FDA Confirms 30 mg Dose for Efti, US Phase III Trial Sites Now Opening

FDA Alignment Marks Key Milestone for Efti

Immutep Limited, a Sydney-based immunotherapy specialist, has announced a significant regulatory achievement with the US Food and Drug Administration (FDA) confirming 30 mg as the optimal biological dose for its lead oncology candidate, efti (eftilagimod alfa). This confirmation follows the successful completion of the FDA’s Project Optimus requirements, a regulatory initiative aimed at refining dose selection to improve drug development outcomes.

Christian Mueller, Immutep’s Chief Development Officer, highlighted the strategic importance of this milestone, describing it as a major de-risking event that strengthens the foundation for future Biological License Applications (BLAs). The FDA’s endorsement not only validates the dosing strategy but also accelerates the clinical development timeline for efti, a first-in-class immunotherapy designed to activate the immune system against cancer.

Advancing the TACTI-004 Phase III Trial

With the dosing question settled, Immutep is now progressing the registrational TACTI-004 (KEYNOTE-F91) Phase III trial, which evaluates efti in combination with Merck’s KEYTRUDA (pembrolizumab) and chemotherapy. This trial targets first-line treatment of advanced or metastatic non-small cell lung cancer (NSCLC), irrespective of PD-L1 expression levels, a patient population with significant unmet medical needs.

The announcement confirms that clinical sites in the United States are in the process of opening, signaling the imminent expansion of the trial’s global footprint. This development is crucial for enrolling a diverse patient cohort and generating robust data to support regulatory submissions and eventual market approval.

Efti’s Unique Mechanism and Broader Potential

Efti operates as an MHC Class II agonist, directly stimulating antigen-presenting cells to orchestrate a broad immune response against tumors. This mechanism distinguishes it from other immunotherapies by engaging both the innate and adaptive immune systems, potentially enhancing efficacy when combined with checkpoint inhibitors like KEYTRUDA.

Beyond NSCLC, efti is under investigation for multiple solid tumors including head and neck squamous cell carcinoma, soft tissue sarcoma, and breast cancer. Its favorable safety profile supports combination therapies, which are increasingly becoming the standard of care in oncology.

Strategic Implications and Next Steps

Immutep’s progress with efti represents a critical juncture for the company, reducing clinical and regulatory risks that have historically challenged immunotherapy developers. The FDA’s dose confirmation not only streamlines ongoing trials but also enhances investor confidence ahead of future licensing applications.

Looking ahead, the market will be watching closely for patient recruitment milestones, interim trial data, and eventual regulatory filings. Success in these areas could position efti as a valuable addition to the lung cancer treatment landscape, where competition remains intense but unmet needs persist.