• Novel combination of efti with KEYTRUDA® and chemotherapy generates strong response rates across all PD-L1 expression levels in first-line NSCLC
• Efti's ability to expand responders and enhance efficacy with PD-1 inhibitors holds great promise to change 1L NSCLC treatment paradigm
• Favorable safety profile and strong clinical responses seen when adding efti to KEYTRUDA and chemotherapy

Immutep Limited, a late-stage immunotherapy company, has announced two poster presentations at the European Society for Medical Oncology (ESMO) Congress 2025 that highlight the company's focus on changing the treatment paradigm in first-line non-small cell lung cancer (1L NSCLC). The data from the investigator-initiated INSIGHT-003 trial, with a cut-off date of 01 September 2025, showed that 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. Notably, the ORR and DCR reported in INSIGHT-003 outperform 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%. The combination with efti continues to have a favorable safety profile. Additionally, a Trial in Progress ePoster for the TACTI-004 Phase III trial, evaluating the same immunotherapy/chemotherapy combination used in INSIGHT-003, was presented at ESMO Congress 2025.

Immutep is increasingly confident that efti can set a new standard of care as first-line treatment for non-small cell lung cancer patients through its 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 these have translated into compelling overall survival, especially 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.