Real-world Bruton tyrosine kinase inhibitor (BTKi) treatment patterns and outcomes among patients with chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) in US community oncology practices.

Abstract

e19020 Background: BTKi therapies are standard of care for CLL/SLL, with acalabrutinib (acala) and zanubrutinib (zanu) having improved safety profiles vs ibrutinib (ibru). This study assessed real-world clinical characteristics, treatment patterns, and adverse events (AEs) among BTKi-treated patients with CLL/SLL. Methods: This is a retrospective observational study, updated with 5 months of additional data from a previous analysis. Adults in the US community oncology setting initiated BTKi treatment between Jan 1, 2020, and Jul 31, 2023, and were followed to Oct 31, 2023. De-identified structured electronic health records were analyzed from the Integra Connect-PrecisionQ real-world database. Cardiovascular (CV) AEs (based on ICD codes), time to treatment discontinuation (TTD), and time to next treatment (TTNT) were reported. Results: A total of 3064 patients initiated BTKi therapies during the index period (1L n=2815; 2L+ n=249). Median age (range) was 72 years (33-90) in 1L and 72 years (42-89) in 2L+. There were 63.1% and 65.5% males in 1L and 2L+, respectively. In 1L, 49.3% of patients were treated with ibru, 43.4% with acala, and 7.2% with zanu. Similar trends were observed for 2L+. More patients experienced CV AEs among those who received 1L ibru vs acala or zanu; 12.1%, 7.6%, and 7.3% at month 6 ( P<0.05) and 14.6%, 9.4%, and 8.5% at month 9 ( P<0.05). With longer follow-up, there was a trend for a more favorable CV safety profile for zanu. Of patients treated with 1L ibru, 12.7% discontinued ibru and switched to acala or zanu. Median TTD in 1L was shorter for ibru than acala or zanu (Table). The associated probability of remaining on treatment was higher with zanu vs ibru or acala at months 6 and 12 (Table). Median TTNT was not reached for zanu, while it was 30.2 months for ibru and 35.8 months for acala. Conclusions: While zanu had relatively smaller sample size and shorter follow-up, this study demonstrated better real-world safety and efficacy outcomes for acala and zanu vs ibru. Additional research is needed to explain and validate observed differences favoring zanu over acala. [Table: see text]