Which Urate-Lowering Therapy Quickly Resolves Tophi in Gout?

Pegloticase treatment can quickly resolve the tophi that many patients with gout experience, according to a new study.

The American College of Rheumatology recommends that the target serum urate should be lowered sufficiently in order to reduce or resolve tophi. Pegloticase, a recombinant mammalian uricase conjugated to polyethylene glycol, is known to decrease serum urate in biochemical responders to less than 1 mg/dl.

To assess the velocity of tophus resolution in patients treated with pegloticase, the researchers analyzed data from 2 randomized controlled trials of pegloticase in chronic refractory gout.

Each participant was randomly assigned to 6 months of treatment with intravenous infusions of either pegloticase, 8 mg, at each infusion (8 mg q2w); pegloticase, 8 mg, alternating with placebo (q4w); or placebo.

Tophi were assessed by computer-assisted measurements of standardized digital photographs taken of the hands and feet at baseline and repeated at 13, 19, and 25 weeks.

The mean total tophus area at baseline was 585.8 mm² for responders—those who received pegloticase without generating high-titer antidrug antibodies—, 661.5 mm² for nonresponders, and 674.4 mm² for participants who received placebo.

All photographed tophi was completely resolved in 34.8% of biochemical responders, 11.6% of nonresponders, and 0% of placebo-treated participants.

The mean velocity of resolution of all tophi was 60.1 mm²/month in responders with a mean projected time of complete resolution of 9.9 months.

“Pegloticase treatment causes a rapid resolution of tophi in responders, as predicted from the profound and persistent serum urate lowering associated with this therapy,” the researchers concluded. “Even transient reductions in serum urate observed in nonresponders may result in complete resolution of tophi in some patients over the course of 6 months or less.”

—Colleen Murphy

Reference:

Mandell BF, Yeo AE, Lipsky PE. Tophus resolution in patients with chronic refractory gout who have persistent urate-lowering responses to pegloticase. Arthritis Res Ther. 2018;20(286). https://doi.org/10.1186/s13075-018-1782-x.