Fludarabine, cyclophosphamide, and rituximab (FCR) is the gold treatment for fit and young patients with Chronic Lymphoid Leukemia (CLL). However, patients with a mutation known as IGVH unmutated and patients with a particular characteristic known as 'disrupted TP53' show an inferior outcome after FCR in terms of survival. Venetoclax as a single agent or combined with rituximab is an effective treatment for relapsed/refractory patients with IGVH unmutated CLL and/or del(17p) and is associated with a high rate of clinical responses.

Fludarabine, cyclophosphamide, and rituximab (FCR) is the gold treatment for fit and young (age ≤65 years) patients with CLL. However, IGVH unmutated patients and patients with disrupted TP53 show an inferior outcome after FCR in terms of PFS and OS. Venetoclax as a single agent or combined with rituximab is an effective treatment for relapsed/refractory patients with IGVH unmutated CLL and/or del(17p) and is associated with a high rate of clinical responses and MRD-negative responses. The achievement of a MRD negative response in CLL is the best treatment endpoint since it is associated with an improved PFS.

In treatment-naive patients with unmutated IGVH and/or disrupted TP53 the venetoclax and rituximab combination could be a more effective regimen than FCR with a 15% increase in the CR rate.

Inclusion Criteria:

• Patients older than18 years and 65 years or less.
• Diagnosis of CLL meeting the IWCLL 2008 criteria.
• Total CIRS <6, creatinine clearance >30 ml/min [Cockcroft-Gault]) and ECOG performance status of 0-1.
• No prior treatment.
• Umutated IGVH and/or disrupted TP53.
• Active disease meeting at least 1 of the following the IWCLL 2008 criteria for treatment requirement.
• Adequate bone marrow function without transfusion <2 weeks of screening as follows: absolute neutrophil count (ANC) ≥1.0 x 109/L (growth factors administration is allowed); platelets ≥30 x 109/L. If thrombocytopenia due to BM involvement, platelets should be ≥ 30 x 109/L; hemoglobin value ≥8.0 g/dl.
• Adequate renal and hepatic function per local reference laboratory reference ranges
• Female patients of childbearing potential and non-sterile male patients must practice at least one of method of birth control with partner(s) beginning with initial treatment administration and continuing to 12 months after the last dose of Rituximab.
• Male patients must agree to refrain from sperm donation, from initial treatment administration until 12 months after the last dose of Rituximab.
• A signed informed consent document indicating that they understand the purpose of and procedures required for the study, including biomarkers, and are willing to participate in the study.

Exclusion Criteria:

• Any significant concurrent, uncontrolled medical condition or organ system dysfunction and/or laboratory abnormality or psychiatric disease, which, in the investigator's opinion, could compromise the subject's safety or put the study outcomes at undue risk or prevent the subject from signing the informed consent form.
• Transformation of CLL to aggressive NHL (Richter's transformation or pro-lymphocytic leukemia).
• History of other malignancies Pregnant or lactating females.
• Inadequate renal function: CrCl <30 mL/min.
• Uncontrolled autoimmune hemolytic anemia or thrombocytopenia.
• Subject is known to be positive for HIV.
• Evidence of other clinically significant uncontrolled condition(s)
• Prior or concomitant fruits and/or specific drugs.