Pharmacokinetics and pharmacodynamics of pegloticase infused at three-week intervals. Panels A and B: Data for the first pegloticase dosing cycle on all 29 patients. (A) Plasma uricase activity (pUox), plotted on a logarithmic scale (y-axis). The dashed line at 1 mU/mL is shown as a reference. (B) Plasma uric acid concentration (pUA). The dashed line at 6 mg/dL is shown as a reference. Symbols: blue = patients with a persistent response to pegloticase (PR); red = patients with a transient response to pegloticase (TR); open red triangles = 3 non-naïve TR, who had received pegloticase >1 year prior to the present trial. P- values shown are for comparison of the means for PR and TR. Panels C and D: Mean pUox and pUA during all five dosing cycles for PR (C) and TR (D). Symbols: blue circles = pUox; red squares = pUA; n = number of patients under treatment in each cycle. Error bars, standard deviation.