Effect of ruxolitinib on spleen size and myelofibrosis symptoms for patients enrolled at MDACC in study INCB18424-251. (A) Spleen length was measured at each study visit by manual palpation. Mean change from baseline (± SEM) for all 97 patients with palpable spleen at baseline and the 61 patients who demonstrated a ≥ 50% reduction in spleen length, confirmed 12 weeks later, is shown. (B) The modified Myelofibrosis Symptom Assessment Form (MFSAF) was used at serial clinic visits in 71 patients enrolled at MDACC, and a composite score corresponding to the symptoms of abdominal pain and discomfort, itching, night sweats, and bone/muscle pain was determined. The figure depicts the median percentage of change in this total symptom score over time.