T-cell Density Research Articles

PrE0807 phase Ib feasibility trial of neoadjuvant nivolumab (N)/lirilumab (L) in cisplatin-ineligible muscle-invasive bladder cancer (BC).

TPS4594 Background: Neoadjuvant cisplatin-based chemotherapy before radical cystectomy (RC) improves outcomes but ~50% of patients (pts) are cisplatin-unfit. Anti-PD(L)1 agents can prolong overall survival (OS) in platinum-resistant advanced BC and have shown high pathologic complete response rate (pCR) and safety as single agent in phase II trials in the neoadjuvant setting. The combination of anti-PD-1 and anti-KIR agents is feasible and very attractive based on complementary and non-overlapping roles in regulating adaptive and innate immune response as well as impacting the function CD8+ T and NK-cells. Higher CD8+ T cell density (TCD) at RC tissue correlates with longer OS. We hypothesize, that combining anti-PD1 (N) with anti-KIR (L) is safe and feasible as neoadjuvant therapy in cisplatin-unfit pts and results in high CD8+ TCD at RC. Methods: Phase Ib multi-institutional trial evaluating 2 doses (4 weeks apart) of N alone or N+L in 2 cohorts; pts will be assigned sequentially to N (Cohort 1), and if there is no negative safety signal after the first 12 pts, subsequent pts will be assigned to N+L (Cohort 2). Key eligibility: cT2-4aN0-1M0 stage, ≥20% tumor at TURBT, adequate organ function, no autoimmune disease within 2 years, no concurrent invasive upper urinary tract carcinoma or other active cancer. Primary endpoint: safety based on CTCAE v5.0 measured as the rate of ≥G3 treatment related adverse events (AE). Key secondary endpoints: CD8+ TCD absolute and % change between TURBT and RC, % of pts who do not get RC within 6 weeks after neoadjuvant treatment due to treatment-related AE, % pCR, recurrence-free survival, and evaluation of biomarkers in tumor tissue, blood, urine. Rates of ≥Grade 3 AE with neoadjuvant treatment will be reported along with 90% exact binomial CI. In Cohort 1, maximum CI width is 0.51; in Cohort 2, it is 0.36. Our hypothesis is that the change in CD8+ TCD between TURBT and RC will be about 3 CD8+ T cells / 100 tumor cells within HPF. Up to 43 pts will be enrolled for 36 eligible, treated pts (12:N, 24:N+L). Cohort 1 and 2 have 81% and 98% power, respectively, to detect the hypothesized difference with 1-sided type I error rate of 0.05. Trial is open to accrual in US. Clinical trial information: NCT03532451.

Intratumoral CD3+ and CD8+ T-cell densities in patients with deficient DNA mismatch repair (dMMR) metastatic colorectal cancer (mCRC) receiving programmed death-1 (PD-1) blockade.

3532 Background: Colorectal cancer with dMMR display heterogeneity in the extent of intratumoral T-cell infiltration which may explain their variable responsiveness to PD-1 blockade. We examined the association of intratumoral CD3+ and CD8+ T-cell densities (TCD) with objective response rate (ORR) and response duration in patients with dMMR mCRCs receiving pembrolizumab (PEM). Methods: Record review was performed on 12 patients with dMMR mCRC treated with PEM (200 mg intravenously every 3 weeks) after failure of prior chemotherapy [median no. of regimens was 1 (range 1-4)] between 01/2015 and 12/2017. CD3+ and CD8+ TCDs were analyzed in the primary tumor core (CT) and at the invasive margin (IM) by immunohistochemistry and automated image analysis to determine density score (0 to 100) for each T-cell subtype and compartment (Ventana Medical Systems, Inc.). Patients were categorized as 1) responders [CR (complete response) + PR (partial response)] vs. non responders [SD (stable disease) + PD (progressive disease)] per RECIST version 1.1, and 2) by duration of response (< or > 12 months). Results: Median follow-up post PEM was 19.5 (9-41) months. Responders included 2 CR and 5 PR; non-responders included 4 SD and 1 PD. The ORR and median time to response were 58.3% (7/12) and 12 weeks (range 9-40), respectively. CD3+ and CD8+ TCD scores were higher in responders vs. in non-responders as well as in patients who had disease control for > 12 months; differences were greatest for CD8+ CT (Table). Conclusions: Among patients treated with PEM, data suggest higher intratumoral CD3+ and CD8+ TCDs in responders versus non-responders and in those with a longer duration of disease control. If confirmed, TCDs may potentially predict responsiveness to PD-1 blockade in dMMR mCRCs. [Table: see text]

Integrative molecular analysis of metastatic Merkel cell carcinoma to identify predictive biomarkers of response to avelumab.

