On August 31, 2026 PharmaEssentia USA Corporation, a subsidiary of PharmaEssentia Corporation (TWSE: 6446) reported the U.S. Food and Drug Administration (FDA) has approved BESREMi (ropeginterferon alfa-2b-njft) for the treatment of adults with essential thrombocythemia (ET), making it the first new FDA-approved treatment for ET in nearly three decades. BESREMi has been approved for adults with ET, regardless of their genotype or disease status, including newly diagnosed patients who are naive to cytoreductive therapy. The ET approval expands the BESREMi product label, which has been commercially available for the treatment of adults with polycythemia vera (PV).
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This approval marks a major milestone for people living with ET, a rare chronic blood cancer characterized by an overproduction of platelets. Patients with ET often require years of ongoing disease management and remain at risk for serious complications, such as heart attacks, strokes and pulmonary embolism.1 The approval of BESREMi provides a new ET treatment option and offers the potential for durable disease control, addressing a longstanding unmet need in ET care.
BESREMi is a long-acting interferon-based therapy designed to provide sustained disease management for ET. It offers a differentiated treatment option compared with current therapies that primarily focus on controlling platelet counts and symptoms, with limited impact on the underlying disease biology.2 Using novel monopegylation technology and an extended half-life, BESREMi is designed to target disease-driving cells in the bone marrow while reducing elevated platelet counts and disease burden.
"For nearly 30 years, people living with ET and the physicians treating them have had limited treatment innovation," said Ruben Mesa, M.D., principal investigator of the SURPASS-ET trial and President of Advocate Health’s Cancer National Service Line, which includes Atrium Health Levine Cancer Institute and the Comprehensive Cancer Center at Atrium Health Wake Forest Baptist. "In my experience, patients need treatment options that not only control blood counts but also address the underlying disease. The approval of BESREMi provides an important new treatment option that is supported by strong clinical evidence and that also works at the source of the disease rather than solely managing symptoms."
The FDA approval of BESREMi is based on clinical data demonstrating durable modified European Leukemia Net (ELN) responses and durable hematologic control in adults with ET. In the global Phase 3 SURPASS ET clinical trial (NCT04285086), BESREMi achieved superior durable response rates compared with anagrelide and reduced thromboembolic events over 12 months of treatment.
"Today’s FDA approval of BESREMi for ET is a significant advancement for patients and reflects PharmaEssentia’s longstanding commitment to advancing innovative therapies for people living with myeloproliferative neoplasms," said Ko-Chung Lin Ph.D., founder and CEO of PharmaEssentia. "We have been working closely with the FDA, healthcare providers, advocacy organizations and payers to bring this important treatment option to the ET community."
This announcement follows BESREMi’s recent regulatory approval in Japan and Taiwan for ET and further expands the company’s MPN portfolio. BESREMi for ET is expected to be available in the United States immediately upon approval. Additional information, including Prescribing Information, is available here.
(Press release, PharmaEssentia, AUG 31, 2026, View Source [SID1234670469])