This Phase 2 study is designed to examine the efficacy and safety of multiple dose levels of IPI-145 in subjects with active moderate-to-severe Rheumatoid Arthritis receiving a background stable dose of methotrexate. The study will employ a randomized, double-blind, placebo-controlled, parallel design.~Approximately 316 adult subjects who meet all eligibility criteria at Screening will be randomized at Baseline in a 1:1:1:1 ratio to one of 4 dose groups.~All treatments will be administered twice a day (BID). After randomization, subjects will enter a 12-week Treatment Period, where study drug (IPI-145 or placebo) will be self-administered BID as an outpatient. During the Treatment Period, subjects will return to the clinic for efficacy and safety assessments every 2 weeks. Following Treatment Period completion at Week 12, subjects will enter a 3-week Follow-up Period which includes one clinic visit approximately 3 weeks after the last dose of study drug.
The purpose of this study is to investigate the safety and efficacy of multiple dose levels of the investigational product (study drug), IPI-145, in combination with methotrexate compared to methotrexate alone in subjects with active moderate-to-severe Rheumatoid Arthritis.