Immutep Limited announced 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-N 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.

The trial is primarily funded with an approved grant from the Polish government awarded by the Polish Medical Research Agency program. The study's primary endpoint is the pathologic response rate (defined as percentage of tumor hyalinization/fibrosis) to the treatment assessed at the time of surgical resection. The lower the number of viable tumor cells and the higher the extent of hyalinization/fib fibrosis observed in patients' tumor specimens will determine the therapy's effectiveness.

The trial is ongoing with 14 patients now enrolled and additional clinical data is planned to be presented at a medical conference in second half of 2022. Soft Tissue Sarcoma (STS), an orphan disease, represents a high unmet medical need with a poor prognosis. The incidence of STS varies in different regions, with approximately 23,400 cases annually and a crude incidence of 4.7 per 100,000 in Europe, according to the RARECARE project.

In the United States, the number of new cases is estimated to be 13,400 annually with 5,140 deaths, according to the American Cancer Society.