Immutep (ASX:IMM) has unveiled a pair of significant clinical developments that underscore its ambition to reshape cancer treatment, announcing positive results in both soft tissue sarcoma and first-line non-small cell lung cancer at the 2025 European Society for Medical Oncology Congress in Berlin.
The company reported that the investigator-initiated EFTISARC-NEO Phase 2 trial evaluating eftilagimod alfa (efti) with radiotherapy and MSD's KEYTRUDA (pembrolizumab) in resectable soft tissue sarcoma (STS) met its primary endpoint, achieving a median 51.5 per cent tumour hyalinization/fibrosis in the evaluable patient population. This represents a more than threefold improvement over historical outcomes from standard radiotherapy alone. Tumour hyalinization is considered an early surrogate for improved survival and recurrence-free outcomes in STS patients.
Lead investigator Dr Katarzyna Kozak said the results “significantly exceeded the trial’s original target” and support efti’s unique mechanism of stimulating antigen-presenting cells to enhance both innate and adaptive immune responses. Immutep CEO Marc Voigt added that the findings highlight the “potential to address a substantial unmet medical need” for patients with STS, a rare disease with poor prognosis and limited treatment options.
In a separate presentation, the company revealed new data from the INSIGHT-003 trial in advanced non-squamous first-line NSCLC. The combination of efti with KEYTRUDA and chemotherapy delivered a 61.7 per cent objective response rate in patients with low or no PD-L1 expression (TPS <50 per cent), a group that typically sees lower responses with PD-1 inhibitors alone. This compares with a historical control of 40.8 per cent, marking a meaningful clinical improvement.
Dr Akin Atmaca, Head of Thoracic Oncology at Krankenhaus Nordwest, Frankfurt, described the findings as “highly promising,” particularly for the two-thirds of NSCLC patients with limited treatment options under current standards. Favourable safety outcomes further supported the data.
These results are expected to inform the pivotal TACTI-004 Phase 3 trial, which is currently enrolling more than 750 patients globally and will assess the same combination across the full spectrum of PD-L1 expression levels.
Voigt said the dual set of results demonstrates the versatility of efti as a first-in-class MHC Class II agonist capable of enhancing the effectiveness of existing immunotherapies. “We are increasingly confident efti can redefine how we approach treatment for patients across multiple solid tumour types,” he said.
Immutep’s momentum at ESMO reflects a strategic push to expand its late-stage clinical portfolio and position efti as a foundational component of next-generation immunotherapy combinations.