Abstract 1044P
Background
Despite the wide use of immunotherapy in the treatment of solid tumours, it is effective only in 20 - 40 % of patients according to histopathological type. The aim of our project is to predict response to immunotherapy based on a comprehensive analysis of the tumour, its microenvironment, and the host.
Methods
To date, we have prospectively enrolled 60 patients with advanced or metastatic solid tumours who were treated with anti-PD-1/L1 antibodies. We perform complex molecular characterization of the tumour and the host environment. Tumour tissue is assessed by IHC staining for different immune cell subpopulations (CD3+, CD8+, CD4+, CD45RO+, FoxP3+) and markers (PD-L1, Tim-3, Granzyme B, IDO1, IFN-γ, MMR proteins). TMB will be evaluated by whole-exome sequencing. Within peripheral blood cells, we perform descriptive immunoprofiling of baseline immune regulators and effectors and their dynamics during immunotherapy.
Results
Here we present a preliminary analysis of descriptive immunoprofiling in 22 patients (14 melanoma, 5 NSCLC, 1 renal, 1 bladder cancer), median age 69 years, and 16 men. Patients were stratified into 1/ responder (achieved a complete or partial response, R) or 2/ non-responder group (stabilization or disease progression, NR). Median PFS in the R and NR group was 17.0 and 4.7 months, respectively. Median OS in R was not reached, in NR group was 14.8 months. We performed descriptive immunoprofiling of peripheral blood immune regulators and effectors and their dynamics during immunotherapy. We observed significantly higher baseline (prior to therapy) T cell count ( p = 0.008) and proportion of CD8+ cytotoxic T-cells (p = 0.013) in responders. There was no significant difference in CD4+, ALC (absolute lymphocytes count) and regulatory T cells (Tregs). Dynamics of cell-based immune parameters (effector CD8+, Treg, M-MDSC, neutrophil-lymphocyte Ratio – NLR, ALC) were evaluated using peripheral blood immunograms.
Conclusions
According to our early preliminary results, the descriptive immunoprofiling of peripheral blood could be used as an integrated biomarker to predict response in patients treated with immunotherapy. Supported by Ministry of Health of the Czech Republic, grant nr. NV18-03-00339.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Ministry of Health of the Czech Republic, grant nr. NV18-03-00339.
Disclosure
S. Borilova: Advisory/Consultancy: Bristol-Myers Squibb; Travel/Accommodation/Expenses: Merck & Co. All other authors have declared no conflicts of interest.