Conditions: Lymphocytic Leukemia, Chronic
Allocation: NA | Intervention model: SINGLE_GROUP
Enrollment: 100
Healthy volunteers: no

Brief summary:
This single arm study will assess the safety and effect on response rate of a combination of rituximab and chlorambucil in previously untreated participants with B-cell chronic lymphocytic leukemia. Participants will receive 6 monthly cycles of combination treatment, followed by up to 6 cycles of chlorambucil alone. Rituximab will be administered on Day 1 of each cycle, at a dose of 375 milligrams per square meter (mg/m\^2) intravenously (IV) in Cycle 1, and 500 mg/m\^2 in subsequent cycles, and chlorambucil will be administered on Days 1-7 of each cycle at a dose of 10 mg/m\^2/day per oral (PO).

Detailed description:

Arms:
arm 1: Participants will receive combination therapy of rituximab plus chlorambucil for first 6 cycles and then chlorambucil alone for a maximum of 6 additional cycles.

Interventions: intervention 1: Rituximab intervention 2: Chlorambucil
Intervention descriptions: intervention 1: 375mg/m\^2 IV on Day 1 of Cycle 1; 500mg/m\^2 on Day 1 of Cycles 2-6. intervention 2: 10 mg/m\^2/day PO on Days 1 to 7 of each cycle for a maximum of 12 cycles.

Protocol document: