Injections of pegloticase, a modified porcine enzyme, can produce significant and sustained clinical improvements in 2 out of 5 patients with chronic gout that is resistant to conventional therapies, researchers report in the August 17, 2011, issue of JAMA.

In two controlled clinical trials, pegloticase rapidly lowered high levels of uric acid, the biochemical abnormality in gout, and kept it in the normal range for six months or more in 42 percent of patients receiving the drug every two weeks. Forty percent of patients had complete resolution of at least one of the painful swollen joint nodules, known as tophi, a hallmark of severe gout.