Key Highlights

  • INSIGHT-003 trial reports mature median overall survival of 30.9 months in both the overall population (N=51) and in patients with TPS at or above 50% (N=4)
  • The 30.9-month mOS result is compared by the company to a 22.0-month mOS reported in a registrational trial of anti-PD-1 therapy combined with doublet chemotherapy in non-squamous 1L NSCLC
  • The announcement also provides an update on the TACTI-004 program, following the Phase III trial's discontinuation in March 2026 after an interim futility analysis
  • Immutep continues to develop eftilagimod alfa across a broader pipeline spanning head and neck cancer, soft tissue sarcoma, breast cancer and autoimmune disease

Immutep Limited (ASX:IMM) has issued a clinical update covering mature overall survival data from its INSIGHT-003 trial in first-line non-small cell lung cancer, together with a further update on its TACTI-004 program. The announcement, dated 13 July 2026, reports a mature median overall survival of 30.9 months in patients treated with the company's lead candidate, eftilagimod alfa, in combination with standard-of-care therapy.

INSIGHT-003 Overall Survival Data

According to the announcement, INSIGHT-003 has demonstrated a mature median overall survival of 30.9 months in both the overall study population, comprising 51 patients, and in the subgroup of patients with a Tumour Proportion Score of 50% or above, comprising four patients. Immutep states that this result continues to compare favourably to a 22.0-month median overall survival reported from a registrational trial of anti-PD-1 therapy combined with doublet chemotherapy in non-squamous first-line NSCLC, irrespective of PD-L1 expression.

INSIGHT-003 is an investigator-initiated Phase I trial conducted by the Institute of Clinical Cancer Research at Krankenhaus Nordwest in Frankfurt, evaluating eftilagimod alfa in combination with pembrolizumab and chemotherapy in non-squamous first-line NSCLC. The trial has previously reported maturing survival figures as patient follow-up has extended, with the company noting in earlier disclosures a median overall survival of 32.9 months based on a smaller, less mature patient subset. The update reported in this announcement reflects a larger patient base with continued follow-up.

Context for the TACTI-004 Update

The announcement also provides an update on TACTI-004, the company's Phase III trial evaluating eftilagimod alfa in combination with pembrolizumab and chemotherapy as first-line therapy for advanced or metastatic NSCLC. TACTI-004 was a randomised, double-blind, placebo-controlled study conducted in collaboration with MSD, designed to enrol approximately 756 patients across more than 150 sites in over 25 countries, with progression-free survival and overall survival as dual primary endpoints.

In March 2026, Immutep disclosed that the Independent Data Monitoring Committee for TACTI-004 had recommended discontinuation of the trial following a planned interim futility analysis, concluding that the treatment combination was unlikely to meet its primary endpoints. Enrolment was halted at that time, and the company commenced an orderly wind-down of the study, including patient follow-up and site close-out, alongside an internal review of the trial data and its root causes. The company has previously stated that this outcome was unexpected given eftilagimod alfa's performance in other studies, including INSIGHT-003, which tested a similar combination in the same non-squamous 1L NSCLC setting.

Broader Pipeline and Company Background

Immutep describes itself as a late-stage biotechnology company developing immunotherapies for cancer and autoimmune disease, built around Lymphocyte Activation Gene-3, or LAG-3, biology. Its lead candidate, eftilagimod alfa, is a MHC Class II agonist designed to activate antigen-presenting cells and stimulate a broader anti-cancer immune response. Beyond the NSCLC programs, the company has ongoing studies of eftilagimod alfa in head and neck squamous cell carcinoma through TACTI-003, in soft tissue sarcoma through EFTISARC-NEO, and in metastatic breast cancer through AIPAC-003.

The company also has an autoimmune disease program centred on IMP761, a first-in-class LAG-3 agonist antibody, which has reported favourable safety data from an ongoing Phase I study in healthy volunteers. Immutep holds a collaboration with MSD relating to combination use of eftilagimod alfa with pembrolizumab, and has separately entered into licensing arrangements covering markets outside North America, Europe, Japan and Greater China.

Financial Position

Immutep has previously disclosed a cash and term deposit position in the order of A$110 million, which the company has said provides a runway extending into the first half of calendar year 2028, a period that was extended following the discontinuation of TACTI-004 and the associated reduction in trial-related expenditure. The company has also flagged cost-reduction measures as it winds down the TACTI-004 study and reassesses its capital allocation priorities across the remaining pipeline.

Market Context

The discontinuation of TACTI-004 in March 2026 followed a period in which the trial had progressed through enrolment milestones, including confirmation in February 2026 that the study had reached 50% of its target enrolment. The reversal from an actively enrolling registrational trial to a discontinued study within a short period has previously drawn scrutiny from investors and, according to public reporting, has been the subject of separate shareholder litigation relating to prior disclosures about the trial's progress. This context forms part of the backdrop against which the company's continuing NSCLC-related disclosures, including the INSIGHT-003 update in this announcement, are being assessed by the market.

Conclusion

The 13 July 2026 announcement combines a further maturation of favourable survival data from the earlier-stage INSIGHT-003 trial with continued disclosure relating to the discontinued TACTI-004 Phase III program. For a company whose near-term registrational strategy in NSCLC centred on TACTI-004, the trial's discontinuation in March 2026 represents a material change in the pipeline's risk profile, and the ongoing root-cause review of that outcome remains a relevant reference point for how investors interpret newer data such as the INSIGHT-003 results. The broader pipeline, spanning head and neck cancer, sarcoma, breast cancer and autoimmune disease, continues to progress alongside this NSCLC update.