Efti is Immutep’s proprietary soluble LAG-3 clinical stage candidate that is a first-in-class antigen presenting cell (APC) activator for the treatment of cancer, capitalising on LAG-3’s unique characteristics to stimulate both innate and adaptive immunity. Through its high affinity for a subset of MHC II ligands, efti binds to and activates APCs (e.g. dendritic cells, monocytes) leading to expansion and proliferation of CD8+ (cytotoxic) T cells, CD4+ (helper) T cells, dendritic cells, NK cells, and monocytes. It also upregulates the expression of key biological molecules like IFN-ƴ and CXCL10 that further boost the immune system’s ability to fight cancer.

Efti is under evaluation for a variety of solid tumours including non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), and HER2–neg/low metastatic breast cancer. Its favourable safety profile enables various combinations, including with anti-PD-[L]1 immunotherapy and/or chemotherapy. Efti has received Fast Track Designation in 1st line HNSCC and in 1st line NSCLC from the United States Food and Drug Administration (FDA).

EOC Pharma has the exclusive development rights for efti in the territory of Greater China (namely mainland China, Hong Kong SAR, Macao SAR, and Taiwan). Immutep received a $1 million milestone from EOC Pharma in January 2018 and is eligible to receive additional milestone payments and sales-based royalties.

Immutep retains development rights for efti in all other countries worldwide and has the option of out-licensing it for further geographic territories.

IMP761 is a first-in-class immunosuppressive agonist antibody to LAG-3, which has the potential to address the root cause of autoimmune diseases by specifically silencing autoimmune memory T cells that accumulate at the disease site and which express LAG-3 as an “exhaustion marker” after being repeatedly stimulated with dominant self-peptides.

In early 2019, Immutep reported encouraging pre-clinical results from its studies with IMP761. The in vivo studies showed that IMP761 decreases inflammatory T cell infiltration induced by intra-dermal injection of an antigen. These findings were published in the Journal of Immunology in January 2020. Additional pre-clinical research findings from a juvenile arthritis ex-vivo model were published in Pediatric Research in May 2021. In these studies, IMP761 was shown to decrease effector T cell cytokine secretion.

In December 2022, Immutep announced that a GMP compliant manufacturing process had been established for IMP761, and in July 2024 IMP761 received regulatory clearance for a first-in-human Phase I study. The first participant in the Phase I clinical trial was successfully dosed in August 2024.

Our third product candidate is IMP731, a depleting (cytotoxic) antibody that is intended to destroy LAG-3 expressing activated T cells involved in autoimmunity.

Our fourth product candidate is LAG525, an antagonist (blocking) antibody targeting the LAG-3 molecule on T cells with potential applications in the treatment of cancer. It is designed to block the negative signal that may stop T cells from responding to the cancer. LAG525 is a humanized form of IMP701, a pioneering anti-LAG-3 antibody targeting LAG-3 designed by Immutep that was licensed to CoStim Pharmaceuticals, or CoStim, under an exclusive license and collaboration agreement. In February 2014, CoStim became a wholly owned subsidiary of Novartis. LAG525 is being evaluated by Novartis in Phase I and Phase II clinical trials for the treatment of cancer.

Novartis has full responsibility for the development of the antibody program and Immutep is eligible to receive development-based milestone payments and royalties.