Star Therapeutics recently announced new financing (totaling $125 million) that will help the San Francisco-based biotechnology company continue to develop their investigational von Willebrand disease therapy VGA039. The U.S. Food and Drug Administration granted Fast Track designation to the experimental subcutaneous von Willebrand disease therapy (VWD) in January 2025.
VGA039 is a subcutaneous monoclonal antibody therapy designed to target Protein S as a means of restoring proper blood clotting in people with all types of VWD. As a key regulator of clotting within the coagulation cascade, protein S works with other coagulation proteins in the body to prevent the formation of excessive blood clots. Subcutaneous (Sub-Q) therapies require an injection just under the skin, as opposed to intravenously- administered products which necessitate venous access with each dose. As an easier to administer therapy, Sub-Q treatments have the advantage of greater convenience which in turn may increase rates of adherence.
The latest stage of development for VGA039 is the recent initiation of a phase 3 trial, which is currently recruiting in the US.
“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, PhD, 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,” added Rosenthal.
Source: Star Therapeutics press release dated September 30, 2025
