For older patients with chronic lymphocytic leukemia (CLL), treatment with obinutuzumab plus chlorambucil (G-Clb) may not be as effective as rituximab plus chlorambucil (R-Clb), according to study results published in Hematological Oncology.
A team of investigators from the real-world GO-CLLEAR Study (ClinicalTrials.gov Identifier: NCT03881592) from the Czech CLL Study Group, aimed to compare G-Clb, R-Clb, and bendamustine plus rituximab (BR) as frontline treatments in patients with CLL. They included 398 participants from 10 hematology centers and aimed to determine the safety and efficacy of G-Clb, R-Clb, and BR in this patient population. They assigned 63 patients to the G-Clb group, 78 to the R-Clb group, and 257 to the BR group.
The researchers reported that prognostic or predictive markers did not differ across the treatment groups, but age at therapy initiation and cumulative illness rating scale (CIRS) scores were significantly different between groups.
Patients in the G-Clb group had a median age of 74 years upon initiation of treatment compared with 79 years in the R-Clb group and 71 years in the BR group. CIRS scores greater than 6 were found in 65.5% of evaluated patients in the G-Clb group, in approximately 85% of evaluated patients in the R-Clb group, and in 67% of evaluated patients in the BR group.
The overall response rates were 76.2% for patients receiving G-Clb, 75.6% with R-Clb, and 85.2% for BR. Complete remission was seen in 30.2% of patients taking G-Clb, 21.8% with R-Clb, and 47.5% with BR. Median event-free survival times were 49.0 months with G-Clb, 20.3 months with R-Clb, and 37.0 months with BR.
Grade 3 or 4 neutropenia was reported among 43% of patients receiving G-Clb, in 31% of those taking R-Clb, and in 49% of those receiving BR. Grade 3 or 4 infections were reported among 17% of patients with G-Clb, 6.4% of those in the R-Clb group, and 17% in the BR group. Regarding the number of cycles, treatment was shortened in 52% and 44% of BR-group and R-Clb-group patients, respectively. Conversely, 84% of G-Clb participants completed all planned treatment cycles.
The researchers indicated that activity with G-Clb in the real world seemed to be similar to what was shown in prospective clinical trials and that R-Clb appeared suitable for older patients and those with more severe comorbidities.
Disclosures: Several study authors have declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Panovská A, Němcová L, Nekvindová L, et al. Real-world data on efficacy and safety of obinutuzumab plus chlorambucil, rituximab plus chlorambucil and rituximab plus bendamustine in the frontline treatment of chronic lymphocytic leukemia: The GO-CLLEAR Study by the Czech CLL Study Group [published online May 13, 2020]. Hematol Oncol. doi: 10.1002/hon.2744