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Marta Casarrubios



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    FP12 - Tumor Biology and Systems Biology - Basic and Translational Science (ID 188)

    • Event: WCLC 2020
    • Type: Posters (Featured)
    • Track: Tumor Biology and Systems Biology - Basic and Translational Science
    • Presentations: 1
    • Moderators:
    • Coordinates: 1/28/2021, 00:00 - 00:00, ePoster Hall
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      FP12.09 - Molecular Insight into NADIM Clinical Trial: Potential Immune Biomarkers of Pathological Response for NSCLC Patients. (ID 3552)

      00:00 - 00:00  |  Author(s): Marta Casarrubios

      • Abstract
      • Presentation
      • Slides

      Introduction

      Many studies have demonstrated that chemo-immunotherapy is a promising approach for NSCLC patients but still exists a lack of prediction biomarkers of survival. We have recently showed that pathological response is a surrogate of progression free survival (PFS) including infiltrating immune cells as potential biomarker of pathological response in NADIM clinical trial (Provencio et al., 2020. Lancet Oncology, in press).

      New biomarkers in peripheral blood are being described, focused on the immune system response. Preliminary data was presented at WCLC 2019 however additional results are included in this report. Here we describe the effect of chemo-immune neoadjuvant treatment on resectable NSCLC stage III patients’ immune system and describe blood biomarkers that could help to identify responders to this combination therapy.

      Methods

      Peripheral mononuclear cells (PBMCs) and plasma from NADIM clinical trial patients before and after chemo-immune neoadjuvant treatment were used. Phenotyping and activation levels of immune cell populations were analyzed by flow cytometry, focused on CD4 T cells, CD8 T cells, T cells NK like and NK cells. Moreover, characterization of the immune response was evaluated by a cytokine array.

      Clinical evaluation of pathological response, classified patients in 3 groups, complete (CPR, 0% tumor cells), major (MPR, <10% viable tumor) and incomplete (IPR, >10% viable tumor). Wilcoxon and Kruskall-Wallis statistic tests were used.

      Results

      Even though we have previously described a decrease of T lymphocytes on tissue after treatment, we do not see these changes on blood. Thus, percentages of PBMCs (T cells, B cells, NK cells and macrophages) did not vary after neoadjuvant treatment. However, lower levels of activated CD4 T cells and NK cells were observed. Interestingly, this decrease was exclusively statistically significant for patients who achieved a CPR, but no differences were observed for MPR or IPR. As expected, detection of PD1+ cells after neoadjuvant Nivolumab (anti-PD1) treatment was almost completely abrogated, however, a trend for higher PD1+ cell proportions was observed in patients achieving CPR at diagnosis.

      Furthermore, many cytokines involved in immune response and described as putative biomarkers for immunotherapy in NSCLC as IL-2, IL-15, IL-6, IL-13 or IFN-gamma, among others, were decreased after neoadjuvant treatment. Notably, stratifying by pathological responses, this decrease was statistically significant only for non-complete responses.

      Conclusion

      The analysis of immune cell markers on blood samples could be a source for potential surrogate markers of pathological response to neoadjuvant treatment on NSCLC patients.

      Similarly, to what occurs in tissue, CPRs showed differences compared to MPR or IPR in some blood markers, both at the cellular and cytokine level. Thus, after treatment, patients achieving CPRs do not seem to reduce their levels of cytokines such as IL-2, IL-15, IL-6, IL-13 or IFN-g associated with anti-tumor response, but they do reduce their levels of activated CD4 and NK cells

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    P60 - Tumor Biology and Systems Biology - Basic and Translational Science - Immune Bio (ID 198)

    • Event: WCLC 2020
    • Type: Posters
    • Track: Tumor Biology and Systems Biology - Basic and Translational Science
    • Presentations: 2
    • Moderators:
    • Coordinates: 1/28/2021, 00:00 - 00:00, ePoster Hall
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      P60.07 - TMB and Selected Mutations in Resectable Stage IIIA NSCLC Patients Receiving Neo-Adjuvant Chemo-Immunotherapy from NADIM Trial (ID 2142)

      00:00 - 00:00  |  Author(s): Marta Casarrubios

      • Abstract
      • Slides

      Introduction

      Tumor Mutational Burden (TMB) assessment and identification of specific mutations associated to anti-PD1 blockade therapy resistance have become a novel approach to predict the clinical benefit to anti-PD1/PDL1 therapy. However, the clinical relevance of these parameters in terms of pathological response and PFS in neo-adjuvant chemo-immunotherapy has not been established. To answer this question we analysed samples from the NADIM study (NCT03081689), in which resectable stage IIIA NSCLC patients were treated with neoadjuvant chemo-immunotherapy with Nivolumab.

      Methods

      Pretreatment TMB, defined as the number of nonsynonymous variants (missense and nonsense single nucleotide variants (SNVs)), plus insertion and deletion variants (INDELs) detected per megabase (Mb) of exonic sequence, was estimated from 27 patients that had enough diagnostic material for next generation sequencing using the Oncomine Tumor mutation Load assay (ThermoFisher) following manufacturer’s instructions. The panel covers 1.7 Mb of 409 genes with known cancer associations. Regarding pathological responses, patients were classified into 3 groups: pathologic complete response (pCR) (0% viable tumour at any localization tested), major pathologic response (MPR, <10% viable tumour) and pathologic incomplete response (pIR) (>10% of viable tumour). At data analysis, median follow-up time was 22.7 months.

