The European Medicines Agency (EMA) has accepted AstraZeneca’s marketing application for gout treatment lesinurad, setting it up for a possible approval later this year.
The filing comes on the back of positive data from three phase III trials of lesinurad which showed the drug improved treatment when added to xanthine oxidase (XO) inhibitors such as generic allopurinol or Takeda’s Uloric (febuxostat), which are the most-commonly used drugs for gout. AZ acquired lesinurad as part of its $1bn takeover of Ardea Biosciences in 2012.
In gout, uric acid crystals are deposited in the joints, creating intense pain and inflammation similar to that seen in an acute arthritis flare. Lesinurad is a selective uric acid re-absorption inhibitor (SURI) and stimulates uric acid excretion from the body to reduce blood levels and prevent crystals being formed.
Gout is becoming more common thanks to increasing rates of obesity and poor diet, with the number of cases in the UK rising by 30% between 1997 and 2012 according to a study published at the end of 2013 in the journal Annals of the Rheumatic Diseases.
One in 40 people in the UK are now affected by gout, although treatment rates remain low with less than 19% of newly diagnosed patients currently prescribed urate-lowering drugs within the first six months from diagnosis.
While many people with gout can manage using lifestyle changes, the rate of drug therapy was considered ‘suboptimal’ by the authors of the study, from the University of Nottingham and Keele University in the UK and Chang Gung Memorial Hospital in Taiwan.
AZ notes that between 40% and 80% of patients do not achieve recommended urate treatment goals with the current standard of care of an XO inhibitor alone.
AZ has filed for approval of a 200mg dose of lesinurad as the trials revealed a risk of kidney toxicity at a higher 400mg dose that was also tested in trials, and this – coupled with the fact that the 200mg dose failed to improve the efficacy of febuxostat when the two drugs were used in combination – has pegged back peak sales expectations.
Lesinurad has been considered a wildcard at AZ for some time – despite the size of the patient population – as some consider a greater impact on gout will come from encouraging greater use of the existing drugs in untreated sufferers.
While some analysts have suggested lesinurad could top $1bn a year in sales, AZ did not include in the list of blockbusters published last May as it made a case for independence in response to takeover interest from Pfizer.
Another recent entrant into the gout market – Savient Pharmaceuticals – was forced to file for bankruptcy in 2013 after poor sales of its gout therapy Krystexxa (pegloticase).