A targeting agent is more effective in improving progression-free survival (PFS) and overall survival (OS) than conventional therapy in older patients with a treatment-naïve B-cell malignancy, according to research presented at the 22nd Congress of the European Hematology Association (June 22-25, 2017; Madrid, Spain).
A recent phase III trial (RESONATE-2) demonstrated significant improvement of PFS and OS with ibrutinib versus chlorambucil in older patients (aged ≥65 years) with treatment-naïve chronic lymphocytic leukemia (CLL). Limited research exists that directly compares single-agent ibrutinib with other frequently used treatments in this patient population. Further comparative evidence observed in clinical practice could provide useful insight on the relative efficacy of ibrutinib versus conventional therapy.
Michael Doubek, PhD, department of internal medicine, hematology and oncology, University Hospital, Masaryk University (Czech Republic), and colleagues conducted a study to investigate the relative treatment effect on PFS and OS for ibrutinib verses real-world treatment in daily clinical practice for older patients with treatment-naïve CLL. Researchers used adjusted comparison of patient-level data from RESONATE-2 (n = 136) versus real-world data from the CLL Registry (n = 418; Czech Republic) and Lyon-Sud databases (n = 110; France).
Median follow-up was 35.7 months for patients in the Lyon-Sud sample, 16.8 months in the CLL Registry sample, and 28.1 in the RESONATE-2 sample.
Fludarabine plus cyclophosphamide and rituximab (n=117), bendamustine plus rituximab (n=91), chlorambucil alone (n=43), chlorambucil plus rituximab (n=45), and other rituximab-containing regimens (n=154) were the most commonly used treatment regimens across both real-world cohorts.
Adjusted comparisons showed ibrutinib to be more effective compared with real-world treatments; Ibrutinib demonstrated a 4.1-fold improvement in PFS and a 3-fold improvement in OS. When comparing ibrutinib with the most commonly used real-world treatments, statistically significant benefits were recorded for ibrutinib versus all treatment regimens in regards to PFS and for the majority of comparisons in regards to OS.
“These results further support the existing evidence that ibrutinib significantly improves PFS and OS versus common regimens used in treatment-naïve CLL settings, and has important implications for clinical practice,” researchers concluded.—Zachary Bessette