AstraZeneca remains on course for US approval of its first-in-class gout drug lesinurad after an FDA panel backed the drug late last week.
The advisory committee voted 10-4 in favour of approving the selective uric acid reabsorption inhibitor – which has the proposed trade name of Zurampic – for use alongside xanthine oxidase (XO) inhibitors such as generic allopurinol or Takeda’s Uloric (febuxostat) in gout.
Panellists were unanimous that the drug was effective, but the vote on safety was much tighter, with lesinurad edging it at 7-6 with one abstention. The FDA is now due to deliver its verdict on lesinurad by December 29, and the drug is also under regulatory review in Europe.
The positive vote is a relief for AZ, as documents released by the FDA reviewer ahead of the panel meeting raised questions about the safety of lesinurad, particularly with regard to patient deaths related to heart and kidney problems.
Lesinurad encourages the excretion of uric acid – which crystallises in the joints and causes the excruciating pain and inflammation associated with gout flares. It has a complementary action to XO inhibitors, which block the over-production of uric acid.
In the recently-reported CRYSTAL study, the combination of lesinurad and Uloric was shown to be more effective than Uloric alone at reducing serum uric acid. However, the results were not a home run, with the combination failing to show a significant improvement on some outcome measures and a sizable block of test subjects failing to reach target uric acid levels.
Despite the somewhat compromised clinical data, AZ’s drug has been tipped to become a potential blockbuster thanks to increasing levels of gout, which is in turn becoming more common thanks to a rising tide of obesity and poor diet, particularly in western economies.
With an FDA approval now looking more likely AZ has a chance to turn the project – long considered a wildcard in its pipeline – into a revenue generator.
Gout is also chronically under-treated, with just one in five newly-diagnosed patients being prescribed uric acid-lowering drugs in the six months, and the company will have to work hard to raise awareness of treatment options.
Another recent entrant into the market – Savient Pharmaceuticals – was unable to make headway with its Krystexxa (pegloticase) therapy and was forced to file for bankruptcy in 2013.
AZ acquired lesinurad as part of its $1.3bn takeover of Ardea Biosciences in 2012, an acquisition which also included a second gout candidate (RDEA3170) that is in mid-stage clinical testing.
“The committee’s positive recommendation for lesinurad is an encouraging step for patients suffering from the debilitating effects of gout,” commented AZ’s chief medical officer Sean Bohen.
“We look forward to the outcome of the FDA’s review and the opportunity to provide a new treatment option,” he added.