A Study of MabThera (Rituximab) Plus Chlorambucil in Patients With Previously Untreated Chronic Lymphocytic Leukemia.

CR defined as: 1) laboratory CR: peripheral blood lymphocytes (PBL) less than (<) 4000/microliter (μL), neutrophils (PMN) greater than (>) 1500/μL, platelets >100,000/μL, and hemoglobin (Hb) >11 grams per deciliter (g/dL); 2) clinical CR: lymph nodes (LN) <1.5 centimeter (cm), and no constitutional symptoms, hepatomegaly (HM) or splenomegaly (SM); 3) instrumental CR: LN <1.5 cm and no HM/SM, and 4) bone marrow (BM) CR: normocellular aspirate/biopsy for participant age <30 percent (%) lymphocytes, and no B cell lymphoid nodules. CRi was defined as CR with anemia, thrombocytopenia, or neutropenia not related to chronic lymphocytic leukemia (CLL), with no clonal infiltrate in aspirate or biopsy. PR defined as: a 50% decrease in PBL, a 50% decrease in LN size, no increase in LN size, no new enlarged LN, a 50% reduction from baseline (BL) in the HM/SM, and 1 of the following: PMN >1500/μL, platelets >100,000/μL or >50% improvement from BL, and Hb >11.0 g/dL or >50% improvement from BL.

CR defined as: 1) laboratory CR: PBL <4000/μL, PMN > 1500/μL, platelets > 100,000/μL, and Hb > 11 g/dL; 2) clinical CR: LN < 1.5 cm, and no constitutional symptoms, HM or SM; 3) instrumental CR: LN < 1.5 cm and no HM/SM, and 4) bone marrow CR: normocellular aspirate/biopsy for participant age < 30% lymphocytes, and no B cell lymphoid nodules. CRi was defined as CR with anemia, thrombocytopenia, or neutropenia not related to CLL, with no clonal infiltrate in aspirate or biopsy. PR defined as: a 50% decrease in PBL, a 50% decrease in LN size, no increase in LN size, no new enlarged LN, a 50% reduction from BL in the HM/SM, and 1 of the following: PMN > 1500/μL, platelets > 100,000/μL or > 50% improvement from BL, and Hb >11.0 g/dL or > 50% improvement from BL.

CR, CRi, and PR as previously defined. PD was defined by 1 of the following: 1) lymphadenopathy: any new lesion, HM/SM, or other organ infiltrates, or a greater than or equal to (≥) 50% increase in greatest diameter of any previously noted lesion; 2) a ≥ 50% increase in previously noted HM/SM, or new appearance of HM/SM; 3) a ≥ 50% increase in blood lymphocyte count with at least 5000 B lymphocytes/μL; 4) transformation to a more aggressive histology, e.g., Richter's syndrome; or 5) occurrence of cytopenia attributable to CLL. SD was defined by the absence of necessary criteria to achieve CR or PR, but no advancement to PD. Relapse was defined by a previously noted CR or PR with advancement to PD after a period of ≥ 6 months. Nodular PR was defined by the presence of residual lymphoid nodules.

CR, and PR as previously defined. PD was defined by 1 of the following: 1) lymphadenopathy: any new lesion, HM/SM, or other organ infiltrates, or a ≥ 50% increase in greatest diameter of any previously noted lesion; 2) a ≥50% increase in previously noted HM/SM, or new appearance of HM/SM; 3) a ≥50% increase in blood lymphocyte count with at least 5000 B lymphocytes/μL; 4) transformation to a more aggressive histology, e.g., Richter's syndrome; or 5) occurrence of cytopenia attributable to CLL. SD was defined by the absence of necessary criteria to achieve CR or PR, but no advancement to PD. Relapse was defined by a previously noted CR or PR with advancement to PD after a period of ≥6 months. Nodular PR was defined by the presence of residual lymphoid nodules.

Immunophenotypic CR was defined as the absence of minimal residual disease (MRD) evaluated in participants with CR by 4-color flow cytometry of PB and BM B cells to confirm that tissue was comprised of non-CLL cells. Molecular CR was defined as the absence of MRD evaluated in participants with CR by quantitative polymerase chain reaction (PCR) in PB and BM B cells to confirm that tissue was comprised of non-CLL cells.

CR, CRi, PR, SD, PD, relapse, and nodular PR as previously defined.

