Survival Improvement of Patients with Chronic Lymphocytic Leukemia (CLL) in Routine Care. a Retrospective Analysis of All Patients with CLL Who Were Treated in an Oncology Group Practice in Germany Between 1995-2015

Introduction:Progress has been made in the diagnosis and treatment of patients with CLL who receive their treatment within prospective clinical trials. Clinical trials only include patients who fulfill the selection criteria and hence do not reflect outcomes in routine practice. Data with regards to the diagnosis, treatment and survival of patients in routine care reflecting the improvements in survival following implementation of newer therapy strategies and agents are not available.

Methods: A retrospective analysis of all patients with CLL who were treated in an oncology group practice in Germany between 1995-2015. Relevant clinical data concerning diagnosis, treatment and survival were transferred from clinical files into a database and analysed statistically using SPSS.

Results:676 CLL patients with a median age of 67 (35-92) were identified. At initial diagnosis 521 patients (77.1%) were in Binet stage A, 83 (12.3%) Binet stage B and 36 (5.3%) Binet stage C. Due to external diagnosis of 36 patients (5.3%) the stage at initial diagnosis couldn't be retrieved. 361 patients (53.4%) never received any treatment. 315 patients (46.6%) needed therapy with a median of 2 therapy lines (1-13). Regimens most frequently applied were: Bendamustine-containing (68.9%), Rituximab-containing (65.4%), Chlorambucil-containing (55.9%), Bendamustine+Rituximab combinations (48.3%) and Fludarabine-containing (39.4%). Regimens containing recently approved drugs could be found as well. 5.1% received Ibrutinib, 2.9% Obinutuzumab and 2.2% Idelalisib. 17.8% of patients were treated within a clinical trial. 5 and 10 year overall survival was 84.5% and 60.4%. Median overall survival according to Binet stage was 13 years for Binet A, 9 years for Binet B and 9 years for Binet C. Patients who needed therapy had a median overall survival of 11 years (0-42) compared to 17 years (0-27) of patients who never needed any therapy.

Conclusions: 53.4% of CLL-patients never needed any therapy. Patients who needed therapy had a much lower life expectancy compared to patients who never needed therapy. Treatment consisted mainly of Bendamustine, Rituximab, Chlorambucil, Bendamustine+Rituximab combinations and Fludarabine leading to a marked prolongation of survival compared to historical controls and registry data.