The U.S. Food and Drug Administration (FDA) has approved ropeginterferon alfa-2b-njft (Besremi) for the treatment of adults with polycythemia vera. The new agent is a monopegylated, long-acting interferon, which exhibits its cellular effects in polycythemia vera in the bone marrow.
Ropeginterferon alfa-2b was approved with a boxed warning for the risk of serious disorders including aggravation of neuropsychiatric, autoimmune, ischemic, and infections disorders. The manufacturer is preparing to make it available in the coming weeks in the United States.
About Polycythemia Vera
Polycythemia vera is a rare, chronic, and life-threatening blood cancer caused by a mutation in stem cells in the bone marrow, resulting in the overproduction of blood cells. When this occurs, it puts a person at risk for serious health problems, including blood clots, stroke, and myocardial infarction. Most cases are caused by a JAK2 V617F mutation; without proper management, this cancer can progress to myelofibrosis and malignancies, including acute myeloid leukemia.
“The FDA approval of [ropeginterferon alfa-2b] for people with polycythemia vera represents the next step in advancing patient care, as it provides a critical addition to managing not only symptom burden and near-term complications, but also treating the cancer early, which may help reduce the risk of disease progression over time,” said Srdan Verstovsek, MD, PhD, Director of the Hanns A. Pielenz Clinical Research Center for Myeloproliferative Neoplasms, Department of Leukemia at The University of Texas MD Anderson Cancer Center. “With the availability of an FDA-approved, next-generation interferon for this indication, it’s time that we focus on preserving the long-term health of patients with polycythemia vera.”
Pivotal Trials
The FDA approval was based on safety from the PEGINVERA and PROUD/ CONTINUATION-PV studies and efficacy data from the PEGINVERA clinical study program. PEGINVERA showed that after 7.5 years of treatment with ropeginterferon alfa-2b, 61% of patients with polycythemia vera experienced a complete hematologic response (defined as hematocrit < 45% without phlebotomy for at least 2 months since last phlebotomy, platelets ≤ 400 × 109/L, leukocytes ≤ 10 × 109/L, and normal spleen size [longitudinal diameter ≤ 12 cm for females and ≤ 13 cm for males]).
Of note, 80% of patients achieved a hematologic response (based on objective laboratory parameters alone, with the exclusion of normal spleen size and thrombosis). In the pooled safety population of patients treated with ropeginterferon alfa-2b, the most common adverse reactions (incidence > 40%) were influenza-like illness, arthralgia, fatigue, pruritus, nasopharyngitis, and musculoskeletal pain. Serious adverse reactions (incidence > 4%) were urinary tract infection, transient ischemic attack, and depression.
