ASCO 2021: Phase III Noninferiority Trial of Acalabrutinib Versus Ibrutinib in CLL
Posted: Tuesday, June 8, 2021
In a phase III open-label, randomized, noninferiority trial, acalabrutinib demonstrated noninferior progression-free survival versus ibrutinib in patients with chronic lymphocytic leukemia (CLL). The results, which were presented by John C. Byrd, MD, of The Ohio State University Wexner Medical Center, Columbus, and colleagues during the virtual edition of the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 7500), also revealed that treatment with this Bruton tyrosine kinase inhibitor resulted in less cardiotoxicity and fewer discontinuations in treatment due to adverse events.
Previously treated patients with del(17p) or del(11q) were randomly assigned to receive oral acalabrutinib (n = 268) or ibrutinib (n = 265). At a median follow-up of 40.9 months, acalabrutinib seemed to be noninferior to ibrutinib; the median duration of progression-free survival was 38.4 months in both arms (hazard ratio = 1.00). According to the investigators, acalabrutinib seemed to be statistically superior to ibrutinib in all-grade atrial fibrillation incidence (9.4% vs. 16.0%; P = .023). The incidence rates grade 3 or higher (acalabrutinib: 30.8%; ibrutinib: 30.0%) and Richter’s transformation (3.8% vs. 4.9%, respectively) were comparable between the arms.
The median duration of overall survival was not reached in either arm (hazard ratio = 0.82); a total of 63 and 73 deaths were reported with acalabrutinib and ibrutinib, respectively. Compared with ibrutinib, treatment with acalabrutinib was reported to be associated with a lower incidence of any-grade hypertension (9.4% vs. 23.2%), arthralgia (15.8% vs. 22.8%), and diarrhea (34.6% vs. 46.0%); however, headache (34.6% vs. 20.2%) and cough (28.9% vs. 21.3%) were observed more frequently with acalabrutinib. Adverse events led to treatment discontinuation in 14.7% and 21.3% of patients given acalabrutinib and ibrutinib, respectively. Among any-grade adverse events of clinical interest, cardiac (24.1% vs. 30.0%), hypertension (9.4% vs. 23.2%), and bleeding (38.0% vs. 51.3%) events were reported less frequently with acalabrutinib.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.