Key Highlights
- Immutep shares climbed 101% Wednesday following FDA Orphan Drug Designation approval for eftilagimod alfa (efti).
- The designation applies to soft tissue sarcoma treatment, a condition affecting under 200,000 Americans annually.
- Advantages include market exclusivity for seven years, tax incentives, waived fees, and enhanced regulatory assistance.
- Phase II EFTISARC-NEO trial results supporting the FDA determination showed successful achievement of primary goals across 38 participants.
- Recent discontinuation of TACTI-004 Phase III study allows the company to preserve resources, pushing financial runway past Q2 2027.
Australian biotechnology firm Immutep experienced remarkable market performance Wednesday when shares more than doubled following confirmation that the U.S. Food and Drug Administration awarded Orphan Drug Designation to eftilagimod alfa, the company’s primary cancer therapeutic candidate.
The Australia Securities Exchange-listed biotechnology company witnessed shares surge 101.3% to reach A$0.079 throughout Wednesday’s trading session.
The regulatory designation encompasses efti’s application for soft tissue sarcoma (STS) cases, representing a rare malignancy with significant unmet therapeutic requirements across the United States.
Orphan Drug Designation delivers substantial advantages: specialized regulatory consultation, access to tax incentives, exemption from certain administrative fees, and seven years of commercial exclusivity upon final approval.
Supporting evidence for the FDA determination came from the Phase II EFTISARC-NEO clinical study. This investigation evaluated efti combined with radiation therapy and Merck’s KEYTRUDA (pembrolizumab) among patients diagnosed with resectable soft tissue sarcoma prior to surgical intervention.
Among 38 assessed participants, the investigation achieved its primary objective. Researchers documented a median tumour hyalinization/fibrosis rate reaching 51.5%, substantially exceeding the predetermined threshold of 35% and significantly outperforming the historical standard of approximately 15% associated with radiation therapy alone.
Findings demonstrated consistency across diverse sarcoma classifications. The treatment demonstrated a favorable safety record, with zero reported delays to scheduled surgical procedures.
TACTI-004 Program Cessation
The encouraging FDA determination follows closely after Immutep discontinued its TACTI-004 Phase III clinical program during early March. That investigation evaluated efti for first-line non-small cell lung cancer therapy.
An Independent Data Monitoring Committee advised terminating the study based on futility findings. The organization currently manages TACTI-004 closure through systematic procedures.
Immutep indicated the program termination should significantly extend available financial resources beyond earlier projections pointing to Q2 2027.
Development Programs and Financial Position
Beyond soft tissue sarcoma and lung cancer applications, Immutep operates five LAG-3 focused programs. Among these initiatives, IMP761 currently advances through Phase I evaluation targeting autoimmune conditions.
The organization recorded a net deficit of A$61.4 million throughout the 2025 fiscal year, compared with A$42.7 million during 2024.
Operating as a pre-revenue biotechnology enterprise, Immutep continues requiring capital infusions to maintain research and development activities.
Strategic collaborations with leading pharmaceutical corporations, including Merck (MSD), provide crucial support for advancing the development pipeline.
The EFTISARC-NEO clinical data, serving as the foundation for Wednesday’s FDA designation, incorporated translational research findings aligned with efti’s therapeutic mechanism — immune system activation through LAG-3 pathway engagement.

