Immutep Limited has successfully completed the single ascending dose phase of its IMP761 trial, showing promising safety and immunosuppressive effects in healthy volunteers. The biotech’s novel LAG-3 agonist could reshape autoimmune disease treatment.
- Single ascending dose phase of IMP761 completed with no safety concerns
- IMP761 shows durable inhibition of T-cell responses after one dose
- Multiple ascending dose phase underway, expected to finish Q3 2026
- Data to be presented at EULAR conference in June 2026
- IMP761 targets autoimmune diseases by selectively silencing pathogenic T cells
Phase I Progress Marks Key Milestone for IMP761
Immutep Limited (ASX:IMM) has announced encouraging progress in its Phase I clinical trial of IMP761, a first-in-class LAG-3 agonist antibody designed to treat autoimmune diseases. The company has completed the single ascending dose (SAD) portion of the study, reporting that IMP761 was well tolerated at doses up to 14 mg/kg with no safety issues or dose-limiting toxicities observed.
This initial phase involved healthy participants and was placebo-controlled and double-blind, underscoring the rigorous approach Immutep is taking to evaluate the safety profile of this novel immunotherapy. The positive tolerability results pave the way for the ongoing multiple ascending dose (MAD) phase, which is currently underway and expected to conclude in the third quarter of 2026.
Targeting the Root Cause of Autoimmunity
IMP761’s mechanism is unique in that it acts as an agonist to LAG-3, a checkpoint molecule that naturally inhibits T-cell receptor signalling. By enhancing this inhibitory function, IMP761 aims to selectively silence pathogenic, self-antigen-specific memory T cells that drive autoimmune diseases such as rheumatoid arthritis, Type 1 diabetes, and multiple sclerosis.
Dr Frédéric Triebel, Immutep’s Chief Scientific Officer, highlighted the durable immunosuppressive effect observed after a single dose, demonstrated by inhibition of T-cell responses in an intra-dermal antigen challenge. This targeted approach could offer a more precise therapy with fewer side effects compared to existing treatments that broadly suppress the immune system.
Looking Ahead to Phase II and Market Potential
The Phase I data, including the latest safety and pharmacokinetic findings, will be presented at the European Alliance of Associations for Rheumatology (EULAR) annual congress in London on 4 June 2026. This presentation will be closely watched by investors and industry observers eager to assess IMP761’s potential as a breakthrough therapy.
Autoimmune diseases represent a significant and growing market opportunity, with current treatments often limited by efficacy and safety concerns. Immutep’s approach to restoring immune tolerance by modulating LAG-3 activity could position IMP761 as a first-in-class therapy addressing the underlying cause of these disorders rather than just managing symptoms.
While the Phase I results are promising, the company’s next challenge will be to demonstrate efficacy and safety in patients during Phase II trials. The ongoing MAD phase and upcoming data releases will be critical in shaping the future development path and commercial prospects of IMP761.
Bottom Line?
Immutep’s IMP761 is on track to redefine autoimmune treatment, but upcoming Phase II data will be the true test.
Questions in the middle?
- How will IMP761 perform in autoimmune patients during Phase II trials?
- What safety signals, if any, emerge from the multiple ascending dose phase?
- How does IMP761’s efficacy compare to existing autoimmune therapies in development?