Star Therapeutics has secured $125 million in Series D venture funding to propel its experimental Von Willebrand disease drug VGA039 through Phase 3 clinical testing, marking a significant milestone for the biotech company's lead program targeting the most common bleeding disorder.
The funding round was co-led by Sanofi Ventures and Viking Global Investors, with participation from 18 total investors. According to CEO and founder Adam Rosenthal, the capital will support the company's transition from a "hub-and-spoke" biotech model to focus primarily on VGA039, which has advanced from preclinical development to Phase 3 trials.
Addressing an Underserved Market
Von Willebrand disease affects up to 1% of the U.S. population according to the Centers for Disease Control and Prevention, making it the most common bleeding disorder. Like hemophilia, the condition prevents blood from clotting properly, leading to frequent bleeding episodes that can "be really severe and disruptive to daily life," Rosenthal explained.
Despite its prevalence, innovation in Von Willebrand disease has lagged behind hemophilia treatment advances. The condition is still largely managed with replacement clotting factors requiring frequent infusions or injections, while hemophilia has seen dramatic improvements with more convenient, longer-lasting preventive therapies.
"There hasn't been any innovation because there hasn't been that recognition of the disease burden and the market potential, and I think now that is starting to change," Rosenthal said.
Competitive Landscape Evolving
The treatment landscape is beginning to shift, however. The Food and Drug Administration expanded the use of a Takeda drug for Von Willebrand disease in September. Roche's hemophilia drug Hemlibra is also in advanced testing for the condition, while privately held Hemab Therapeutics has a therapy in early development.
Star aims for VGA039 to become for Von Willebrand disease what Hemlibra—one of Roche's best-selling drugs—is for hemophilia. Like Hemlibra, VGA039 is a preventive antibody drug designed to prevent bleeding episodes for longer periods than available therapies through subcutaneous injection.
Novel Mechanism of Action
VGA039 targets protein S, which boosts generation of the blood-clotting enzyme thrombin. This mechanism potentially differentiates it from competitors, as the drug might be effective regardless of Von Willebrand disease type.
"We can treat all types of patients, and all types of bleeds," Rosenthal said. "We're still in generation 1.0 and we're hoping to leapfrog all that incremental innovation and go straight to a subcutaneous therapy."
Clinical Progress and Future Plans
Star presented interim results from an early-stage study at the American Society of Hematology meeting last year, which "got the attention of a lot of investors," according to Rosenthal. The company launched its Phase 3 trial in September and is exploring VGA039's potential in other blood disorders, though specifics haven't been disclosed.
The company maintains flexibility regarding commercialization strategy, remaining open to independent market entry or pharmaceutical partnerships. An initial public offering hasn't been ruled out either.
"It's one of those rare circumstances where the market potential is so big, but the spend to get to market is actually quite small," Rosenthal noted. "It's something that an independent biotech can very easily do on their own."
In announcing the financing, Sanofi Ventures managing director Jason Hafler called VGA039 "a compelling opportunity," reflecting growing investor confidence in the Von Willebrand disease treatment space.
