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Humam Kadara



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    MA11 - Immunotherapy in Special Populations and Predictive Markers (ID 135)

    • Event: WCLC 2019
    • Type: Mini Oral Session
    • Track: Immuno-oncology
    • Presentations: 1
    • Now Available
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      MA11.09 - Increased Frequency of Bystander T Cells in the Lungs Is Associated with Recurrence in Localized Non-Small Cell Lung Cancer (Now Available) (ID 955)

      14:00 - 15:30  |  Author(s): Humam Kadara

      • Abstract
      • Presentation
      • Slides

      Background

      Non-small cell lung cancer (NSCLC) exhibits a high mutational burden. As a result, patients afflicted by this tumor type experience greater responses to immune checkpoint blockade. This is largely due to the ability of T cells to destroy tumor cells on the basis of antigens recognized by their T cell receptor (TCR). However, the lungs are exposed to carcinogens and pathogens which can also trigger a T cell response distinct from cancer. Therefore, a better understanding of the T cell repertoire in the lungs is needed to improve upon the success of current immunotherapies in NSCLC.

      Method

      We obtained peripheral blood, tumors, and adjacent uninvolved lungs from a cohort of 236 early stage NSCLC patients. Whole exome sequencing, RNA microarray, immunohistochemistry (CD3, CD4, CD8, CD57, CD68, FoxP3, CD45RO, GzmB, PD-1, and PD-L1) and T cell repertoire sequencing were performed in NSCLC patients and lungs from organ donors and COPD patients. Antigen specificity was predicted using the Grouping of Lymphocyte Interactions by Paratope Hotspot (GLIPH) algorithm. Single cell TCR and RNA sequencing as well as sequencing of the virome are underway.

      Result

      Clonality was associated with CD8 T cells (r=0.31; p=0.0003), GzmB (r=0.29; p=0.001) and IFN-γ (r=0.52; p<0.0001) production as well as with tumor mutational burden (r=0.19; p=0.015), HLA-B (r=0.29; p=0.0005) and β2-m expression (r=0.20; p=0.018). Patients with classical EGFR mutations exhibited lower T cell clonality (p=0.003) even after adjustment for TMB, highlighting the impact of this driver mutation on the T cell response. Surprisingly, clonality was higher in the adjacent uninvolved lung than tumor (p<0.0001), suggesting an active antigenic response outside the tumor. Comparison of the composition of the T cell repertoire between the uninvolved lung and tumor revealed 57% of the top 100 T cells in the tumor were also found in the adjacent normal lung, highlighting certain parallels in the ongoing antigenic responses. Deeper analysis suggested that shared T cells may have been reactive against mutations shared between the normal lung and tumor (r=0.23, p=0.028) or viruses (p<0.0001). Accordingly, patients with a more reactive T cell repertoire outside the tumor (i.e. bystanders) exhibited shorter disease-free survival (p=0.036) suggesting these responses against shared mutations and/or viruses may detract from the anti-tumor T cell response.

      Conclusion

      Our findings highlight the importance of understanding the specificity of the T cell repertoire in the lungs in patients with NSCLC treated with immunotherapy. As a high proportion of bystander T cells appear to reside in the lungs, their reactivation could contribute to the impaired responses and/or increased toxicity observed in certain patients with NSCLC treated with immunotherapy.

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    P1.04 - Immuno-oncology (ID 164)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Immuno-oncology
    • Presentations: 2
    • Moderators:
    • Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
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      P1.04-07 - Immune Suppressive Microenvironment and Highly Clonal Concordance of TCR Repertoire in Brain Metastases from Non-Small Cell Lung Cancer (ID 2018)

      09:45 - 18:00  |  Author(s): Humam Kadara

      • Abstract
      • Slides

      Background

      The tumor immune microenvironment (TIME) of lung cancer brain metastasis is largely unexplored. We performed immune profiling and sequencing analysis of paired resected primary tumors and brain metastases of non-small cell lung carcinoma (NSCLC).

      Method

      TIME profiling of archival formalin-fixed and paraffin embedded specimens of paired primary tumors and brain metastasis from 39 patients with surgically resected NSCLCs was performed using a 770 immune gene expression panel (NanoString Technologies, Seattle, WA) and by T cell receptor beta repertoire (TCRß) sequencing (Adaptive Biotechnologies, Seattle, WA). Immunohistochemistry was performed for validation. Targeted sequencing was performed to catalog hot spot mutations in cancer genes (ThermoFisher Scientific, Waltham, MA).

