Change in spleen volume (CT/MRI) from baseline at week 24. n = number of patients with both baseline and week 24 MRI/CT spleen volume assessment. N = number of patients treated. $Shown for patients with both baseline and end of week 24 MFSAF TSS assessment and baseline TSS ≥10. #From BL to week 24 or at EOT assessment if the EOT visit is within the week 24 assessment window (169 ± 28 days). BL, baseline; CT, computed tomography; EOT, end of treatment; MRI, magnetic resonance imaging; NA, not available; RUX, ruxolitinib; SVR, spleen volume reduction; TSS, total symptom score; W24, week 24.