The MPN World in the JAK2 Inhibitor Era
– Dr. Richard Silver

Despite the recent advances in the MPN world it is important to make a correct initial diagnosis of a Ph negative MPN, as there are obvious therapeutic and prognostic implications.  This requires proper attention to clinical, hematologic and molecular analysis.

Polycythemia Vera (PV): Drugs employed in the treatment of PV include hydroxyurea, interferon and ruxolitinib.  The latter is highly effective for symptomatic relief.    

Essential Thrombocythemia (ET): In general, the mainstay treatment for ET is low dose aspirin.  Caution is required for patients with high platelet counts since bleeding may occur because of the effect of increased platelets on von Willebrand factor.  Treatment to reduce platelet counts include hydroxyurea, anagrelide and interferon. Busulfan and ruxolitinib (off-label) may also be considered for treatment.

Myelofibrosis: Significant advances in symptomatic relief of patients with myelofibrosis, both primary and secondary, has been made with the use of ruxolitinib, the only FDA approved drug for this to date.  Several new drugs and concepts are being evaluated in myelofibrosis.   

The last 10 years have witnessed remarkable advances in our understanding of these diseases and new treatments have been identified.  Other agents to look out for in the future that affect proliferation include imatinib, interferon, ruxolitinib, transplantation & other treatment modalities. The future, indeed, looks bright.