Assess Safety and Tolerability of Two Different Dose Levels of Subcutaneous Pegloticase in Subjects with Uncontrolled Gout Receiving Methotrexate

The primary objective is to assess the safety and tolerability of a single dose of subcutaneous (SC) pegloticase injection at 2 different doses with oral MTX, as measured by the incidence of severe delayed injection site reactions (ISRs) related to pegloticase occurring between Day 3 and prior to injection on Day 29, in adults with uncontrolled gout.