Paragon’s latest venture targets Alzheimer’s via delivery platform designed to cross the blood-brain barrier.
US biotech Korsana Biosciences has emerged from stealth with $175 million in funding and a focus on developing next-generation biologics designed to reach the brain more effectively and improve the treatment of neurodegenerative diseases. The Waltham, Massachusetts-based company is the sixth biotech to emerge from the stable of venture creator Paragon Therapeutics, and is initially targeting Alzheimer’s disease with its lead antibody program, supported by a proprietary platform designed to overcome long-standing drug delivery challenges associated with the blood-brain barrier.
Korsana’s strategy is built on a transferrin receptor-based antibody “shuttle” technology designed to improve delivery of large-molecule drugs across the blood-brain barrier. Crossing this barrier has historically been one of the most significant obstacles in developing therapies for central nervous system disorders, as many biologic drugs fail to reach sufficient concentrations in brain tissue. The company says its approach combines clinically validated transferrin receptor biology with a therapeutic antibody modification technique called “Fc engineering” to enhance brain penetration.
Korsana’s lead candidate, KRSA-028, is a monoclonal antibody targeting amyloid beta, a protein long implicated in Alzheimer’s disease. The therapy selectively binds forms of amyloid beta enriched in plaques and is designed to increase plaque clearance while reducing the risk of amyloid-related imaging abnormalities and other adverse events that have complicated first-generation treatments. Unlike currently marketed amyloid-targeting therapies that often require frequent intravenous infusions and intensive monitoring, KRSA-028 is being developed as a low-volume subcutaneous injection, an approach intended to ease treatment logistics for patients and caregivers.
“Only two disease-modifying therapies have been approved to treat Alzheimer’s, and both carry safety warnings, offer only modest efficacy, and impose a high burden of care,” said Korsana CEO Dr Jonathan Violin. “Patients deserve better options than what is currently available, and we believe our lead program KRSA-028 can deliver a best-in-class product to treat Alzheimer’s.”
Beyond Alzheimer’s disease, Korsana is building a broader pipeline of candidates aimed at other neurodegenerative conditions, though specific targets remain undisclosed. The company’s broader thesis rests on the idea that improving delivery into the brain could unlock new opportunities for biologics across multiple neurological indications, where traditional therapies have struggled to achieve sufficient exposure at sites of disease.
Korsana’s war chest includes a $25 million seed round led by Fairmount and Venrock Healthcare Capital Partners, followed by a $150 million Series A financing completed in September 2025, co-led by Wellington Management and TCGX.
“We believe Korsana is well positioned to overcome the limitations of not just first-generation Alzheimer’s therapies, but also of earlier shuttle technologies,” said Venrock partner Dr Andrew Gottesdiener. “Leveraging a well-established regulatory pathway, Korsana is advancing the next generation of therapies for Alzheimer’s disease and other neurodegenerative disorders, with a clear path to creating value for patients.”
The company’s financing is expected to fund its operations into 2028, targeting mid-2027 for initial Phase1 data from healthy volunteers, including evidence of central nervous system penetration, followed by early proof-of-concept results in Alzheimer’s patients by the end of that year.
