Immutep announces new biomarker data from TACTI-002 Phase II

Immutep announces new biomarker data from the TACTI-002/KEYNOTE-798 Phase II trial evaluating eftilagimod alpha, a soluble LAG-3 protein and first-in-class MHC Class II agonist administered subcutaneously, in combination with MSD’s anti-PD-1 therapy KEYTRUDA as first-line treatment for patients with previously untreated unresectable or metastatic non-small cell lung cancer. The biomarker data related to blood samples from TACTI-002 patients presented at the Society for Immunotherapy of Cancer Annual Meeting 2023 substantiates efti’s unique immune system stimulation and can be linked to its success in first line treatment of metastatic NSCLC patients, including the positive Overall Survival results recently reported at ESMO Congress 2023. Sustained and significant increase of interferon-gamma and C-X-C motif chemokine ligand 10 serum biomarkers for systemic Th1 response were seen at three months and six months on-therapy. Among patients with a partial or complete response, 86% showed a greater than or equal to1.4-fold change of IFN-gamma and 100% showed a greater than or equal to1.4-fold change CXCL10, after the first efti dosing. Additionally, the early increase of absolute lymphocyte count (ALC) was significantly greater in patients that experienced a clinical benefit, and is a potential on-treatment biomarker for response to this therapy. Furthermore, blood-based gene expression profiling analyses revealed significant enrichment of genes involved in immune activation and cytotoxicity, including CD8 T cells, in patients with a favourable tumor response. This biomarker data from the TACTI-002 Phase II is similar to the biomarker analysis from Immutep’s randomized, double-blind AIPAC Phase IIb trial in HER2-/HR+ metastatic breast cancer, which combined efti solely with paclitaxel chemotherapy and did not include any anti-PD-1 therapy. In that trial, the number of circulating immune cells and CXCL10 serum levels with efti increased in a statistically significant fashion compared to baseline. The increase in pharmacodynamic markers, including ALC and CD8 T Cells, were also significantly linked to improved overall survival in the efti group.