Stock Surges Amid FDA Orphan Drug Recognition for Rare Cancer Treatment

Summary

• Immutep shares surged by more than 101% on Wednesday following the FDA’s grant of Orphan Drug Designation for eftilagimod alfa (efti).
• The designation is for soft tissue sarcoma, a rare malignancy that impacts fewer than 200,000 people across the United States.
• Perks of this status include seven years of market exclusivity, tax incentives, fee waivers, and enhanced regulatory guidance.
• The FDA’s move was prompted by Phase II EFTISARC-NEO trial results, which reached its primary goal in a group of 38 patients.
• This news follows the recent suspension of the TACTI-004 Phase III study, a decision expected to push the company’s cash runway past the second quarter of 2027.

(SeaPRwire) –   The stock price of Immutep more than doubled on Wednesday after the Australian biotechnology firm was granted Orphan Drug Designation (ODD) by the U.S. Food and Drug Administration for its lead cancer immunotherapy, eftilagimod alfa.

Immutep Limited, IMMP

The ASX-listed biotech saw its shares jump 101.3% to reach A$0.079 during Wednesday’s session.

The FDA’s ODD status applies to the use of efti in treating soft tissue sarcoma (STS), a rare cancer type with significant unmet clinical needs in the U.S.

Securing ODD offers several advantages: specialized regulatory advice, potential tax credits, exemption from user fees, and seven years of exclusive marketing rights if the therapy receives final approval.

The FDA’s decision was informed by data from the Phase II EFTISARC-NEO study. This trial evaluated efti in combination with radiotherapy and Merck’s KEYTRUDA (pembrolizumab) for patients with resectable soft tissue sarcoma prior to surgery.

Among 38 evaluable participants, the study achieved its primary endpoint, recording a median tumor hyalinization/fibrosis rate of 51.5%. This result significantly outperformed the 35% target and the historical benchmark of roughly 15% typically seen with radiotherapy alone.

The findings were consistent across various sarcoma subtypes. Additionally, the safety profile was reported as favorable, with no interruptions to scheduled surgical procedures.

Winding Down TACTI-004

The positive regulatory update comes shortly after Immutep suspended its TACTI-004 Phase III trial in early March. That study was investigating efti as a first-line treatment for non-small cell lung cancer.

Following a recommendation from an Independent Data Monitoring Committee based on futility, the company is now conducting an orderly wind-down of the TACTI-004 trial.

Immutep stated that the termination of this study is expected to extend its financial runway well beyond the previously projected date of Q2 2027.

Pipeline and Financial Status

Beyond its efforts in STS and lung cancer, Immutep is managing five LAG-3-focused programs. One such candidate, IMP761, is currently in a Phase I trial for the treatment of autoimmune diseases.

The company reported a net loss of A$61.4 million for the 2025 fiscal year, an increase from the A$42.7 million loss seen in 2024.

As a pre-commercial entity, Immutep continues to require additional capital to fund its research and development activities.

The firm maintains collaborations with major pharmaceutical companies, including Merck (MSD), to support the advancement of its clinical pipeline.

The EFTISARC-NEO trial data, which underpinned Wednesday’s FDA designation, included translational evidence consistent with efti’s mechanism of action—activating the immune system via LAG-3.