Ruxolitinib discontinuation syndrome: incidence, risk factors, and management in 251 patients with myelofibrosis

RRuxolitinib (RUX) is the first JAK1/JAK2 inhibitor (JAKi) approved for the treatment of splenomegaly and symptoms related to myelofibrosis (MF) 1 , 2 . By JAK1 inhibition, RUX reduces the production of several inflammatory cytokine (IL-6, IL-1rα, MIP-1β, TNF-β, and CRP), whereas myelosuppression is mainly exerted through JAK2 inhibition. Despite considerable clinical efficacy, some patients fail to obtain and/or maintain a stable response or are intolerant to RUX 3 , 4 . Thus, ~40% of patients discontinue RUX within 3 years of therapy 5 .