Interim results from INSIGHT-003 suggest Immutep’s efti could reshape first-line treatment for non-small cell lung cancer
Immutep (ASX:IMM) has reported encouraging interim data from its ongoing INSIGHT-003 trial, revealing high response and disease control rates in patients with advanced non-small cell lung cancer (NSCLC). The results highlight the promise of its immunotherapy candidate, eftilagimod alpha (efti), in combination with Merck’s KEYTRUDA (pembrolizumab) and standard chemotherapy.
The triple therapy achieved a 60.8% overall response rate and a 90.2% disease control rate in first-line NSCLC, according to RECIST 1.1 criteria. Notably, nearly all participants had low levels of PD-L1 expression—around 92% had tumour proportion scores below 50%, including 43% with scores below 1%, a group that has historically been difficult to treat.
Compared to historical benchmarks, the results show significant gains across all PD-L1 expression levels. For patients with PD-L1 <1%, response rates rose to 54.5%—well above the 32.3% seen with previous anti-PD-1 and chemotherapy regimens. Those with mid-range PD-L1 (1–49%) saw a 64% response rate, and even patients with high expression levels (>50%) reported a 75% rate.
Immutep CEO Marc Voigt said the results reinforce confidence in efti’s potential as a new standard of care, noting consistent performance across multiple trials. The company’s pivotal Phase III trial, TACTI-004, uses the same treatment combination.
Safety data from INSIGHT-003 continues to be favourable, with no new adverse signals. Additional data from the study is expected to be presented later in the year.
INSIGHT-003 is being run by the Frankfurt Institute of Clinical Cancer Research in Germany and is a third arm of the broader Phase I INSIGHT trial. The study’s focus on low-PD-L1 patients addresses a major gap in current cancer therapies.
Efti, a first-in-class MHC Class II agonist, is designed to activate both the innate and adaptive immune system. It has also received FDA fast-track designation for use in both NSCLC and head and neck cancer.
