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FDA Approves the First Interferon for Adults With Polycythemia Vera

Rye Brook, N.Y., November 16, 2021 – The U.S. Food and Drug Administration (FDA) last week announced approval of ropeginterferon alfa-2b-njft (ropeg, BESREMi®) for the treatment of polycythemia vera (PV). This is the first medication approved for PV that patients can take regardless of their treatment history, meaning it can be used to treat this rare form of cancer early, which may help reduce the risk of progression over time.


PV is an uncommon form of cancer that causes overproduction of red blood cells that can lead to blood clots and an increased risk of strokes and heart attacks. PV can also progress to more aggressive forms of cancer, such as myelofibrosis, acute myeloid leukemia, or myelodysplastic syndromes.


The drug’s effectiveness and safety were evaluated in a 7.5-year trial among 51 adults with PV. Patients received the treatment for an average of about five years and 61% had a complete hematological response, meaning they had a normalized red blood cell count, as well as normal white cells, platelet counts, a normal size spleen and no blood clots.


LLS recognized the possible role of interferon in PV and made several early research grants that helped establish its ability to control PV and essential thrombocytosis, a related disorder. The limiting factors were the frequency of dosing and that older forms of interferon were not well tolerated by patients.


This long-acting version is administered by subcutaneous injection (under the skin) once every two weeks. If blood counts remain stable for one year, frequency may be reduced to once every four weeks. Ropeg is a new formulation that is better tolerated; however, the drug still comes with a warning about the risk of serious disorders including aggravation of neuropsychiatric, autoimmune, ischemic and infections disorders.