FDA grants Immutep (NASDAQ: IMMP) orphan drug status in soft tissue sarcoma
Rhea-AI Filing Summary
Immutep Limited reports that the U.S. FDA has granted Orphan Drug Designation to its immunotherapy candidate eftilagimod alfa (efti) for treating Soft Tissue Sarcoma, a rare cancer with significant unmet need. Orphan status can provide regulatory support, potential tax credits, fee exemptions, and seven years of market exclusivity upon approval.
The designation is supported by Phase II EFTISARC-NEO trial data in 38 evaluable patients, where efti with radiotherapy and KEYTRUDA achieved a median tumour hyalinization/fibrosis of 51.5%, beating the pre-set 35% target and historical ~15% with radiotherapy alone, with immune activation signals and a favourable safety profile.
Positive
- FDA Orphan Drug Designation for efti in Soft Tissue Sarcoma adds regulatory support, potential tax credits, fee exemptions, and up to seven years of U.S. market exclusivity upon approval, materially enhancing the asset’s development and commercial profile in a rare cancer with significant unmet medical need.
- Strong Phase II EFTISARC-NEO data for efti combination therapy showed median tumour hyalinization/fibrosis of 51.5% in 38 evaluable Soft Tissue Sarcoma patients, surpassing the 35% pre-specified target and historical ~15% with radiotherapy alone, with immune activation signals and a favourable safety profile.
Negative
- None.
Insights
FDA orphan status validates efti’s STS potential and supports late-stage development.
The FDA’s Orphan Drug Designation for eftilagimod alfa in Soft Tissue Sarcoma is a meaningful regulatory milestone. Orphan status can bring fee exemptions, potential tax credits, and seven years of market exclusivity after approval, improving the economic case for further development.
The decision is anchored in Phase II EFTISARC-NEO data: efti plus radiotherapy and KEYTRUDA produced median tumour hyalinization/fibrosis of 51.5% in 38 evaluable patients, above the 35% target and roughly 15% seen with radiotherapy alone. Immune activation consistent with efti’s mechanism and a favourable safety profile strengthen the rationale.
Management notes they are conducting a comprehensive review after discontinuing the Phase III TACTI-004 trial, and that the orphan designation, together with the EFTISARC-NEO results, may provide a direct path toward a late-stage neoadjuvant study in resectable Soft Tissue Sarcoma, subject to future strategic decisions.
Key Figures
Key Terms
Orphan Drug Designation regulatory
Soft Tissue Sarcoma medical
neoadjuvant setting medical
Phase II medical
Lymphocyte Activation Gene-3 (LAG-3) medical
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 6-K
REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Date as April 15, 2026
Commission File Number 001-35428
IMMUTEP LIMITED
(Exact Name as Specified in its Charter)
N/A
(Translation of Registrant’s Name)
Level 32, Australia Square
264 George Street, Sydney
NSW 2000, Australia
(Address of principal executive office)
Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.
Form 20-F ☒ Form 40-F ☐
Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐
Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐
Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.
Yes ☐ No ☒
If “Yes” is marked, indicated below the file number assigned to the registrant in connection with Rule 12g3-2(b): Not applicable.
EXHIBIT INDEX
| Exhibit |
Description of Exhibit | |
| 99.1 |
Immutep Receives FDA Orphan Drug Designation for Eftilagimod Alfa in Soft Tissue Sarcoma | |
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.
Date: April 15, 2026
| IMMUTEP LIMITED | ||
| By: | /s/ Marc Voigt | |
| Name: | Marc Voigt | |
| Title: | Chief Executive Officer | |
Exhibit 99.1
Immutep Receives FDA Orphan Drug Designation for
Eftilagimod Alfa in Soft Tissue Sarcoma
SYDNEY, AUSTRALIA – April 15, 2026 – Immutep Limited (ASX: IMM; NASDAQ: IMMP) (“Immutep” or “the Company”), a clinical-stage biotechnology company targeting cancer and autoimmune diseases, today announces that the United States Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) for eftilagimod alfa (“efti”) for the treatment of Soft Tissue Sarcoma (STS), a rare cancer with significant unmet medical need.
The FDA’s Orphan Drug Designation program is designed to encourage development of therapies for rare diseases affecting fewer than 200,000 people in the United States. Benefits of ODD may include regulatory support, potential tax credits, fee exemptions, and seven years of market exclusivity upon approval.
This designation recognises the potential therapeutic relevance of efti in STS, supported by encouraging clinical data from the investigator-initiated Phase II EFTISARC-NEO trial which has been evaluating efti in combination with radiotherapy and KEYTRUDA® (pembrolizumab) in the neoadjuvant setting in patients with resectable soft tissue sarcoma. In 38 evaluable patients, the study met its primary endpoint, demonstrating a median tumour hyalinization/fibrosis of 51.5%, significantly exceeding the pre-specified target of 35% and historical benchmarks of ~15% with radiotherapy alone.1
These results were observed across multiple sarcoma subtypes and were supported by translational data showing immune activation consistent with efti’s mechanism of action, with a favourable safety profile and no delays to planned surgery.2
CEO of Immutep, Marc Voigt said: “We are pleased that the FDA has recognised the potential of efti for patients with soft tissue sarcoma, a rare and difficult to treat cancer. As previously communicated, the Company is currently undertaking a comprehensive review and analysis following the discontinuation of its Phase III TACTI-004 trial and the outcome will influence the decision regarding any potential future clinical trial with efti. The FDA’s designation, based on very encouraging data from the EFTISARC-NEO trial, provides us with a potential direct step forward into a late-stage study in the neoadjuvant setting for STS.”
About Immutep
Immutep is a clinical-stage biotechnology company developing novel immunotherapies for cancer and autoimmune diseases. The Company is a pioneer in the understanding and advancement of therapeutics related to Lymphocyte Activation Gene-3 (LAG-3), and its diversified product portfolio harnesses LAG-3’s ability to stimulate or suppress the immune response. Immutep is dedicated to leveraging its expertise to bring innovative treatment options to patients in need and to maximise value for shareholders. For more information, please visit www.immutep.com.
1. ESMO Congress 2025 Proffered Paper presentation, “EFTISARC-NEO: A phase II study of neoadjuvant eftilagimod alpha, pembrolizumab and radiotherapy in patients with resectable soft tissue sarcoma”.
2. CTOS 2025 Annual Meeting Oral Presentation, “Primary endpoint and translational correlates from EFTISARC-NEO: Phase II trial of neoadjuvant eftilagimod alfa (efti), pembrolizumab and radiotherapy in patients with resectable soft tissue sarcoma”.
KEYTRUDA® is a registered trademark of Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA.
Australian Investors/Media:
Eleanor Pearson, Sodali & Co.
+61 2 9066 4071; eleanor.pearson@sodali.com
U.S. Investors/Media:
Matthew Beck, astr partners
Ph: +1 (917) 415-1750; matthew.beck@astrpartners.com
This announcement was authorised for release by the CEO of Immutep Limited.