This is a Phase 1b, randomized, multi-dose, placebo-controlled, dose-escalation, multi-center study of AMP-110 in adult 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
• Must have at least 4 tender joints and 4 swollen joints (28-joint assesssment)
• Use of >/= 1 non-steroidal anti-inflammatory drugs is allowed, subject must be on a stable dose for >/= 2 weeks prior to randomization
• Use of >/= 1 Disease Modifying Anti-rheumatic Drugs (DMARD) for >/= 3 months and a stable dose for >/= 6 weeks prior to randomization
• Stable use of low dose oral corticosteroids (</= 10 mg prednisone per day or equivalent) is allowed; subjects must be on a stable dose for >/= 4 weeks prior to randomization

Exclusion Criteria:

• Prior to Day 0, use of:

  1. Rituximab within 6 months
  2. Abatacept within 3 months
  3. Infliximab, Adalimumab, Certolizumab, Tocilizumab, Cyclosporine, Azathioprine or Mycophenolate mofetil within 2 months
  4. Etanercept, Anakinra, immunoglobulin or blood products within 28 days
  5. Prior immunotherapy, including high dose oral corticosteroids or systemic corticosteroids such as prednisone, biologics, Janus kinase (JAK) inhibitors, such as tofacitinib or investigational therapy must have completed at least 5 half-lives or 30 days, whichever is longer
  6. Prior exposure to T cell depleting agents such as Campath (alemtuzumab)

• Evidence of any active or recent infection

• History of systemic autoimmune disease other than Rheumatoid Arthritis; secondary Sjogren's syndrome, rheumatoid vasculitis and orther extra-articular manifestations of RA allowed

• History of allergic reactions

• 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 with live attenuated viruses within the 2 weeks prior to Day 0

• Pregnant or breastfeeding women