9569 Background: Avelumab, an FDA-approved human anti–PD-L1 IgG1 monoclonal antibody for patients (pts) with metastatic Merkel cell carcinoma, showed an objective response rate (ORR; by RECIST v1.1) of 31.8% in a second-line phase 2 trial (NCT02155647). We assessed the association of tumor mutational burden (TMB; nonsynonymous somatic variants/megabase), PD-L1 expression, Merkel cell polyomavirus (MCPyV) status, and CD8+ tumor-infiltrating T-cell density with ORR and survival. Molecular profiles (RNAseq and WEX) also were analyzed. Methods: Baseline tumors (n = 36) were profiled using RNAseq and WEX sequencing. PD-L1 expression (≥1% cutoff), MCPyV status, and CD8+ T-cell density at the tumor invasive margin were evaluated by IHC. MHC locus expression was measured with OptiType and loss of heterozygosity (LOH) with LOHHLA. Results: Of 36 pts profiled, 12 had a response, 27 were PD-L1+, and 23 were MCPyV+. The TMB upper tertile and quartile values were 1.34 and 3.16, respectively. Consistent with literature, MCPyV− pts had a higher median TMB (2.72) than MCPyV+ pts (0.49). PD-L1+ tumors trended toward a higher TMB. An empirical cohort-specific TMB cutoff of ≥2 was chosen to include sufficient pts per subgroup. Pts with TMB ≥2 vs TMB < 2 had higher ORR (5 of 11 [45.5%] vs 7 of 25 [28.0%]) and 6-mo PFS rates (60% vs 38%). Among pts with TMB ≥2, the highest ORRs were reported in MCPyV− (4 of 7 pts), PD-L1+ (5 of 9 pts), and CD8+ T-cell density higher than median (5 of 6 pts) subgroups. MHC expression trended with ORR and survival. Higher mean MHC expression was found in pts with CD8+ T-cell density higher than median (p < 0.05). Mutations in antigen presentation genes were detected: LOH at the HLA locus in 9 of 30 pts (28%), including 4 with a response; an NK cell activation signature was also associated with response. These data may suggest that ADCC contributes to response. Factorial analysis of gene signature scores identified signatures (eg, IFNγ, TP53 pathway) associated with MCPyV status and response. Conclusions: Responses in this data set were not attributed to any specific biomarker alone. Future analysis is focused on validating these results and identifying rational drug combinations with avelumab. Clinical trial information: NCT02155647.

Relationship between Helicobacter pylori and expression of programmed death-1 and its ligand in gastric intraepithelial neoplasia and early-stage gastric cancer.

Background: Many studies have shown that programmed cell death protein 1 (PD-1) and its ligand, PD-L1, are expressed in advanced gastric cancer. Furthermore, detection of these proteins is associated with infiltrating CD8+ T-cells, indicating that an adaptive immune resistance mechanism occurs in advanced gastric cancer. However, PD-L1 and PD-1 expression in gastric intraepithelial neoplasia and early-stage gastric cancer (EGC) has yet to be elucidated.Patients and methods: Fifty-four resections of low-grade intraepithelial neoplasia (LGIN), high-grade intraepithelial neoplasia (HGIN), and EGC were stained by immunohistochemistry for PD-1, PD-L1, and CD8. CD8+ T-cell densities both within tumors and in the tumor-stromal interface were analyzed. Flow cytometry (FACS) was used to analyze the PD-1 expression in tumor tissues and peripheral blood mononuclear cells. Furthermore, the relationship between Helicobacter pylori (Hp) infection and PD-1 and PD-L1 was also evaluated.Results: We demonstrated that PD-L1 expression was significantly increased in HGIN and EGC compared with LGIN, and both PD-1 and PD-L1 showed similar expression patterns, being mainly detected in infiltrating immune cells. FACS also showed that PD-1 was expressed on both CD4+ and CD8+ T-cells. However, no difference was found in CD8+ T-cell infiltration between LGIN and HGIN+EGC, and this was not not found to be associated with PD-L1 or PD-1 expression. However, Hp infection was significantly associated with expression of PD-L1 and PD-1.Conclusions: The PD-1/PD-L1 checkpoint is involved in intraepithelial neoplasia and EGC, but an adaptive immune resistance mechanism does not occur. Expression of PD-1/PD-L1 is also associated with Hp infection, and so Hp infection may be an important initiating factor.Clinical Trial Registration information: This study was approved by the Institutional Review Board of Ruijin Hospital and written informed consent was obtained from all patients.

Multiple Immune-Suppressive Mechanisms in Fibrolamellar Carcinoma.

