For Healthcare Professionals

Comparison of the Treatments of Obinutuzumab + Venetoclax Versus Obinutuzumab + Chlorambucil in Patients With Chronic Lymphocytic Leukemia


About the study

This open-label, multicenter, randomized Phase III study is designed to compare the efficacy and safety of a combined regimen of obinutuzumab and venetoclax versus obinutuzumab + chlorambucil in participants with chronic lymphocytic leukemia (CLL) and coexisting medical conditions. The time on study treatment was approximately one year and the follow-up period will be up to 9 years.

Who can take part

You may be eligible to participate in the study if you meet the following criteria:


Inclusion Criteria:

  1. Documented previously untreated CLL according to the International Workshop on Chronic Lymphocytic Leukemia (IWCLL) criteria
  2. CLL requiring treatment according to IWCLL criteria
  3. Total Cumulative Illness Rating Scale (CIRS score) greater than (>) 6
  4. Adequate marrow function independent of growth factor or transfusion support within 2 weeks of screening as per protocol, unless cytopenia is due to marrow involvement of CLL
  5. Adequate liver function
  6. Life expectancy > 6 months
  7. Agreement to use highly effective contraceptive methods per protocol


Exclusion Criteria:

  1. Transformation of CLL to aggressive Non-Hodgkin's lymphoma (Richter's transformation or pro-lymphocytic leukemia)
  2. Known central nervous system involvement
  3. Participants with a history of confirmed progressive multifocal leukoencephalopathy (PML)
  4. An individual organ/ system impairment score of 4 as assessed by the CIRS definition limiting the ability to receive the treatment regimen of this trial with the exception of eyes, ears, nose, throat organ system
  5. Participants with uncontrolled autoimmune hemolytic anemia or immune thrombocytopenia
  6. Inadequate renal function
  7. History of prior malignancy, except for conditions as listed in the protocol if participants have recovered from the acute side effects incurred as a result of previous therapy
  8. Use of investigational agents or concurrent anti-cancer treatment within the last 4 weeks of registration
  9. Participants with active bacterial, viral, or fungal infection requiring systemic treatment within the last two months prior to registration
  10. History of severe allergic or anaphylactic reactions to humanized or murine monoclonal antibodies or known sensitivity or allergy to murine products
  11. Hypersensitivity to chlorambucil, obinutuzumab, or venetoclax or to any of the excipients
  12. Pregnant women and nursing mothers
  13. Positive test results for chronic hepatitis B virus (HBV) infection (defined as positive hepatitis B surface antigen [HBsAg] serology) or positive test result for hepatitis C (hepatitis C virus [HCV] antibody serology testing)
  14. Participants with known infection with human immunodeficiency virus (HIV) or human T-cell leukemia virus-1 (HTLV-1)
  15. Requires the use of warfarin, marcumar, or phenprocoumon
  16. Received agents known to be strong and moderate Cytochrome P450 3A inhibitors or inducers within 7 days prior to the first dose of study drug

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Study Locations

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How to Apply

Contact the study center to learn if this study is a good match for you.

Study’s details


Lymphocytic Leukemia, Chronic

Age (in years)



Phase 3

Participants needed


Est. Completion Date

Aug 31, 2025

Treatment type



Hoffmann-La Roche identifier


Study number


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