AstraZeneca has reported positive Phase 3 data for gout candiate lesinurad

This alert comes from our UpdatesPlus-Gout service, a regular analysis providing depth information on all key recent events in the area.  To receive further information or instruction on how to access the full report please contact fiona.watts@leaddiscovery.co.uk [for a summary of our most recent full report click here]

• AstraZeneca has reported topline data for its URAT1 inhibitor from three gout studies, CLEAR1, CLEAR2 and CRYSTAL
• In CLEAR1 and CLEAR2 daily lesinurad (200 or 400mg) in combination with the xanthine oxidase inhibitor allopurinol increased the proportion of patients reaching the target sUA goal (less than 6.0mg/dL) after 6mo
  
• CRYSTAL studied lesinurad at the same dose in combination with a second xanthine oxidase inhibitor, febuxostat in patients with tophi.  The target sUA goal was slightly lower at less than 5.0mg/dL and this was met at 400mg after 6mo but not 200mg (superiority was however observed at other earlier and later time points)
• Of note, in CRYSTAL,  renal-related adverse events and incidence of kidney stones was increased at the higher 400mg dose

Comments:   The company has commented that it is preparing for regulatory submissions but at the lower 200mg dose.  We expect filing to also be this year, approximately in line with earlier expectations.  A fourth study, LIGHT was reported in 2013 demonstrating efficacy at 400mg as a monotherapy in gout patients unable to take an xanthine oxidase inhibitor.  In this study renal AEs were also elevated. We presume that the 400mg dose is not being submitted due to AEs and this may limit the potential of lesinurad, especially as approval will likely not be for monotherapy.   Given that submission will be limited to 200mg, the degree of efficacy at this dose will be important.  AstraZeneca has indicated that full data are expected later this year.