JAK2 and anemia (phenotype): After median (range) treatment duration of 15.3 months (0.1–48.8), the overall response rate in the 166 patients multicenter study was 58% and included no complete remissions and only 1 partial remission and the drug did not affect the mutant JAK2 allele burden; anemia response was 59% and red cell transfusion-independency was achieved by 75% whereas palpable spleen response was reported at 40%.