The proportion of participants with assessment of the minimal residual disease under venetoclax treatment (assessed by flow cytometry or Polymerase Chain Reaction).

ORR is defined as the proportion of participants who reach either CR, CRi, nPR, or PR to treatment, according to physician's assessment.

The EQ-5D-5L has five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. These dimensions are measured on a five-level scale: no problems, slight problems, moderate problems, severe problems, and extreme problems. The scores for the 5 dimensions are used to compute a single utility index score ranging from zero (0.0) to 1 (1.0) representing the general health status of the individual. The EQ-5D-5L also contains a visual analog scale (VAS) to assess the subject's overall health.

The time to best response to treatment is defined by the time between the date of the first venetoclax intake and the date of the assessment having documented the best response among CR, CRi, nPR, PR, SD, and DP.

The response duration will be calculated in the sub-population of participants experiencing treatment response (CR, CRi, nPR, or PR) from the date when response is first met to the date of first following documented progression.

The PFS after disease progression following venetoclax treatment will be calculated in the sub-population of patients experiencing disease progression under venetoclax. The PFS following venetoclax treatment is defined as the time from the date of first next CLL treatment intake to the date of the following documented progression or death from any cause.

OS is defined as the time from the date of first venetoclax intake to the date of death from any cause.

The best response under next CLL treatment will be calculated in the sub-population of patients having a next CLL treatment after venetoclax discontinuation.

PFS is defined as the time from the date of first venetoclax intake to the date of the first documented disease progression or death from any cause.

The Time To Progression (TTP) is defined as the time from the date of first venetoclax intake to the date of the first documented disease progression.