Key Highlights

  • Root cause analysis of TACTI-004 identified structural differences between the 2,000L and 200L scale efti Manufacturing batches as a potential contributor to the trial's unexpected outcome.
  • Immutep will refocus registration-directed efti development on HNSCC patients with CPS <1 and neoadjuvant soft tissue sarcoma, with study start targeted for H2 CY27.
  • IMP761, an agonist anti-LAG-3 antibody for autoimmune diseases, is now a co-priority alongside efti and will be presented at the ACR Convergence in November 2026.
  • Cash and term deposits of A$48.50 million at September 30, 2026, with runway expected into H1 CY28.

Immutep Limited (ASX: IMM; NASDAQ: IMMP), a clinical-stage biotechnology company targeting cancer and autoimmune diseases, reported activities for the first quarter of FY2027, ending September 30, 2026. The quarter was defined by significant strategic decisions stemming from the earlier discontinuation of TACTI-004, the company's Phase III trial of eftilagimod alfa (efti) in first-line non-small cell lung cancer. Root cause analysis identified potentially critical manufacturing differences between the efti used in TACTI-004 and earlier successful studies, prompting a strategic refocus of the clinical program.

TACTI-004 Root Cause Analysis Findings

Immutep's detailed root cause analysis of the early discontinuation of TACTI-004 identified structural differences between the efti used in the Phase III trial and the efti manufactured at 200L scale used in prior successful Phase I and Phase II studies. Specifically, subtle differences in N-glycan structure were identified between the 2,000L scale batches used exclusively in TACTI-004 and the ten GMP batches manufactured at 200L scale used in successful earlier trials including TACTI mel, TACTI-002 and INSIGHT-003. The company believes this discrepancy may be relevant given the markedly different immune activation profile observed in TACTI-004 relative to prior studies. Based on these findings, Immutep has contracted a new manufacturing run of efti at 200L scale.

The root cause analysis explicitly ruled out clinical factors such as protocol design, treatment arm imbalances or safety findings, as well as trial execution factors such as randomization or general conduct, as explanations for TACTI-004's unexpected outcome. This conclusion directs attention squarely toward manufacturing as the key variable to address in future studies.

Strategic Refocus on HNSCC and Sarcoma

Based on the root cause analysis findings and interactions with the FDA, Immutep is refocusing potential registration-directed development of efti on two indications: head and neck squamous cell carcinoma (HNSCC) patients with a Combined Positive Score (CPS) below 1, and the neoadjuvant setting of soft tissue sarcoma (STS). These indications were selected based on compelling clinical data from prior trials, FDA regulatory designations, unmet medical need and market potential. Study start for the new registration-directed trials is targeted for the second half of calendar year 2027, subject to strategy finalization, regulatory interactions and manufacturing timelines.

IMP761 Elevated to Co-Priority

Alongside the efti program, Immutep elevated IMP761 — its agonist anti-LAG-3 antibody being developed for autoimmune diseases — to a co-priority within its pipeline. IMP761 represents a differentiated approach to autoimmune disease treatment via the LAG-3 pathway and was selected to be the subject of a late-breaking poster at the American College of Rheumatology (ACR) Convergence in November 2026, signaling the company's intent to raise the scientific profile of this asset.

Immutep enters the remainder of FY2027 with a refined clinical strategy informed by the manufacturing root cause analysis, cash of A$48.50 million that is expected to fund operations into H1 CY28, and a pipeline anchored in the efti and IMP761 programs. The company's ability to execute on the new registration-directed development timeline and secure the necessary manufacturing, regulatory and financial resources will be the key milestones for Stakeholders to monitor in the year ahead.