The FDA has approved Besremi (ropeginterferon alfa-2b) for adults with essential thrombocythemia (ET) — described as the first FDA-approved treatment for ET in nearly 30 years.
ET is a rare, chronic blood cancer in which the bone marrow makes too many platelets, raising the risk of dangerous clots — heart attacks, strokes and pulmonary embolism. Besremi, from PharmaEssentia, is a long-acting interferon that targets disease-driving cells in the marrow while lowering platelet counts. It was already approved for the related blood cancer polycythemia vera, and can now be prescribed for ET regardless of genotype or disease status, including newly diagnosed patients.
The evidence
Approval rests on the Phase 3 SURPASS ET trial, in which Besremi showed superior efficacy to anagrelide (an older ET drug) — with durable disease responses, sustained control of blood counts, and reduced clot-related (thromboembolic) events over 12 months.
Why it matters
Patients with ET have had few modern options, often relying on decades-old therapies. “Today’s FDA approval of Besremi for ET is a significant advancement for patients,” said PharmaEssentia CEO Ko-Chung Lin. A therapy that both controls platelets and lowers clot risk — the main danger of the disease — is a meaningful update to a long-static treatment landscape.