Real-World Treatment Patterns and Outcomes of Zanubrutinib in Chronic Lymphocytic Leukemia and Small Lymphocytic Leukemia (CLL/SLL).

Zanubrutinib is a next-generation selective Bruton's tyrosine kinase inhibitor (BTKi) with superior efficacy and lower cardiotoxicity rates seen in clinical trials over first-generation ibrutinib in CLL/SLL patients. We present real-world treatment patterns based on a practice change from ibrutinib to zanubrutinib in CLL/SLL patients in an integrated community oncology practice. We retrospectively analyzed adult patients who filled at least 3 months of zanubrutinib at Kaiser Permanente Northern California. Treatment patterns, adverse events (AE), and mortality were reported. Two hundred eighty-one patients received zanubrutinib; 190 patients switched from ibrutinib. Similar AE rates were seen with both BTKis, with a lower proportion of patients with treatment-limiting AEs and lower cardiac AE rates with zanubrutinib. Most patients remained on zanubrutinib at the end of data collection without treatment-related deaths reported. In the real-world setting, zanubrutinib is effective and safe in patients with or without prior ibrutinib use, with low cardiotoxicity and AE rates, though data was limited by a difference in follow-up time.