Real-world evidence comparing clinical outcomes between venetoclax and Bruton tyrosine kinase inhibitors (BTKis) in patients with frontline (1 L) chronic lymphocytic leukaemia (CLL) is lacking. We compared treatment effectiveness of 1 L venetoclax plus obinutuzumab (VenO) versus BTKi-based regimens. This retrospective observational study using Optum Clinformatics Data Mart® included adult patients with CLL (≥2 outpatient or ≥1 inpatient claim) who received VenO or BTKi-based regimens in 1 …