Company to present at 44th Annual J.P. Morgan Healthcare Conference on Thursday, January 15

Label expansion submissions for BESREMi^®(ropeginterferon alfa-2b-njft) filed with FDA

BURLINGTON, Mass.--(BUSINESS WIRE)--Dec. 15, 2025-- PharmaEssentia USA Corporation, a subsidiary of PharmaEssentia Corporation (TWSE: 6446), a global biopharmaceutical innovator leveraging deep expertise and proven scientific principles to deliver new biologics in hematology and oncology, today outlined key accomplishments from 2025 and provided an overview of strategic priorities and anticipated milestones for 2026. The Company also announced its attendance at the 44^th Annual J.P. Morgan Healthcare Conference, with a presentation scheduled for Thursday, January 15 at 10:30 a.m. PT (1:30 p.m. ET).

“PharmaEssentia delivered a year of substantial progress in 2025, driven by the strong performance of BESREMi^® and preparation for continued growth supported by exceptional commercial execution and important pending product milestones,” said Ko-Chung Lin, Ph.D., Founder and CEO of PharmaEssentia. “BESREMi^® has become a key growth engine for our company with the potential to transform treatment across multiple patient populations living with serious myeloproliferative neoplasms (MPNs). In 2025, we saw strong performance in polycythemia vera (PV) and are well positioned for further acceleration. With our injection pen submitted to the FDA and a supplemental BLA under review for the essential thrombocythemia (ET) indication, we are preparing for meaningful opportunities to expand adoption and patient reach. Alongside these anticipated 2026 catalysts, we continue to advance our pipeline, including the ongoing Phase 3 study evaluating BESREMi^® in pre-fibrotic/early primary myelofibrosis (Early PMF), and preparing to move additional earlier-stage programs into the clinic.”

2025 Major Accomplishments

Commercial Performance of BESREMi^®

• Delivered strong commercial growth of BESREMi^® in PV, with substantial year-over-year revenue growth (Q3 2025 revenue of $127.8 million, representing 44% YoY growth)
• Strengthened commercial and medical affairs readiness for anticipated 2026 product launches

Regulatory & Clinical Progress

• Submitted the BESREMi^® injection pen presentation to the FDA for review
• Submitted supplemental BLA seeking BESREMi^® label expansion for ET based on positive head-to-head Phase 3 results
• Continued global enrollment in the Phase 3 trial in Early PMF

Earlier Stage Program Progress

• Advanced six high value programs to the IND-enabling stage:
  • PEG-IL-2 and P11838 for immunology and inflammation indications
  • PD-1–IL-2 immunocytokine for solid tumors
  • Dual-targeting LILRB1/2 monoclonal antibody for solid tumors
  • Novel ADC candidate for solid tumors
  • KRAS and NY-ESO TCR-T cell therapies for solid tumors

2026 Anticipated Milestones

BESREMi^®

• U.S. launch of BESREMi Pen™ expected (H1 2026)
• Potential FDA approval and commercial launch of ET indication (H2 2026)
• Completion of enrollment in the global Early PMF Phase 3 clinical trial (H1 2026)

Pipeline & Portfolio Growth

• File IND submissions for multiple earlier-stage pipeline programs
• Share initial clinical results from multiple earlier-stage programs

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 Polycythemia Vera
Polycythemia vera, or PV, is a rare and chronic blood cancer. It’s part of a group of blood cancers called myeloproliferative neoplasms, or MPNs. PV starts in the bone marrow. Normally the body keeps all types of blood cells in a healthy balance, but with PV, the body produces too many red blood cells and may create excess white blood cells and platelets.

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.

View source version on businesswire.com: https://www.businesswire.com/news/home/20251215883518/en/

Media Contact
Muriel Huang
Director, Investor Relations and Corporate Communication
muriel_huang@pharmaessentia.com

Source: PharmaEssentia USA Corporation