Fibrolamellar carcinoma (FLC) is a rare type of liver cancer that affects adolescents and young adults. The most effective treatment for FLC is surgical resection, but no standardized systemic therapy exists for patients with recurrent or unresectable FLC. As a first step to understand the immune microenvironment of FLC, we investigated targetable immune-checkpoint pathways, PD-1, PD-L1, B7-H3, IDO-1, and LAG3, in relation to CD8+ cytotoxic T-lymphocyte density. Thirty-two FLC tumor specimens were analyzed using IHC staining for PD-L1, CD8, PD-1, IDO, LAG3, and B7-H3. Sixty-three percent of FLC cases demonstrated membranous PD-L1 expression on tumor cells, and almost 70% of cases demonstrated PD-L1+ tumor-infiltrating lymphocytes and tumor-associated macrophages (TIL/TAM). Myeloid-derived cells appeared to be a major component of PD-L1+ tumor-infiltrating immune cells. Forty percent of the cases showed B7-H3 expression in the tumor zone, with 91% cases showing B7-H3 expression in TILs and TAMs. IDO and PD-1 expression was highest in the tumor interface zone. B7-H3 or IDO expression on tumor cells significantly correlated with higher CD8+ T-cell density. In conclusion, a high proportion of FLC cases showed robust expression of PD-1, PD-L1, B7-H3, and IDO in an adaptive immune-resistance pattern. Our findings provide further basis for targeting these different immune-checkpoint axes in FLC.

Calcium Intake and Risk of Colorectal Cancer According to Tumor-infiltrating T Cells.

Calcium intake has been associated with a lower risk of colorectal cancer. Calcium signaling may enhance T-cell proliferation and differentiation, and contribute to T-cell-mediated antitumor immunity. In this prospective cohort study, we investigated the association between calcium intake and colorectal cancer risk according to tumor immunity status to provide additional insights into the role of calcium in colorectal carcinogenesis. The densities of tumor-infiltrating T-cell subsets [CD3+, CD8+ , CD45RO (PTPRC) + , or FOXP3+ cell] were assessed using IHC and computer-assisted image analysis in 736 cancer cases that developed among 136,249 individuals in two cohorts. HRs and 95% confidence intervals (CI) were calculated using Cox proportional hazards regression. Total calcium intake was associated with a multivariable HR of 0.55 (comparing ≥1,200 vs. <600 mg/day; 95% CI, 0.36-0.84; P trend = 0.002) for CD8+ T-cell-low but not for CD8+ T-cell-high tumors (HR = 1.02; 95% CI, 0.67-1.55; P trend = 0.47). Similarly, the corresponding HRs (95% CIs) for calcium for low versus high T-cell-infiltrated tumors were 0.63 (0.42-0.94; P trend = 0.01) and 0.89 (0.58-1.35; P trend = 0.20) for CD3+ ; 0.58 (0.39-0.87; P trend = 0.006) and 1.04 (0.69-1.58; P trend = 0.54) for CD45RO+ ; and 0.56 (0.36-0.85; P trend = 0.006) and 1.10 (0.72-1.67; P trend = 0.47) for FOXP3+ , although the differences by subtypes defined by T-cell density were not statistically significant. These potential differential associations generally appeared consistent regardless of sex, source of calcium intake, tumor location, and tumor microsatellite instability status. Our findings suggest a possible role of calcium in cancer immunoprevention via modulation of T-cell function.

PD-L1 expression in carcinoma of the esophagogastric junction is positively correlated with T-cell infiltration and overall survival

IntroductionIn recent years antitumor immunity and inhibition of checkpoint molecules, such as PD-1 and PD-L1, have emerged as potential therapeutic strategies in advanced stages of various malignancies. We investigated PD-L1 expression in adenocarcinomas of the esophagogastric junction and correlated the results with densitiy of intratumoral T-lymphocytes. MethodsImmunohistochemical staining for PD-L1 was carried out on 135 samples using a tissue microarray. Scoring was done according to the combined positivity score. Results48.1% of tumors (65 cases) showed PD-L1 positivity with a score ≥ 1 while 51.9% were PD-L1 negative (70 cases). A positive correlation between PD-L1 negativity and mucinous and poorly cohesive carcinoma could be shown (p = 0.043), while no association existed for either gender, T-stage, N-stage, grading, surgical resection status, neoadjuvant therapy, distant metastases, lymphovascular or perineural invasion. No correlation of PD-L1 expression and overall survival could be detected (p = 0.497). Again, when stratified according to presence or absence of neoadjuvant therapy, no survival differences could be shown for either group (p = 0.540 and p = 0.736). When PD-L1 expression was correlated with density of tumor-infiltrating T-lymphocytes a positive correlation between PD-L1 positivity and denser T-cell infiltration could be shown (p = 0.001). Concerning overall survival, in PD-L1 negative cases, denser CD8-positive T-cell infiltrates were associated with prolonged survival times (p = 0.045). No differences could be shown for PD-L1 positive cases or CD103-positive T-cells. ConclusionPD-L1 expression is frequent in esophagogastric adenocarcinoma and - when combined with dense CD8 infiltration – PD-L1 negativity correlates with prolonged overall survival.

PTEN-deficient prostate cancer is associated with an immunosuppressive tumor microenvironment mediated by increased expression of IDO1 and infiltrating FoxP3+ T regulatory cells.

