Alzheimer’s disease can be treated with antibodies that clear away plaques of amyloid protein, but these medicines require frequent dosing and they introduce serious safety risks. Korsana Biosciences is developing a next-generation drug that could offer improvements on both fronts and the startup launched this past week, revealing $175 million in financing raised to date.
The FDA-approved antibodies for Alzheimer’s are Leqembi from partners Eisai and Biogen, and Kisunla from Eli Lilly. But as large molecules, these drugs have a hard time penetrating the brain. Korsana’s drug is also an antibody, but it uses a “shuttle” technology that enables it to get into the brain.
The drug, KRSA-028, comes from Korsana’s proprietary Therapetic Targeting, or THETA, technology, which engineers the antibody to bind to the transferrin receptor, which is found on the surface of cells including those that make up the blood-brain barrier. This approach leverages the receptor’s transport capabilities to carry the therapy across the protective membrane.
Shuttling a therapy into the brain has clinical validation from Roche, whose Alzheimer’s drug trontinemab has reached late-stage clinical development. AbbVie added a transferrin receptor transported Alzheimer’s drug to its pipeline with the $1.4 billion acquisition of startup Aliada Therapeutics in 2024. This drug is still in early clinical development. Last month, Novartis agreed to pay $165 million up front to start a collaboration on SciNeuro’s amyloid-targeting antibody for Alzheimer’s that leverages a proprietary blood-brain barrier shuttle technology.
Korsana claims its approach can be best in the new class of brain-shuttled Alzheimer’s drugs. Roche’s drug requires intravenous dosing and is associated with a high rate of infusion-related reactions. Like the first generation of anti-amyloid drugs, trontinemab still comes with the risk of brain bleeding complications. In a corporate presentation, Korsana said its drug could offer comparable efficacy to Roche’s trontinemab but better safety and more convenient dosing as a monthly subcutaneous injection.
Clinical testing will help Korsana build its case for KRSA-028. Korsana estimates its capital is sufficient to fund its research into 2028. Key milestones ahead include safety data in healthy volunteers that the startup expects in mid-2027 followed by initial proof-of-concept data by the end of 2027.
Korsana is the sixth startup from Paragon Therapeutics, a company that conducts biotechnology research and forms subsidiaries to advance that research. The cash that Korsana revealed is not newly raised money. Paragon founded Korsana in 2024 with $25 million in seed financing from Fairmount and Venrock Healthcare Capital Partners. Last September, Wellington Management and TCGX co-led Korsana’s $150 million Series A round. The company did not announce the financing until this past week. Korsana is led by CEO Jonathan Violin, who is also a venture partner at Fairmount.
“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,” Violin said in a prepared statement. “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.”
Here’s a recap of other recent biotech company financings:
—Altesa BioSciences raised $75 million to fund Phase 2b testing of vapendavir, an oral small molecule antiviral drug in development for treating rhinovirus in patients with chronic obstructive pulmonary disease. The company also believes vapendavir has potential applications in other high-risk respiratory populations, including people with asthma. Altesa’s Series B round was led by Forbion.
—QuantX Biosciences, a company that uses artificial intelligence to drive its drug discovery efforts, raised $85 million to support clinical development of two oral small molecules, a STAT6 inhibitor and an IL-17 inhibitor. The company said it will also continue work discovering oral therapies for immunology and inflammation. LAV and Sanofi Ventures co-led QuantX’s Series B round.
—Third Arc Bio secured $52 million to continue its development of antibody drugs for applications in oncology and immunology. Lead asset ARC101, a bispecific T cell engager targeting CLDN6, is currently in a Phase 1 dose-escalation study enrolling patients with advanced solid tumors. New investor Andreessen Horowitz led the new financing, which Third Arc said extends the previously announced $165 million Series A round.
—Biotech startup Aerska raised $39 million as it moves closer to clinical testing of its RNA interference therapies for neurological diseases. The company’s drug candidates leverage a proprietary “brain shuttle” technology to bring its therapies across the blood-brain barrier. London- and Dublin-based Aerska says its approach could apply to genetically driven forms of Alzheimer’s disease and other neurological disorders. Aerska’s Series A financing, led by EQT Dementia Fund and age1, comes four months after the startup launched, with $21 million in seed funding.
