This study is designed to evaluate the safety and tolerability of multiple intravenously administered doses of PD 0360324 in patients with rheumatoid arthritis receiving methotrexate.

Inclusion Criteria:

• Diagnosis of RA for at least 6 months based upon the American College of Rheumatology (ACR) 1987 Revised Criteria.
• Must have been treated with methotrexate (≥7.5 mg/week to ≤25 mg/week) for at least 16 weeks immediately prior to enrollment. The dose of methotrexate must be stable for at least 6 weeks prior to enrollment.
• Females of childbearing potential are required to simultaneously use 2 effective contraceptive methods, 1 of which must be a barrier (condoms, diaphragm or cervical cap) with spermicide. Non-vasectomized men must be willing to abstain from sexual intercourse or willing to use a condom in addition to having their female partner use another form of contraception, if the woman could become pregnant from the time of the first dose of study medication until completion of follow up procedures
• Contact your local site for more inclusion criteria.

Exclusion Criteria:

• Diagnosis of any other inflammatory arthritis (eg, spondyloarthropathies); or a non-inflammatory arthritis or musculoskeletal condition (eg, osteoarthritis, fibromyalgia) that, in the investigator's opinion, may interfere with clinical assessments.
• Evidence of active or latent infection with Mycobacterium tuberculosis (TB).
• Use of etanercept, anakinra, or oral DMARDs with the exception of methotrexate, within the 4 weeks prior to enrollment. Use of biological DMARDs within the 8 (adalimumab or infliximab) or 12 (abatacept) or 56 (rituximab) weeks prior to enrollment. Use of oral corticosteroids, acetaminophen, NSAIDs, and opioids are permitted within the dose ranges defined in the protocol.
• Contact your local site for more inclusion criteria.