Accumulating evidence shows that tumor cell-specific genomic changes can influence the cross talk between cancer cells and the surrounding tumor microenvironment (TME). Loss of the PTEN tumor suppressor gene is observed in 20% to 30% of prostate cancers (PCa) when first detected and the rate increases with PCa progression and advanced disease. Recent findings implicate a role for PTEN in cellular type I interferon response and immunosuppression in PCa. However, the way that PTEN inactivation alters antitumor immune response in PCa is poorly understood. To investigate the changes associated with PTEN loss and an immunosuppressive TME in PCa, we used CIBERSORT to estimate the relative abundance of 22 immune-cell types from 741 primary and 96 metastatic tumors. Our in silico findings were then validated by immunohistochemical analysis of immune cells and IDO1 and PDL1 checkpoint proteins in a cohort of 94 radical prostatectomy specimens. FoxP3+ T regulatory cells (Tregs) were significantly increased in PTEN-deficient PCa in all three public domain cohorts. Loss of PTEN in bone metastases was associated with lower CD8+ T-cell abundance, but in liver metastasis, FoxP3+ Tregs were present at higher levels. PTEN-deficient lymph node metastasis had a distinct profile, with high levels of CD8+ T cells. Moreover, we found that metastatic PCa presents higher abundance of FoxP3+ Treg when compared to primary lesions. Since PTEN-deficient tumors are likely to be immunosuppressed as a consequence of increased FoxP3+ Tregs, we then evaluated the localization and expression of IDO1, PDL1 immune checkpoints, and the corresponding density of FoxP3+ Treg and CD8+ T cells using our validation cohort (n = 94). We found that IDO1 protein expression and FoxP3+ Treg density were higher in neoplastic glands compared with benign adjacent tissue. Moreover, higher densities of FoxP3+ Treg cells in both stromal (P = 0.04) and tumor (P = 0.006) compartments were observed in PTEN-deficient tumors compared to tumors that retained PTEN activity. Similarly, IDO1 protein expression was significantly increased in the tumor glands of PTEN-deficient PCa (P < 0.0001). Spearman correlation analysis showed that IDO1 expression was significantly associated with FoxP3+ Treg and CD8+ T-cell density (P < 0.01). Our findings imply that PTEN deficiency is linked to an immunosuppressive state in PCa with distinct changes in the frequency of immune cell types in tumors from different metastatic sites. Our data suggest that determining PTEN status may also help guide the selection of patients for future immunotherapy trials in localized and metastatic PCa.

Density of CD8-positive tumor-infiltrating T-lymphocytes is an independent prognostic factor in adenocarcinoma of the esophagogastric junction.

Tumor-infiltrating lymphocytes (TILs) have commonly been associated with markedly improved prognosis in a variety of human cancers, including carcinomas of the upper and lower gastrointestinal tract. Especially the presence of T-cells (cytotoxic as well as helper cells) seems to define a subgroup of patients with prolonged overall and event-free survival. The density of TILs was assessed via immunohistochemistry for CD8 and CD103 in a population of 228 adenocarcinomas of the esophagogastric junction. Density of CD8+ T-lymphocytes was inversely correlated with depth of tumor infiltration (p=0.013) while no correlation with any of the analyzed clinicopathologic factors could be established for CD103-density. High density of CD8-positive T-cells additionally showed significantly longer overall survival (OS) with a p-value of 0.024 while density of CD103+ cells was associated with prolonged tumor free survival (p-value 0.011). Independence could be demonstrated applying Cox proportional hazard analysis (Hazard Ratio 0.742; 95%-Confidence Interval 0.579-0.951; p=0.019). High density of CD8-positive T-lymphocytes identifies a patient subgroup with significantly prolonged overall survival, is correlated with tumor stage and might open up new therapeutic possibilities via immunomodulating drugs.

Automated Analysis of Lymphocytic Infiltration, Tumor Budding, and Their Spatial Relationship Improves Prognostic Accuracy in Colorectal Cancer.

Both immune profiling and tumor budding significantly correlate with colorectal cancer patient outcome but are traditionally reported independently. This study evaluated the association and interaction between lymphocytic infiltration and tumor budding, coregistered on a single slide, in order to determine a more precise prognostic algorithm for patients with stage II colorectal cancer. Multiplexed immunofluorescence and automated image analysis were used for the quantification of CD3+CD8+ T cells, and tumor buds (TBs), across whole slide images of three independent cohorts (training cohort: n = 114, validation cohort 1: n = 56, validation cohort 2: n = 62). Machine learning algorithms were used for feature selection and prognostic risk model development. High numbers of TBs [HR = 5.899; 95% confidence interval (CI) 1.875-18.55], low CD3+ T-cell density (HR = 9.964; 95% CI, 3.156-31.46), and low mean number of CD3+CD8+ T cells within 50 μm of TBs (HR = 8.907; 95% CI, 2.834-28.0) were associated with reduced disease-specific survival. A prognostic signature, derived from integrating TBs, lymphocyte infiltration, and their spatial relationship, reported a more significant cohort stratification (HR = 18.75; 95% CI, 6.46-54.43), than TBs, Immunoscore, or pT stage. This was confirmed in two independent validation cohorts (HR = 12.27; 95% CI, 3.524-42.73; HR = 15.61; 95% CI, 4.692-51.91). The investigation of the spatial relationship between lymphocytes and TBs within the tumor microenvironment improves accuracy of prognosis of patients with stage II colorectal cancer through an automated image analysis and machine learning workflow.

