Real-world outcomes after discontinuation of covalent BTK inhibitor-based therapy in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma

This study described real-world treatment patterns and outcomes among patients with CLL/SLL in the post-cBTKi setting. Included were patients who received at least one cBTKi and subsequent line of therapy (LOT) within the Flatiron Health nationwide electronic health record-derived de-identified database (FHD; <i>N</i> = 1,479) and Optum's de-identified Clinformatics^® Data Mart Database (CDM; <i>N</i> = 1,020). Frequently observed post-cBTKi treatments in both databases included cBTKi monotherapy (23-30%), anti-CD20 mab monotherapy (∼10%), BCL2i monotherapy (∼9%), BCL2i + anti-CD20 mab (∼9%), cBTKi + BCL2i (∼3%), and cBTKi + anti-CD20 mab (5-7%). From start of immediate LOT following cBTKi discontinuation, median time-to-treatment-discontinuation ranged across databases between 6 and 9 months; median time-to-next-treatment and median overall survival ranged between 18-23 months and 36-57 months, respectively. Observed heterogeneity in treatment patterns and outcomes in two cohorts of patients with CLL/SLL suggests lack of clarity in clinical evidence for treatment choice, and there remains a need for treatment options that deliver improved outcomes in the post-cBTKi setting.