Potential expansion of the BESREMi® (ropeginterferon alfa-2b-njft) product label to include adult patients with essential thrombocythemia (ET)

BURLINGTON, Mass, Jan. 13, 2026–PharmaEssentia USA Corporation, a subsidiary of PharmaEssentia Corporation (TWSE: 6446), a global biopharmaceutical innovator based in Taiwan leveraging deep expertise and proven scientific principles to deliver new biologics in hematology and oncology, today announced that the U.S. Food and Drug Administration (FDA) has accepted the Company’s supplemental Biologics License Application (sBLA) for ropeginterferon alfa-2b-njft for the treatment of adult patients with essential thrombocythemia (ET). The review classification for this application is Standard. The user fee target date is August 30, 2026.

The FDA has completed its filing review of the Company’s sBLA and determined that the submission is sufficiently complete to proceed with a substantive review. The FDA’s correspondence did not identify any filing review issues.

“ET is a rare blood cancer driven by excessive platelet production that can result in severe complications like organ damage and stroke. Despite these serious risks, no new therapies have been approved by the FDA for over two decades,” said Ko-Chung Lin, Ph.D., Founder and CEO of PharmaEssentia. “We look forward to collaborating with the FDA as they review our application, with the goal of bringing ropeginterferon alfa-2b-njft, an investigational therapy, to the ET community as quickly as possible.”

The sBLA under review is supported by statistically significant and clinically meaningful results from the global Phase 3 SURPASS-ET clinical trial (NCT04285086) as well as confirmatory evidence from the North American Phase 2b EXCEED-ET clinical trial (NCT05482971). The potential final approved indication and changes to the Prescribing Information will be addressed during the review process.

“Living with ET can be exhausting—physically and emotionally—for patients who must navigate a chronic cancer with limited treatment choices,” 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. “If approved, ropeginterferon alfa-2b-njft could offer clinicians a meaningful new treatment option for their patients with ET.”

About PharmaEssentia

PharmaEssentia USA Corporation, located in Burlington, Massachusetts, is a subsidiary of PharmaEssentia Corporation (TWSE: 6446). PharmaEssentia Corporation, headquartered in Taipei, Taiwan, is a global and rapidly growing biopharmaceutical innovator. Leveraging deep expertise and proven scientific principles, PharmaEssentia aims to deliver effective new biologics for challenging diseases in the areas of hematology, oncology, and immunology with one approved product and a diversifying pipeline. Founded in 2003 by a team of Taiwanese-American executives and renowned scientists from U.S. biotechnology and pharmaceutical companies, today PharmaEssentia is expanding its global presence with operations in the U.S., Japan, China, and Korea, along with a world-class biologics production facility in Taichung, Taiwan.

For more information about PharmaEssentia USA, visit the website, LinkedIn or X (formerly Twitter).

About Essential Thrombocythemia (ET)

Essential thrombocythemia is a rare blood disorder and type of myeloproliferative neoplasm (MPN). It is characterized by the bone marrow overproducing platelets. Patients with ET are at an increased risk of blood clots, abnormal bleeding and enlarged spleens. ET is often caused by genetic mutations such as a JAK2 genetic mutation.

About BESREMi® (ropeginterferon alfa-2b-njft)

Ropeginterferon alfa-2b-njft is currently FDA-approved and marketed as BESREMi® for the treatment of adults with polycythemia vera (PV). The Company plans to seek a ropeginterferon alfa-2b-njft label expansion to include ET and has submitted a sBLA with the U.S. FDA.

BESREMi® holds orphan drug designation in the United States for the treatment of polycythemia vera (PV) in adults. It has received regulatory approval in over 40 countries, including from the European Medicines Agency (2019), the U.S. Food and Drug Administration (2021), and the Pharmaceuticals and Medical Devices Agency in Japan (2023). The product was developed by PharmaEssentia. PharmaEssentia retains full global intellectual property rights across all indications.

INDICATION

BESREMi® is indicated for the treatment of adults with polycythemia vera.

IMPORTANT SAFETY INFORMATION

WARNING: RISK OF SERIOUS DISORDERS

Interferon alfa products may cause or aggravate fatal or life-threatening neuropsychiatric, autoimmune, ischemic, and infectious disorders. Patients should be monitored closely with periodic clinical and laboratory evaluations. Therapy should be withdrawn in patients with persistently severe or worsening signs or symptoms of these conditions. In many, but not all cases, these disorders resolve after stopping therapy.

CONTRAINDICATIONS

Existence of or history of severe depression, suicidal ideation, or suicide attempt

Hypersensitivity to interferons or any inactive ingredients

Moderate or severe hepatic impairment

History or presence of active serious or untreated autoimmune disease

History of transplantation and receiving immunosuppressant agents

WARNINGS AND PRECAUTIONS

Patients exhibiting the following events should be closely monitored and may require dose reduction or discontinuation of therapy:

• Depression and Suicide: Monitor closely for symptoms and need for treatment.
• Endocrine Toxicity: Discontinue if endocrine disorders occur that cannot be medically managed.
• Cardiovascular Toxicity: Avoid use in patients with severe, acute or unstable cardiovascular disease. Monitor patients with history of cardiovascular disorders more frequently.
• Decreased Peripheral Blood Counts: Perform blood counts at baseline, every 2 weeks during titration, and at least every 3-6 months during maintenance treatment.
• Hypersensitivity Reactions: Stop treatment and immediately manage reaction.
• Pancreatitis: Consider discontinuation if confirmed pancreatitis
• Colitis: Discontinue if signs or symptoms of colitis
• Pulmonary Toxicity: Discontinue if pulmonary infiltrates or pulmonary function impairment
• Ophthalmologic Toxicity: Advise patients to have eye examinations before and during treatment. Evaluate eye symptoms promptly and discontinue if new or worsening eye disorders.
• Hyperlipidemia: Monitor serum triglycerides before BESREMi® treatment and intermittently during therapy and manage when elevated.
• Hepatotoxicity: Monitor liver enzymes and hepatic function at baseline and during treatment. Reduce dose or discontinue depending on severity.
• Renal Toxicity: Monitor serum creatinine at baseline and during therapy. Discontinue if severe renal impairment develops.
• Dental and Periodontal Toxicity: Advise patients on good oral hygiene and to have regular dental examinations.
• Dermatologic Toxicity: Consider discontinuing if clinically significant dermatologic toxicity.
• Driving and Operating Machinery: Advise patients to avoid driving or using machinery if they experience dizziness, somnolence, or hallucination.

Please see full Prescribing Information, including Boxed Warning.

Contacts

Media Contact

Muriel Huang

Director, Investor Relations and Corporate Communication

muriel_huang@pharmaessentia.com