Immutep announces clinical results from Phase II trial of eftilagimod alpha

Immutep (IMMP) announces new clinical data from the TACTI-002 all-comer PD-L1 Phase II trial evaluating Immutep’s lead product candidate, eftilagimod alpha in combination with MSD’s (MRK) anti-PD-1 therapy KEYTRUDA in 114 patients with 1L NSCLC. The new data was presented today in a late-breaking abstract oral presentation at the 37th Annual Society of Immunotherapy of Cancer Meeting by Wade T. Iams, MD, Assistant Professor of Medicine, Vanderbilt-Ingram Cancer Center Division of Hematology/Oncology. Key Findings from TACTI-002 Phase II Trial in 1L NSCLC Patients – Data cut-off date 1 July 2022: Primary Endpoint – The primary endpoint of overall response rate by iRECIST increased to 40.4% in the TACTI-002 all-comer PD-L1 Phase II trial in 1L NSCLC. ORR improved across all PD-L1 status groups by central assessment compared with data reported at the American Society of Clinical Oncology’s Annual Meeting in June 2022. Encouraging ORR of 48.3%, 44.7%, 55.0%, and 31.3% was established in patients expressing a PD-L1 Tumor Proportion Score of greater than1%, 1-49%, greater than50%, and less than1%, respectively. Secondary Endpoints – Despite ~75% of patients in the trial having PD-L1 TPS less than50%, promising results were achieved in secondary endpoints of interim median Progression Free Survival and Disease Control Rate: Median PFS was 6.6 months overall and 9.3 months for patients with a PD-L1 TPS of greater than or equal to1%, an increase from 8.4 months as reported at ASCO 2022. DCR of 79.3% for patients with TPS of greater than1% and improved for all PD-L1 groups except TPS less than1%. Of note, efti in combination with pembrolizumab has been granted Fast Track designation in combination with pembrolizumab in 1L NSCLC patients expressing PD-L1 TPS greater than or equal to1%. Duration of Response – Deep and durable responses, with interim median DoR of 21.6 months, compares favourably to historical controls, including anti-PD-1 therapy combined with chemotherapy: Response onset is early, and responses are long-lasting; Less than 10% of responding patients progress within 6 months. Tumour Response by Tumor Type – Comparable ORR & DCR for squamous and non-squamous histologies. Pharmacodynamic Analysis – First pharmacodynamic data from efti plus pembrolizumab combination shows statistically significant increase in IFN- and CXCL10 serum biomarkers for systemic TH1 response, further substantiating efti’s unique systemic stimulation of the immune system. This is similar to the biomarker analysis from Immutep’s randomized AIPAC Phase IIb trial in metastatic breast cancer, which showed efti in combination with chemotherapy significantly increased the number of circulating immune cells and CXCL10 serum levels, compared to baseline. The increase in these pharmacodynamic markers was significantly linked to improved OS in the efti group, but not in the placebo group in the AIPAC trial. Safety – Treatment with efti plus pembrolizumab is safe and well-tolerated with no new safety signals, continuing the combination’s favourable safety profile to date that is consistent with previously reported studies for pembrolizumab monotherapy. Only 9.6% of patients have discontinued due to adverse events related to study treatment, which is in line with the data reported at ASCO 2022, consistent with the discontinuation rate for pembrolizumab monotherapy, and below historical discontinuation rates from other immunotherapy-immunotherapy & immunotherapy-chemotherapy combination trials. The combination of efti plus pembrolizumab is showing encouraging efficacy in 1L NSCLC patients across all PD-L1 status groups, including in PD-L1 low and PD-L1 negative patients. The combination is very well tolerated, and the low discontinuation rate is consistent with pembrolizumab monotherapy. The data support continued late-stage development in this indication.