Obinutuzumab Plus Chlorambucil May Improve Survival Outcomes in Chronic Lymphocytic Leukemia
Researchers randomly assigned previously untreated patients with CD20-positive CLL to receive obinutuzumab plus chlorambucil, rituximab plus chlorambucil, or chlorambucil alone.
Obinutuzumab plus chlorambucil leads to a variety of improved outcomes among patients with chronic lymphocytic leukemia (CLL) with comorbidities compared with chlorambucil alone or with rituximab, according findings presented during the Presidential Symposium at the 23rd Annual Congress of the European Hematology Association in Sweden.1
For the CLL11 study, researchers randomly assigned 781 previously untreated patients with CD20-positive CLL to receive obinutuzumab plus chlorambucil, rituximab plus chlorambucil, or chlorambucil alone. In the current analysis, the authors present the findings of a 2-year follow-up.
After a median follow-up of 62.5 months, patients treated with obinutuzumab plus chlorambucil had a median progression-free survival (PFS) of 31.1 months compared with 11.1 months among patients treated with chlorambucil alone (hazard ratio [HR], 0.21, 95% CI, 0.16–0.28; P < .0001), and the overall survival (OS) was not reached versus 66.7 months, respectively (HR 0.68; 95% CI, 0.49–0.94; P = .0196). The time to new treatment (TTNT) was 55.7 months and 15.1 months in the obinutuzumab plus chlorambucil arm and chlorambucil alone arm, respectively (HR 0.25; 95% CI, 0.19–0.35; P< 0.0001).
After a median observation time of 59.4 months, obinutuzumab plus chlorambucil led to clinically meaningful improvements in outcomes compared with rituximab plus chlorambucil as well. The median PFS was 28.9 months compared with 15.7 months (HR 0.49; 95% CI, 0.41-0.58; P < .0001), respectively, and the TTNT was 56.4 months compared with 34.9 months (HR 0.58; 95% CI, 0.46-0.73; P < .0001), respectively. The median OS was not reached in the obinutuzumab plus chlorambucil arm compared with 73.1 months among patients treated with rituximab plus chlorambucil (HR 0.76; 95% CI, 0.60-0.97; P = .0245).
The 2-year survival rate was 91% and 66% in the obinutuzumab plus chlorambucil arm and rituximab plus chlorambucil arm, respectively, and the 5-year survival rate was 84% and 57%, respectively. Thirty seven percent of patients treated with obinutuzumab plus chlorambucil died compared with 57% of patients who received rituximab plus chlorambucil.
The authors concluded that “These findings support the use of [obinutuzumab plus chlorambucil] as first-line treatment for CLL patients with comorbidities, and suggest [obinutuzumab] as the preferred anti-CD20 antibody in future combination regimens for CLL.”
- Goede V, Fischer K, Dyer MJS, et al. Overall survival benefit of obinutuzumab over rituximab when combined with chlorambucil in patients with chronic lymphocytic leukemia and comorbidities: final survival analysis of the CLL11 study. Oral presentation at: 2018 European Hematology Association 23rd Annual Congress; June 2018; Stockholm, Sweden.