A Study Exploring the Safety, Tolerability and Efficacy of a 4 Week Course of INCB018424 in Subjects With Active Rheumatoid Arthritis

A Double-blind, Placebo-controlled Study Exploring the Safety, Tolerability and Efficacy of a 4 Week Course of INCB018424 in Subjects With Active Rheumatoid Arthritis

The purpose of this study is to understand the safety and tolerability of INCB018424 in patients with rheumatoid arthritis

Inclusion Criteria:

1. Established diagnosis of rheumatoid arthritis
2. Patients receiving methotrexate must be treated with for at least 6 months and receiving a stable weekly dose between 10 and 25 mg for at least 8 consecutive weeks prior to study entry.

Exclusion Criteria:

1. Patients who have taken the following drugs within the timeframe below:

   • Leflunomide, infliximab, etanercept, adalimumab, abatacept, or other biological therapies (except rituximab) - Within 12 weeks prior to the first dose of study medication;
   • Rituximab - Within 12 months prior to the first dose of study medication;
   • Disease-modifying anti-rheumatic drugs (DMARDs) or other anti-rheumatic therapies not specified above including but not limited to: gold, penicillamine, dapsone, azathioprine, 6-mercaptopurine, chlorambucil, cyclophosphamide, cyclosporin, mycophenolate mofetil - Within 12 weeks prior to the first dose of study medication;

2. Treatment with any investigational medication within 12 weeks prior to the first dose of study medication.