Dr. Mesa Discusses JAK Inhibitors for Myelofibrosis

Ruben A. Mesa, MD, Professor of Medicine, Chair, Division of Hematology & Medical Oncology, Mayo Clinic, Arizona, discusses the success of JAK1 and JAK2 inhibitors for the treatment of patients with myelofibrosis, a disease in which the bone marrow is replaced by fibrous scar tissue.

Inhibiting JAK pathways allows physicians to better manage the side effects associated with myelofibrosis. Prior treatment options, such as transplants, had only been slightly effective at easing symptoms. The recently approved agent ruxolitinib (Jakafi), an oral JAK1 and JAK2 inhibitor, was the first agent approved specifically to treat patients with myelofibrosis and has helped reduce the symptoms of the disease.

Many different JAK inhibitors are currently under investigation. Other agents being investigated include SAR302503, which is currently in phase III studies, and the agents CYT387 and SB1518 that are both in phase II studies.

JAK inhibiting agents have been very effective at improving splenomegalia, a serious side effect that can cause morbidity or mortality. These targeted agents have eased many of the symptoms associated with myelofibrosis, such as feeling tired, night sweats, anemia, and bone pain.