A Study to Evaluate the Risk of Tumor Lysis Syndrome (TLS) in Adult Participants Receiving Oral Venetoclax in Combination With Intravenously Infused Obinutuzumab or Oral Acalabrutinib for Previously Untreated Chronic Lymphocytic Leukemia (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.Performance status * 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.Renal Exclusion Criteria: - Active/uncontrolled infection, no Richter's transformation, no active immune thrombocytopenia.