[Efficacy and safety of ruxolitinib in patients with myelofibrosis: a single-center retrospective analysis].

We retrospectively analyzed 30 patients with myelofibrosis who had been treated with ruxolitinib at our hospital. Although dose reduction was required for 13 patients due to anemia or thrombocythemia, it was later possible to increase the dose of ruxolitinib in 10 patients (77%). A total of five patients became transfusion dependent. Among them, one patient who continued ruxolitinib therapy exhibited subsequent symptom improvement and reduction in splenomegaly while also becoming transfusion independent. Four patients whose platelet counts were <50×109/l were also treated with ruxolitinib, one of whom was able to continue ruxolitinib therapy for 25 months with some response. For one patient, ruxolitinib therapy was withdrawn due to non-response. However, upon reintroduction of ruxolitinib after 5 months without treatment, spleen size and LD levels decreased, which lasted for around 5 months. This retrospective study supports the current understanding on ruxolitinib therapy for Japanese patients with cytopenia.