Marstacimab-hncq

Star Therapeutics patched together a $125 million Series D in what it thinks is pharma’s next big therapeutic category. The South San Francisco startup expects the funds to add a few years of runway and get its sole clinical-stage drug most of the way through a Phase 3 trial in von Willebrand disease while also expanding into other disorders, CEO Adam Rosenthal told Endpoints News . The experimental drug, called VGA039, is currently in a Phase 1/2 study testing multiple doses against placebo in patients with VWD. Rosenthal said Star will “probably show some of that data” at this year’s American Society of Hematology annual meeting in Orlando in December. The trial is fully enrolled. Star initiated an open-label Phase 3 , with patients expected to begin crossing over into that trial next year, Rosenthal said. It’s expected to have results from the 60-patient study in 2028, according to the US federal trials database. The inherited bleeding disorder can lead to bleeding in the joints, muscles, gastrointestinal tract, mouth and elsewhere. “One of the most overlooked aspects of the disease is heavy menstrual bleeding,” Rosenthal said. Patients’ periods “could last weeks or even months at a time with really, really heavy volume loss, which can also lead patients to be anemic and transfusion-dependent,” he said. He predicts that VWD could be “one of the next frontiers in benign heme.” “I&I has been the hot area for a while, but it’s quite competitive,” Rosenthal said. “So a lot of investors are targeting hematology as the next big therapeutic area and looking for assets there.” Takeda markets an enzyme replacement therapy known as Vonvendi for patients with VWD. Patients must receive IV infusions twice a week. That’s a large burden on patients, Rosenthal said. However, Star’s VGA039 could offer once-a-month dosing via an under-the-skin injection done by the patient at home, Rosenthal said. The monoclonal antibody targets Protein S with the goal of rebalancing blood clotting. He likened the category to the evolving hemophilia treatment market. Roche’s subcutaneous antibody, Hemlibra, is approved for hemophilia A. It’s the Swiss pharma’s second-largest product, with more than $5 billion in sales last year. “We think that the heme B space has just recently transitioned to subQ products in the last year. Now it’s time for VWD,” Rosenthal said. Pfizer’s hemophilia A and B treatment Hympavzi was greenlit last October . Some of Star’s team of 40-plus employees previously worked on multiple hemophilia programs, including Hemlibra, Rosenthal said. A few come from True North Therapeutics, which was bought by Bioverativ in 2017 and then, in turn, was acquired by Sanofi. The French pharma markets Enjaymo for a rare type of anemia called cold agglutinin disease, which was developed by True North. Sanofi is now reconnecting with Rosenthal and some former True Northers. The pharma’s corporate venture arm, which has a new $625 million commitment, is one of the main investors in the Series D round. Viking Global Investors, Janus Henderson Investors, Frazier Life Sciences, GordonMD Global Investments and others also took part. In the first half of 2026, Star will talk about expanding VGA039 into other indications, which will likely start with small Phase 2 trials, Rosenthal said. VGA039 used to be part of a Star business known as Vega Therapeutics , but it’s all part of one team now, Rosenthal said. The company also used to have a branch called Electra Therapeutics, but that biotech was spun out in 2023 when it independently raised $80 million , Rosenthal said. Electra is testing a monoclonal antibody for a rare condition known as secondary hemophagocytic lymphohistiocytosis.