Percentage of Pegloticase Infusions in Gout Patients who had Uric Acid Testing Performed and had G6PD Testing

Pegloticase is a pegylated uricase indicated for the treatment of chronic gout in adult patients refractory to conventional urate-lowering therapy. It is given as an IV infusion every 2 weeks. Anaphylaxis and immune reactions can occur and are based on the formation of antibodies. The antibodies result in a loss of effect of the drug, which has been shown to precede the reactions in 91% of cases. Typically, uric acid levels fall below 1 mg/dL after each pegloticase infusion; with loss of effect, uric acid levels are higher. This has led to the recommendation that a uric acid level be checked before each infusion. Treatment should be discontinued if uric acid rises to 6.0 mg/dL or higher on 2 consecutive tests.

In 2018, 136 pegloticase infusions were performed in 13 patients; serum uric acid was checked 135/136 (99.3%) prior to infusions given, and 133/136 (97.8%) were <6.0 mg/dL. In 2019, 118 pegloticase infusions were performed in 15 patients; serum uric acid was checked 118/118 (100%) prior to infusions given, and 114/118 (96.6%) were <6.0 mg/dL. In 2020, 81 pegloticase infusions were performed in 8 patients: serum uric acid was checked 80/81 (98.8%) prior to infusions given, and 78/81 (96.3%) were <6.0 mg/dL. In 2021, 175 pegloticase infusions were performed in 18 patients: serum uric acid was checked 175/175 (100%) prior to infusions given, and 160/175 (83.3%) were <6.0 mg/dL. In 2022, 323 pegloticase infusions were performed in 29 patients: serum uric acid was checked 320/323 (99.1%) prior to infusions given, and 273/323 (84.5%) were <6.0 mg/dL. All patients from 2018 - 2021 with 2 consecutive uric acid levels > 6.0 mg/dL had pegloticase infusions discontinued. In 2022, all but 1 patient had infusion discontinued with 2 consecutive uric acid levels >6.0 mg/dl.

Glucose-6-phosphate dehydrogenase (G6PD) levels should be checked prior to pegloticase infusion because of the risk for hemolysis in G6PD-deficient patients; 97.8% in 2018-2019, 100% in 2020-2021, and 99.4% in 2022 had G6PD testing.