GVHD is a condition where the donated bone marrow or peripheral blood stem cells see the recipient’s body as foreign and attack the body.
It is a significant cause of morbidity and mortality in transplant patients. There are no currently approved treatments for the disorder.
Jakafi is approved in the US to treat people with polycythemia vera (PV) who have had an inadequate response to or are intolerant of hydroxyurea.
It is also indicated to treat people with intermediate or high-risk myelofibrosis (MF), including primary MF, post-polycythemia vera MF, and post-essential thrombocythemia MF.
Incyte chief medical officer Steven Stein said: "Receiving Breakthrough Therapy Designation from the FDA recognizes the severe nature of acute GVHD, the clear unmet medical need of these patients, and the potential, based on clinical evidence to-date, for ruxolitinib to address the urgent needs of patients with this life-threatening disease.
"We are committed to working closely with the FDA in an effort to bring ruxolitinib to patients with GVHD as soon as possible."
Eli Lilly owns worldwide rights to ruxolitinib through a deal signed in 2009. Incyte regained the rights to the GVHD indication in April.
Novartis licensed ruxolitinib from Incyte to develop and commercialize outside the US.