Positive Initial Clinical Data Reported from Immutep’s Efti Combined with Radiotherapy and Checkpoint Inhibitor from Phase II Trial in Soft Tissue Sarcoma

Media Release

• Novel triple combination of efti with radiotherapy and anti-PD-1 therapy is well tolerated and has led to encouraging initial efficacy data in EFTISARC-NEO Phase II trial
• Four of six patients treated have very good, near-complete pathologic responses (primary endpoint of study) that are rarely observed with standard therapies
• Soft tissue sarcoma is a hard-to-treat orphan disease with poor prognosis & high unmet medical need
• Additional data from EFTISARC-NEO planned for a medical conference in H2 CY2024

SYDNEY, AUSTRALIA, May 02, 2024 (GLOBE NEWSWIRE) -- Immutep Limited (ASX: IMM; NASDAQ: IMMP) ("Immutep” or “the Company”), a clinical-stage biotechnology company developing novel LAG-3 immunotherapies for cancer and autoimmune disease, today announces initial encouraging data from EFTISARC-NEO, a Phase II investigator-initiated trial of eftilagimod alpha (efti) in combination with radiotherapy, a standard-of-care treatment, plus KEYTRUDA (pembrolizumab) for patients with soft tissue sarcoma (STS).

The EFTISARC-NEO study is the first to evaluate efti in a neoadjuvant setting, which takes place before intended surgery, and the first to combine efti with radiotherapy. Importantly, the neoadjuvant setting allows for the impact of this novel combination to be assessed in the tumour microenvironment (TME).

The triple combination has revealed no new safety findings and has been well tolerated in the first six patients who have completed the 10 weeks of treatment followed by surgery 2-3 weeks later. Initial efficacy data is very encouraging with 4 of 6 patients (67%) having near-complete responses according to EORTC-STBSDG, which measures responses via tissue pathology after surgery. These deep responses are rarely seen in STS patients with standard therapeutic approaches including radiotherapy.

Katarzyna Kozak, M.D., Ph.D., and Paweł Sobczuk, M.D., Ph.D., medical oncologists at the Department of Soft Tissue/Bone Sarcoma and Melanoma at MSCNRIO (Warsaw), and the trial’s principal investigators stated: “The initial pathologic responses from this novel combination are very encouraging and supportive of the potential synergistic effects of this new therapeutic approach. Indeed we have seen a high degree of hyalinization/fibrosis in the surgical samples which we rarely see with standard treatments. We look forward to continuing this study.”