Start Your Search
MA15 - Immunotherapy Prediction (ID 400)
- Event: WCLC 2016
- Type: Mini Oral Session
- Track: Chemotherapy/Targeted Therapy/Immunotherapy
- Presentations: 1
MA15.06 - Predictive Value of Measuring Somatic Mutations and Tumor Infiltrating Lymphocytes for PD-1 Axis Therapy in Non-Small Cell Lung Cancer (NSCLC) (ID 6255)
14:20 - 15:50 | Author(s): E. Kaftan
Diverse factors have been associated with clinical benefit to PD-1 axis blockers in NSCLC including PD-L1 protein expression by immunohistochemistry and increased mutation load/predicted class-I neoantigens. However, the association and predictive value of the tumor genomic landscape, composition of the tumor immune microenvironment and T-cell function remain unclear.
We performed whole exome DNA sequencing and multiplexed quantitative immunofluorescence (QIF) for T-cells in pre-treatment FFPE samples from 45 NSCLC patients treated with PD-1 axis blockers (alone or in combination) in our institution. Genomic analysis was used to evaluate the mutational load and predicted class-I neoantigens. Multiplexed QIF-based immunoprofiling was used to measure the level of CD3+ tumor infiltrating lymphocytes (TILs), in situ T-cell proliferation (Ki-67 in CD3+ cells) and T-cell activation (Granzyme-B in CD3+ cells). We studied the association between the tumor somatic mutations, predicted neoantigens, T-cell infiltration/function and clinical benefit /survival.
Increased mutational load was positively associated with predicted class-I neoantigens, variants in DNA-repair genes, smoking and absence of activating mutations in EGFR; but not associated with the level of CD3+ T-cells, T-cell proliferation (Ki-67 in CD3+ cells) and function (Granzyme-B in CD3+ cells). Increased mutations and candidate class-I neoantigens were significantly associated with response to therapy (P=0.02 and 0.03, respectively), but not with overall survival at 3-years (median cut-point, log rank P=0.92 and 0.80, respectively). Higher CD3 positivity was not associated with response to therapy (P=0.17), but was significantly associated with overall survival (median cut-point, log rank P=0.03). Regardless of the mutational load and candidate neoantigen content, elevated CD3 with low Ki-67/Granzyme-B in CD3 predicted longer survival after PD-1 axis blockade than high CD3/high Ki-67/Granzyme-B in CD3, or low T-lymphocyte infiltration.
Increased somatic mutations are associated with smoking and response to PD-1 agents, but not with tumor T-cell infiltration/activation and overall survival. Regardless of the mutational load, increased T-cell infiltration using QIF is significantly associated with longer survival after PD-1 axis blockade in NSCLC. The subgroup of NSCLC with the highest potential of benefit to immune reinvigoration using PD-1 axis blockade comprise tumors with elevated lymphocyte infiltration but low in situ activation/proliferation.
Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.
P3.02c - Poster Session with Presenters Present (ID 472)
- Event: WCLC 2016
- Type: Poster Presenters Present
- Track: Advanced NSCLC
- Presentations: 1
- Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)
P3.02c-070 - Combination Immunotherapy with MEK Inhibitor for Treatment of Kras-Mutant Lung Cancer in Animal Model (ID 5503)
14:30 - 15:45 | Author(s): E. Kaftan
Lung cancer remains a major cause of cancer mortality. Malignant lesions are normally endogenously corrected by the immune surveillance system. However, tumors evade this immunity by inducing immunosuppressive microenvironments during cancer progression. Recent studies demonstrate that multiple cancer types, including melanoma, lung, kidney, bladder, and stomach, respond to immune checkpoint inhibitors, such as PD-L1 and PD-1 with 11-30% response rates and durable responses. However, a substantial number of patients still fail to respond to immunotherapy and the refractory mechanisms are largely unknown. In this study, we focus on KRas-driven lung cancers, as there are no clinically effective targeted drugs available for treating this type of lung cancer.
We examined tumor infiltrated immune cells using FACS, CyTOF2, and Immunostaining of lung sections during the progression of lung tumors in KRas mutation and p53 knockout-driven lung cancer mouse models; KRas[G12D/+];p53[-/-] (KP). Using this mouse model, we determined the anti-cancer efficacy of combined inhibition of MEK and immune checkpoint molecules.
We demonstrate that there is a gradual increase in the number of myeloid derived suppressor cells (MDSC) and that the combination of either anti-PD-1 or anti-PD-L1 antibody along with a MEK inhibitor shows anticancer efficacy in these animal models. These combinations, in comparison to either single agent alone, effectively blocks the growth of subcutaneously injected syngeneic mouse lung cancer cells in immune competent transgenic KP mice, significantly increasing the survival rates: 37.5% (for anti-PD-1 antibody and MEK inhibitor), 62.5% (for anti-PD-L1 antibody and MEK inhibitor) vs. 0% single agents or control at the end of treatment. We find that the tumors in the control treated group harbor a substantial number of immune cells, including PD-L1 expressing MDSC.
The combination treatment with either an anti-PD-1 or anti-PD-L1 antibody along with a MEK inhibitor dramatically modulates the composition and the activity of tumor infiltrated immune cells. Tumors in the combination treatment group show a significant decrease in PD-L1 expressing MDSC in comparison with control tumors. Additionally, combination treatment blocks PD-L1 activity of the infiltrated PD-L1 expressing MDSC in malignant tumors and thus lead to improved survival. These results point to a potential therapeutic opportunity for currently untargetable KRas-driven lung cancers.