Immutep Reports Progress from Phase I Study of LAG-3 Agonist for Autoimmune Diseases
Rhea-AI Summary
Immutep (NASDAQ: IMMP) reported successful completion of the single ascending dose (SAD) portion of its first‑in‑human Phase I study of IMP761, a LAG‑3 agonist for autoimmune diseases, with dosing up to 14 mg/kg and no dose‑limiting toxicities observed.
The multiple ascending dose (MAD) portion is ongoing, with MAD completion expected in Q3 2026. According to the company, IMP761 produced a durable immunosuppressive effect in an intradermal antigen challenge after a single administration. Phase I data will be presented at EULAR on 4 June 2026.
Positive
- SAD completed to 14 mg/kg
- No dose‑limiting toxicities observed across SAD dose levels
- Durable immunosuppressive effect seen in healthy participant antigen challenge
Negative
- No patient efficacy data yet; results are from healthy participants only
Key Figures
Market Reality Check
Peers on Argus
Only one momentum peer, ACIU, screened with a +7.44% move and no same-day news-linked sector wave. Other biotech peers in the list show mixed, mostly negative price changes, pointing to a stock-specific reaction for IMMP tied to the IMP761 Phase I update.
Previous Clinical trial Reports
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Mar 13 | Phase III futility stop | Negative | -82.4% | TACTI-004 Phase III in 1L NSCLC discontinued after interim futility analysis. |
| Feb 06 | Enrollment milestone | Positive | +0.0% | TACTI-004 Phase III reached 50% enrolment with 378 of planned patients. |
| Dec 22 | IMP761 Phase I update | Positive | +4.9% | IMP761 SAD cohorts up to 7 mg/kg showed favorable safety and immunosuppression. |
| Dec 16 | TACTI-004 progress | Positive | +2.0% | Strong operational progress and robust enrolment in global TACTI-004 Phase III trial. |
| Dec 02 | AIPAC-003 data | Positive | -7.1% | Breast cancer Phase II data with strong responses ahead of SABCS presentation. |
Clinical-trial news for Immutep has produced mixed reactions: strong selloff on negative pivotal data, modest gains on positive early-stage updates, and occasional divergence where positive data did not translate into upside.
Over the last few months, Immutep’s clinical newsflow has centered on its LAG‑3 pipeline. A key setback came on Mar 13, 2026 when the TACTI‑004 Phase III lung cancer trial was discontinued after a futility analysis, triggering a -82.44% move. Earlier, TACTI‑004 operational progress and enrolment milestones in Dec 2025–Feb 2026 generated small or flat reactions. By contrast, prior IMP761 Phase I data on Dec 22, 2025 led to a 4.94% gain, showing investors have previously responded positively to this autoimmune program.
Historical Comparison
Past clinical-trial headlines moved IMMP an average of -16.5%. Today’s IMP761 Phase I progress contrasts with recent TACTI‑004 disappointment, highlighting diversification within the LAG‑3 pipeline.
IMP761 has advanced from earlier SAD cohorts (2.5–7 mg/kg) with PK/PD signals to completion of the full SAD up to 14 mg/kg and transition into MAD dosing, supporting future Phase II dose selection in autoimmunity.
Market Pulse Summary
This announcement highlights completion of the IMP761 single ascending dose phase up to 14 mg/kg with no dose-limiting toxicities and progression into multiple ascending dose cohorts. It follows a period marked by both positive IMP761 data and a major setback from TACTI‑004 futility. Investors may track full Phase I results at EULAR on 4 June 2026, the planned MAD completion in Q3 2026, and how this autoimmune program balances risk after recent oncology disappointments.
Key Terms
single ascending dose medical
multiple ascending dose medical
pharmacokinetics medical
immune checkpoint medical
AI-generated analysis. Not financial advice.
- Immutep has completed the single ascending dose (SAD) portion of its IMP761 study
- IMP761 was well tolerated across all dose levels
- IMP761 data and Phase I results will be presented at the EULAR conference on 4 June 2026
SYDNEY, AUSTRALIA, March 19, 2026 (GLOBE NEWSWIRE) -- Immutep Limited (ASX: IMM; NASDAQ: IMMP) (“Immutep” or “the Company”), a clinical-stage biotechnology company targeting cancer and autoimmune diseases, today announces a positive update from the placebo-controlled, double-blind first-in-human Phase I study in healthy participants evaluating IMP761, a first-in-class LAG-3 agonist antibody which enhances the physiological inhibitory function of LAG-3 on T-cell receptor signaling, potentially suppressing pathogenic T cell responses in autoimmune diseases.
The Company reported that the single ascending dose (SAD) portion of the study has been successfully completed, with dosing up to 14 mg/kg. IMP761 was well tolerated across all dose levels, and no safety concerns or dose-limiting toxicities were observed to date.
