Immutep’s IMP761 Shows Promising Immunosuppressive Effects in Phase I Trial

Immutep Advances Novel Autoimmune Therapy

Immutep Limited, a biotechnology company focused on immunotherapies, has announced promising results from the Phase I clinical trial of IMP761, a first-in-class LAG-3 agonist antibody designed to treat autoimmune diseases. The single-ascending dose portion of the study has successfully completed dosing at 2.5 and 7 mg/kg levels, demonstrating a favorable safety profile and significant immunosuppressive effects.

IMP761 works by enhancing the LAG-3 immune checkpoint, a mechanism that acts as a brake on overactive T cells responsible for autoimmune responses. By silencing these dysregulated T cells, IMP761 aims to restore immune balance and address the root cause of diseases such as rheumatoid arthritis, Type 1 diabetes, and multiple sclerosis, conditions that represent multi-billion dollar markets globally.

Safety and Efficacy Signals

The Phase I trial, conducted in healthy participants, showed that IMP761 was well tolerated with no treatment-related adverse events beyond mild intensity. Importantly, the antibody produced a dose-dependent immunosuppressive effect, significantly inhibiting T cell activity in response to a strong foreign antigen over a prolonged period, with effects observed up to 23 days post-injection.

Dr. Frédéric Triebel, Immutep’s Chief Scientific Officer, highlighted the establishment of a solid pharmacokinetic and pharmacodynamic relationship across dosing levels. He emphasized the potential of IMP761 to silence the dysregulated T cells central to many autoimmune diseases, noting increased external interest in the program as clinical progress continues.

Looking Ahead

Given these encouraging early results, the trial will proceed as planned with further updates expected in the first half of 2026. Immutep anticipates presenting additional data at a major medical conference focused on autoimmune diseases, which could further validate IMP761’s potential as a targeted immunotherapy with fewer side effects than existing treatments.

While these initial findings are promising, it is important to note that the data comes from healthy volunteers, and efficacy in patients with autoimmune conditions remains to be demonstrated in subsequent trial phases. Nonetheless, IMP761’s novel mechanism and early safety signals position it as a compelling candidate in the evolving landscape of autoimmune disease therapies.