PharmaEssentia buys FORUS Therapeutics for $36.5 million

Acquisition deepens PharmaEssentia’s presence in the Canadian hematology-oncology MPN market to accelerate BESREMi® (ropeginterferon alfa-2b) commercialization BURLINGTON, Mass. — PharmaEssentia Corporation (TWSE: 6446), a global biopharmaceutical company headquartered in Taiwan, today announced the acquisition of FORUS Therapeutics Inc. (“FORUS”), a Canadian specialty pharmaceutical company, in a transaction valued at US$36.5 million. The acquisition represents an important component of PharmaEssentia’s North American commercial strategy and marks a significant milestone in the company’s global expansion. PharmaEssentia entered into a commercial licensing agreement with FORUS for BESREMi® in

Canada in 2024. FORUS has deep roots in the Canadian hematology and oncology space, with an experienced team and established regulatory, medical, commercial, and market-access infrastructure. FORUS submitted a New Drug Submission to Health Canada for ropeginterferon alfa-2b for polycythemia vera (PV) in July 2025, with regulatory approval expected in Q3 2026. A submission for the additional indication of essential thrombocythemia (ET) is being prepared, further expanding the market opportunity. By acquiring 100% of FORUS, PharmaEssentia will fully integrate Canadian regulatory and medical affairs, marketing,

and commercial channel resources — consolidating competitive advantages for BESREMi® and future products in the market. This opportunity also allows PharmaEssentia to explore potential important market synergies and opportunities in Canada with FORUS’s other partner, Karyopharm and its lead asset, XPOVIO. “This acquisition is the culmination of a strong and proven partnership with the FORUS team,” said Dr. Ko-Chung Lin, Founder and Chief Executive Officer of PharmaEssentia. “By bringing their regulatory expertise, market relationships, and medical/commercial capabilities fully in-house, we are best positioned to accelerate

BESREMi®‘s availability to patients with MPN across Canada, and to build a durable North American platform for our growing portfolio.” The FORUS team brings more than 25 years of hematology and oncology commercialization experience, with backgrounds at Celgene, Roche, Pfizer, and other leading global pharmaceutical companies. Collectively, the team has launched more than 10 products, generating over C$2 billion in cumulative sales. FORUS CEO Kevin Leshuk spent 13 years at Celgene, where he established the Canadian subsidiary and built a leading hematology-oncology team, successfully launching

multiple critical oncology therapies. “Joining PharmaEssentia marks an exciting new chapter and opportunity for the FORUS team,” said Kevin Leshuk, CEO of FORUS Therapeutics. “Our respective organizations share a deep commitment to the hematology community and to bringing ropeginterferon alfa-2b to the Canadian patients who need it. This acquisition now provides the local team the opportunity to build upon the existing experience with XPOVIO and leverage combined capabilities, infrastructure, and expertise as we build a leading MPN and hematology-oncology franchise in Canada.” PharmaEssentia remains committed

to advancing innovation, building strategic international partnerships, and expanding access to transformative therapies for patients worldwide. 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 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 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/20260611462117/en/ Media Muriel Huang Director, Investor Relations and Corporate Communication muriel_huang@pharmaessentia.com

PharmaEssentia, FORUS Therapeutics, acquisition, BESREMi, ropeginterferon alfa-2b, Canada, Health Canada, polycythemia vera, essential thrombocythemia, MPN