Clinical use of ruxolitinib in an academic medical center in unselected patients with myeloproliferative neoplasms not on clinical study

Ruxolitinib is the only approved therapy for myelofibrosis (MF). However, its use in patients with myeloproliferative neoplasms (MPN) not participating in clinical studies has been poorly described. We reviewed the medical records of 45 patients (35 MF, 10 others) treated with ruxolitinib at our center, off clinical study, during the year after its approval. Patients had advanced features and were refractory to multiple therapies. Ruxolitinib was effective in reducing splenomegaly (51% response rate) and constitutional symptoms (42% response rate). It controlled blood counts in patients with polycythemia and thrombocythemia but was not effective in patients with non-classic MPNs. Ruxolitinib was an active therapy in patients previously treated with a JAK inhibitor and was safely combined with hypomethylating agents in patients with elevated blasts. Median overall survival was 24 months; 10 patients transformed to acute leukemia. Its use in combination with other active agents should be further explored in clinical studies.