This article has been medically reviewed by Dr. Brian Koffman on April 26, 2023.
The Bottom Line:
In the real world, patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) treated with acalabrutinib had lower discontinuation rates and a prolonged time to discontinuation compared with patients treated with ibrutinib.
Who Performed the Research and Where Was it Presented:
Dr. Lindsey Roeker from Memorial Sloan Kettering Cancer Center and colleagues presented the results at the American Society for Hematology Annual Meeting in 2022.
Background:
Next-generation Bruton tyrosine kinase inhibitors (BTKi) acalabrutinib and zanubrutinib have received FDA approval for use in CLL / SLL. Acalabrutinib and ibrutinib have been compared in the ELEVATE R/R study, a phase 3 clinical trial in patients with relapsed/refractory CLL / SLL. That study found that acalabrutinib treatment was just as effective as ibrutinib but with fewer side effects, especially cardiac side effects like atrial fibrillation (abnormal heart rhythm). However, looking at real-world data helps see how medications perform outside clinical trials, which are very controlled settings. Sometimes, the effectiveness and/or the side effect profile can be slightly different in a real-world setting. Additionally, many patients receive BTKi as first-line therapy rather than for relapsed/refractory CLL / SLL.
In this video, Dr. Brian Hill, Director of the Lymphoid Malignancies Program and a Staff Physician at the Cleveland Clinic Taussig Cancer Institute, and Dr. Lindsey Roeker, Assistant Attending Physician in the CLL program at Memorial Sloan Kettering Cancer Center. They discussed the results of a real-world study that used electronic health records to compare acalabrutinib and ibrutinib.
Methods and Participants:
This retrospective study used electronic health record data from the Flatiron Health Database. It included patients with CLL or SLL who initiated acalabrutinib or ibrutinib in any line of therapy on or after January 1, 2018
Results:
- The health record database identified 2509 patients with CLL / SLL. More patients received ibrutinib (90%) than acalabrutinib (14%).
- It is not surprising that the number of patients receiving acalabrutinib was much smaller since acalabrutinib was not approved by the FDA until November 2019.
- Time to treatment discontinuation was longer for acalabrutinib than ibrutinib, meaning patients could stay on the drug longer before stopping due to side effects or disease progression.
- After one year of treatment, 31% of patients taking ibrutinib had stopped, while 22% of patients taking acalabrutinib had stopped.
- These results are very similar to what was seen in the ELEVATE R/R clinical trial, where fewer patients taking acalabrutinib had to discontinue their medication compared with ibrutinib.
- Zanubrutinib was not a part of this study due to the tiny number of patients treated with it (it received FDA approval in January 2023).
- Though they have not been directly compared, acalabrutinib and zanubrutinib appear to have similar efficacy with slightly different side effect profiles.
- Both acalabrutinib and zanubrutinib are great options for patients. Deciding between them may come down to looking at the side effect profile and considering the patient’s other conditions.
Conclusions:
This study shows that in the real world, patients treated with acalabrutinib have lower discontinuation rates and a prolonged time to discontinuation compared with patients treated with ibrutinib. A lot has changed in the last five years, and we are fortunate to now have multiple BTKi options for treating CLL / SLL.
Links and Resources:
Watch the interview on the abstract here:
You can read the actual ASH abstract here: Comparing Acalabrutinib and Ibrutinib in the Real World: A Study of 2,509 Patients with Chronic Lymphocytic Leukemia
Take care of yourself first.
Ann Liu, PhD
