Study of Single Doses of SBT777101 in Subjects With Rheumatoid Arthritis

Who May Qualify: - Body mass index (BMI) \<35 kg/m\^2, inclusive - Adult-onset, moderate-to-severe rheumatoid arthritis (RA) - Moderate-to-severe active disease - Clinical and/or ultrasound evidence of synovitis - Prior inadequate response to or unable to tolerate available RA therapies - Stable doses of RA medications for at least 30 days - Use of highly effective methods of contraception Who Should NOT Join This Trial: - Major surgery within 12 weeks prior to screening or planned within 12 months after dosing - Uncontrolled cardiovascular, pulmonary, renal, hepatic, endocrine, or gastrointestinal disease - Recurrent infections or active infection - Active or untreated latent tuberculosis - Primary or secondary weakened immune system - History of or current inflammatory joint disease other than RA Always talk to your doctor about whether this trial is right for you.