SOUTH SAN FRANCISCO, Calif., Sept. 30, 2025 — Star Therapeutics announced it has closed an oversubscribed $125 million Series D financing round to accelerate clinical development of its lead antibody program VGA039, a first-in-class therapy for von Willebrand disease (VWD). Proceeds will also support pipeline growth across hematology and immunology.
Science Significance
VGA039 is a monoclonal antibody targeting Protein S, designed as a universal hemostatic therapy to restore clotting balance. Unlike standard prophylaxis requiring two to three weekly IV infusions, VGA039 offers once-monthly subcutaneous dosing and is being tested in a pivotal Phase 3 trial. The therapy has potential to transform management of VWD, the most common inherited bleeding disorder, while expanding to other clotting diseases.
Regulatory Significance
VGA039 has already received FDA Fast Track and Orphan Drug designations, which provide expedited review pathways and market exclusivity incentives. Advancing into Phase 3 represents a major step toward future regulatory filings. These designations also highlight regulatory recognition of the therapy’s potential to meet significant unmet needs.
Business Significance
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The Series D financing, co-led by leading life sciences investors, demonstrates strong market confidence in Star’s strategy. The capital supports late-stage development and commercialization planning, positioning the company to expand its leadership in hematology. Investor participation reinforces the business viability of novel antibody platforms addressing high-burden diseases.
Patients’ Significance
For patients with VWD, who face frequent bleeding and burdensome IV infusions, VGA039 could offer greater convenience, reduced treatment burden, and improved adherence. Broader application across bleeding disorders could deliver long-term improvements in quality of life for thousands of patients globally.
Policy Significance
The financing highlights the importance of venture capital support in rare disease innovation. Policies enabling orphan drug development and fast-track reviews remain vital to encourage investment in high-need areas, ensuring patients gain earlier access to breakthrough treatments.
Star Therapeutics’ $125 million Series D financing underscores strong scientific, regulatory, and investor momentum behind VGA039 and the company’s broader pipeline. With pivotal trials underway and substantial capital support, Star is well-positioned to deliver transformative therapies for bleeding disorders and reshape standards of care in hematology.
Source: Star Therapeutics press release
