Effective Treatment Combination in JAK Inhibitor-naive Patients with Myelofibrosis

In this analysis, Francesco Passamonti and colleagues assessed 32 patients (median age, 69) who received NAV+RUX. The population of interest all had primary or secondary MF with splenomegaly and had not received any prior treatment of JAK-3 therapy, nor had they ever taken bromodomain and extraterminal motif (BET) inhibitors. The primary outcome of interest was spleen volume reduction of 35% or more from baseline after 24 weeks.  The secondary endpoints were at least a 50% reduction in total symptom score, bone marrow (BM) fibrosis reduction, and anemia response.

According to the results, over half of patients (52%) achieved spleen reduction, meeting the primary endpoint. While 97% of patients reported least one adverse event (AE), only 19% exhibited serious AEs. The most common Grade ≥3 AEs were anemia (34%), thrombocytopenia (31%), and neutropenia (19%), the researchers noted.

In conclusion, the researchers stated that the “combination of NAV+RUX was well tolerated and demonstrated early and robust reductions in spleen volume, anemia, and BM fibrosis in pts without prior JAK-2 inhibitor exposure.”