Posted: 11 November
Immutep Limited, a clinical-stage biotechnology company developing novel LAG-3 immunotherapies for cancer and autoimmune disease, announced compelling new clinical data from the TACTI-002 all-comer PD-L1 Phase II trial evaluating Immutep’s lead product candidate, eftilagimod alpha (“efti” or “IMP321”) in combination with MSD’s (Merck & Co., Inc., Rahway, NJ., USA) anti-PD-1 therapy KEYTRUDA® (pembrolizumab) in 114 patients with 1L NSCLC.
The new data was presented today in a late-breaking abstract oral presentation (Abstract #1470) at the 37th Annual Society of Immunotherapy of Cancer (SITC) Meeting by Wade T. Iams, MD, Assistant Professor of Medicine, Vanderbilt-Ingram Cancer Center Division of Hematology/Oncology. Today’s presentation followed the abstract data that had been discussed at the SITC 2022 Press Conference on 8 November 2022.
Key Findings from TACTI-002 Phase II Trial in 1L NSCLC Patients (N=114) – Data cut-off date 1 July 2022:
- Primary Endpoint – The primary endpoint of overall response rate (ORR) 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 (ASCO) 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 (TPS) of >1%, 1-49%, >50%, and <1%, respectively.
- Secondary Endpoints – Despite ~75% of patients in the trial having PD-L1 TPS <50%, promising results were achieved in secondary endpoints of interim median Progression Free Survival (PFS) and Disease Control Rate (DCR):
- Median PFS was 6.6 months overall and 9.3 months for patients with a PD-L1 TPS of ≥1%, an increase from 8.4 months as reported at ASCO 2022.
- DCR of 79.3% for patients with TPS of >1% and improved for all PD-L1 groups except TPS <1%.
- 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 ≥1%.
- 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 (N=40, 37.5% ORR & 82.5% DCR) and non-squamous histologies (N=72, 40.3% ORR & 66.7% DCR)
- Pharmacodynamic Analysis – First pharmacodynamic data from efti plus pembrolizumab combination shows statistically significant increase in IFN-ƴ 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 (monocytes, activated CD8 T cells) and CXCL10 serum levels, compared to baseline. The increase in these pharmacodynamic markers (monocytes, CD8 T cells and CXCL10) 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 (1) in line with the data reported at ASCO 2022, (2) consistent with the discontinuation rate for pembrolizumab monotherapy, and (3) below historical discontinuation rates from other immunotherapy-immunotherapy & immunotherapy-chemotherapy combination trials.
