Immutep announces investigator-initiated Phase II trial evaluating LAG-3 candidate eftilagimod alpha (efti) in soft tissue sarcoma

• Expansion of the efti clinical development pipeline with a new Phase II setting
• Efti Phase II trial awarded EUR 1.5M (AUD 2.2M) in funding as part of the Polish Medical Research Agency program funded by the Polish government
• Collaboration with the Maria Sklodowska-Curie National Research Institute to evaluate efti in triple combination with Keytruda (pembrolizumab) and radiotherapy, followed by surgery
• First patient dose anticipated by H1 2023

Sydney, Australia, September 6, 2022 – Immutep Limited (ASX: IMM; NASDAQ: IMMP) ("Immutep” or “the Company”), is pleased to announce it has signed a Material Transfer Agreement (“Agreement”) with the Maria Skłodowska-Curie National Research Institute of Oncology in Warsaw, Poland to enable an investigator-initiated open label Phase II clinical trial. The trial will evaluate Immutep’s lead product candidate efti in combination with pembrolizumab and radiotherapy in the neoadjuvant setting (prior to surgery) in up to 40 patients with select soft tissue sarcoma (STS).

Subject to the necessary approvals from the Polish State Institute for Drug Control and ethics committee, the dosing of the first patient is anticipated in the first half of calendar year 2023, with initial interim data expected in the fourth quarter of CY 2024.

Under the Agreement, the Maria Sklodowska-Curie National Research Institute of Oncology will primarily fund the study with an approved grant from the Polish government of EUR 1.5M (AUD 2.2M) awarded by the Polish Medical Research Agency program. Immutep will provide efti at no cost to the Maria Skłodowska-Curie National Research Institute of Oncology and will technically support the trial. The trial will be led by Principal Investigators, Dr. Katarzyna Kozak, M.D. PhD., and Pawel Sobczuk, M.D., medical oncologists at the Department of Soft Tissue/Bone Sarcoma and Melanoma at the Maria Skłodowska-Curie National Research Institute of Oncology.

Immutep CEO, Marc Voigt, said: "We were delighted to be approached by Dr Pawel Sobczuk and Dr Katarzyna Kozak to form this collaboration with the Maria Sklodowska-Curie National Research Institute of Oncology to explore the potential of efta combination with pembrolizumab and radiotherapy in soft tissue sarcoma. We thank the Polish government for granting EUR 1.5M in non-dilutive cash funding for this trial. Recurrence and lack of deep and durable responses are challenges with the limited standards of care available for this rare and difficult-to-treat disease. Efti's novel mechanism of action offers potential to enhance anti-tumours responses for the patients. The latest expansion of the efti pipeline is further evidence of the increased interest from a variety of interested parties to investigate the broad potential of efta to improve patient outcomes in yet another cancer indication and treatment regimen."

Immutep CSO and CMO, Dr Frederic Triebel said: “Efti stimulates the immune system through a differentiated mechanism that targets LAG-3-driven activation of antigen-presenting cells. By working upstream of T-cells, efti has potential to generate a broad and robust anti-tumour immune response even in the immunosuppressed tumour microenvironment of soft tissue sarcomas. Therefore, we are very pleased to be collaborating with our colleagues at the Maria Skłodowska-Curie National Research Institute of Oncology.”

Maria Sklodowska-Curie National Research Institute of Oncology, Medical Oncology Fellow and Co-Principal Investigator, Dr. Paweł Sobczuk said: "The need for new approaches in this rare and aggressive disease is evident by the still dismal responses with no current standards of care including surgery, radiotherapy and chemotherapy. Clinical data in other solid tumours suggest that efti can synergize with radiotherapy and pembrolizumab for robust responses across PD-L1 status, supporting the potential of this combination to mount effective immunity against aggressive malignancies like soft tissue sarcoma and replace the need for chemotherapy.”

Efti’s Mechanism of Action

Efti is a first-in-class antigen presenting cell (APC) activator currently being developed by Immutep for the treatment of cancer. Efti binds to antigen presenting cells such as dendritic cells, monocytes and macrophages via MHC II molecules. This activates the APCs causing them to become professional antigen presenting cells, thereby presenting antigen to the adaptive immune system. This leads to activation and proliferation of CD4+ (helper) and CD8+ (cytotoxic) T cells. Thus, the aim of efti is to 'push the gas' on the body’s innate and adaptive immune systems making it a suitable candidate to evaluate not only for the treatment of cancer, but also for the treatment of infectious diseases.