Immunophenotypic CR was defined as the absence of MRD evaluated in participants who achieved CR by 4-color flow cytometry of PB and BM B cells to confirm that tissue was comprised of non-CLL cells.

Molecular CR was defined as the absence of MRD evaluated in participants who achieved CR by quantitative PCR in PB and BM B cells to confirm that tissue was comprised of non-CLL cells.

Event-free Survival (EFS) was defined as the time from the first dose of study treatment to the date of first documentation of disease progression, relapse for participants with previous CR, death due to any cause, withdrawal due to AE, or beginning new CLL treatment. CR and PD as previously defined. Participants were censored at the time of data cut-off to the most recent date of disease assessment. Participants without a post-BL disease assessment were censored at the time of first dose of study treatment.

The median time, in days, from the the date of first dose of study treatment to the date of first documentation of disease progression, relapse for participants with CR, death due to any cause, withdrawal due to AE, or new CLL treatment. CR and PD as previously defined. Participants were censored at the time of data cut-off to the most recent date of disease assessment. Participants without a post-BL disease assessment were censored at the time of first dose if study treatment. The 95% CI was determined using Kaplan-Meier methodology.

Progression-free survival (PFS) was defined as the time from the first dose of study treatment to the first documentation of disease progression or death. PD as previously defined. Participants who were withdrawn from the study without documented disease progression were censored at the date of the last tumor assessment when the participant was known to be progression-free. Participants without a post-BL tumor assessment, but known to be alive, were censored at the time of the first dose of study treatment.

The median time, in days, from the date of the first dose of study treatment to the date of first documentation of disease progression or death. CR and PD as previously defined. Participants who were withdrawn from the study without documented disease progression were censored at the date of the last tumor assessment when the participant was known to be progression-free. Participants without a post-BL tumor assessment, but known to be alive, were censored at the time of the first dose of study treatment. The 95% CI was determined using Kaplan-Meier methodology.

Time to new CLL treatment (TTNT) was defined as the time from the first dose of study treatment to the date of new CLL treatment received or the date of death from any cause. Participants who did not receive new CLL treatment and were alive at the time of the analysis were censored at the date of the last follow-up assessment. Participants without a follow-up assessment were censored at the day of last dose of study treatment.

The mean time, in days, from the date of the first dose of study treatment to the date of new CLL treatment or the date of death from any cause. Participants who did not receive new CLL treatment and were alive at the time of the analysis were censored at the date of the last follow-up assessment. Participants without a follow-up assessment were censored at the day of last dose of study treatment. Mean survival time and it's standard error (SE) were underestimated because the largest observation was censored and the estimation was restricted to the largest event time.

Overall Survival (OS) was defined as the time from the date of the first dose of study treatment to the date of death due to any cause. Participants were censored at the date of the last follow-up assessment. Participants without a follow-up assessment were censored at the day of last dose of study treatment.

The mean time, in days, from the date of the first dose of study treatment to the date of death due to any cause. Participants were censored at the date of the last follow-up assessment. Participants without a follow-up assessment were censored at the day of last dose of study treatment. The mean survival time and it's SE were underestimated because the largest observation was censored and the estimation was restricted to the largest event time.

Duration of response was defined as the time from the date of the first documented CR, CRi, or PR to the date of disease progression or death. CR, CRi, PR, and PD as previously defined. Participants with no documented PD after CR, CRi, or PR were censored at the last date at which they were known to have had CR, CRi, or PR, respectively.

The mean time, in days, from the date of first documented CR, CRi or PR to the date disease progression or death. CR, CRi, PR, and PD as previously defined. Participants with no documented PD after CR, CRi, or PR were censored at the last date at which they were known to have had CR, CRi, or PR, respectively.

Disease-free survival was defined at the time from the date of first documented CR or CRi to the date of disease progression or death. CR, CRi, and PD as previously defined. Participants with no documented PD after CR or CRi were censored on the last date at which they were known to have had CR or CRi.

The mean time, in days, from the date of first documented CR or CRi to the date of disease progression or death. CR, CRi, and PD as previously defined. Participants with no documented PD after CR or CRi were censored on the last date at which they were known to have had CR or CRi. In both groups, the mean survival time and its standard error were underestimated because the largest observation was censored and the estimation was restricted to the largest event time.