Star Therapeutics Announces Oversubscribed $125 Million Series D Financing

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SOUTH SAN FRANCISCO, Calif.--(BUSINESS WIRE)--Sep 30, 2025--

Star Therapeutics, a clinical stage biotechnology company discovering and developing best-in-class antibodies for bleeding disorders and other diseases, today announced an oversubscribed $125 million Series D financing. The financing round was co-led by Sanofi Ventures and Viking Global Investors with participation from both existing and other new investors, including Janus Henderson Investors, Frazier Life Sciences and GordonMD Global Investments. Existing investors include Agent Capital, Blue Owl Capital, Catalio Capital Management, Cormorant Asset Management, New Leaf Venture Partners, NYBC Ventures, OrbiMed, Qatar Investment Authority (QIA), RA Capital Management, Redmile Group, Sofinnova Investments, Soleus Capital and Westlake BioPartners.

Proceeds from the Series D financing will support the continued advancement of Star’s pipeline including its lead program, VGA039, a first-in-class monoclonal antibody that targets Protein S to restore balance in blood clotting. VGA039 is being developed as a universal hemostatic therapy for multiple bleeding disorders, starting with von Willebrand disease (VWD). Star has initiated a pivotal Phase 3 clinical trial of VGA039 in patients with all types of VWD, designed to evaluate VGA039 administered once monthly via subcutaneous injection.

“We’re making significant progress across our pipeline, highlighted by the recent initiation of our Phase 3 trial of VGA039 to prevent bleeding in people with all types of VWD, the most common inherited bleeding disorder, with more than 50,000 patients diagnosed and treated in the U.S.,” said Adam Rosenthal, Ph.D., CEO and Founder of Star Therapeutics. “VGA039 has the potential to be transformative for VWD patients and could meaningfully reduce the treatment burden, given its once monthly subcutaneous dosing regimen, in comparison to factor replacement prophylaxis which requires two to three IV infusions per week. This new funding from leading life sciences investors reinforces the urgency and impact of our mission: to bring life-changing therapies to people living with serious bleeding disorders and other diseases in hematology and immunology.”

In conjunction with the financing, Jason Hafler, Ph.D., from Sanofi Ventures will join Star’s board of directors, and Maneka Mirchandaney of Viking Global Investors will join as a board observer.

“At Sanofi Ventures, we’re proud to bring meaningful experience in supporting innovative therapies for bleeding disorders and remain deeply committed to exploring best-in-class therapies to better meet the needs of patients. VWD represents a compelling opportunity, with a sizable patient population and significant unmet need,” said Jason Hafler, Ph.D., Managing Director at Sanofi Ventures. “With VGA039 advancing into Phase 3 for VWD, Star is well-positioned to deliver both substantial patient impact and long-term value. We’re proud to support a team with a strong track record and a bold vision for transforming care in VWD and beyond.”

About VGA039

VGA039 is a monoclonal antibody therapy with a novel mechanism of action that targets Protein S, thereby restoring balance to the blood clotting process. VGA039 has potential to be a universal hemostatic therapy that can treat numerous bleeding disorders, starting with VWD. As a subcutaneously self-administered antibody therapy with a convenient once monthly dosing regimen, VGA039 has the potential to dramatically reduce treatment burden for patients. VGA039 has received Fast Track and orphan drug designations from the United States Food and Drug Administration (FDA).

Interim positive data from VIVID-2, a Phase 1 single ascending dose study of VGA039 in patients with VWD, were previously reported at the Annual Meeting of the American Society of Hematology (ASH) in December 2024. A Phase 1/2 multidose study, VIVID-3, is ongoing ( NCT05776069 ). VGA039 has advanced into a Phase 3 study, VIVID-6 ( NCT07115004 ), a global single arm cross-over study designed to investigate the safety and efficacy of subcutaneous administration of VGA039 as prophylaxis for bleeding in patients with every type of VWD. For additional information on VIVID-6, including how to enroll, please visit the website here.

About von Willebrand disease

Von Willebrand disease (VWD) is the most common inherited bleeding disorder in which the blood does not clot properly, caused by absent or defective von Willebrand factor (VWF). VWD patients may experience excessive bleeding with variability in severity and frequency, negatively impacting their daily lives. Current therapies for VWD prophylaxis include factor replacement therapies requiring multiple intravenous (IV) infusions every week. More than 50,000 people in the United States are estimated to be receiving treatment for VWD.

About Star Therapeutics

Star Therapeutics is a clinical stage biotechnology company discovering and developing best-in-class antibodies to create life-changing therapies for patients, initially addressing unmet needs in hematology and immunology. The company applies its expertise in antibody innovation to interrogate areas of biology that have been overlooked and have the potential to address multiple diseases with a single therapy. Star’s leadership team has deep expertise in novel antibody drug development, having invented four first-in-class antibodies including the first approved drug (ENJAYMO ® ) for cold agglutinin disease, a hematology disease, and other therapies that have demonstrated clinical proof of concept. Based in South San Francisco, Star has raised more than $300 million from leading life sciences investors. For more information, please visit Star-Therapeutics.com and follow us on LinkedIn and X.

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KEYWORD: CALIFORNIA UNITED STATES NORTH AMERICA

INDUSTRY KEYWORD: SCIENCE BIOTECHNOLOGY RESEARCH PHARMACEUTICAL FINANCE HEALTH PROFESSIONAL SERVICES CLINICAL TRIALS

SOURCE: Star Therapeutics

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PUB: 09/30/2025 06:30 AM/DISC: 09/30/2025 06:29 AM

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