A Study to Evaluate the Efficacy and Safety of Mabthera Alone and in Combination With Either Cyclophosphamide or Methotrexate in Patients With Rheumatoid Arthritis

Participants will receive 750 mg infusions of cyclophosphamide on Days 3 and 17

Participants will receive \>= 10 mg/week methotrexate orally up to 24 weeks

Participants will receive placebo in place of cyclophosphamide on Days 3 and 17

Participants will receive weekly oral placebo in place of Methotrexate

Participants will receive placebo in place of rituximab on days 1 and 15

Participants will receive 1g infusions of rituximab on Days 1 and 15