Ann Rheum Dis doi:10.1136/annrheumdis-2012-201795
  • Clinical and epidemiological research
  • Extended report

Long-term safety of pegloticase in chronic gout refractory to conventional treatment

Open AccessPress Release
  1. John S Sundy8
  1. 1Rheumatology Section, The University of Chicago, Chicago, Illinois, USA
  2. 2Center for Rheumatology and Bone Research, Wheaton, Maryland, USA
  3. 3Reliant Medical Group, Worcester, Massachusetts, USA
  4. 4Rheumatology Section, Kaiser Permanente Medical Center, San Francisco, California, USA
  5. 5Department of Rheumatology, Hospital General de Mexico, Mexico City, Mexico
  6. 6Savient Pharmaceuticals, Inc., East Brunswick, New Jersey, USA
  7. 7Department of Medicine, University of Michigan, Ann Arbor, Michigan, USA
  8. 8Duke Clinical Research Unit, Duke University Medical Center, Durham, North Carolina, USA
  1. Correspondence to Dr Michael A Becker, 237 East Delaware Pl, Chicago, IL 60611-1713, USA; mbecker{at}
  • Accepted 9 August 2012
  • Published Online First 10 November 2012


Objective To evaluate the long-term safety (up to 3 years) of treatment with pegloticase in patients with refractory chronic gout.

Methods This open-label extension (OLE) study was conducted at 46 sites in the USA, Canada and Mexico. Patients completing either of two replicate randomised placebo-controlled 6-month trials received pegloticase 8 mg every 2 weeks (biweekly) or every 4 weeks (monthly). Safety was evaluated as the primary outcome, with special interest in gout flares and infusion-related reactions (IRs). Secondary outcomes included urate-lowering and clinical efficacy.

Results Patients (n=149) received a mean±SD of 28±18 pegloticase infusions and were followed for a mean of 25±11 months. Gout flares and IRs were the most frequently reported adverse events; these were least common in patients with a sustained urate-lowering response to treatment and those receiving biweekly treatment. In 10 of the 11 patients with a serious IR, the event occurred when uric acid exceeded 6 mg/dl. Plasma and serum uric acid levels remained <6 mg/dl in most randomised controlled trial (RCT)-defined pegloticase responders throughout the OLE study and were accompanied by sustained and progressive improvements in tophus resolution and flare incidence.

Conclusions The safety profile of long-term pegloticase treatment was consistent with that observed during 6 months of RCT treatment; no new safety signals were identified. Improvements in clinical status, in the form of flare and tophus reduction initiated during RCT pegloticase treatment in patients maintaining goal range urate-lowering responses were sustained or advanced during up to 2.5 years of additional treatment.

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