Study to Assess the Safety, Tolerability, and Pharmacokinetics of AMP-110 in Subjects With Rheumatoid Arthritis

Inclusion Criteria: * Must be able to provide written informed consent * Body mass index 18.5 to 35.0 kg/m2 * Diagnosis of Rheumatoid Arthritis according to 1987 revised American College of Rheumatology (ACR) criteria * Global Functional Class I, II, or III according to ACR 1991 revised criteria * Stable use of \>/= 1 Disease Modifying Anti-rheumatic Drugs (DMARD) for \>/= 4 weeks prior to Day 0, including: 1. Methotrexate (MTX) 7.5 - 25 mg/week 2. Hydroxychloroquine (HCQ) \</= 400 mg/day 3. Sulfasalazine (SSZ) 1,000 - 3,000 mg/day 4. Leflunomide 5 - 20 mg/day 5. Azathioprine 150 mg/day or 2 mg/kg/day 6. Combinations of MTX, HCQ, and/or SSZ allowed Exclusion Criteria: * Prior to Day 0, use of 1. Abatacept 2. Rituximab within 6 months 3. Infliximab, Adalimumab, Certolizumab, Tocilizumab, Cyclosporine, or Mycophenolate mofetil within 2 months 4. Etanercept or Anakinra within 28 days 5. Immunoglobulin or blood products within 28 days * Evidence of any active or recent infection including ongoing, chronic infectious disease such as chronic renal infection or chronic chest infection with bronchiectasis or sinusitis * History of systemic autoimmune disease other than Rheumatoid Arthritis * History of allergic reactions to other protein therapeutics such as monoclonal antibodies or fusion proteins * History of anaphylaxis or allergic diathesis * Clinically significant cardiac disease, including: unstable angina; myocardial infarction within 6 months; congestive heart failure; arrhythmia requiring active therapy, with the exception of clinically insignificant extrasystoles, or minor conduction abnormalities; and history of clinically significant abnormality on electrocardiogram * Evidence of active or latent tuberculosis * Vaccination wtih live attenuated viruses within the 2 weeks prior to Day 0 * Evidence of infection with hepatitis B virus, hepatitis C virus, human immunodeficiency virus 1 or 2, or active infection with hepatitis A * Pregnant or breastfeeding women