Immutep (ASX:IMM) has announced that the investigator-initiated EFTISARC-NEO Phase 2 trial evaluating its eftilagimod alpha (efti) with radiotherapy plus MSD's KEYTRUDA (pembrolizumab) in the neoadjuvant setting for resectable soft tissue sarcoma has met its primary endpoint.
Efti is Immutep’s proprietary soluble LAG-3 protein and MHC Class 2 agonist that stimulates both innate and adaptive immunity for the treatment of cancer.
Immutep said the combination significantly exceeded the study’s prespecified median of 35 per cent tumour hyalinisation and fibrosis, compared to 15 per cent for historical data from radiotherapy alone in patients with resectable soft tissue sarcoma (STS).
Tumour hyalinisation and fibrosis are early surrogate endpoints at the time of surgical resection that have been associated with improved overall survival and recurrence-free survival for STS patients.
The trial’s investigators at the Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, the national reference centre for STS in Poland, plan to present detailed results from the study at a future medical meeting.
The trial’s principal investigators, oncologists Katarzyna Kozak Paweł Sobczuk, said, “It is very encouraging to see the chemotherapy-free combination with efti far exceed the ambitious target we initially set for the trial's primary endpoint in resectable soft tissue sarcoma. These results support our belief that efti's activation of antigen-presenting cells, and in turn a broad adaptive and innate immune response, helps transform the immunosuppressed tumour microenvironment of soft tissue sarcomas leading to strong anti-cancer efficacy. There remains a very high unmet need in this aggressive orphan cancer indication and we look forward to presenting detailed results at a medical meeting later this year.”
STS is an orphan disease with high unmet medical need and a poor prognosis for patients. The incidence of STS varies in different regions globally. In the US, the number of new STS cases in 2025 is estimated to be around 13,520 with approximately 5,420 deaths, according to the American Cancer Society.
