Jakafi is the first FDA-sanctioned drug for the disease, which occurs when too many red blood cells are produced in the bone marrow. This may lead to a swollen spleen and phlebitis, characterized by blood clots near the surface of the skin.
The disease also increases the risk of heart attack, the agency said Thursday in a news release.
Jakafi has been approved for polycythemia vera patients who cannot tolerate or have an inadequate response to other drugs. In clinical studies involving 222 people, Jakafi's most common side effects included low counts of red blood cells and blood platelets, dizziness, constipation and shingles.
The drug was first approved in 2011 to treat another bone marrow disorder, myelofibrosis.
Jakafi is marketed by Incyte Corp., based in Wilmington, Del.
Visit the FDA to learn more.