      Result

      Somatic hot spot mutations were mostly shared between both tumor sites (28/39 patients; 71%). We identified 161 differentially expressed genes, indicating inhibition of dendritic cell maturation, Th1, and leukocyte extravasation signaling pathways, in brain metastases compared to primary tumors (p < 0.01). The proinflammatory cell adhesion molecule vascular cell adhesion protein 1 was significantly suppressed in brain metastases compared to primary tumors. Brain metastases exhibited lower T cell and elevated macrophage infiltration compared with primary tumors (p < 0.001). T cell clones were expanded in 64% of brain metastases compared with their corresponding primary tumors. Further, while TCR repertoires were largely shared between paired brain metastases and primary tumors, T cell densities were sparse in the metastases.

      Conclusion

      We present findings that the TIME in brain metastases is immunosuppressed when compared to matched primary tumors in NSCLC patients, and that thus may help guide immunotherapeutic strategies for NSCLC brain metastases.

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      P1.04-79 - CD73 Expression in Lung Adenocarcinomas and Immunological and Molecular Associations (ID 2412)

      09:45 - 18:00  |  Author(s): Humam Kadara

      • Abstract

      Background

      Immune checkpoints inhibitors (ICI), in monotherapy or combination with chemotherapy, are the standard of care for lung adenocarcinoma (ADC) patients. Unfortunately, only a restricted number of patients will respond to ICI. Combination therapies such as CD73 inhibitors, are being studied with the goal to achieve synergic effects. CD73 is a membrane-bound protein with immunosuppressive functions. We previously reported that higher immune cell infiltration was associated mainly to CD73 basolateral (BL) expression, in this abstract, we show the correlation of CD73 expression at luminal (L) and BL membrane of ADC malignant cells (MCs), with annotated clinicopathological characteristics, immune and molecular biomarkers.

      Method

      CD73 IHC expression (clone D7F9A) was evaluated in 106 archived ADCs from patients that underwent surgical treatment without neoadjuvant therapy between February 1999 and February 2012 at MD Anderson Cancer Center (Houston, Texas, USA). We scored % and H-score of CD73 expression at the luminal (L) and basolateral (BL) membrane, we calculated the Total (T) CD73 as the average of L and BL, and classified ADCs in three groups: ‘T High’ (TH) (upper quartile for all tumors); ‘T Low’ (TL); ‘T Neg’ (TN) (<1%). We correlated T, L and BL expression and the three groups with clinicopathological characteristics, mutational status of KRAS and EGFR, TP53, STK11 and Tumor mutation burden (TMB), and cell densities of CD3, CD8, CD68, CD45RO, FOXP3, and Granzyme B, and PD-L1 expression (clone E1L3N) in MCs.

      Result

      T CD73 expression was found in 76%; BL in 60% and L in 57%; among ADCs with luminal membrane present (n=72), L CD73 was present in 83%. T+ and L+ expression was more frequent in never smokers (p=0.02 and p=0.003). Also higher frequency of L+ was found in older patients (>65) (p=0.01), tumors with non-solid histology patterns (p<0.001), EGFR mutation (p=0.048), non-mutated p53 (p=0.002), negative PD-L1 (p=0.03), and low TMB (<10 mut/MB) (p=0.001). Higher levels of L expression were found in KRAS mutated tumors (p=0.049). Higher BL expression positively correlated with p53 mutated tumors (p=0.038), PD-L1+ in MCs (p=<0.0001), and higher TMB (p=0.040).

      Our group analyses revealed that TH and TN were associated with ADCs from patients with >30 pack-year of smoking history (p=0.04), presence of any-solid histology pattern (p=0.03), p53 mutation (p= 0.005) and higher TMB (p=0.003) compared with TL. TH also had higher frequency of PD-L1+ tumors, and a higher cell density of CD3 (p=0.0001), CD8 (p=0.001), CD68 (p=0.048), CD45RO (p=0.036), FOXP3 (p=0.053), and Granzyme B (p=0.024) compared to TL and TN. TN showed higher frequency of STK11 mutation (p=0.034).

      Conclusion

      Based on the CD73 expression we defined subsets of lung adenocarcinomas that have distinct histological, molecular and immunological characteristics that may play a role in the response to ICI.

      Our characterization could help us to understand patient’s response to ICI, and identify patients that could potentially benefit from combination therapies.