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 best response documented (CR, CRi, nPR, and PR).

DoR defined as the number of days from the date of first response (CR, CRi, nPR, or PR) to the date of disease progression or death from any cause, whichever comes first.

The time to next treatment is defined as the time between the date of the first venetoclax intake and the date of the first next treatment intake after venetoclax discontinuation.

Patients will be defined as having a clinical remission in the absence of MRD when they have blood or marrow with less than one CLL cell per 10000 leucocytes.

OS is defined as number of days from the date of first dose to the date of the observational period end or death for all dosed patients.

Progression-free survival is defined as the interval between the first treatment day to the first sign of disease progression or death from any cause

Patient quality of life was measured by the RAND-36 health-related quality of life (HRQoL) survey instrument. This questionnaire is comprised of 36 items that assess eight health concepts: physical functioning, role limitations caused by physical health problems, role limitations caused by emotional problems, social functioning, emotional well-being, energy/fatigue, pain, and general health perceptions.