Immutep’s Phase II Trial Meets Endpoint in Polish Soft Tissue Sarcoma Study

Immutep Limited announced that its Phase II EFTISARC-NEO trial testing a novel combination of eftilagimod alfa (efti) with radiotherapy and Merck's KEYTRUDA® (pembrolizumab) in patients with resectable soft tissue sarcoma (STS) has met its primary endpoint. The trial showed a median tumour hyalinization/fibrosis rate of 50%, significantly exceeding the prespecified 35% target and the 15% rate observed historically with radiotherapy alone. This tumor tissue transformation is an early surrogate marker linked to improved overall and recurrence-free survival, highlighting the potential of this chemotherapy-free regimen to improve patient outcomes in a rare cancer with limited treatment options. The study was conducted at the Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, Poland, with full enrollment of 40 patients completed and detailed results expected to be presented later in 2025. Efti, Immutep’s proprietary soluble LAG-3 protein, activates antigen-presenting cells to stimulate immunity and has received Fast Track designation from the FDA for other cancer indications. The company is also advancing clinical programs for efti in other solid tumors including non-small cell lung cancer and head and neck squamous cell carcinoma, with ongoing regulatory discussions underway.