EHA 2018: Obinutuzumab or Rituximab Plus Chlorambucil in CLL
Data from the final analysis of the CLL11 study evaluating obinutuzumab (Gazyva)-based treatment in previously untreated chronic lymphocytic leukemia (CLL) was presented by Goede et al during the Presidential Symposium at the 23rd Annual Congress of the European Hematology Association (EHA) (Abstract S151).
5-Year Follow-Up
After a follow-up of nearly 5 years, final results showed clinically meaningful improvements with obinutuzumab plus chlorambucil across multiple endpoints, including progression-free survival (PFS) and overall survival (OS), when compared head-to-head with rituximab (Rituxan) plus chlorambucil. Obinutuzumab-based treatment reduced the risk of death by 24% compared to rituximab-based treatment (median OS not reached vs 73.1 months, hazard ratio [HR] = 0.76; 95% confidence interval [CI] = 0.60–0.97; P < .0245). These new data add to the growing body of evidence for the OS benefit with obinutuzumab in first-line CLL after the previously reported OS benefit with obinutuzumab combined with chlorambucil vs chlorambucil alone.
After a median observation time of nearly 5 years (59.4 months) this final analysis of the CLL11 study demonstrated:
- A reduction in the risk of disease progression or death of 51% for patients treated with obinutuzumab plus chlorambucil vs those treated with rituximab plus chlorambucil (median PFS 28.9 vs 15.7 months, HR = 0.49; 95% CI = 0.41–0.58; P < .0001).
- A clinically meaningful improvement in OS for patients receiving obinutuzumab plus chlorambucil compared to rituximab plus chlorambucil. At the time of final analysis, the median OS in the obinutuzumab plus chlorambucil arm was not yet reached, which means that more than half of these patients were still alive after nearly 5 years. A 24% reduction in the risk of death was observed with obinutuzumab plus chlorambucil treatment (median OS not reached vs 73.1 months, HR = 0.76; 95% CI = 0.60–0.97; P < .0245).
- A prolonged time to initiation of the next therapy (time to new treatment; TTNT) with obinutuzumab plus chlorambucil (median 56.4 vs 34.9 months, obinutuzumab plus chlorambucil vs rituximab plus chlorambucil, HR = 0.58; 95% CI = 0.46–0.73; P < .0001).
- Patients treated with obinutuzumab plus chlorambucil achieved a higher rate of minimal residual disease (MRD) negativity vs those treated with rituximab plus chlorambucil (24% vs 2% of patients MRD-negative, obinutuzumab plus chlorambucil vs rituximab plus chlorambucil).
- No new or unexpected safety concerns for the combination of obinutuzumab plus chlorambucil.
Obinutuzumab is currently approved in more than 90 countries in combination with chlorambucil for people with previously untreated CLL based on previously reported data from the CLL11 study.
About the CLL11 study
CLL11 is a phase III, multicenter, open-label, randomized three-arm study to investigate the safety and efficacy profile of obinutuzumab plus chlorambucil compared rituximab plus chlorambucil or chlorambucil alone in nearly 800 people with previously untreated CLL and comorbidities. The primary endpoint of the study is PFS with secondary endpoints including response rate, molecular remission rate, OS, TTNT, and safety profile. In terms of analysis, the study was divided into three stages:
- Stage 1a compared the addition of obinutuzumab to chlorambucil vs chlorambucil alone
- Stage 1b compared the addition of rituximab to chlorambucil vs chlorambucil alone
- Stage 2 compared obinutuzumab plus chlorambucil to rituximab plus chlorambucil
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