Paradoxical effect of regulatory T-cell density in the invasive margin on colon cancer disease-free survival.

47 Background: Increased numbers of FoxP3+ regulatory T cells (Treg), an immunosuppressive T cell subpopulation, in the tumor microenvironment (TME) has been associated with decreased recurrence risk in colon cancer. We assessed the association of Treg levels and disease-free survival (DFS) to confirm correlation with recurrence risk and to evaluate the impact on DFS in patients with colon cancer. Methods: Cases of colonic adenocarcinoma with endoscopic biopsies who had curative resection were collected from 2006-2016. The tissue sections were stained with FoxP3 immunohistochemical stain. FoxP3+ cells (Tregs) were counted with a digital imager software program and reported as cells per square mm. DFS from time of surgery was determined with a retrospective chart review. FoxP3 levels were compared with a Man-Whitney U test and DFS was compared with a Spearman’s test and regression. Results: 109 matched endoscopic biopsy colonic adenocarcinoma specimens were gathered. 94 cases had at least 4 months of follow up and were analyzed. The recurrence rate was 21.3% (20/94) with a median recurrence time of 13.5 months. The median time to follow up in patients with no recurrence was 39 (range 4-116) months. Tregs in those that recurred had a mean density of 152 (range 9-1267) at the invasive margin compared to 251 (range 15-485) in the cases that did not yet recur (p = 0.005). The same association was observed with Treg density in the center of the tumor (p = 0.03). In the cases that had a recurrence, there was a moderate, inverse correlation between Tregs at the invasive margin and time to recurrence (Spearman’s correlation coefficient = -0.46, p = 0.04.) A logarithmic inverse relationship between Tregs at the invasive margin and time to recurrence was observed (Correlation coefficient -0.63, p = 0.003). Conclusions: Treg density in endoscopic biopsies in colon adenocarcinoma is associated with recurrence risk, consistent with previously reported observations. Paradoxically, in patients who did recur, higher Treg density was associated with shorter time to recurrence. This discordant relationship of Treg density and colon cancer prognosis warrants further investigation.

TP53 missense mutation is associated with increased tumor-infiltrating T cells in primary prostate cancer

The makeup of the tumor immune microenvironment may be associated with tumor somatic genomic alterations and plays a key role in tumor progression and response to immunotherapy. We examined the association of tumor-infiltrating T-cell density with TP53 status in surgically treated primary prostate cancer using 3 independent tissue microarray sets, including one set of tumors from grade-matched patients of European American or African American ancestry (n = 391), a retrospective case-cohort of intermediate- and high-risk patients enriched for adverse outcomes (n = 267), and a set of tumors with primary Gleason pattern 5 (n = 77). The presence of TP53 missense mutation, indicated by p53 nuclear accumulation using a genetically validated assay, was significantly associated with increased CD3+ T-cell density (median, 341 versus 231 CD3+ T cells/mm2; P = .004) in the matched European American and African American ancestry patient sets. The same association was present in patients of both ancestries when analyzed separately, despite the fact that p53 nuclear accumulation was less frequent among African American compared with European American tumors (7% versus 3%, P = .2). The validation cohorts of intermediate/high-risk and primary Gleason pattern 5 patients corroborated the association of increased CD3+ T-cell density with presence of p53 nuclear accumulation. In a pooled analysis of all sets, adjusting for clinicopathological variables, CD3+ and CD8+, but not FOXP3+, T-cell densities remained significantly higher in tumors with p53 nuclear accumulation compared with those without. TP53 mutation is associated with higher tumor-infiltrating T-cell density, which may be relevant in future clinical trials of immunotherapy in prostate cancer.

Abstract P2-03-01: Akt inhibition associated with change in immunophenotype of tumor microenvironment (TME) in breast cancer (BC)

