Star Therapeutics has received Fast Track designation from the U.S. Food and Drug Administration (FDA) for VGA039, an investigational monoclonal antibody for the treatment of von Willebrand disease (VWD). This designation aims to accelerate the development and review of VGA039, which targets Protein S to restore balance in blood clotting. The therapy is being developed as a universal hemostatic agent delivered subcutaneously with a convenient dosing regimen for all types of VWD.
VGA039: A Novel Approach to VWD Treatment
VGA039 represents a novel approach to managing VWD by targeting Protein S, a key component in the blood clotting process. This mechanism of action has the potential to address various bleeding disorders beyond VWD. The convenience of subcutaneous administration aims to reduce the treatment burden for patients, who currently rely on multiple intravenous infusions per week with existing therapies.
Adam Rosenthal, Ph.D., CEO and Founder of Star Therapeutics, stated, "VGA039 is the first drug candidate to receive Fast Track designation for VWD, and we are committed to advancing drug innovation for this debilitating disease that has lagged behind other bleeding disorders. Fast Track designation enables us to potentially accelerate the development path for VGA039 as a therapy that can transform the way VWD is treated with a convenient, subcutaneous therapy for patients with all types of VWD."
Promising Clinical Data
Interim clinical data from the VIVID 2 Phase 1 single ascending dose (SAD) study of VGA039 in VWD patients were presented at the American Society of Hematology (ASH) meeting in December 2024. The data indicated that a single subcutaneous dose of VGA039 was associated with substantial reductions in annualized bleed rate (ABR) in line with currently approved VWD prophylaxis therapies. In three VWD patients with high bleeding rates (ABRs greater than 50 bleeds per year), a single 4.5 mg/kg subcutaneous dose of VGA039 resulted in 75% to 88% reductions in ABR.
The study also highlighted that VGA039 sustained multi-week therapeutic concentrations following a single subcutaneous dose, contrasting with current VWD prophylaxis therapies that require multiple intravenous infusions weekly. The therapy was found to be safe and well-tolerated, with no injection site reactions observed in the seven VWD patients evaluated for safety, pharmacodynamic (PD), and pharmacokinetic (PK) activity.
Addressing Unmet Needs in VWD
Von Willebrand disease is the most common inherited bleeding disorder, affecting up to 1% of the general population, with equal frequency among men and women. However, women are more likely to experience symptoms due to increased bleeding during menstruation, pregnancy, and childbirth. Current treatments often involve factor replacement therapies requiring frequent intravenous infusions, posing a significant burden on patients.
Additional data presented at ASH 2024 from real-world VWD patient datasets highlighted the significant disease burden and unmet treatment needs. These analyses, involving data from over 50,000 diagnosed and treated VWD patients in the US, revealed that VWD patients experience high rates of bleeding comorbidities, including anemia, heavy menstrual bleeding, nosebleeds, gastrointestinal bleeds, and joint bleeds, often requiring blood transfusions. The data also indicated low prophylaxis use, likely due to the high treatment burden of existing therapies, underscoring the need for less frequent treatment options.
Next Steps for VGA039
Based on the positive results from the VIVID 2 study, Star Therapeutics plans to initiate a multi-dose study with VGA039 in early 2025. This study will further evaluate the safety and efficacy of VGA039 in VWD patients, with the goal of providing a more convenient and effective treatment option for this prevalent bleeding disorder.
Gary Patou, MD, Chief Medical Officer of Star Therapeutics, commented, "These initial results showing a significant reduction of bleeds in VWD patients highlight the exciting prospects ahead for VGA039. We are keenly aware of the unmet need of VWD patients and are working to bring the first potential subcutaneous therapy for patients with all types of VWD."
