Immutep announces new data from TACTI-002 / KEYNOTE-798 Phase II trial

Immutep Limited announces excellent new clinical data from the TACTI-002 / KEYNOTE-798 Phase II trial evaluating eftilagimod alpha, a soluble LAG-3 protein and first-in-class MHC Class II agonist, in combination with MSD’s anti-PD-1 therapy KEYTRUDA as first-line treatment for patients with previously untreated unresectable or metastatic non-small cell lung cancer, NSCLC. The updated TACTI-002 data, with a cut-off date of August 15, 2023 and a median follow up of over 2 years, was presented by Dr. Enric Carcereny, Catalan Institute of Oncology, Badalona, Spain, during a Mini Oral session at ESMO Congress 2023 on Saturday, October 21st. Key takeaways include: Promising Overall Survival, Overall Response Rate, Progression Free Survival, and Duration of Response are visible across all PD-L1 subgroups, which clearly differentiates efti in combination with KEYTRUDA from other chemo-free immuno-oncology (IO) combinations for first-line treatment of NSCLC. A significant overall survival benefit was achieved, with a 35.5-month median Overall Survival in patients with TPS greater than or equal to1%, 23.4-month mOS in TPS 1-49%, and mOS not yet reached in TPS greater than or equal to50%. Notably, the mOS in TPS greater than or equal to1% was attained with central assessment of PD-L1 and a larger patient group with central + local assessment of PD-L1, and the 35.5-month mOS compares very favourably to standard-of-care IO, IO-IO, IO-chemo, and IO-IO-chemo therapies; Exceptional durability and quality of responses are increasingly evident with strong overall survival and progression free survival rates across patients expressing PD-L1. The 3-year OS rates are 45.6%, 31.0%, and 63.6% in TPS greater than1%, TPS 1-49%, and TPS greater than50%, respectively. The 12-month PFS rates are 46.8%, 42.1%, and 55.0% for TPS greater than1%, TPS 1-49%, and TPS greater than50%, respectively. The entire patient population regardless of PD-L1 expression (N=114) showed encouraging efficacy with 20.2-month mOS, 21.6-month mDoR, and a 36-month OS rate of 36% despite ~75% of patients having negative or low PD-L1 expression.