I haven’t seen compelling data to select one BTK over another based on 17p status. Comparing Acalabrutinib to ibrutinib in previously treated (not frontline) CLL patients, a randomized, noninferiority, phase 3 ELEVATE-RR trial (NCT02477696) studied acalabrutinib and ibrutinib in 533 patients. 45.2% of patients had del(17p). At a median follow-up of 40.9 months, acalabrutinib was noninferior to ibrutinib, with a PFS of 38.4 months in both arms (HR, 1.00; 95% CI, 0.79-1.27). Acalabrutinib was superior in all-grade atrial fibrillation incidence compared to ibrutinib (9.4% versus 16.0%, respectively; P = .023). When considering de-novo atrial fibrillation flutter occurring in patients who had never had this before, the difference between ibrutinib and acalabrutinib was greater. Patients with acalabrutinib had a 6.2% incidence, whereas ibrutinib was 14.9%. Acalabrutinib, however, did have a higher incidence of headache (34.6% vs 20.2%, respectively) and cough (28.9% vs 21.3%) than ibrutinib. Other end points were comparable. Average OS was not reached in either arm. There were 63 (23.5%) deaths in the acalabrutinib arm and 73 (27.5%) in the ibrutinib arm. Although numerically different, the survival was not statistically significant. Acalabrutinib is a more selective inhibitor of BTK and has a more favorable toxicity profile. Although we don’t yet have frontline data, I would extend this to first line patients and give prefer acalabrutinib in general.