Immutep (ASX:IMM) has reported encouraging early progress in developing a first-in-class therapy that could reshape how autoimmune diseases are treated, following completion of a key stage in its first human clinical trial.
The Sydney-based biotechnology company announced that it has successfully completed the single-ascending-dose portion of its Phase I study of IMP761, an experimental LAG-3 agonist antibody designed to regulate immune system activity. The trial, conducted in healthy participants, tested escalating doses of the therapy up to 14 mg per kilogram and found it well-tolerated at all doses, with no safety concerns or dose-limiting toxicities observed.
The study has now progressed into its next stage, where multiple ascending doses are being evaluated to further assess safety and pharmacokinetics, with completion expected in the third quarter of 2026.
At the centre of the announcement is growing confidence in the therapy's behaviour in the human immune system.
Dr Frédéric Triebel, Immutep’s Chief Scientific Officer, said the results point to a meaningful biological effect even at this early stage. “IMP761 continues to show a clear immunosuppressive effect in healthy participants challenged with a foreign antigen in an intradermal reaction, with durable inhibition of T cell-mediated responses after a single administration,” he said.
He added that the findings reinforce the company’s underlying scientific approach. “These first-in-human findings support our mechanistic aim of selectively silencing pathogenic, self-antigen-specific memory T cells via LAG 3 agonism and provide the basis for dose levels to be tested in a future phase II trial in patients with autoimmunity.”
IMP761 represents a new direction in immunotherapy, aiming not simply to suppress symptoms but to address the root cause of autoimmune diseases by restoring immune tolerance. The therapy works by enhancing the natural inhibitory function of LAG 3, effectively acting as a brake on overactive T cells that mistakenly attack the body’s own tissues.
This targeted mechanism could prove significant in diseases such as rheumatoid arthritis, type 1 diabetes and multiple sclerosis, all of which are driven by dysregulated immune responses and collectively represent major global health burdens.
Further data from the Phase I study will be presented at the European Alliance of Associations for Rheumatology congress in London on 4 June 2026, where the company is expected to provide deeper insight into the therapy’s clinical profile and future development pathway.