gout to achieve target treatment goals.

Gout is a serious, chronic, progressive, and debilitating form of inflammatory arthritis. Currently, there are more than 8.3 million patients suffering from gout in the US. The underlying cause of gout is hyperuricemia (elevated serum uric acid (sUA)), which leads to the deposition of crystals primarily in the joints and in other tissues. This can result in recurrent attacks of inflammatory arthritis and, if left uncontrolled, could lead to chronic, progressive arthritis, and tophus (visible deposits of urate crystals) formation.

The goal of sUA lowering treatment is to reduce sUA levels to the target level of <6.0mg/dL (360 µmol/L) as recommended by both the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR). To improve signs and symptoms such as tophaceous gout, the ACR guidelines state that achieving and maintaining sUA levels <5.0mg/dL (300 µmol/L) may be required.

Among patients treated in clinical trials, less than 50 per cent of patients on allopurinol 300mg reached sUA target levels <6.0mg/dL (360 µmol/L). This suggests approximately two million gout patients in the US on urate lowering therapy remain inadequately controlled. For patients who cannot reach target on an XOI alone, the current ACR guidelines recommend adding an agent that increases uric acid excretion.