Study of LX3305 in Subjects With Active Rheumatoid Arthritis on Stable Methotrexate

A Phase 2, Multi-center, Randomized, Double Blind, Placebo-controlled, Multiple-dose Study to Determine the Safety and Efficacy of Daily Orally Administered LX3305 in Subjects With Active Rheumatoid Arthritis (RA) on Stable Methotrexate (MTX) Therapy

The purpose of the study is to evaluate the safety, tolerability, and effectiveness of LX3305 versus a placebo control in subjects with active rheumatoid arthritis on stable methotrexate therapy.

Inclusion Criteria:

• Males and females aged 18-75 years old
• Rheumatoid arthritis present for at least 6 months, functional class I, II, or III as defined by ACR criteria
• Active disease as determined by the presence of ≥6 swollen joints, ≥6 tender joints, and serum C-reactive protein level > upper limit of normal
• Receiving stable dose of MTX (≥10 mg/wk) and folate supplementation at least 8 weeks prior to Day 1
• Ability to provide written informed consent

Exclusion Criteria:

• RA diagnosis prior to 16 years of age (Juvenile RA)
• Lack of response to >3 disease modifying anti-rheumatic drugs (DMARDs) or exposure to >1 biologic DMARD
• Use of DMARDs other than MTX within 12 weeks prior to Day 1
• Intra-articular and/or parenteral corticosteroids within 4 weeks prior to study Day 1
• Blood donation or receipt of live vaccine within 4 weeks prior to Day 1
• Major surgical procedure within 8 weeks prior to Day 1
• Any systemic inflammatory condition, recurrent infection, or current infection other than onychomycosis
• History of cancer within 5 years prior to Day 1
• Presence of hepatic or biliary disease
• History of tuberculosis
• History of human immunodeficiency virus (HIV)