A Phase 2 Dose-finding Study of Atacicept in Subjects With Rheumatoid Arthritis (AUGUST I)

Inclusion Criteria:

1. Rheumatoid arthritis (RA) satisfying American College of Rheumatology (ACR)
diagnostic criteria with a disease history of at least one year

2. Male or female greater than or equal to (>=)18-years of age at time of informed
consent

3. Active RA as defined by:

- >=8 swollen joints (66-joint count),

- >=8 tender joints (68-joint count), and

- C-reactive protein (CRP) >=10 milligram per liter (mg/L) (central laboratory)
and/or erythrocyte sedimentation rate (ESR) >= to 28 millimeter per hour (mm/h)

4. Failure of at least one TNFa antagonist therapy (previously or at the time of
screening) as specified in the protocol

5. Other protocol defined inclusion criteria could apply

Exclusion Criteria:

1. Any condition, including laboratory findings or findings in the medical history or
pre-trial assessments, that in the opinion of the Investigator constitutes a risk or
a contraindication for the subject's participation in the trial or that could
interfere with the trial objectives, conduct or evaluation

2. Treatment with biologics aiming at B cell modulation such as rituximab or belimumab
within 2 years before study Day 1

3. Any previous treatment with anakinra (Kineret), abatacept (Orencia) or tocilizumab
within 3 months before study Day 1

4. Use of etanercept (Enbrel) within 28 days before study Day 1, or of infliximab
(Remicade) or adalimumab (Humira) within 60 days before study Day 1

5. Participation in any interventional clinical trial with an unapproved investigational
therapy within the 3 months before the start of this study (or within 5 half-lives of
the investigated compound before study Day 1, whichever is longer)

6. Other protocol defined exclusion criteria could apply