Neoadjuvant PD-1 Blockade Research Articles

P4.07E.08 Single-Cell TCR Barcoding and RNA Sequencing Illuminate Distinct Tumor-Draining Lymph Node T Cell Responses to Neoadjuvant PD-1 Blockade

P4.07E.08 Single-Cell TCR Barcoding and RNA Sequencing Illuminate Distinct Tumor-Draining Lymph Node T Cell Responses to Neoadjuvant PD-1 Blockade

Pembrolizumab in combination with lenvatinib in participants with hepatocellular carcinoma (HCC) before liver transplant as neoadjuvant therapY-PLENTY pilot study.

The high recurrent rate after liver transplantation (LT) remains a clinical challenge, especially for those exceeding the Milan criteria (MC) and with high RETREAT scores. Therefore, the authors aim to investigate whether neoadjuvant systemic therapy allows safely administered and effectively reduces post-LT recurrence for those patients. In this prospective, randomized, open-label, pilot study, patients with HCC exceeding the MC were randomly assigned to PLENTY or control group before LT. The primary endpoint of the study was the recurrence-free survival after LT. Twenty-two patients were enrolled and randomly assigned: 11 to the PLENYT group and 11 to the control group. The 30-month tumor-specific RFS was 37.5% in the PLENTY group and 12.5% in the control group. The 12-month tumor-specific RFS after LT was significantly improved in the PLENTY group (87.5%) compared to the control group (37.5%) (P=0·0022). The objective response rate in the PLENTY group was 30 and 60% when determined by RECIST 1.1 and mRECIST, respectively. Six patients (60%) had significant tumor necrosis, including three (30%) who had complete tumor necrosis at histopathology. No acute allograft rejection after LT occurred in the PLENTY and Control group. Neoadjuvant pembrolizumab plus lenvatinib before LT appears to be safe and feasible, associated with significantly better RFS for patients exceeding the MC. Despite the limitations of small sample size, this is the first RCT to evaluate neoadjuvant PD-1 blockade combined with tyrosine kinase inhibitors in LT recipients, the results of this study will inform future research.

Circulating T cell status and molecular imaging may predict clinical benefit of neoadjuvant PD-1 blockade in oral cancer

BackgroundAddition of neoadjuvant immune checkpoint inhibition to standard-of-care interventions for locally advanced oral cancer could improve clinical outcome.MethodsIn this study, 16 evaluable patients with stage III/IV oral cancer were treated...

Blood-based molecular and cellular biomarkers of early response to neoadjuvant PD-1 blockade in patients with non-small cell lung cancer

BackgroundDespite the improved survival observed in PD-1/PD-L1 blockade therapy, a substantial proportion of cancer patients, including those with non-small cell lung cancer (NSCLC), still lack a response.MethodsTranscriptomic profiling was conducted on a discovery cohort comprising 100 whole blood samples, as collected multiple times from 48 healthy controls (including 43 published data) and 31 NSCLC patients that under treatment with a combination of anti-PD-1 Tislelizumab and chemotherapy. Differentially expressed genes (DEGs), simulated immune cell subsets, and germline DNA mutational markers were identified from patients achieved a pathological complete response during the early treatment cycles. The predictive values of mutational markers were further validated in an independent immunotherapy cohort of 1661 subjects, and then confirmed in genetically matched lung cancer cell lines by a co-culturing model.ResultsThe gene expression of hundreds of DEGs (FDR p < 0.05, fold change < -2 or > 2) distinguished responders from healthy controls, indicating the potential to stratify patients utilizing early on-treatment features from blood. PD-1-mediated cell abundance changes in memory CD4 + and regulatory T cell subset were more significant or exclusively observed in responders. A panel of top-ranked genetic alterations showed significant associations with improved survival (p < 0.05) and heightened responsiveness to anti-PD-1 treatment in patient cohort and co-cultured cell lines.ConclusionThis study discovered and validated peripheral blood-based biomarkers with evident predictive efficacy for early therapy response and patient stratification before treatment for neoadjuvant PD-1 blockade in NSCLC patients.

252P Neoadjuvant chemoradiotherapy plus PD-1 blockade for high or very high-risk locally advanced rectal cancer

252P Neoadjuvant chemoradiotherapy plus PD-1 blockade for high or very high-risk locally advanced rectal cancer

Neoadjuvant long-course chemoradiation plus PD1 blockade for locally advanced rectal cancer: Results of a phase 2, open-label, randomized controlled trial.

