Immutep's Efti with Radiotherapy & KEYTRUDA® (pembrolizumab) Meets Primary Endpoint in Phase II for Soft Tissue Sarcoma

Core Insights - Immutep Limited's investigator-initiated EFTISARC-NEO Phase II trial has successfully met its primary endpoint, demonstrating a significant increase in tumour hyalinization/fibrosis in patients with resectable soft tissue sarcoma (STS) when treated with eftilagimod alfa (efti) combined with radiotherapy and KEYTRUDA® [1][7]. Company Overview - Immutep is a late-stage biotechnology company focused on developing innovative immunotherapies for cancer and autoimmune diseases, particularly leveraging the Lymphocyte Activation Gene-3 (LAG-3) pathway [7]. - The company is pioneering the understanding and advancement of therapeutics related to LAG-3, aiming to provide novel treatment options for patients and maximize shareholder value [7]. Trial Details - The EFTISARC-NEO trial showed a median of 50% tumour hyalinization/fibrosis in a preliminary analysis of 21 patients, significantly exceeding the prespecified median of 35% [3]. - The trial is primarily funded by a grant from the Polish government, with a total enrollment of 40 patients completed in January 2025 [3][4]. Medical Significance - Tumour hyalinization/fibrosis serves as an early surrogate endpoint linked to improved overall survival and recurrence-free survival in STS patients [2]. - STS is classified as an orphan disease with a high unmet medical need and poor prognosis, with an estimated 13,520 new cases and 5,420 deaths in the U.S. in 2025 [4]. Eftilagimod Alfa (efti) Profile - Efti is a proprietary soluble LAG-3 protein and MHC Class II agonist that stimulates both innate and adaptive immunity, enhancing the immune response against cancer [5]. - Efti is under evaluation for various solid tumours, including non-small cell lung cancer and head and neck squamous cell carcinoma, and has received Fast Track designation from the FDA for certain indications [6].