Immutep reports pooled analysis of five trials showing eftilagimod alfa–induced immune activation linked to significant overall survival gains in late-stage cancers, with ALC responders achieving a 7.7‑month median OS benefit.
Written By: Dr. Preethi Putti, PharmD
Reviewed By: Pharmacally Editorial Team
Immutep has reported new clinical findings showing that systemic immune activation induced by eftilagimod alfa (“efti”) was associated with statistically significant improvements in overall survival across multiple advanced cancer indications.
The findings come from an exploratory pooled evaluation of five clinical trials TACTI-mel (NCT02676869), TACTI-002 (NCT03625323), TACTI-003 (NCT04811027), AIPAC (NCT02614833), and AIPAC-003 (NCT05747794) involving eftilagimod alfa in combination with standard-of-care (SOC) therapies. The analysis included 592 patients with advanced or metastatic cancers, including non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), metastatic breast cancer (MBC), and melanoma.
According to the company, treatment with 30 mg subcutaneous eftilagimod alfa plus SOC was associated with significant increases in circulating absolute lymphocyte count (ALC), a blood-based marker commonly linked to immune activation.
Survival Association Observed in ALC Responders
Patients classified as ALC responders in the efti plus SOC treatment arms demonstrated a median overall survival improvement of 7.7 months compared with ALC non-responders, with the analysis reaching statistical significance (p=0.0017).
The association between increased ALC and improved survival outcomes was not observed in patients treated with SOC therapy alone, suggesting the immune effects may be linked to eftilagimod alfa’s biological activity.
Immutep stated that the findings support a potential relationship between systemic immune activation and the clinical benefits previously observed with eftilagimod alfa across several studies. The company also noted that the association appeared consistent across multiple tumor types and irrespective of whether the therapy was combined with chemotherapy or PD-1 inhibitor-based immunotherapy.
Biomarker and Gene Expression Findings
Beyond lymphocyte expansion, treatment with eftilagimod alfa plus SOC was associated with rapid increases in circulating TH1-related biomarkers, further supporting activation of anti-tumor immune responses.
Gene expression analyses additionally showed enhanced T-cell function scores among responding patients, providing further evidence of broad immune system activation involving cellular, cytokine, and transcriptional pathways.
Collectively, the findings suggest eftilagimod alfa may stimulate multiple components of the immune system that could contribute to improved clinical outcomes in patients with advanced cancers.
Mechanistic Support for APC Activation Strategy
Frederic Triebel, Chief Scientific Officer of Immutep, said the results establish an important connection between eftilagimod alfa’s immune-activating mechanism and survival outcomes previously observed in clinical studies.
Eftilagimod alfa is an antigen-presenting cell (APC) activator that binds to MHC class II molecules and is part of Immutep’s broader immunotherapy platform focused on LAG-3-related immune modulation strategies.
The company continues to investigate immune activation approaches designed to enhance anti-tumor immune responses across multiple cancer indications.
ASCO 2026 Presentation and TACTI-004 Context
The data will be presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting in a poster titled, “Eftilagimod alfa, an APC activator via MHC class II, induced lymphocyte activation linked to improved survival in metastatic cancer patients.”
Immutep also clarified that the current exploratory analysis does not include data from the Phase III TACTI-004 trial in first-line NSCLC, which was discontinued earlier in 2026 following a planned interim futility analysis. According to the company, immune biomarker data collection from TACTI-004 had not been completed at the time of the present evaluation.
Reference
Immutep | LAG-3 Immunotherapy for Cancer & Autoimmune Disease
About the Writer
Dr.Preethi Putti, PharmD (LinkedIn) is a pharmaceutical researcher with experience in healthcare and pharmaceutical market research and competitive intelligence. She specializes in analyzing drug pipelines, clinical data, and industry trends and translating complex scientific data into clear and structured medical content. Strong foundation in clinical research, data interpretation, and evidence-based healthcare analysis. Committed to advancing a global career in clinical research and healthcare innovation.