3611 Background: Several single-arm trials have reported pathological complete response (pCR) rates of 23-50% after combining neoadjuvant radiotherapy with immune checkpoint inhibitors in locally advanced rectal cancer (LARC). We aim to further clarify the efficacy and safety of adding PD1 inhibitors to the neoadjuvant long-course chemoradiation of LARC patients with this phase 2, randomized, controlled trial. Methods: Patients with mid-low, locally advanced rectal cancer were randomly allocated to receive neoadjuvant chemoradiation plus concurrent Tislelizumab (experiment group A), or neoadjuvant chemoradiation plus sequential Tislelizumab (experiment group B), or neoadjuvant chemoradiation only (control group). Patients of all three groups are scheduled to receive radical surgery after neoadjuvant treatment. The primary endpoint is pCR rate. Results: A total of 186 patients were enrolled. In the modified intention-to-treat population, which consist of patients having received chemoradiation and at least 1 cycle of PD1 blockade for the experiment groups and patients having received chemoradiation only for the control group, the pCR rates were 33.9% and 34.5% for experiment group A and B respectively, both significantly higher than the pCR rate of 15.5% in the control group (p=0.021 and 0.019). There were no significant differences between either one of the experiment groups and the control group regarding disease progression rate, grade 3-4 treatment-related adverse event rate and grade 3-4 surgical complication rate. Conclusions: For patients with mid-low locally advanced rectal cancer, the addition of PD1 inhibitors to neoadjuvant long-course chemoradiation, whether concurrently or sequentially, increases pCR rate, meanwhile raises no significant safety concerns. For the next step, phase 3 trials with larger sample sizes are encouraged. Clinical trial information: NCT05245474 .

Neoadjuvant tislelizumab with afatinib for locally advanced head and neck squamous cell carcinoma (neoCHANCE-1): An open-label, single-arm, phase 2 study.

6073 Background: For patients with locally advanced head and neck squamous cell carcinoma (HNSCC), even receiving surgery with adjuvant radiotherapy or chemoradiotherapy, those remain at high risk of recurrence or metastasis. Neoadjuvant immunotherapy has been used in HNSCC, but provides only modest pathological response. Given single agent activity and unique mechanism of action of immune checkpoint inhibitors and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), we aimed to evaluate the antitumour activity and safety of neoadjuvant PD-1 blockade with EGFR inhibition in locally advanced HNSCC. Methods: This open-label, single-arm, phase 2 trial was done at a a tertiary hospital in China. Eligible patients were aged 18 years or older and had resectable HNSCC disease, had an Eastern Cooperative Oncology Group performance status of 0–1, had at least one measurable target lesion according to the RECIST 1.1, had no prior antitumor therapy for HNSCC. Patients received neoadjuvant treatment with intravenous tislelizumab (200 mg) on the first day of each 3 week, with totally two cycles and orally afatinib (30 mg) starting on the first treatment day and ending on the day before surgery, with totally six weeks, and then patients proceeded to receive surgical resection. The primary endpoint was major pathological response, defined as the presence of 10% or less residual viable tumour at the time of surgery. Results: A total of 25 patients were enrolled completed the neoadjuvant therapy. Eight of 23 evaluable patients exhibited a major pathological response (MPR) (35%; 95% confidence interval [CI], 16%—57%), of which four had a complete pathological response of primary tumor (17%, 95%CI, 5%—39%). The overall response rate was 48% (12/25, 95%CI: 28%—69%) and disease control rate was 100% (25/25, 95%CI: 86%—100%). Common grade 3—4 adverse events included diarrhea (5/25 [20%]), hypokalemia (4/25 [16%]) and rash (3/25 [12%]). No treatment related fatalities were observed. Immunologically, post-neoadjuvant treatment demonstrated increased CD3, CD8, and CD56 expression within the tumor microenvironment. The increase of CD8 and CD56 expression level was significant higher in patients achieving MPR, along with elevated circulatory NK cells at baseline, compared to those in patients achieving non-MPR. Conclusions: This study underscores encouraging antitumor activity, manageable toxicity profile and promising immune activation elicited by neoadjuvant tislelizumab plus afatinib for HNSCC, which deserves further assessment. Clinical trial information: NCT05517330 .

Antigen-specific profiling for neoadjuvant anti-PD-1 therapy in melanoma.

