A study at the American Society of Clinical Oncology (ASCO) Annual Meeting (May 29-31, 2020) evaluated fixed duration venetoclax monotherapy in patients with relapsed or refractory chronic lymphocytic leukemia (CLL) with or without preexisting grade 3 or higher neutropenia.
Patients with CLL who received venetoclax monotherapy for relapsed or refractory disease often experience grade 3 or higher neutropenia.
Mary Ann Anderson, MBBS, FRACP, FRCPA, Walter and Eliza Hall Institute Medical Research (Australia), and colleagues conducted a post-hoc analysis that pooled data from multiple phase IIIb clinical trials: VENICE-I and VENICE-II. Patients in these trials (n = 468) had relapsed or refractory CLL and had received at least one dose of venetoclax monotherapy (ramp-up to 400 mg QD).
Grade 4 hematologic malignancies and grade 3 or higher neutropenia ( < 1000 cells/mm3) were managed through dose interruption or reduction. Granulocyte colony stimulating factor (G-CSF) was used in grade 3 or higher neutropenia, researchers noted.
Dr Anderson and colleagues reported that the median on-study duration of venetoclax was 20.2 months and the median number of prior CLL therapies was two.
At data cutoff of June 30, 2019, 9% (n = 44) of patients had grade 3 or higher neutropenia at baseline, 80% of whom received G-CSF during the study. Thirty-eight percent of patients had lower than grade 3 neutropenia at baseline.
Serious infections were experienced by 23% and 16% of patients in the grade 3 or higher and lower than grade 3 neutropenia groups, respectively. The most common adverse event leading to treatment discontinuation was second primary malignancy (3%). Only 1% of patients in the total population discontinued treatment due to neutropenia or febrile neutropenia, researchers acknowledged.
In their concluding remarks, authors of the study wrote that, “Patients with preexisting neutropenia can be managed on venetoclax, though concurrent use of G-CSF is likely to be required.” Data analysis is ongoing, they added.—Zachary Bessette
