Key Highlights

  • Immutep reports 81.1% 12-month disease-free survival in its EFTISARC-NEO sarcoma trial.
  • The figures are secondary endpoints from 38 evaluable patients after a median follow-up of 19.1 months.
  • Local recurrence-free survival was 94.1% and distant metastasis-free survival was 86.2%.
  • The data come from an investigator-led Phase II study of eftilagimod alfa, known as efti.

Immutep Limited (ASX:IMM) is among the healthcare names in focus on the ASX today after the clinical-stage biotechnology company released the first survival data from EFTISARC-NEO, a Phase II trial testing its lead candidate eftilagimod alfa, known as efti, in patients with resectable soft tissue sarcoma. In an abstract released ahead of the Connective Tissue Oncology Society (CTOS) 2026 Annual Meeting, the trial reported a 12-month disease-free survival rate of 81.1% across 38 evaluable patients. Immutep also announced a new United States Patent covering efti-based combination therapies, with protection running to March 2038. The company has described the survival results as preliminary, and follow-up of patients is continuing.

What the EFTISARC-NEO abstract shows

EFTISARC-NEO is testing efti in combination with KEYTRUDA (pembrolizumab) and radiotherapy as a neoadjuvant treatment, meaning it is given before an operation to remove the tumour. According to Immutep's release dated 11 November 2026, the survival data come from 38 evaluable patients with a data cut-off of 30 April 2026 and a median follow-up of 19.1 months.

At the 12-month mark, the disease-free survival rate was 81.1%. The local recurrence-free survival rate, which tracks whether the cancer returns at the original site, was 94.1%. The distant metastasis-free survival rate, which tracks spread to other parts of the body, was 86.2%. No differences were observed across tumour grade, stage or histological subtype.

Investigators also reported that high levels of tumour-infiltrating lymphocytes and greater post-therapy hyalinisation or fibrosis of the tumour may be associated with better disease-free survival. Immutep noted that longer follow-up is needed to confirm these observations. The investigators concluded that the regimen showed promising preliminary long-term outcomes that Warrant registrationally relevant trials in soft tissue sarcoma.

How the trial is structured

EFTISARC-NEO is an investigator-initiated, open-label Phase II study registered as NCT06128863. It is led by the Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, Poland, and is primarily funded by a grant from the Polish Medical Research Agency. Immutep's role is to Supply efti for the study. A total of 40 patients were enrolled.

The trial's primary endpoint is pathological response, measured as the degree of tumour hyalinisation or fibrosis at the time of resection. Immutep has previously reported that this endpoint was met, with a median of 51.5% in 38 evaluable patients against a pre-specified target of 35%. The company has compared this with a historical figure of around 15% for radiotherapy alone.

The survival measures released this week are secondary endpoints. Other secondary endpoints include safety, overall survival, radiological response and health-related quality of life. Immutep said follow-up for disease-free survival and overall survival is ongoing, so the current figures represent an interim view rather than a final read-out.

Quality of life data and regulatory designations

The new survival figures follow quality of life data presented at the ESMO Congress 2026 in October. Immutep reported that those results showed no significant deterioration in health-related quality of life during treatment and a statistically significant improvement after resection.

On the regulatory front, the United States Food and Drug Administration granted efti Orphan Drug Designation for soft tissue sarcoma in April 2026. Efti also holds Fast Track Designation from the FDA in first-line head and neck squamous cell carcinoma and first-line non-small cell lung cancer.

Efti is a soluble LAG-3 protein that acts as an MHC Class II agonist. Immutep describes it as activating antigen-presenting cells, with the aim of engaging both the innate and adaptive immune systems, including the priming of cytotoxic CD8+ T cells. The company says its safety profile allows it to be combined with anti-PD-1 or anti-PD-L1 therapies, radiotherapy and chemotherapy.

New US patent extends protection to 2038

In a separate release, Immutep announced that the United States Patent and Trademark Office has granted US Patent No. 12,788,796, titled "Combined Preparations for the Treatment of Cancer or Infection". The patent is the fifth United States patent in this family, following an earlier grant in July 2026 and others before that.

The claims cover combined preparations and pharmaceutical compositions of efti with a PD-1 pathway inhibitor. The release names BMS-936559, durvalumab, atezolizumab and avelumab among the inhibitors covered. The patent is due to expire on 23 March 2038, a date that includes 806 days of patent term adjustment. Immutep has also filed a continuation application to pursue additional embodiments.

Chief executive Marc Voigt said a good patent portfolio "remains an important strategic asset", adding that it supports future development and partnering. He also said the company believes carefully selected clinical settings could offer further opportunities to evaluate efti in combination with these inhibitors.

What happens next for Immutep

The next scheduled event is a poster discussion at the CTOS 2026 Annual Meeting, which runs from 18 to 21 November 2026 in Seoul, South Korea. The EFTISARC-NEO poster discussion is set for 19 November, when further detail and new analyses are due to be presented. Immutep has said it will release a further announcement after the presentation and post the updated poster on its website.

Beyond the conference, the key items to watch are the ongoing disease-free survival and overall survival follow-up, along with any steps towards the registrationally relevant trials the investigators have recommended.

Immutep is listed on both the ASX and the Nasdaq, where it trades under the code IMMP, and describes itself as a pioneer in LAG-3 therapeutics for cancer and autoimmune disease.

Key Takeaways

Immutep's EFTISARC-NEO abstract reported a 12-month disease-free survival rate of 81.1%, local recurrence-free survival of 94.1% and distant metastasis-free survival of 86.2% in 38 evaluable patients with resectable soft tissue sarcoma, after a median follow-up of 19.1 months. The figures are secondary endpoints from an investigator-initiated study led in Poland, and the company has stressed that they are preliminary, with longer follow-up still under way.

Alongside the clinical data, the grant of US Patent No. 12,788,796 extends protection for efti combinations with several PD-1 pathway inhibitors to March 2038. The next milestone is the CTOS poster discussion in Seoul on 19 November, after which Immutep has said it will provide a further update on the trial.