Immutep's IMP321 activates wide range of immune cells

French drugmaker Immutep SA has published a research paper showing that its lead product, IMP321, induces activation of a wide range of human effector cytotoxic cells. According to the firm, its ImmuFact IMP321 is a potent natural human immunostimulatory factor designed to amplify the T cell immune response. It can be used either as an immunopotentiator in therapeutic vaccines or alone at higher doses as a monotherapy or in combination with chemotherapy. Six clinical trials have been initiated with ImmuFact IMP321 in the last 30 months.

The research team found that IMP321, which is a soluble recombinant form of the human LAG-3 protein, binds to all circulating dendritic cells and a fraction of MHC class II+ monocytes. Four hours after addition of IMP321 to blood cells these antigen-presenting cells produce cytokines important for initiating the immune response. At 18 hours, following this activation of the APC, a significant number of CD8+ T cells and NK cells are fully activated in their turn and produce Tc1 cytokines such as interferon-y or tumor necrosis factor-a. Similar induction was observed in metastatic cancer patients.