—Vaccines for pertussis, also called whooping cough, are given as injections. Illiad Biotechnologies has raised $115 million for Phase 3 testing of its next-generation pertussis vaccine, which is administered through the nose. BPZE1 is a live attenuated intranasal pertussis vaccine intended to block Bordetella pertussis from colonizing the nasal passages, protecting adults and adolescents and potentially preventing transmission. BPZE1 was developed in France at the Institut Pasteur de Lille in the lab of Camille Locht and Nathalie Mielcarek. RA Capital Management led the Series B financing of Weston, Florida-based Illiad.
—Tenpoint Therapeutics closed $85 million in Series B financing to support commercialization of Yuvezzi, a recently approved eye drop combination drug that treats presbyopia. The Series B round was led by Janus Henderson, EQT Nexus, Hillhouse, and British Business Bank. Tenpoint also secured $150 million credit facility with Hercules Capital.
—TRex Bio, a developer of regulatory T cell therapies, closed $50 million in new financing. The capital will support its pipeline, including its most advanced program, TRB-061, a TNFR2 agonist in Phase 1a/b testing for atopic dermatitis.
—Breakthru Medicines emerged from stealth, revealing a $60 million Series A round but no details about its financial backers and limited information about its research. The startup says it is has an emerging molecular glue platform as well as a pipeline of small molecules and novel antibody drug conjugate payloads. Breakthru did say that these programs focus on targeted therapy areas affecting many cancer patients.
—Clinical-stage Angitia Biopharmaceuticals raised $130 million to support three biologic therapeutic candidates in development for postmenopausal osteoporosis, osteogenesis imperfecta, and spinal fusion. Frazier Life Sciences and Venrock Healthcare Capital Partners co-led Angitia’s Series D round.
—Cellares, maker of an enclosed and automated cell therapy manufacturing system called Cell Shuttle, raised $257 million. The company said the capital will support the global buildout of its automated integrated development and manufacturing organization (IDMO) smart factories in South San Francisco; Bridgewater, New Jersey; Leiden, the Netherlands; and Kashiwa City, Japan. The company expects to be able to support clinical manufacturing in the first half of this year and commercial-scale manufacturing in 2027.
Cellares is also preparing for an IPO. The company’s Series D round added new investors that include accounts advised by T. Rowe Price Investment Management, Baillie Gifford, Duquesne Family Office, Intuitive Ventures, EDBI, and Gates Frontier.
—Fortitude Biomedicines launched with $13 million to develop degrader antibody drug conjugates for cancer and autoimmune disease. The preclinical startup is based on research from Baylor University. K2 Bio Partners, Shanghai Healthcare Angel Capital, and Eikon Venture co-led Fortitude’s seed financing.
—Rare disease drug developer Mendra launched with $82 million. Founded by OrbiMed and 5AM Ventures, the startup says it uses AI technology to accelerate patient identification, clinical trial enrollment, and access to global markets. But Mendra does not have any drug candidates yet. The San Francisco-based company will use the new capital to acquire and develop assets. Mendra’s Series A round was co-led by OrbiMed, 8VC, and 5AM.
—Vibrant Therapeutics raised $61 million to support a pipeline led by VIB305, a dual-targeting masked T cell engager in Phase 1 testing for EGFR-positive solid tumors. The financing includes participation from new investors Pfizer Ventures and Apricot Capital. Vibrant said it has raised $100 million total to date.
—Corxel Pharmaceuticals secured up to $287 million in what it describes as a Series D1 financing. The Shanghai-based biotech said proceeds will support ongoing Phase 2 tests of CX11, an oral GLP-1 drug in development for obesity and diabetes mellitus. The capital will also support Phase 3 tests by Vincentage Pharma, the China-based company from which Corxel licensed the drug in 2024.
—Think Bioscience unveiled $55 million to support a lead program in development for Noonan syndrome, a rare inherited disorder that leads to life-threatening cardiac and lymphatic issues, among other complications. There are currently no approved therapies for Noonan’s underlying biology. Think’s synthetic biology platform technology addresses elusive disease targets by identifying pockets where a small molecule drug can bind. The startup’s Series A round was led by Regeneron Ventures, Innovation Endeavors, and Janu Henderson Investors.
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