A Prospective, Open-Label, Phase IIb/III Study to Evaluate the Risk of TLS and Optimization of the Initiation of Venetoclax in Combination with Obinutuzumab or Acalabrutinib With Different Ramp- Up Periods in Previously Untreated Subjects with CLL

Inclusion Criteria:
*  Diagnosis of documented, previously untreated, chronic lymphocytic leukemia (CLL) requiring treatment according to the 2018 international workshop on chronic lymphocytic leukemia (iwCLL) criteria and have a life expectancy of \> 6 months.
*  Previously untreated small lymphocytic lymphoma (SLL) meeting the 2018 iwCLL criteria for treatment will also be equally considered as CLL for eligibility, screening, treatment and evaluation.
*  Eastern Cooperative Oncology Group (ECOG) performance status \<= 2.
*  Adequate marrow function independent of growth factor or transfusion support within 2 weeks of screening, unless cytopenia is due to marrow involvement of CLL as listed in the protocol.
*  Creatinine clearance (CrCl) \>= 30 mL/min using the Cockcroft-Gault formula are eligible for inclusion.

Exclusion Criteria: \- Active/uncontrolled infection, no Richter's transformation, no active immune thrombocytopenia.