Abstract Background: The PI3K/Akt/mTOR pathway is a known oncogenic pathway in BC. In addition, this pathway has demonstrated capacity to modulate host immune activity and may indirectly affect tumorigenesis. Clinicopathologic studies have demonstrated that lymphocyte density within the TME is predictive of chemosensitivity and improved prognosis in BC, while myeloid infiltration may play a deleterious role. To define the impact of Akt inhibition on the TME, we analyzed tumor tissue from patients (pts) with early-stage BC treated with single agent MK-2206, an Akt inhibitor, enrolled on a presurgical trial (NCT01319539). Methods: Quantitative immunofluorescence (qmIF) was performed for CD3, CD8, CD4, FOXP3, CD68, Pancytokeratin on 4uM sections from biopsy and surgical specimens of MK-2206 (n=5) and control (n=5) pts. Images were analyzed using Vectra/inForm software (PerkinElmer), allowing for multiparameter phenotyping. Transcriptomic analysis was performed on surgical specimens to assess if differences exist in mRNA expression of tumor-associated and immune genes between pts treated with MK-2206 (n=5) and untreated matched controls (n=5) (nanoString). Statistical analysis was performed using t-Test, NetBID, and multiple comparison analysis by Benjamini-Hochberg. Gene set enrichment analysis (GSEA) was performed within R with gene sets from Molecular Signatures Database (Hallmark, Reactome, GO). Results: On qmIF analysis, MK-2206 treated pts exhibited a significant increase in median cytotoxic T-cell (CD3+CD8+, CTL) density between pretreatment biopsy and surgical excision specimens, as compared to the control pts (87% vs.0.2%, p &amp;lt; 0.05). Mean macrophage density (CD68+) was numerically lower in surgical specimens of pts who received MK-2206 vs. control pts, although CD68+ infiltration was overall low (p=ns). mRNA expression supports in vivo activity of MK-2206 with lower expression levels of cell cycle, proliferation and anti-apoptotic genes (e.g. CTNNB1, CCND2, BAX) and greater expression of pro-apoptotic genes (e.g. BAD) associated with MK-2206 treatment (raw p-value &amp;lt;0.05). Additionally, greater mRNA copy number of IGF1R, a receptor tyrosine kinase (RTK) previously identified as upregulated in BC in the context of Akt inhibition, was found in post-MK-2206 surgical specimens as compared to control, non-MK-2206 specimens (raw p-value &amp;lt;0.05). MK-2206 was also associated with reduced expression of myeloid markers (e.g. CSF1R, CD163) (raw p-value &amp;lt;0.05). By GSEA, canonical gene sets related to interferon signaling were increased in post-MK-2206 specimens as compared to non-MK-2206 specimens, whereas monocyte chemotaxis genes were decreased in treated pts (adj p-value &amp;lt;0.05). RT-PCR is currently underway to compare biopsy and surgical specimens for a subset of RTK, immune and apoptosis related genes identified above. Conclusion: mRNA and qmIF analysis suggest that Akt inhibition, may increase interferon signaling, CTL density, and decrease myeloid infiltration. Thus, Akt inhibition may promote a favorable TME. At present, there are both FDA approved and investigational agents that target the PI3K/mTOR pathway. Further investigation is warranted to understand the impact of Akt inhibition on the TME and potential therapeutic implications. Citation Format: Marks DK, Gartrell RD, Pan Q, El Asmar M, Hart TD, Esancy CL, Lu Y, Yu J, Hibshoosh H, Connolly E, Kalinsky K, Saenger YM. Akt inhibition associated with change in immunophenotype of tumor microenvironment (TME) in breast cancer (BC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-03-01.

Prognostic implications of residual disease tumor-infiltrating lymphocytes and residual cancer burden in triple-negative breast cancer patients after neoadjuvant chemotherapy.

For primary triple-negative breast cancer (TNBC) treated with neoadjuvant chemotherapy (NAC), higher pretreatment tumor-infiltrating lymphocytes (TILs) correlates with increased pathologic complete response (pCR) rates, and improved survival. We evaluated the added prognostic value of residual disease (RD) TILs to residual cancer burden (RCB) in predicting survival post-NAC. We combined four TNBC NAC patient cohorts who did not achieve pCR. RD TILs were investigated for associations with recurrence-free survival (RFS), and overall survival (OS) using Cox models with stromal TILs as a continuous variable (per 10% increment). The likelihood ratio test was used to evaluate added prognostic value of RD TILs. A total of 375 RD TNBC samples were evaluable for TILs and RCB. The median age was 50 years, with 62% receiving anthracycline/taxane chemotherapy. The RCB class after NAC was 11%, 50%, and 39% for I, II, and III, respectively. The median RD TIL level was 20% (IQR 10-40). There was a positive correlation between RD TIL levels and CD8+ T-cell density (ρ = 0.41). TIL levels were significantly lower with increasing post-NAC tumor (P = 0.005), nodal stage (P = 0.032), but did not differ by RCB class (P = 0.84). Higher RD TILs were significantly associated with improved RFS (HR: 0.86; 95% CI 0.79-0.92; P < 0.001), and improved OS (HR: 0.87; 95% CI 0.80-0.94; P < 0.001), and remained significant predictors in multivariate analysis (RFS P = 0.032; OS P = 0.038 for OS). RD TILs added significant prognostic value to multivariate models including RCB class (P < 0.001 for RFS; P = 0.021 for OS). The positive prognostic effect of RD TILs significantly differed by RCB class for RFS (PInt=0.003) and OS (PInt=0.008) with a greater magnitude of positive effect observed for RCB class II than class III. TIL levels in TNBC RD are significantly associated with improved RFS and OS and add further prognostic information to RCB class, particularly in RCB class II.

