Translational Data and Significant Pathologic Response Rates from EFTISARC-NEO Phase II Highlighted in Oral Presentation at CTOS 2025

Core Insights - Immutep Limited announced positive results from the EFTISARC-NEO trial, demonstrating significant efficacy in treating resectable soft tissue sarcoma (STS) with a novel combination of eftilagimod alfa (efti), radiotherapy, and KEYTRUDA [1][2] Study Results - The Phase II study showed a median 51.5% tumor hyalinization/fibrosis in the evaluable patient population (N=38), significantly exceeding the prespecified pathologic response rates (p<0.001) [2] - The trial included patients with ten different STS subtypes, including aggressive tumors with poor prognosis such as myxofibrosarcoma (N=16) and undifferentiated pleomorphic sarcoma (N=10) [3] Immune Response - Early data indicated strong immune system activation, with significant increases in key cytokines and chemokines, including CXCL9 (2.5x, p<0.01), CXCL10 (1.8x, p<0.0001), IL-23 (2.2x, p<0.05), and IFN-γ (2.5x, p<0.05) [4][5] - The increase in immune response biomarkers correlated with pathologic responses, suggesting a higher probability of favorable clinical outcomes [5] Clinical Implications - The achieved tumor hyalinization/fibrosis rate is over three times greater than standard-of-care radiotherapy based on historical data, indicating potential for improved overall survival and recurrence-free survival in STS patients [6] - The findings support the hypothesis that efti's activation of antigen-presenting cells enhances both adaptive and innate immunity, which is crucial for effective cancer treatment [7][10] Future Directions - The results suggest that efti may have applications beyond advanced or metastatic cancer, potentially benefiting patients with localized and resectable tumors [10] - Ongoing translational studies aim to further explore the correlation between immune responses and clinical outcomes [6] Recognition - The EFTISARC-NEO trial received the Golden Scalpel Award in Poland, highlighting its innovation and impact in medical research and clinical practice [9][12] Company Overview - Immutep is a late-stage biotechnology company focused on developing novel immunotherapies for cancer and autoimmune diseases, leveraging its expertise in Lymphocyte Activation Gene-3 (LAG-3) [15]