...patients (pts) with newly diagnosed active WM who received BR between January 2012 and July 2021....Among 42 (20%) pts with a known CXCR4WHIM mutation status, 28% harbored CXCR4WHIM mutation. The ≥VGPR rate for pts with CXCR4WHIM genotype was numerically lower….A trend towards shorter PFS among pts with CXCR4WHIM genotype [estimated median PFS for 3.9 years (95% CI: 0.8-NR) vs 5.5 years (95% CI 5.3-NR) for pts with CXCR4WT genotype, (p=0.05) was observed.