      Results

      Median TMB was 5.89 (range 1.68 – 73.95). No differences in TMB value between histologies (adenocarcinoma vs squamous cell), smoking status (former vs current), age or sex were observed. Somatic mutations were identified in lung cancer driver genes such as TP53, KRAS, EGFR, CDKN2A, NOTCH1, BRAF and in specific genes associated with resistance to immunotherapy such as STK11, KEAP1, and RB1. No genomic alterations in ALK, ROS1, PTEN or ERBB2 were found.

      Based on literature, a poor prognosis mutation signature (presence of EGFR, STK11, KEAP1 or RB1 mutations) was generated. A third of the sequenced patients (9/27) harboured at least one mutation in one of these genes.

      Pathological response data was available from 23 out of 27 patients sequenced. Both the TMB value and the presence of these resistance mutations were not associated with the degree of pathological response.

      Regarding PFS, TMB alone was not predictive of disease progression using different thresholds. However, the presence of these resistance mutations was associated with shorter PFS (log-rank p-value=0.032). The median PFS for mutated patients was 21.4 months (95% CI 16-26 months) while median PFS was not reached in non-mutated patients.

      Additionally, the combination of this mutational signature with TMB (absence of resistance mutations and TMB-Higher than median) was able to distinguish patients that strongly benefit from this therapy. Although the median PFS was not reached in both groups yet, statistically significant differences were observed (log-rank p-value=0.046). PFS at 18 and 24 months was 100% (95% CI not estimable) for Non-mutated patients with TMB-High vs 70% (95% CI 50-89%) and 58% (95% CI 35-81%) for the rest of patients (mutated patients plus Non-mutated patients with TMB-Low).

      Conclusion

      TMB did not predict benefit from chemo-immunotherapy induction in our cohort. However, the presence of EGFR/STK11/KEAP1/RB1 mutations alone, or in combination with TMB, may help identify patients that unlikely benefit from neo-adjuvant chemo-immunotherapy

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      P60.11 - TCR Repertoire Predicts Pathological Response in NSCLC Patients Receiving Neoadjuvant Chemoimmunotherapy from NADIM Trial (ID 3417)

      00:00 - 00:00  |  Presenting Author(s): Marta Casarrubios

      • Abstract
      • Slides

      Introduction

      Characterization of the T-cell receptor (TCR) repertoire has become a novel approach to monitor immunotherapy responses, however there is lack of knowledge about its clinical relevance as predictive biomarker of pathological response in neoadjuvant chemoimmunotherapy. For this purpose, we analysed samples from the NADIM study (NCT03081689), in which resectable stage IIIA NSCLC patients were treated with neoadjuvant Paclitaxel + Carboplatin + Nivolumab for 3 cycles, achieving a 63% of complete pathologic responses (CPR). PD-L1 TPS and TMB as CPR biomarkers showed AUC ROC of 0.77 and 0.55, respectively, reinforcing the need for new biomarkers (Provencio, M. et al. 2020).

      Methods

      TCR repertoires from primary tumours or lymph nodes of 19 NSCLC patients were obtained, at both time points: diagnosis and after neoadjuvant treatment. TCR repertoire was analysed in terms of convergence, diversity, evenness and clonal space, defined as the summed frequency of clones belonging to a frecuency group (top 1%, top 1% to 2%, 2% to 5%, and >5%) relative to the total T-cell repertoire. The results were correlated with pathological response groups and ROC curve analysis was performed to test if TCR repertoire-derived parameters could identify patients with CPR.

      Results

      There were no statistically significant differences observed in TCR repertoire in biopsy samples in terms of diversity (p = 0,797) or convergence (p = 0,202) between the three pathological response groups or between biopsy and surgery samples. However, we observed differences in terms of evenness in biopsy samples between the pathologic response groups (p=0.037), which were lower in those patients who achieved CPR. The AUC for evenness was 0.844 (IC: 0.667-1.000), p=0,011. An evenness value of <0.8639 showed a sensitivity of 50% and specificity of 100% identifying patients with CPR.

      Moreover, the clonal space of the TOP 1% clones in diagnostic samples was higher in patients that achieved CPR (p=0.002). The AUC of this novel biomarker was 0.9667 (IC: 0.897-1.036) (p=0.0006). A TOP 1% clonal space higher than 0.1607 showed a sensitivity of 90% and specificity of 88.9% identifying patients with CPR.

      nadim trasl_tcr_image.jpg

      Conclusion

      Our results support the association between the uneven distribution of T-lymphocytes clones proportions present in the tissue at diagnosis and response to chemoimmunotherapy. Specifically, higher clonal space occupied by the TOP 1% clones seems to outperform PD-L1 and TMB as predictive biomarker of CPR in NSCLC patients receiving neoadjuvant chemoimmunotherapy.

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