Abstract A182: T-cell exhaustion assessment using a fully automated sequential chromogenic multiplex assay

Abstract Cancer immunotherapy by anti-PD-1 or anti-PD-L1 antibodies is now established as an efficient approach to restore the cytotoxic activity of exhausted T-cells. However, the strong and durable response observed in non-small cell lung cancer (NSCLC) patients is limited to a fraction of the treated population. Biomarkers, such as PD-L1 expression on tumor cells or tumor mutational burden, are approved as predictive markers of the response to anti-PD-1 or anti-PD-L1 antibodies. However, they are far from perfect to select patients eligible to immunotherapy. Since exhausted T-cells express more than one checkpoint inhibitor, it is hypothesized that an anti-PD1 antibody may not be sufficient to restore the activity of exhausted cells. Multiplex detection of the major immune checkpoints, i.e., PD-1, LAG-3 and TIM-3, on T-cells within the tumor microenvironment could, on one hand, predict the poor response to a single agent and could, on the other hand, predict the best combination of antibodies targeting more than one immune checkpoint. Here we present an automated sequential chromogenic multiplex assay allowing the assessment of the expression of PD-1, LAG-3 and TIM-3 on CD3+/CD8+ cells on a single FFPE tumor tissue section. Briefly, a tissue section is sequentially stained, digitized, unstained and restained with antibodies targeting the five markers. Images of the whole slide are then analyzed by digital pathology. First, a newly developed software is used to co-register the 5 virtual slides and perform colors deconvolution. Detection of positive cells is performed for each marker independently, using Indica Lab’s HALO software. Then, individual cells can be analyzed to identify complex phenotypes and assess their density on the entire tissue section. In addition, tissue segmentation tools are used to assess densities of exhausted T-cells expressing the major immune checkpoints in parenchyma, tumor stroma and invasive margin regions. The quantitative evaluation of T-cells’ exhaustion based on the expression of more than one immune checkpoint could improve patient stratification and lead to individualized combinations of immunotherapy agents. Citation Format: Aurélie Collignon, Assil Benchaaben, Anna Martirosyan, Matthieu Duval, Emilie Bonzom, Emmanuel Prestat, Christophe Haond, Jacques Fieschi. T-cell exhaustion assessment using a fully automated sequential chromogenic multiplex assay [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A182.

Intertumoral Heterogeneity of CD3+ and CD8+ T-Cell Densities in the Microenvironment of DNA Mismatch-Repair–Deficient Colon Cancers: Implications for Prognosis

Colorectal cancers with deficient DNA mismatch repair (dMMR) are presumed to uniformly have dense lymphocytic infiltration that underlies their favorable prognosis and is critical to their responsiveness to immunotherapy, as compared with MMR-proficient (pMMR) tumors. We examined T-cell densities and their potential heterogeneity in a large cohort of dMMR tumors. CD3+ and CD8+ T-cell densities were quantified at the invasive margin (IM) and tumor core (CT) in 561 stage III colon cancers (dMMR, n = 278; pMMR, n = 283) from a phase III adjuvant trial (N0147). Their association with overall survival (OS) was determined using multivariable Cox analysis. Although CD3+ and CD8+ T-cell densities in the tumor microenvironment were higher in dMMR versus pMMR tumors overall, intertumoral heterogeneity in densities between tumors was significantly higher by 30% to 88% among dMMR versus pMMR cancers (P < 0.0001 for all four T-cell subtypes [CD3+IM, CD3+CT, CD8+IM, CD8+CT]). A substantial proportion of dMMR tumors (26% to 35% depending on the T-cell subtype) exhibited T-cell densities as low as that in the bottom half of pMMR tumors. All four T-cell subtypes were prognostic in dMMR with CD3+IM being the most strongly prognostic. Low (vs. high) CD3+IM was independently associated with poorer OS among dMMR (HR, 4.76; 95% confidence interval, 1.43-15.87; P = 0.0019) and pMMR tumors (P = 0.0103). Tumor-infiltrating T-cell densities exhibited greater intertumoral heterogeneity among dMMR than pMMR colon cancers, with CD3+IM providing robust stratification of both dMMR and pMMR tumors for prognosis. Potentially, lower T-cell densities among dMMR tumors may contribute to immunotherapy resistance.

Vascular Targeting to Increase the Efficiency of Immune Checkpoint Blockade in Cancer.

