Patients with CLL often are presented with a treatment choice between acalabrutinib and zanubrutinib. While the efficacy of these second-generation BTK inhibitors is similar to that of ibrutinib, the first BTK inhibitor approved for the treatment of CLL, they are less toxic than ibrutinib. Therefore, acalabrutinib and zanubrutinib tend to be preferred options over ibrutinib in patients with both previously untreated and relapsed/refractory disease.
Acalabrutinib and zanubrutinib have similar efficacy and side-effect profiles. Both are oral medicines that target specific proteins to restrict CLL cell growth. Both may be prescribed to patients with previously untreated CLL or relapsed/refractory CLL, as monotherapy or in combination with obinutuzumab. (See “Innovation of CLL Treatments: Modern Targeted Therapies” for a brief overview.) How do you choose between them? Your doctor’s recommendation is important, of course – but you are engaged in your healthcare and wish to participate in the decision.
In 2023, HealthTree reported study results from a statistical comparison of ASCEND trial data (which evaluated acalabrutinib) and ALPINE trial data (which evaluated zanubrutinib) that suggested similar efficacy for the two medicines, but a better side-effect profile for acalabrutinib. Both trials were in patients with relapsed/refractory CLL.
Now, different researchers have completed a newer statistical comparison based on data from the same two trials but focused solely on efficacy. Study author Mazyar Shadman, MD, MPH, at the Fred Hutch Cancer Center and the University of Washington, notes that the 2023 analysis had significant limitations hindering the efficacy comparison, like the exclusion of data from the final analysis of ALPINE and lack of adjustment for the impact of the COVID-19 pandemic on outcomes.
The current effectiveness results show, for zanubrutinib versus acalabrutinib:
Considering effectiveness only, zanubrutinib may be a better choice than acalabrutinib for patients with relapsed/refractory CLL. However, a consideration of tolerability is desirable.
In the 2023 analysis, Dr. Adam Kittai, a CLL specialist with the Ohio State University Comprehensive Cancer Center, and team found that acalabrutinib had fewer side effects than zanubrutinib. The advantages were found mostly in high blood pressure and hemorrhage, and in any medically significant but not immediately life-threatening side effect that may require hospitalization (ie, grade 3 side effects).
Of note, a poster at the European Hematology Association 2023 annual congress presented an analysis of ibrutinib, acalabrutinib, and zanubrutinib side effects across 61 trials. (Most of the trials were in CLL/SLL.) The comparison between acalabrutinib and zanubrutinib showed a higher risk with zanubrutinib for a large number of serious (≥ grade 3) side effects.
Medical research in B-cell malignancies such as CLL is extremely active right now, which is exciting for patients but also potentially confusing as newly released data updates previous knowledge. You and your doctor will have even more options as investigations proceed on a new class of drugs called BTK degraders. They are for patients with CLL that has developed mutations, making the disease resistant to BTK inhibitors. BTK degraders are still in the early phases of testing in humans, but subscribe to the “HealthTree for CLL” Newsletter for updates on this potential treatment option.
Sources:
Patients with CLL often are presented with a treatment choice between acalabrutinib and zanubrutinib. While the efficacy of these second-generation BTK inhibitors is similar to that of ibrutinib, the first BTK inhibitor approved for the treatment of CLL, they are less toxic than ibrutinib. Therefore, acalabrutinib and zanubrutinib tend to be preferred options over ibrutinib in patients with both previously untreated and relapsed/refractory disease.
Acalabrutinib and zanubrutinib have similar efficacy and side-effect profiles. Both are oral medicines that target specific proteins to restrict CLL cell growth. Both may be prescribed to patients with previously untreated CLL or relapsed/refractory CLL, as monotherapy or in combination with obinutuzumab. (See “Innovation of CLL Treatments: Modern Targeted Therapies” for a brief overview.) How do you choose between them? Your doctor’s recommendation is important, of course – but you are engaged in your healthcare and wish to participate in the decision.
In 2023, HealthTree reported study results from a statistical comparison of ASCEND trial data (which evaluated acalabrutinib) and ALPINE trial data (which evaluated zanubrutinib) that suggested similar efficacy for the two medicines, but a better side-effect profile for acalabrutinib. Both trials were in patients with relapsed/refractory CLL.
Now, different researchers have completed a newer statistical comparison based on data from the same two trials but focused solely on efficacy. Study author Mazyar Shadman, MD, MPH, at the Fred Hutch Cancer Center and the University of Washington, notes that the 2023 analysis had significant limitations hindering the efficacy comparison, like the exclusion of data from the final analysis of ALPINE and lack of adjustment for the impact of the COVID-19 pandemic on outcomes.
The current effectiveness results show, for zanubrutinib versus acalabrutinib:
Considering effectiveness only, zanubrutinib may be a better choice than acalabrutinib for patients with relapsed/refractory CLL. However, a consideration of tolerability is desirable.
In the 2023 analysis, Dr. Adam Kittai, a CLL specialist with the Ohio State University Comprehensive Cancer Center, and team found that acalabrutinib had fewer side effects than zanubrutinib. The advantages were found mostly in high blood pressure and hemorrhage, and in any medically significant but not immediately life-threatening side effect that may require hospitalization (ie, grade 3 side effects).
Of note, a poster at the European Hematology Association 2023 annual congress presented an analysis of ibrutinib, acalabrutinib, and zanubrutinib side effects across 61 trials. (Most of the trials were in CLL/SLL.) The comparison between acalabrutinib and zanubrutinib showed a higher risk with zanubrutinib for a large number of serious (≥ grade 3) side effects.
Medical research in B-cell malignancies such as CLL is extremely active right now, which is exciting for patients but also potentially confusing as newly released data updates previous knowledge. You and your doctor will have even more options as investigations proceed on a new class of drugs called BTK degraders. They are for patients with CLL that has developed mutations, making the disease resistant to BTK inhibitors. BTK degraders are still in the early phases of testing in humans, but subscribe to the “HealthTree for CLL” Newsletter for updates on this potential treatment option.
Sources:
about the author
Jacqueline M. Mahon, MA
Jacqueline is delighted to be writing for HealthTree Foundation. She has extensive experience working in blood cancers as well as other oncologic and therapeutic areas. When not writing, she may be gardening, hiking, or playing with her rescue cat, Merlin.
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