Immutep has released the first survival data from EFTISARC NEO, a Phase II trial of its immunotherapy eftilagimod alfa in patients with soft tissue sarcoma that can be surgically removed. The results will be presented at the Connective Tissue Oncology Society annual meeting in Seoul later this month.
The trial was initiated by investigators and is led by the Maria Skłodowska Curie National Research Institute of Oncology in Warsaw. It is testing efti with MSD's KEYTRUDA (pembrolizumab) and radiotherapy, given before surgery. The Polish Medical Research Agency provides most of the funding through a grant, and Immutep supplies efti. Forty patients were enrolled, and enrolment finished in January 2025.
The abstract covers 38 evaluable patients with a median follow-up of 19.1 months, using data up to 30 April 2026. At 12 months, the disease-free survival rate was 81.1 per cent. The rate of survival free of local recurrence was 94.1 per cent, and the rate of survival free of distant metastasis was 86.2 per cent. Disease-free survival did not differ by tumour grade, stage or histological subtype.
The investigators concluded that efti plus pembrolizumab on top of standard radiotherapy as neoadjuvant therapy showed promising preliminary long-term outcomes warranting registrationally relevant trials in patients with soft tissue sarcoma. They also found that patients whose tumours had high levels of tumour-infiltrating lymphocytes, or more hyalinisation and fibrosis after treatment, may have better disease-free survival.
These survival measures are secondary endpoints. The trial met its primary endpoint in October 2025, reporting a median tumour hyalinisation and fibrosis of 51.5 per cent at resection. That was well above the trial's target of 35 per cent and the roughly 15 per cent usually seen with radiotherapy alone. At the ESMO Congress in October, quality-of-life data showed no significant decline during treatment and a statistically significant improvement after surgery.
The US Food and Drug Administration gave efti Orphan Drug Designation for soft tissue sarcoma in April 2026. Efti also has Fast Track designation in first-line head and neck squamous cell carcinoma and first-line non-small cell lung cancer.