Retrospective Study Asks Which BTK Inhibitor Has the Best Safety, Efficacy

Acalabrutinib and zanubrutinib demonstrated better safety and efficacy outcomes when compared with ibrutinib in patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL), according to a retrospective, observational study presented at the 2024 Pan Pacific Lymphoma Conference in Lahaina, Hawaii.

The authors, led by Jing-Zhou Hou, MD, PhD, a clinical hematological oncologist at the UPMC Hillman Cancer Center, also noted that patients who were treated with zanubrutinib were not largely accounted for in this study.

“While zanubrutinib had [a] relatively smaller sample size and shorter follow-up, this study demonstrated better real-world safety and efficacy outcomes for acalabrutinib and zanubrutinib versus ibrutinib,” they wrote in the poster presentation.

The investigators analyzed deidentified structured electronic health records from the Integra Connect PrecisionQ real-world database of adults within the United States receiving treatment with a Bruton tyrosine kinase (BTK) inhibitor between January 1, 2020, and July 31, 2023, in the community oncology setting. A total of 3,064 patients were followed until October 31, 2023.

The median patient age was 72 years (range, 33-90 years) in the first-line group and 72 years (range, 42-89 years) in the second-line group. In the first-line group, 49.3% of patients were treated with ibrutinib, 43.4% with acalabrutinib, and 7.2% with zanubrutinib. Similar treatment distributions were observed in the second-line group, the authors wrote.

More cardiovascular adverse events occurred among patients receiving first-line ibrutinib compared with those receiving acalabrutinib or zanubrutinib, with 12.1%, 7.6%, and 7.3% affected at month six (P<.05) and 14.6%, 9.4%, and 8.5% affected at month nine (P<.05), respectively. Among patients treated with first-line ibrutinib, 12.7% discontinued the medication and switched to either acalabrutinib or zanubrutinib. The median time to treatment discontinuation in the first-line group was shorter for ibrutinib compared with acalabrutinib or zanubrutinib.

The investigators noted that more research is needed to understand observed differences in treatment outcomes between zanubrutinib and acalabrutinib.

Reference

Hou JZ, Blanc S, Maglinte G. Real-world Bruton tyrosine kinase inhibitor treatment patterns and outcomes among patients with chronic lymphocytic leukemia or small lymphocytic lymphoma in US community oncology practices. Abstract presented at the 2024 Pan Pacific Lymphoma Conference; July 15-19, 2024; Lahaina, Hawaii.