Study of Pomalidomide in Persons With Myeloproliferative-Neoplasm-Associated Myelofibrosis and RBC-Transfusion-Dependence

The multicenter global study was conducted in 15 countries including Australia, Austria, Belgium, Canada, China, France, Germany, Italy, Japan, the Netherlands, Russia, Spain, Sweden, the United Kingdom, and the United States. The global study enrolled participants with myeloproliferative neoplasm (MPN)-associated myelofibrosis and RBC-transfusion-dependence. Participants were randomly assigned to receive pomalidomide or placebo in a blinded fashion. In most countries participating in the global study, RBC-transfusions are typically given for a hemoglobin level \<80-90 g/L. In China, RBC-transfusions are rarely given unless the hemoglobin level is \<60 g/L. Consequently, few Chinese with MPN-associated myelofibrosis meet RBC-transfusion-dependence criteria of the global study. A China-specific extension was developed to test the ability of pomalidomide to improve severe anemia (defined as a hemoglobin \< 80 g/L for ≥ 84 days in persons not receiving RBC-transfusions). The China-specific extension study consisted of a single-arm, open-label study in adults with MPN-associated myelofibrosis and severe anemia not receiving RBC transfusions with the objective of describing the frequency of anemia response. The Global (intent-to-treat \[ITT\] and safety) population in the main study and the China extension (ITT and safety) population are mutually exclusive.