Boosting natural immunity against malignant cells has had a major breakthrough in clinical cancer therapy. This is mainly due to the successful development of immune checkpoint blocking antibodies, which release a break on cytolytic anti-tumor-directed T-lymphocytes. However, immune checkpoint blockade is only effective for a proportion of cancer patients, and a major challenge in the field is to understand and overcome treatment resistance. Immune checkpoint blockade relies on successful trafficking of tumor-targeted T-lymphocytes from the secondary lymphoid organs, through the blood stream and into the tumor tissue. Resistance to therapy is often associated with a low density of T-lymphocytes residing within the tumor tissue prior to treatment. The recruitment of leukocytes to the tumor tissue relies on up-regulation of adhesion molecules and chemokines by the tumor vasculature, which is denoted as endothelial activation. Tumor vessels are often poorly activated due to constitutive pro-angiogenic signaling in the tumor microenvironment, and therefore constitute barriers to efficient leukocyte recruitment. An emerging possibility to enhance the efficiency of cancer immunotherapy is to combine pro-inflammatory drugs with anti-angiogenic therapy, which can enable tumor-targeted T-lymphocytes to access the tumor tissue by relieving endothelial anergy and increasing adhesion molecule expression. This would pave the way for efficient immune checkpoint blockade. Here, we review the current understanding of the biological basis of endothelial anergy within the tumor microenvironment, and discuss the challenges and opportunities of combining vascular targeting with immunotherapeutic drugs as suggested by data from key pre-clinical and clinical studies.

Predictive markers for anti-PD-1/PD-L1 therapy in non-small cell lung cancer-where are we?

The selection of patients for immunotherapy remains challenging given the lack of highly specific and highly sensitive biomarkers. Nevertheless, it is essential that testing laboratories are able to fulfil licencing criteria by providing the tests which have been validated as providing useful predictive information. Programmed cell death protein 1 (PD-1) expression assessment is now established in routine practice, although the situation regarding the selection of a particular assay remains complex, and testing protocols are likely to change in future. It is probable that programmed death-ligand 1 (PD-L1) expression assessment will be supplemented in the near future by tumour mutation burden (TMB), but this will require novel solutions to allow testing to be completed using small tissue samples and within narrow timeframes. While DNA mismatch repair (MMR) testing and CD8 T-cell density may also have a role to play in predicting immunotherapy response, their roles are not well-defined at present. Above all, the main challenge facing laboratories will be to perform this multitude of tests alongside the molecular markers already established in clinical practice [e.g., epidermal growth factor receptor (EGFR) mutation, anaplastic lymphoma kinase (ALK) translocation, ROS proto-oncogene 1 (ROS1) translocation]; the challenge for pathologists and clinicians will be to develop algorithms which will integrate the complex set of results from these tests and provide clinically-useful management regimens.

The Link between the Multiverse of Immune Microenvironments in Metastases and the Survival of Colorectal Cancer Patients

Treatment of metastatic colorectal cancer is based upon the assumption that metastases are homogeneous within a patient. We quantified immune cell types of 603 whole-slide metastases and primary colorectal tumors from 222 patients. Primary lesions, and synchronous and metachronous metastases, had a heterogeneous immune infiltrate and mutational diversity. Small metastases had frequently a low Immunoscore and T and B cell score, while a high Immunoscore was associated with a lower number of metastases. Anti-epidermal growth factor receptor treatment modified immune gene expression and significantly increased Tcell densities in the metastasis core. The predictive accuracy of the Immunoscore from a single biopsy was superior to the one of programmed cell death ligand 1 (PD-L1). The immune phenotype of the least-infiltrated metastasis had a stronger association with patient outcome than other metastases.

TP53, STK11, and EGFR Mutations Predict Tumor Immune Profile and the Response to Anti-PD-1 in Lung Adenocarcinoma.

Purpose: By unlocking antitumor immunity, antibodies targeting programmed cell death 1 (PD-1) exhibit impressive clinical results in non-small cell lung cancer, underlining the strong interactions between tumor and immune cells. However, factors that can robustly predict long-lasting responses are still needed.Experimental Design: We performed in-depth immune profiling of lung adenocarcinoma using an integrative analysis based on immunohistochemistry, flow-cytometry, and transcriptomic data. Tumor mutational status was investigated using next-generation sequencing. The response to PD-1 blockers was analyzed from a prospective cohort according to tumor mutational profiles and PD-L1 expression, and a public clinical database was used to validate the results obtained.Results: We showed that distinct combinations of STK11, EGFR, and TP53 mutations were major determinants of the tumor immune profile (TIP) and of the expression of PD-L1 by malignant cells. Indeed, the presence of TP53 mutations without co-occurring STK11 or EGFR alterations (TP53-mut/STK11-EGFR-WT), independently of KRAS mutations, identified the group of tumors with the highest CD8 T-cell density and PD-L1 expression. In this tumor subtype, pathways related to T-cell chemotaxis, immune cell cytotoxicity, and antigen processing were upregulated. Finally, a prolonged progression-free survival (PFS: HR = 0.32; 95% CI, 0.16-0.63, P < 0.001) was observed in anti-PD-1-treated patients harboring TP53-mut/STK11-EGFR-WT tumors. This clinical benefit was even more remarkable in patients with associated strong PD-L1 expression.Conclusions: Our study reveals that different combinations of TP53, EGFR, and STK11 mutations, together with PD-L1 expression by tumor cells, represent robust parameters to identify best responders to PD-1 blockade. Clin Cancer Res; 24(22); 5710-23. ©2018 AACR.