The present study aims at obtaining more in-depth information on how patients with chronic lymphocytic leukemia treated with idelalisib and rituximab react to treatment.

This cohort study will recruit patients with treatment-naïve chronic lymphocytic leukemia (CLL) with TP53 disruption (i.e. 17p- or TP53 mutations) or relapsed/refractory CLL who were treated with idelalisib and rituximab between 01/07/2014 and 31/05/2017 at European centres adhering to the GIMEMA group and the ERIC group.

Inclusion Criteria:

• Diagnosis of CLL / Small Lymphocytic Lymphoma (CLL/SLL) according to the World Health Organisation (WHO) classification 2008.

• Treatment with idelalisib and rituximab started between the date of Country marketing authorization approval of idelalisib (EMA approval 18/09/2014) and 31/05/2017 given at European centres adhering to the GIMEMA group and the ERIC group.

• One of the two following conditions must be satisfied:

  • Previously untreated CLL requiring therapy according to the NCI criteria (Hallek M et al, Blood 2008)] with deletion 17p13 and/or TP53 mutation.
  • Relapsed refractory CLL., i.e. patients who received at least one previous line of treatment using alkylating agents and/or purine analogues with or without monoclonal antibodies, or high dose steroids requiring therapy according to the NCI criteria (Hallek M et al, Blood 2008)

• Age ≥ 18 years.

• Signed written informed consent, if applicable, according to ICH/EU/GCP and national local law.

Exclusion Criteria:

• Patients with CLL treated with idelalisib within interventional clinical trials or outside the approved indication.

• Patients with:

  • Transformation of CLL to aggressive lymphomas (Richter's Syndrome).
  • HIV infection.
  • Active and uncontrolled HCV and/or HBV infections or liver cirrhosis.

This cohort study will recruit patients with treatment-naïve chronic lymphocytic leukemia (CLL) with TP53 disruption (i.e. 17p- or TP53 mutations) or relapsed/refractory CLL who were treated with idelalisib and rituximab between 01/07/2014 and 31/05/2017 at European centres adhering to the GIMEMA group and the ERIC group.