Immutep’s efti combo hits Phase II goal in soft tissue sarcoma trial

Immutep’s efti combo hits Phase II goal in soft tissue sarcoma trial

By, Admin 30 May 2025

Immutep Limited, a late-stage immunotherapy company focused on cancer and autoimmune diseases, announced that its EFTISARC-NEO Phase II trial has met its primary endpoint. The investigator-initiated study evaluates eftilagimod alfa (efti) in combination with radiotherapy and Keytruda (pembrolizumab) in the neoadjuvant setting for resectable soft tissue sarcoma (STS).

The trial is conducted at the Maria Sklodowska-Curie National Research Institute of Oncology (MSCNRIO) in Warsaw, the national reference centre for STS in Poland.

Primary Endpoint Achieved

The combination therapy significantly exceeded the prespecified median of 35% tumour hyalinization/fibrosis, compared to 15% in historical data for radiotherapy alone in resectable STS patients.

Tumour hyalinization/fibrosis is an early surrogate endpoint measured at the time of surgical resection, associated with:

  • Improved overall survival
  • Enhanced recurrence-free survival

Investigator Commentary

“It is very encouraging to see the chemotherapy-free combination with efti far exceed the ambitious target we initially set,”

  • Katarzyna Kozak and Pawel Sobczuk, principal investigators and medical oncologists at MSCNRIO.

“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, leading to strong anti-cancer efficacy.”

The investigators emphasized the high unmet medical need in this aggressive orphan cancer indication, and confirmed that detailed results will be presented at a medical meeting later in 2025.

Trial Progress and Results

As presented during the Connective Tissue Oncology Society (CTOS) Annual Meeting in November 2024:

  • The combination therapy showed a median 50% tumour hyalinization/fibrosis in a preliminary analysis of 21 patients.
  • The EFTISARC-NEO trial completed full enrolment of 40 patients in January 2025.
  • The study is primarily funded by a grant from the Polish Medical Research Agency.

About Soft Tissue Sarcoma (STS)

Soft tissue sarcoma (STS) is a rare and aggressive cancer with:

  • High unmet medical need
  • Poor patient prognosis

According to the American Cancer Society:

  • Estimated new STS cases in the US in 2025: ~13,520
  • Estimated STS-related deaths: ~5,420

About Eftilagimod Alfa (Efti)

Eftilagimod alfa (efti) is Immutep’s proprietary soluble LAG-3 protein and MHC Class II agonist. It stimulates both innate and adaptive immunity and is being developed as a first-in-class antigen-presenting cell (APC) activator.

Mechanism of Action

Efti binds to MHC Class II molecules on APCs, leading to activation and proliferation of:

  • CD8+ cytotoxic T cells
  • CD4+ helper T cells
  • Dendritic cells
  • Natural Killer (NK) cells
  • Monocytes

It also upregulates the expression of key immune molecules such as:

  • IFN-γ
  • CXCL10

These effects enhance the immune system’s ability to target and destroy cancer cells.

Broader Development Pipeline

Efti is currently being evaluated for:

  • Non-small cell lung cancer (NSCLC)
  • Head and neck squamous cell carcinoma (HNSCC)
  • Metastatic breast cancer

Its favourable safety profile supports combinations with:

  • Anti-PD-[L] immunotherapy
  • Chemotherapy

The U.S. FDA has granted Fast Track designation for efti in:

  • First-line HNSCC
  • First-line NSCLC

About Immutep

Immutep Limited is a pioneer in LAG-3-based immunotherapy, leveraging deep expertise in immune modulation to treat cancer and autoimmune diseases.

The company’s diversified portfolio harnesses LAG-3 to:

  • Stimulate immune responses (in cancer)
  • Suppress immune responses (in autoimmunity)

Immutep is committed to:

  • Bringing innovative treatment options to patients

Maximizing shareholder value through scientific leadership

Optimize Your trial insights with Clival Database.

Are you exhausted from the uncertainty of trial insights pricing? Clival Database ensures the clarity in the midst of the global scenario for clinical trials to you.

Clival Database is one of the best databases that offers an outstanding number of clinical trial data in terms of 50,000+ molecules and from primary regulatory markets as well as new entrants like Indian and Chinese markets.

With Clival, you get accurate positioning of historical sales data, patent database, company profiling, safety & efficacy, and prediction of launch of new innovative molecules helping you to align your research and driving down the cost.

To add value, we further break down our analytics for you so that improving your operational effectiveness; optimizing your clinical trials; and offering you accurate and high-quality data at lowest possible prices becomes possible.

Elevate your trial success rate with the cutting-edge insights from Clival database.

Check it out today and make more informed sourcing decisions! Learn More!