Dr. Verstovsek on JAK Inhibition in Polycythemia Vera

Srdan Verstovsek, MD, PhD, director of the Hanns A. Pielenz Clinical Research Center for Myeloproliferative Neoplasms at The University of Texas MD Anderson Cancer Center, discusses JAK inhibition in the treatment of patients with polycythemia vera (PV).

The frontline standard regimen for patients with a high risk of thrombosis has traditionally been chemotherapy with hydroxyurea; however, this treatment does not work in all patients, says Verstovsek. About 20% of patients with PV develop resistance to this therapy over time. In 2014, ruxolitinib (Jakafi), a JAK inhibitor, was FDA approved for the second-line treatment of these patients who progress on hydroxyurea.

The JAK pathway, Verstovsek says, is the underlying biological problem that makes cells grow in PV and other myeloproliferative neoplasms. In 2 randomized studies, ruxolitinib has shown superiority in controlling the red and white blood cell levels and platelets compared with best available therapy. These results came irrespective of the patients having an enlarged spleens.