Immutep revealed positive final data from Part C of the TACTI-002 Phase II trial at the ASCO 2023 Annual Meeting in Chicago, US.
The trial evaluated eftilagimod alpha (efti), a soluble LAG-3 protein and first-in-class MHC Class II agonist, in combination with MSD’s (Merck) anti-PD-1 therapy Keytruda (pembrolizumab) in second line head and neck squamous cell carcinoma (2L HNSCC).
The combination treatment was investigated in patients unselected for PD-L1 expression (N=37), with disease progression on, or after, platinum-based therapy (± cetuximab).
The combination of efti plus pembrolizumab led to an encouraging overall response rate (ORR) of 29.7% and Complete Response (CR) rate of 13.5% in 2L HNSCC patients, regardless of PD-L1 expression.
Responses were seen across all PD-L1 subgroups. A promising ORR of 38.5% and 60%, median Overall Survival (mOS) of 12.6 and 15.5 months, and 12-month Overall Survival (OS) rate of 52.0% and 66.7%, were seen in patients with a PD-L1 CPS of ≥1 and a PD-L1 CPS ≥20, respectively.
Results compare favourably to reported results from a registrational trial of anti-PD-1 monotherapy in the same patient population.
Dr Bernard Doger of START Madrid-FJD, Fundación Jiménez Díaz University Hospital and TACTI-002 and TACTI-003 investigator, said: “The high overall and complete response rates for patients in Part C of the TACTI-002 trial, taken alongside their long-lasting persistence with the median Duration of Response not reached, provides a strong foundation for the ongoing TACTI-003 trial in first line HNSCC.
“The combination of the MHC Class II agonist, efti, with pembrolizumab is now showing an encouraging overall survival benefit in two different cancer indications.”
