Study to Assess if ABP798 is Safe & Effective in Treating Moderate to Severe Rheumatoid Arthritis Compared to Rituximab

Inclusion Criteria:

- Men or women ≥ 18 and ≤ 80 years old

- Subjects must be diagnosed with Rheumatoid Arthritis for at least 6 months before
baseline

- Active RA defined as ≥ 6 swollen joints and ≥ 6 tender joints at screening and
baseline and at least one of the following at screening:

- erythrocyte sedimentation rate (ESR) ≥ 28 mm/hr

- serum C-reactive protein (CRP) > 1.0 mg/dL

- Subjects must be taking methotrexate (MTX) for ≥ 12 consecutive weeks and on a stable
dose of MTX 7.5 to 25 mg/week for ≥ 8 weeks prior to receiving the investigational
product (IP), and be willing to remain on a stable dose throughout the study

- Subject has no known history of active tuberculosis

Exclusion Criteria:

- Class IV RA, Felty's syndrome or history of prosthetic or native joint infection

- Major chronic inflammatory disease or connective tissue disease other than RA, with
the exception of secondary Sjögren's syndrome

- Use of commercially available or investigational biologic therapies for RA as follows:

- anakinra, etanercept within 1 month prior to first dose of IP

- infliximab, abatacept, tocilizumab, golimumab, certolizumab within 3 months prior
to first dose of IP

- other experimental or commercially available biologic therapies for RA within 3
months or 5 half-lives (whichever is longer) prior to first dose of IP

- Previous receipt of rituximab or a biosimilar of rituximab

Other Inclusion/Exclusion criteria may apply