First results of the study CLL11 - Optimized treatment of elderly patients with CLL possible
Addition of obinutuzumab (GA101) or rituximab to chlorambucil improved outcomes for elderly patients with chronic lymphocytic leukemia (CLL) and coexisting medical conditions (comorbidities). Phase III data from the CLL11 study to be presented at the Annual Meeting of the American Society of Clinical Oncology (ASCO).
• First large, phase III randomized trial reporting final results on a patient population of significantly advanced age and with coexisting medical conditions
• Addition of GA101 or rituximab to chlorambucil both significantly increased the length of time people lived without their disease worsening vs. chlorambucil alone.
The German CLL Study Group (GCLLSG) announced the first results from CLL11, a phase III study which is being conducted in collaboration with Hoffmann-La Roche. The CLL11 study compared the combination of either GA101 or rituximab and chlorambucil, a standard chemotherapy, to chlorambucil alone in elderly patients with chronic lymphocytic leukemia (CLL). CLL is one of the most common forms of blood cancer and the majority of patients diagnosed with this disease are of advanced age. Many of these have concurrent diseases and therefore may not tolerate more aggressive therapy which is the standard in younger patients. The CLL11 study included elderly people with previously untreated CLL and coexisting medical conditions (comorbidities).
“So far, conclusive evidence that treatments currently available for elderly CLL patients with comorbidities are superior to chlorambucil monotherapy has been lacking. This is the first direct comparison of chlorambucil monotherapy to a combination regimen of chlorambucil plus GA101 or rituximab”, said Dr Valentin Goede, a hematologist of the GCLLSG and the Principal Investigator of the CLL11 trial. “Based on the results we have seen, elderly CLL patients with comorbidities and treated with chlorambucil should also receive a CD20 antibody to improve the outcomes of their treatment”.
GA101 combined with chlorambucil demonstrated a significant 86% reduction in the risk of disease progression, relapse or death. Additionally, the length of time during which people lived without their disease worsening (median progression-free survival, PFS) was more than doubled (23 months compared to 10.9 months, HR=0.14, 95% CI 0.09-0.21, p <.0001) when compared to chlorambucil alone. Rituximab combined with chlorambucil demonstrated a significant 68% reduction in the risk of disease progression, relapse or death. The PFS was significantly increased (15.8 months compared to 10.8 months, HR=0.32, 95% CI 0.24-0.44, p <.0001) when compared to chlorambucil alone.
“To draw final conclusions on the efficacy and safety of combined treatment with GA101 with chlorambucil relative to rituximab plus chlorambucil in this particular patient population, results of the comparison of the two antibody arms of the CLL11 study will be important. These will be available soon,” said Prof Michael Hallek, Director of the Department I of Internal Medicine at the University Hospital Cologne and Head of the GCLLSG.
About the German CLL Study Group (GCLLSG)
Founded in 1996 and headed by Prof Dr Michael Hallek, the GCLLSG has been running various phase III, phase II, and phase I trials in CLL with the goal to provide optimal treatment to patients suffering from this disease. Among those were landmark trials like the CLL8 trial which led to the current standard of care in CLL. For many years, GCLLSG has been aiming to improve not just the treatment of younger and physically fit patients, but also that of elderly and less fit patients. These patients are generally underrepresented in clinical trials although they significantly contribute to the population of CLL patients treated by doctors in daily practice. The German CLL Study Group is an independent non-profit research organization supported by the Deutsche Krebshilfe.
About the CLL11 study
CLL11 is a phase III, multicenter, open-label, randomized three-arm study investigating the safety and efficacy profile of either GA101 added to chlorambucil or rituximab added to chlorambucil compared to chlorambucil alone in 781 previously untreated people with CLL and comorbidities (589 patients are included in this analysis and an additional 192 patients have been enrolled to enable the forthcoming direct comparison of GA101 versus rituximab both in combination with chlorambucil). The study was conducted by the German CLL Study Group (GCLLSG) in collaboration with Hoffmann-La Roche. The primary endpoint of the study was PFS with secondary endpoints including overall response rate (ORR), overall survival (OS), disease-free survival (DFS), minimal residual disease (MRD) and safety profile. Specifically, the CLL11 trial data to be presented during ASCO showed the following:
• The addition of GA101 to chlorambucil led to a statistically significant reduction in the risk of disease progression or death of 86 percent (HR=0.14; p-value=<0.0001).
• The median PFS improved by more than a year from 10.9 months for chlorambucil alone to 23 months for GA101 plus chlorambucil. (see ** in table 1 below)
• The addition of rituximab to chlorambucil significantly reduced the risk of disease progression or death during study follow-up by 68 percent (HR=0.32; p-value=<0.0001).
• Median PFS was 10.8 months for chlorambucil compared to 15.7 months for rituximab plus chlorambucil.
• At this time, no formal comparison between the GA101 and rituximab arms can be made as the number of PFS events required for that formal analysis has not yet been reached.
• No new safety signals were detected for either GA101 or rituximab. The most common grade 3/4 adverse events (AEs) for GA101 were infusion-related reactions (IRRs) and low cell count of certain white blood cells (neutropenia). The incidence and severity of IRRs decreased dramatically after the first infusion and no serious IRRs have been reported beyond the first infusion. The most common adverse events are displayed in table 1 below.
• The most common AEs in the rituximab arm were infections and low white blood cell count and are displayed in table 1 below.
Christoph Wanko | idw