Primary Endpoint Met in EFTISARC-NEO Phase II Evaluating Neoadjuvant Efti in Soft Tissue Sarcoma and Data Presented at ESMO Congress 2025
MWN-AI** Summary
At the 2025 European Society of Medical Oncology (ESMO) Congress in Berlin, Immutep Limited presented promising data from the EFTISARC-NEO Phase II trial, showcasing the efficacy of eftilagimod alfa (efti) in combination with radiotherapy and KEYTRUDA® (pembrolizumab) for patients with resectable soft tissue sarcoma (STS). The trial successfully met its primary endpoint, revealing a median tumor hyalinization/fibrosis rate of 51.5% (p<0.001), significantly surpassing the 35% target and threefold greater than the historical 15% seen with standard radiotherapy alone.
Conducted with 38 evaluable patients, the study demonstrated this high degree of tumor hyalinization across various STS subtypes, a promising indicator correlated with improved overall and recurrence-free survival. Dr. Katarzyna Kozak highlighted that these results support the hypothesis that efti’s ability to stimulate antigen-presenting cells can significantly enhance anti-cancer efficacy by modifying the immunosuppressed tumor microenvironment.
Moreover, the therapy displayed a good safety profile, with only one instance of grade 3 toxicity linked to the immunotherapy. Immutep CEO Marc Voigt emphasized the urgent need for innovative therapies in STS to enhance patient outcomes.
Soft tissue sarcoma remains a challenging area of oncology with a high unmet medical need. In 2025, approximately 13,520 new STS cases are projected in the United States, contributing to a concerning mortality rate. EFTISARC-NEO, funded by a grant from the Polish government, aims to address this gap with its findings potentially paving the way for new therapeutic options in STS treatment. For further details, information about the trial can be found at clinicaltrials.gov under NCT06128863.
MWN-AI** Analysis
The recent presentation of the EFTISARC-NEO Phase II trial results at the ESMO Congress 2025 marks a pivotal moment for Immutep Limited (ASX: IMM; NASDAQ: IMMP) as it advances its innovative cancer therapy, eftilagimod alfa (efti). The trial's primary endpoint was met with a remarkable median tumor hyalinization/fibrosis rate of 51.5% in patients with soft tissue sarcoma (STS), significantly exceeding the predetermined target of 35% and showcasing efti’s effectiveness when combined with radiotherapy and KEYTRUDA® (pembrolizumab).
This outcome is particularly compelling given that the level of tumor response is over three times greater than that historically reported for standard radiotherapy alone (15%). The ability of efti to drive such robust tumor responses across various STS subtypes, coupled with a favorable safety profile—documented by minimal severe toxicity—positions the drug as a promising contender in the treatment landscape for STS.
From an investment perspective, Immutep is strategically positioned for growth in a niche market with high unmet medical need. The positive trial results could enhance the company’s valuation and attract increased investor interest, particularly as it continues to explore partnerships and further studies in oncology, including pivotal Phase III trials like TACTI-004 in non-small cell lung cancer.
Moreover, investors should monitor regulatory developments closely, as efti is already on the FDA’s Fast Track designation list for key indications, paving the way for rapid advancement through the approval process. The promising data, combined with a strong pipeline of clinical trials, indicates that Immutep may experience upward momentum in share performance, making it a noteworthy consideration for investment in the biotechnology sector.
**MWN-AI Summary and Analysis is based on asking OpenAI to summarize and analyze this news release.
- Novel combination including eftilagimod alfa (efti) in neoadjuvant setting drives 51.5% tumour hyalinization/fibrosis in patients with soft tissue sarcoma (p<0.001)
- High level of tumour hyalinization/fibrosis, achieved across multiple STS subtypes, over 3-fold greater than historical results from standard-of-care radiotherapy alone
- Data from investigator-initiated Phase II selected for Proffered Paper oral presentation
SYDNEY, AUSTRALIA, Oct. 20, 2025 (GLOBE NEWSWIRE) -- Immutep Limited (ASX: IMM; NASDAQ: IMMP) (“Immutep” or “the Company”), a late-stage immunotherapy company targeting cancer and autoimmune diseases, today announces positive data from the EFTISARC-NEO Phase II trial were shared in a Proffered Paper oral presentation by Katarzyna Kozak, M.D., Ph.D., Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland, at the 2025 European Society of Medical Oncology (ESMO) Congress in Berlin, Germany.
The investigator-initiated Phase II study evaluating eftilagimod alfa (efti) with radiotherapy plus KEYTRUDA ® (pembrolizumab) in the neoadjuvant setting for resectable soft tissue sarcoma (STS) met the primary endpoint and significantly exceeded the study’s prespecified 35% tumour hyalinization/fibrosis. In the evaluable patient population (N=38), the novel combination with efti reached a median 51.5% tumour hyalinization/fibrosis (p<0.001).
