A Trial to Investigate the Non-inferiority of Pegloticase Administered Every 4 Weeks (Q4W) With MTX Compared With Every 2 Weeks (Q2W) With MTX in Participants With Uncontrolled Refractory Gout

The study consists of 24-week double-blind trial to evaluate the non-inferiority of the efficacy and safety of pegloticase Q4W with MTX versus pegloticase Q2W with MTX, followed by a 24-week open-label extension of pegloticase Q4W with MTX, in participants with uncontrolled refractory gout. The main objective of the study is to evaluate the effect of pegloticase 16 mg administered Q4W with MTX versus pegloticase 8 mg administered Q2W with MTX, on the response rate during Month 6, as measured by the sustained normalization of sUA to \< 6 mg/dL for at least 80% of the time.