Eftilagimod alpha

Novel combination of efti with KEYTRUDA® and chemotherapy generates strong response rates across all PD-L1 expression levels in first line non-small cell lung cancer (1L NSCLC) including 61.7% ORR in low & no PD-L1 (TPS <50%), well above 40.8% from historical controlsEfti’s ability to expand responders & enhance efficacy with PD-1 inhibitors, the best selling class of drugs in oncology, holds great promise to change 1L NSCLC treatment paradigm 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 two poster presentations at the European Society for Medical Oncology (ESMO) Congress 2025 highlight the Company’s focus on changing the treatment paradigm in first line non-small cell lung cancer (1L NSCLC). Promising data from the investigator-initiated INSIGHT-003 trial with a cut-off date of 01 September 2025 were detailed in a poster presented by Dr. med. Akin Atmaca, Head of the Thoracic Oncology, Krankenhaus Nordwest, UCT-University Cancer Center, Frankfurt, Germany. In this multi-centre study, the novel combination of eftilagimod alfa (efti) with KEYTRUDA® (pembrolizumab) and chemotherapy (carboplatin/pemetrexed) has generated strong objective response rates (ORR) and disease control rates (DCR) in 51 evaluable patients with advanced or metastatic non-squamous 1L NSCLC across all PD-L1 expression levels (see table below). Notably, the ORR and DCR reported in INSIGHT-003 outperforms historical controls irrespective of PD-L1 levels. This is particularly important for patients with low and no PD-L1 (TPS <50%), who represent over two-thirds of the 1L NSCLC patient population and for whom PD-(L)1 inhibitors typically perform suboptimally. In patients with TPS <50% (N=47), the combination with efti has achieved a strong and improved 61.7% ORR (with an additional partial response since 06 May 2025 data cutoff) as compared to historical control of 40.8%.1,2 Efti+KEYTRUDA+Chemo Generates High ORR & DCR Across All PD-L1 Levels (RECIST 1.1) No PD-L1 (TPS <1%, N=22)Low PD-L1 (TPS 1-49%, N=25)High PD-L1 (TPS ≥50%, N=4)ORR, %54.568.075.0DCR, %86.492.0100 Dr. Atmaca, Head of Thoracic Oncology at Krankenhaus Nordwest, stated: “While the introduction of PD-(L)1 inhibitors, both alone and with chemotherapy, has revolutionised 1L NSCLC treatment, their limited effectiveness in cases with minimal or absent PD-L1 expression highlights the ongoing need for innovative strategies that better harness the immune system against cancer. The favourable safety results and strong clinical responses seen when adding efti, a novel immunotherapy bridging adaptive and innate immunity, to KEYTRUDA and chemotherapy are highly promising and could benefit NSCLC patients irrespective of their PD-L1 status.” Marc Voigt, CEO of Immutep, stated: “We are increasingly confident that efti can set a new standard of care as first line treatment for non-small cell lung cancer patients through our pivotal TACTI-004 Phase III trial, supported by strong data from multiple clinical trials evaluating efti in lung cancer including INSIGHT-003. Efti has safely and consistently delivered impressive improvements in response rates and progression free survival compared to KEYTRUDA alone or with chemotherapy, and encouragingly these have translated into compelling overall survival. Notably, the data is especially promising in patients with PD-L1 expression under 50%, who have a high unmet need and represent more than two-thirds of the 1L NSCLC patient population.” Further to the strong efficacy data from INSIGHT-003, the combination with efti continues to have a favourable safety profile. Additionally, a Trial in Progress ePoster for the TACTI-004 Phase III was presented at ESMO Congress 2025. This registrational trial is evaluating the same immunotherapy/chemotherapy combination used in INSIGHT-003. This global study will enrol approximately 756 patients with advanced/metastatic 1L NSCLC regardless of PD-L1 expression (Tumour Proportion Score or TPS of 0-100%) with non-squamous or squamous tumours at over 150 clinical sites in over 25 countries. The poster for INSIGHT-003 and the Trial in Progress ePoster for TACTI-004 can be found at the Posters & Publications section 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. Shirish Gadgeel et al. Updated Analysis From KEYNOTE-189: Pembrolizumab or Placebo Plus Pemetrexed and Platinum for Previously Untreated Metastatic Nonsquamous Non–Small-Cell Lung Cancer. JCO 38, 1505-1517(2020). DOI:10.1200/JCO.19.03136Immutep’s Efti with KEYTRUDA® (pembrolizumab) & Chemotherapy Achieves High Response Rates in First-Line Non-Small Cell Lung Cancer - May 2025 press release 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

Confirmation of 30mg efti as optimal biological dose relevant for Immutep’s oncology pipeline and potential future Biological License Applications (BLA)Registrational TACTI-004 (KEYNOTE-F91) Phase III trial in first line non-small cell lung cancer now in process of opening clinical sites in the United States SYDNEY, AUSTRALIA, Oct. 13, 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 that positive and straightforward feedback has been received from the US Food and Drug Administration (“FDA”) regarding the successful completion of Project Optimus requirements and agreement on 30mg as the optimal biological dose for eftilagimod alfa (efti). Immutep’s Chief Development Officer, Christian Mueller, said, “We are very thankful for the FDA’s positive feedback and productive discussions over the past few years. The alignment on efti’s optimal biologic dose has strategic relevance to our efti oncology programs and is a major de-risking event and building block towards future BLA filings. We are excited to successfully conclude this chapter of efti’s clinical development and are intently focused on bringing this novel immunotherapy to market to help address the needs of cancer patients worldwide.” The agreement with the FDA on efti’s optimal biological dosing carries strategic importance in the ongoing and future clinical development of this first-in-class immunotherapy, including the global TACTI-004 (KEYNOTE-F91) Phase III trial evaluating efti in combination with MSD’s (Merck & Co., Inc., Rahway, NJ, USA) anti-PD-1 therapy KEYTRUDA® (pembrolizumab), and chemotherapy as first-line treatment for advanced or metastatic non-small cell lung cancer (1L NSCLC), regardless of PD-L1 expression. With the conclusion of Project Optimus, this registrational study is now in process of opening sites in the United States. 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 ImmutepImmutep 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. 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