This impressive outcome, over three times greater than 15% from standard-of-care radiotherapy alone based on historical data, may hold significance in terms of future outcomes as tumour hyalinization/fibrosis serves as an early surrogate endpoint correlated with enhanced overall survival and recurrence-free survival in STS patients. 1,2
These promising results were achieved across multiple STS subtypes and the study proved a very good safety profile for the therapy, with only one grade ?3 toxicity related to immunotherapy.
Dr. Katarzyna Kozak, said: “The novel combination with neoadjuvant efti has significantly exceeded the originally established target for the trial’s primary endpoint in resectable soft tissue sarcoma. These outcomes achieved in a diverse population of multiple STS subtypes further substantiate the hypothesis that efti’s unique stimulation of antigen-presenting cells, resulting in a robust adaptive and innate immune response, contributes to modifying the immunosuppressed tumour microenvironment and achieving notable anti-cancer efficacy in soft tissue sarcomas. We hope these findings can help pave a path to a new therapeutic option for the substantial unmet medical need in this challenging indication.”
Marc Voigt, CEO of Immutep, noted: “We sincerely thank the principal investigators leading this study, as well as the patients and their families for taking part in this important trial. There is a significant unmet medical need for novel therapies in STS that have the potential to provide better outcomes for patients than the current standard of care radiotherapy.”
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 United States, the number of new STS cases in 2025 is estimated to be ~13,520 with ~5,420 deaths, according to the American Cancer Society. 3
The EFTISARC-NEO study has been primarily funded with a grant from the Polish government awarded by the Polish Medical Research Agency program. For more information on EFTISARC-NEO, visit clinicaltrials.gov (NCT06128863).
The presentation slides can be found on the Posters & Publications page of Immutep’s website.
About Eftilagimod Alfa (Efti)
Efti is a novel immunotherapy that directly activates antigen-presenting cells or APCs (e.g. dendritic cells, monocytes) via the MHC Class II pathway to fight cancer. As an MHC Class II agonist, its activation of APCs engages the adaptive and innate immune system to initiate a broad anti-cancer immune response. This includes priming and activating cytotoxic T cells as well as generating important co-stimulatory signals & cytokines that further boost the immune system’s ability to combat cancer.
Efti is under evaluation for a variety of solid tumours including non-small cell lung cancer (NSCLC) in a pivotal Phase III trial called TACTI-004 (KEYNOTE-F91), as well as head and neck squamous cell carcinoma (HNSCC), soft tissue sarcoma, and breast cancer. Its favourable safety profile enables various combinations like with anti-PD-[L]1 immunotherapy, radiotherapy, and/or chemotherapy. Efti has received Fast Track designation in first line HNSCC and in first line NSCLC from the United States Food and Drug Administration (FDA).
About Immutep
Immutep is a late-stage biotechnology company developing novel immunotherapies for cancer and autoimmune disease . The Company is a pioneer in the understanding and advancement of therapeutics related to Lymphocyte Activation Gene-3 (LAG-3), and its diversified product portfolio harnesses LAG-3’s ability to stimulate or suppress the immune response. Immutep is dedicated to leveraging its expertise to bring innovative treatment options to patients in need and to maximise value for shareholders. For more information, please visit www.immutep.com .
1. Schaefer IM et al. Histologic Appearance After Preoperative Radiation Therapy for Soft Tissue Sarcoma: Assessment of the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group Response Score. Int J Radiat Oncol Biol Phys. 2017 Jun 1;98(2):375-383. doi: 10.1016/j.ijrobp.2017.02.087. Epub 2017 Feb 24. PMID: 28463157.
2. Rao SR et al. Extent of tumor fibrosis/hyalinization and infarction following neoadjuvant radiation therapy is associated with improved survival in patients with soft-tissue sarcoma. Cancer Med. 2022 Jan;11(1):194-206. doi: 10.1002/cam4.4428. Epub 2021 Nov 27. PMID: 34837341; PMCID: PMC8704179.
3. American Cancer Society statistics: https://www.cancer.org/cancer/types/soft-tissue-sarcoma/about/key-statistics.html
KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.
Australian Investors/Media:
Eleanor Pearson, Sodali & Co.
+61 2 9066 4071; eleanor.pearson@sodali.com
U.S. Investors/Media:
Chris Basta, VP, Investor Relations and Corporate Communications
+1 (631) 318 4000; chris.basta@immutep.com
FAQ**
How does the novel combination of eftilagimod alfa (efti) with radiotherapy and KEYTRUDA® impact overall survival rates in soft tissue sarcoma patients, according to the Phase II trial presented by Immutep Limited IMMP?
What are the implications of achieving a 51.5% tumor hyalinization/fibrosis rate with the efti combination treatment for the future development of soft tissue sarcoma therapies by Immutep Limited IMMP?
Could Immutep Limited IMMP share insights on the safety profile observed in the EFTISARC-NEO trial, particularly regarding the single grade >3 toxicity related to immunotherapy?
In light of the promising results from the EFTISARC-NEO trial, what strategic steps will Immutep Limited IMMP take to advance efti further in clinical development for soft tissue sarcoma and other solid tumors?
**MWN-AI FAQ is based on asking OpenAI questions about Immutep Limited (NASDAQ: IMMP).
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