Immutep (NASDAQ:IMMP), a clinical-stage biotechnology company developing LAG-3 immunotherapies, announced today that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to its lead product candidate, eftilagimod alfa (efti), for the treatment of soft tissue sarcoma (STS).
This regulatory milestone provides several key incentives, including potential tax credits for qualified clinical trials, waivers of FDA user fees, and—most significantly—seven years of market exclusivity upon potential regulatory approval.
The FDA's decision was underpinned by promising clinical data from the investigator-initiated Phase II EFTISARC-NEO trial.
The study evaluated the safety and efficacy of efti in combination with radiotherapy and the anti-PD-1 therapy pembrolizumab (Keytruda®) in 38 evaluable patients with resectable STS.
Results showed a median tumor hyalinization/fibrosis rate of 51.5%, which substantially exceeded the study’s pre-specified primary endpoint target of 35%.
This figure is also more than triple the historical benchmark of approximately 15% typically observed with radiotherapy alone.
Crucially, the EFTISARC-NEO trial reported that the combination was well-tolerated and did not cause any delays to planned surgeries.
Translational data from the study further confirmed immune activation consistent with efti’s mechanism of action as an MHC Class II agonist.
Marc Voigt, CEO of Immutep, noted that the ODD status provides a clear regulatory framework for the company as it evaluates a potential direct path into a late-stage study in the neoadjuvant setting for STS.