Immunomodulatory agents in myelofibrosis.

INTRODUCTION: The treatment options for patients with myelofibrosis (MF) remain limited. Anemia, thrombocytopenia, extramedullary hematopoiesis, constitutional symptoms, and disease progression are the primary causes of morbidity and mortality. Traditional non-transplant therapies remain non-curative. Moreover, in the JAK2 inhibitor era, no single pharmacologic agent has been shown to improve all MF-related clinical manifestations. Immunomodulatory agents (IMiDs), such as thalidomide and lenalidomide, have been useful in the treatment of some MF patients while newer IMiDs such as pomalidomide are showing promise in MF. AREAS COVERED: This review focuses on the biologic rationales of IMiDs and the clinical results supporting their use in MF. It includes data on the new IMiD, pomalidomide and also explores the possible utility of combining IMiDs with other agents. A PubMed search of articles related to IMiDs and myelofibrosis were conducted. Relevant studies and clinical studies with sample size of > 15 were included. EXPERT OPINION: In the JAK2 inhibitor era, IMiDs are alternative treatments in managing splenomegaly and constitutional symptoms. They remain useful in the treatment of cytopenias. Pomalidomide's good anemia response may lead to its inclusion as one of the frontline anemia therapies in MF. Molecular biomarkers may allow us to identify patients who will respond to IMiDs.