Ruxolitinib in cytopenic myelofibrosis: Response, toxicity, drug discontinuation, and outcome

Abstract

Background: Patients with cytopenic myelofibrosis (MF) have more limited therapeutic options and poorer prognoses compared with patients with the myeloproliferative phenotype. Aims and Methods: Prognostic correlates of cytopenic phenotype were explored in 886 ruxolitinib-treated patients with primary/secondary MF (PMF/SMF) included in the RUX-MF retrospective study. Cytopenia was defined as: leukocyte count <4 × 109/L and/or hemoglobin <11/<10 g/dL (males/females) and/or platelets <100 × 109/L. Results: Overall, 407 (45.9%) patients had a cytopenic MF, including 249 (52.4%) with PMF. In multivariable analysis, high molecular risk mutations (p =.04), intermediate 2/high Dynamic International Prognostic Score System (p