Time frame: From the date of randomization to disease progression (Up to 3.7 years)
ORR defined as number of participants achieving a complete response (CR), complete response with incomplete marrow recovery (CRi), nodular partial response (nPR) or partial response (PR). IWCLL 2008 criteria: CR- No lymphadenopathy and hepatosplenomegaly, no constitutional symptoms, neutrophils >1.5*10^9/liter (L), platelets >100*10^9/L, Hgb >11 gram per deciliter (g/dL) and absolute lymphocyte count <4000/microliter (mcL); CRi- CR with incomplete recovery of bone marrow; nPR- participants meet criteria for CR, but the bone marrow biopsy shows B-lymphoid nodules, may represent a clonal infiltrate; PR- >=50% drop in lymphocyte count from baseline or <=4.0*10^9/L with following: >=50% decrease in sum products of up to 6 lymph nodes, no new enlarged lymph nodes, When abnormal, >=50% decrease in enlargement of spleen from baseline or normalization and a response in 1 of following: Neutrophils >1.5*10^9/L, Platelets>100000/mcL and Hgb>11 g/dL or >=50% improvement over baseline in all.