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Carmen Behrens



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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): Carmen Behrens

      • 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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    OA15 - Targeted Agents and Immunotherapy for Small Cell Lung Cancer (ID 152)

    • Event: WCLC 2019
    • Type: Oral Session
    • Track: Small Cell Lung Cancer/NET
    • Presentations: 1
    • Now Available
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      OA15.04 - Genomic and TCR Intratumor Heterogeneity of Small-Cell Lung Cancer by Multiregion Sequencing: An Association with Survival (Now Available) (ID 1458)

      14:30 - 16:00  |  Author(s): Carmen Behrens

      • Abstract
      • Presentation
      • Slides

      Background

      Small cell lung cancer (SCLC) is an aggressive cancer. Although sensitive to initial therapy, recurrence is almost inevitable. The molecular mechanisms underlying recurrence are unknown. We have previously demonstrated that complex genomic and T cell receptor (TCR) intratumor heterogeneity (ITH) was associated with increased risks of relapse in non-small cell lung cancers (NSCLC). Genomic ITH and TCR architecture of SCLC and its clinical impact have not been well studied, largely due to lack of tumor specimens as surgery is rarely used to treat SCLC.

      Method

      We performed multiregion whole-exome sequencing and TCR sequencing of 49 tumor samples from 18 resected limited-stage SCLCs to delineate the immunogenomic ITH of SCLC. We compared the results to those in NSCLC and assessed the association of genomic and TCR attributes with patient’s survival.

      Result

      On average, 544 mutations/sample were detected. The median proportion of trunk mutations (mutations identified in all regions within the same tumors) was 80.4% versus 70% in NSCLC (TRACERx, Jamal-Hanjani, NEJM, 2017, p=0.08) and all TP53 and RB1 mutations were trunk mutations, suggesting these mutations were early events during carcinogenesis of this cohort of SCLCs. A higher non-synonymous tumor mutational burden (TMB) was associated with a higher T cell density (infiltration) in the tumor (r=0.46, p=0.005). Compared to the TCR repertoire of NSCLC (Reuben, WCLC, 2017), these SCLC tumors demonstrated significantly lower T-cell density (0.05 versus 0.24, p<0.0001), richness (diversity, 1,043 versus 3,666, p<0.0001) and clonality (reactivity, average 0.02 versus 0.15, p<0.0001) despite similar non-synonymous TMB (average 187 in SCLC versus 176 mutations/sample in NSCLC). Only 0.2% to 14.6% of T cells were detectable across all regions from the same tumors, suggesting substantial TCR ITH. Jaccard index (JI), a parameter quantifying TCR ITH was significantly lower in SCLC than in NSCLC (0.06 versus 0.1, p<0.0001) implying higher level of TCR ITH in SCLC than NSCLC. Interestingly, higher T-cell density, richness or clonality appeared to be associated with lower risk of recurrence numerically. Furthermore, higher TCR JI (less degree of ITH) was associated with significantly longer overall survival (HR=0.15, p=0.04).

      Conclusion

      Limited-stage SCLC tumors have distinct TCR repertoire and genomic ITH architecture. Overall, SCLC may have a more pronounced immunosuppressive microenvironment and higher level of TCR repertoire ITH than NSCLC. Nevertheless, higher degree of T cell infiltration and clonal expansion as well as more homogeneous T cell response may be associated with more favorable clinical outcome in patients with limited-stage SCLC.

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    P1.04 - Immuno-oncology (ID 164)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Immuno-oncology
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/08/2019, 09:45 - 18:00, Exhibit Hall
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      P1.04-79 - CD73 Expression in Lung Adenocarcinomas and Immunological and Molecular Associations (ID 2412)

      09:45 - 18:00  |  Presenting Author(s): Carmen Behrens

      • 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.

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    P2.04 - Immuno-oncology (ID 167)

    • Event: WCLC 2019
    • Type: Poster Viewing in the Exhibit Hall
    • Track: Immuno-oncology
    • Presentations: 1
    • Moderators:
    • Coordinates: 9/09/2019, 10:15 - 18:15, Exhibit Hall
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      P2.04-19 - Neoadjuvant Chemotherapy Is Associated with Immunogenic Cell Death and Increased T Cell Infiltration in Early-Stage NSCLC (ID 1122)

      10:15 - 18:15  |  Author(s): Carmen Behrens

      • Abstract
      • Slides

      Background

      Recent success using immune checkpoint blockade (ICB) in the metastatic setting has raised the need to understand the immune microenvironment (IME) in early-stage disease. Moreover, pre-clinical evidence suggests that cytotoxic agents can modulate this IME. A recent study conducted by our group showed that non-small cell lung cancer (NSCLC) patients who received neoadjuvant chemotherapy followed by surgery (NCT), as compared to patients who received upfront surgery (US), had higher densities of CD3+ lymphocytes and CD68+ tumor-associated macrophages (TAMs). CD3+CD4+ lymphocytes and TAMs also correlated with better clinical outcomes. In this study, we explored the relationships between NCT and the IME by harvesting tumor samples of multiple surgical NSCLC cohorts.

      Method

      The PROSPECT microarray database was queried in NCT (n=45) and US (n=200) patients to investigate differentially expressed genes related to immunogenic cell death (ICD), susceptibility to CD8+ T cell and NK cell cytotoxicity, priming of antigen presenting cells, immunosuppressive enzymes and intra-tumoral cytokines. Available data from the ImmunogenomiC prOfiling of NSCLC (ICON) and other surgical NSCLC cohorts was evaluated to determine: 1) differential immune profiling using FACS (NCT=17; US=39) and multiplex IHC imaging (NCT=10; US=72); 2) plasma circulating cytokines (NCT=18; US=73); 3) tumor mutational burden (TMB) (NCT=40; US=61). Participants who received NCT or US were excluded according to these criteria: 1) concurrent treatment in addition to NCT; 2) sarcomatoid and small cell histologies; 3) clinical or pathological TNM Stage 4 disease; 4) synchronous malignancies other than lung.

      Result

      PROSPECT NCT patients expressed increased damage-associated molecular pattern (DAMP) genes (HSPA2, HSPA4, HSPE1, and S100A2; p<0.05) and T cell-related chemotaxis and antigen presentation genes (CXCR7, CD1A; p<0.05). Concordantly, the ICON cohort FACS results showed that NCT patients display increases in: 1) infiltration of CD8+ T cells (p=0.004); 2) proliferating Ki67+CD8+ T cells (p=0.02); 3) tissue resident memory CD8+CD103+ (p=0.02) and CD4+CD103+ non-Treg cells (p=0.01). Trends from the ICON multiplex IHC also highlighted increases in CD8+ T cells (p=0.09), CD20+ cells (p=0.08), as well as PD-L1+ malignant cells (p=0.08) and PD-L1+ TAMs (p=0.08) in NCT patients, the latter finding being supported by increased circulating MCP-1 (p=0.03). TMB was similar between NCT and US groups (p=0.912).

      Conclusion

      Our data provides the first evidence of ICD (i.e., increased DAMP gene expression) following NCT in human early-stage NSCLC. Furthermore, our data highlights the association of NCT with a favorable IME (i.e., increased T cell infiltration), supporting the rationale of NCT and ICB combinations in localized NSCLC.

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