The study is currently progressing in the multiple ascending dose (MAD) portion, which is evaluating pharmacokinetics and safety across two dose levels. Completion of the MAD portion is expected in the third quarter of 2026.
“IMP761 continues to show a clear immunosuppressive effect in healthy participants challenged with a foreign antigen in an intra-dermal reaction, with durable inhibition of T-cell–mediated responses after a single administration,” said Dr Frédéric Triebel, Chief Scientific Officer, Immutep. “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 data, including Phase I results, will be presented at the European Alliance of Associations for Rheumatology (EULAR) annual congress in London, UK on 4th June 2026 at 1.30 pm UK time in a poster view session.
A LAG-3 agonist represents a novel therapeutic approach aimed at restoring immune tolerance by modulating T-cell activity, with potential applications across a range of autoimmune diseases, including rheumatoid arthritis, Type 1 diabetes, and multiple sclerosis. IMP761 is the first LAG-3 agonist antibody developed to potentially treat these large, increasingly prevalent disorders, each of which represent multi-billion-dollar markets.
By enhancing the physiological “brake” function of LAG-3 to silence dysregulated self-antigen-specific memory T cells, IMP761 is designed to target the cause of autoimmune diseases and restore balance to the immune system. LAG-3 expression on activated T cells demonstrates high specificity for disease sites, especially in tissues characterised by chronic inflammation. This distinct characteristic of the LAG-3 immune checkpoint suggests IMP761 may enable a more targeted therapeutic approach with fewer adverse effects compared to other treatments.
About IMP761
IMP761, a first-in-class immunosuppressive lymphocyte-activation gene-3 (LAG-3) agonist antibody, has the potential to address the root cause of many autoimmune diseases by specifically silencing autoimmune memory T cells that accumulate at disease sites and restoring balance to the immune system. Encouraging pre-clinical in vivo and in vitro studies show IMP761 inhibits peptide-induced T cell proliferation, activation of human primary T cells, and an antigen-specific delayed-type hypersensitivity (DTH) reaction.1 Additional preclinical data in oligoarticular juvenile idiopathic arthritis details how IMP761 led to a decrease in 48 hours in a broad spectrum of effector cytokines in coculture experiments where patients T cells are mixed with autologous synoviocytes.2 Similarly, IMP761 decreased IFNγ, interleukin-4, and tumor necrosis factor α levels in supernatants from cocultures of T cells from patients with systemic sclerosis with their autologous dermal fibroblasts.3
About Immutep
Immutep is a clinical-stage biotechnology company developing novel immunotherapies for cancer and autoimmune disease. The Company is a pioneer in the understanding and advancement of therapeutics related to Lymphocyte Activation Gene-3 (LAG-3), and its diversified product portfolio harnesses LAG-3’s ability to stimulate or suppress the immune response. Immutep is dedicated to leveraging its expertise to bring innovative treatment options to patients in need and to maximise value for shareholders. For more information, please visit www.immutep.com.
Australian Investors/Media:
Eleanor Pearson, Sodali & Co.
+61 2 9066 4071; eleanor.pearson@sodali.com
U.S. Investors/Media:
Matthew Beck, astr partners
Ph: +1 (917) 415-1750; matthew.beck@astrpartners.com
1 Angin M, Brignone C, Triebel F. A LAG-3-Specific Agonist Antibody for the Treatment of T Cell-Induced
Autoimmune Diseases. J Immunol. 2020 15;204:810-818.
2 Sag E, Demir S, Aspari M, Nielsen MA, Skejø C, Hvid M, Turhan E, Bilginer Y, Greisen S, Ozen S, Deleuran
B. Juvenile idiopathic arthritis: lymphocyte activation gene-3 is a central immune receptor in children with
oligoarticular subtypes. Pediatr Res. 2021;90:744-751.
3 Aspari, M., Greisen, S., Hvid, M., Ong, V.H., Denton, C.P., Abraham, D. and Deleuran, B. Lymphocyte
Activation Gene 3 Regulation of Profibrotic Cytokines and Type I Collagen Production in Patients With
Systemic Sclerosis. ACR Open Rheumatology, 2026 8: e70120.
FAQ
What did Immutep (IMMP) announce about IMP761 on March 19, 2026?
When will Immutep present IMP761 Phase I data at EULAR 2026 for IMMP?
What safety findings did Immutep report for IMP761 in the Phase I SAD portion?
What is the expected timeline for completion of the IMP761 MAD portion for IMMP?
What clinical effect did IMP761 show in the Phase I healthy volunteer challenge?
Does Immutep (IMMP) have patient data for IMP761 yet and what are next steps?
