Ruxolitinib (
Jakavi(®),
Jakafi(®)) is an orally administered inhibitor of
Janus kinases (JAK) 1 and 2 used in the management of patients with
myelofibrosis. Clinical trials with
ruxolitinib, notably the phase III COMFORT-I and -II studies and their extensions, have demonstrated marked and durable clinical benefits in terms of reductions in
splenomegaly and disease-related symptoms in patients with intermediate-2 or high-risk
myelofibrosis.
Ruxolitinib was also associated with improvements in health-related quality of life and functioning. Despite the crossover of patients in control groups to
ruxolitinib, results of the COMFORT studies and their extensions indicate a survival advantage for patients randomized to
ruxolitinib. The beneficial effects of
ruxolitinib were observed across subgroups of
myelofibrosis patients, including those not harbouring the JAK2V617F mutation. Improvements in
splenomegaly and disease-related symptoms were also observed in a trial in Japanese/Asian patients with
myelofibrosis and in
myelofibrosis patients with a low baseline platelet count. Dose-related anaemia and
thrombocytopenia were common in clinical trials with
ruxolitinib, but rarely led to discontinuation of
therapy and were managed with dosage modifications and/or transfusions of packed red blood cells. In addition to the USA and EU,
ruxolitinib is now approved in a number of other countries, including Japan, and remains the only approved
drug for the treatment of
myelofibrosis, although various other agents are undergoing investigation. Appropriate monitoring and dosage titration are important to achieve optimal clinical benefits of
ruxolitinib. Further research, including studies evaluating
ruxolitinib-based combination
therapy, may also help to optimise treatment.