9576 Background: Anti-PD-1 therapy (aPD-1) has had significant clinical success in extending survivability of melanoma patients. However, two-third of the patients do not achieve long-lasting benefits, and currently, there exists no reliable method for predicting clinical response. We test whether monitoring melanoma-specific CD8 T cells in blood, lymph node, and tumor enables us to gain insights into the mechanism of clinical resistance, and identify potential predictive biomarkers. Methods: We leveraged a phase 2 clinical trial of neoadjuvant PD-1 blockade at University of Pennsylvania where patients with stage III melanoma patients receive a pre-treatment biopsy, treatment with a single dose of the aPD-1 therapy, followed by tumor and lymph node resection 4 weeks later, allowing for access to paired blood and tumor samples. We used a combinatorial tetramer system to track panels of 10 HLA-restricted melanoma and viral-specific CD8 T cell populations simultaneously. Results: Out of 35 patients analyzed, 53% of patients had detectable melanoma-specific CD8 T cells. Notably, these cells exhibited exhausted phenotypes both in blood and tumor, whereas viral-specific T cells displayed features resembling effector and memory CD8 T cells in blood and tumor, respectively. Thus. the presence of tumor antigen emerges as a crucial determinant in shaping the phenotype of melanoma-specific CD8 T cells, above that of the tissue microenvironment. Analysis of resected lymph node samples following PD-1 blockade reveals their supportive role in activating and proliferating anti-tumor T cells. Finally, pathologic responders to PD-1 blockade are characterized by both a higher quantity and a less exhausted phenotype of tumor-specific CD8 T cells. This suggests that assessing both the quantity and quality of these T cells can serve as a predictive indicator to distinguish responders from non-responders. Conclusions: These findings highlight the feasibility of antigen-specific profiling in a clinical trial setting, the importance of melanoma-specific CD8 T cells in checkpoint blockade responses, and their potential use an early on-treatment biomarker of clinical outcomes.

The single cell immunogenomic landscape after neoadjuvant immunotherapy combined chemotherapy in esophageal squamous cell carcinoma

Neoadjuvant immunotherapy represents promising strategy in the treatment of esophageal squamous cell carcinoma (ESCC). However, the mechanisms underlying its impact on treatment sensitivity or resistance remain a subject of controversy. In this study, we conducted single-cell RNA and T/B cell receptor (scTCR/scBCR) sequencing of CD45+ immune cells on samples from 10 patients who received neoadjuvant immunotherapy and chemotherapy. We also validated our findings using multiplexed immunofluorescence and analyzed bulk RNA-seq from other cohorts in public database. By integrating analysis of 87357 CD45+ cells, we found GZMK + effector memory T cells (Tem) were relatively enriched and CXCL13+ exhausted T cells (Tex) and regulator T cells (Treg) decreased among responders, indicating a persistent anti-tumor memory process. Additionally, the enhanced presence of BCR expansion and somatic hypermutation process within TNFRSF13B + memory B cells (Bmem) suggested their roles in antigen presentation. This was further corroborated by the evidence of the T-B co-stimulation pattern and CXCL13-CXCR5 axis. The complexity of myeloid cell heterogeneity was also particularly pronounced. The elevated expression of S100A7 in ESCC, as detected by bulk RNA-seq, was associated with an exhausted and immunosuppressive tumor microenvironment. In summary, this study has unveiled a potential regulatory network among immune cells and the clonal dynamics of their functions, and the mechanisms of exhaustion and memory conversion between GZMK + Tem and TNFRSF13B + Bmem from antigen presentation and co-stimulation perspectives during neoadjuvant PD-1 blockade treatment in ESCC.

Neoadjuvant tislelizumab plus stereotactic body radiotherapy and adjuvant tislelizumab in early-stage resectable hepatocellular carcinoma: the Notable-HCC phase 1b trial

Notable-HCC (NCT05185531) is a phase 1b trial, aiming to evaluate the safety and preliminary effectiveness of neoadjuvant PD-1 blockade plus stereotactic body radiotherapy (SBRT) in early-stage resectable hepatocellular carcinoma (HCC). Twenty patients with HCC of BCLC stage 0-A received 3×\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ imes $$\\end{document} Gy SBRT and two cycles of tislelizumab, an anti-PD-1 monoclonal antibody before the curative HCC resection. Primary endpoints were the surgery delay, radiographic and pathological tumor response after the neoadjuvant therapy, safety and tolerability. During the neoadjuvant therapy, treatment-related adverse events (TRAEs) of grade 1-2 occurred in all 20 patients (100%), eight patients (40%) had grade 3 TRAEs, no grade 4 to 5 TRAE occurred, and all resolved without corticosteroids treatment. Per mRECIST, the objective response rate was 63.2% (12/19), with 3 complete response; the disease control rate was 100%. Two (10.5%) patients achieved complete pathological response. No surgery delay occurred. The neoadjuvant therapy did not increase the surgical difficulty or the incidence of complications. Secondary endpoints of disease-free survival and overall survival were not mature at the time of the analysis. Our pilot trial shows that neoadjuvant therapy with anti-PD-1 + SBRT is safe and promotes tumor responses in early-stage resectable HCC.

T-cell subsets and cytokines are indicative of neoadjuvant chemoimmunotherapy responses in NSCLC.

