Immutep Limited Wins FDA Orphan Drug Designation For Cancer Drug Eftilagimod Alfa In Soft Tissue Sarcoma

Immutep Limited, a clinical-stage biotechnology company developing immunotherapies for cancer and autoimmune diseases, has announced that the United States Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to eftilagimod alfa (efti) for the treatment of soft tissue sarcoma (STS). STS is a rare and heterogeneous group of cancers with significant unmet medical need and limited treatment options.

The Orphan Drug Designation program is intended to support the development of therapies for rare diseases affecting fewer than 200,000 patients in the United States. It provides a range of potential development and regulatory incentives, including tax credits for clinical research, exemption from certain regulatory fees, assistance with clinical study design, and up to seven years of market exclusivity in the U.S. upon regulatory approval.

The designation for efti is supported by encouraging clinical evidence, particularly from the investigator-initiated Phase II EFTISARC-NEO trial. In this study, eftilagimod alfa was evaluated in combination with radiotherapy and KEYTRUDA® (pembrolizumab) in the neoadjuvant setting for patients with resectable soft tissue sarcoma. Among 38 evaluable patients, the trial met its primary endpoint by achieving a median tumour hyalinization and fibrosis of 51.5%. This result significantly exceeded the pre-specified target of 35% and was substantially higher than historical outcomes of approximately 15% observed with radiotherapy alone.

The study results were observed across multiple sarcoma subtypes and were further supported by translational data indicating immune system activation consistent with efti’s mechanism of action. Importantly, the treatment was reported to have a favourable safety profile, with no delays to planned surgical procedures, reinforcing its potential suitability in a neoadjuvant treatment setting.

Marc Voigt, Chief Executive Officer of Immutep, stated that the FDA’s decision to grant Orphan Drug Designation highlights the potential of efti for patients with soft tissue sarcoma, a rare and difficult-to-treat cancer. He noted that the company is currently conducting a comprehensive review and analysis following the discontinuation of its Phase III TACTI-004 trial, and that the findings from this review will help guide decisions regarding future clinical development. He added that the Orphan Drug Designation, together with the positive Phase II EFTISARC-NEO results, provides a potential pathway toward advancing efti into a late-stage study in the neoadjuvant setting for STS.

Overall, the designation represents an important regulatory milestone for Immutep, supporting the continued development of eftilagimod alfa as a potential immunotherapy option for patients with soft tissue sarcoma and reinforcing its broader clinical potential in oncology.