Immutep Limited (NASDAQ:IMMP) on Tuesday announced that investigators in its Phase 2 trial observed promising preliminary long-term outcomes for its lead candidate, alongside securing a new U.S. patent that shields its combination therapies through 2038.
Clinical investigators evaluated eftilagimod alfa, known as efti, paired with Merck & Co. Inc.’s (NYSE:MRK) Keytruda (pembrolizumab) and radiotherapy as a neoadjuvant therapy for resectable soft tissue sarcoma.
According to the study abstract, the combination demonstrated favorable results that justify advancing the treatment into registration-focused clinical trials.
Encouraging Disease-Free Survival Outcomes
In 38 evaluable patients with a median follow-up of 19.1 months, the EFTISARC-NEO trial yielded an 81.1% disease-free survival (DFS) rate at 12 months.
The interim secondary findings also revealed a 94.1% local recurrence-free survival rate and an 86.2% distant metastasis-free survival rate as of the April 30, 2026, data cutoff.
Researchers observed consistent DFS outcomes regardless of patient tumor stage, grade, or histological subtype.
The team indicated that elevated post-treatment tumor hyalinization and high tumor-infiltrating lymphocyte levels may correlate with improved survival, though monitoring for DFS and overall survival remains ongoing.
The trial previously met its primary endpoint, recording 51.5% median tumor hyalinization and fibrosis, surpassing the 35% protocol target and standard 15% historical radiotherapy benchmarks.
Furthermore, the U.S. Food and Drug Administration granted efti Orphan Drug Designation for STS in April 2026, following positive quality-of-life findings at the ESMO Congress 2026.
US Patent Office Grants New Protection
Separately, on Tuesday, the United States Patent and Trademark Office issued a patent to Immutep.
The grant extends protection for efti combinations with PD-1 inhibitors, covering durvalumab, atezolizumab, avelumab, and BMS-936559.
The patent represents the fifth U.S. grant within this family and expires on March 23, 2038, including an 806-day adjustment.
Immutep has also filed a continuation application to protect additional embodiments.
IMMP Price Action: Immutep shares were up 6.65% at $3.52 at the time of publication on Wednesday, according to Benzinga Pro data.
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