Neoadjuvant PD-1 blockade combined with chemotherapy is a promising treatment for resectable non-small cell lung cancer (NSCLC), yet the immunological mechanisms contributing to tumor regression and biomarkers corresponding to different pathological responses remain unclear. Using dynamic and paired blood samples from NSCLC patients receiving neoadjuvant chemoimmunotherapy, we analyzed the frequencies of CD8 + T-cell and Treg subsets and their dynamic changes during neoadjuvant treatment through flow cytometry. Cytokine profiles and function-related gene expression of CD8 + T cells and Tregs were analyzed through flow cytometry and mRNA-seq. Infiltrating T-cell subsets in resected tissues from patients with different pathological responses were analyzed through multiplex immunofluorescence. Forty-two NSCLC patients receiving neoadjuvant chemoimmunotherapy were enrolled and then underwent surgical resection and pathological evaluation. Nineteen patients had pCR (45%), 7 patients had MPR (17%), and 16 patients had non-MPR (38%). In patients with pCR, the frequencies of CD137 + CD8 + T cells (P = 0.0475), PD-1 + Ki-67 + CD8 + T cells (P = 0.0261) and Tregs (P = 0.0317) were significantly different from those of non-pCR patients before treatment. pCR patients usually had low frequencies of CD137 + CD8 + T cells, PD-1 + Ki-67 + CD8 + T cells and Tregs, and their AUCs were higher than that of tissue PD-L1 expression. Neoadjuvant chemoimmunotherapy markedly improved CD8 + T-cell proliferation and activation, especially in pCR patients, as the frequencies of CD137 + CD8 + (P = 0.0136) and Ki-67 + CD8 + (P = 0.0391) T cells were significantly increased. The blood levels of cytokines such as IL-2 (P = 0.0391) and CXCL10 (P = 0.0195) were also significantly increased in the pCR group, which is consistent with the high density of activated cytotoxic T cells at the tumor site (P < 0.0001). Neoadjuvant chemoimmunotherapy drives CD8 + T cells toward a proliferative and active profile. The frequencies of CD137 + CD8 + T cells, PD-1 + Ki-67 + CD8 + T cells and Tregs at baseline might predict the response to neoadjuvant chemoimmunotherapy in NSCLC patients. The increase in IL-2 and CXCL10 might reflect the chemotaxis and enrichment of cytotoxic T cells at the tumor site and a better response to neoadjuvant chemoimmunotherapy.

Abstract 5173: TRAIL expression in tumor cells predicts and drives poor response to neoadjuvant immunochemotherapy in esophageal squamous cell carcinoma

Abstract Background: Neoadjuvant PD-1 blockade combined with chemotherapy has shown promising antitumor efficacy in the therapy of esophageal squamous cell carcinoma (ESCC). However, effective biomarkers and potential mechanisms of resistance to this treatment are still unclear. Methods: We prospectively collected pre- and post-neoadjuvant treatment ESCC tissues from 40 patients who received PD-1blockade (camrelizumab, 200mg) and chemotherapy (albumin-paclitaxel, 260mg/m2 and carboplatin, area under the curve = 5). Based on their pathological responses to neoadjuvant immunochemotherapy (NICT), patients were classified into “responder” and “non-responder” groups. All samples were subjected to bulk RNA-sequencing and whole-exome sequencing. Of note, samples from 14 patients in both groups were subjected to single cell RNA sequencing and TCR sequencing. We characterized and validated the changes in the immunological landscape of “responder” and “non-responder” groups using multi-omics sequencing data, multiplex immunofluorescence, in vitro and in vivo experiments. External validation cohorts of ESCC treated with NICT were analyzed to validate the predictive biomarkers for NICT. Results: We found that TNF-related apoptosis-inducing ligand (TRAIL) signaling was significantly higher in pre-treatment non-responders than in responders, and was inversely correlated with T cell proliferation and TCR expansion. TRAIL was mainly secreted by tumor cells and bound to its specific receptor DR5 in T cells, thereby inhibiting the activation of T cells. Functional co-culture experiments and T cell cytotoxicity assays revealed that TRAIL+ tumor cells mediated T cell suppression and caused CD8+ T cell dysfunction. Furthermore, TRAIL inhibition could improve the efficacy of anti-PD-1 in a xenografted mouse model. In bulk RNA-seq (n=40), TRAIL expression was associated with worse disease-free survival and overall survival, however, these results were not observed in the ESCC cohort treated with upfront surgery from the TCGA database, suggesting that the predictive value of TRAIL is specific to NICT. In an external validation cohort of ESCC patients treated with NICT (n=81), multivariable Cox regression analysis showed that high TRAIL expression was an independent risk factor for unfavorable outcomes. Importantly, TRAIL expression exhibited a higher accuracy in predicting NICT response compared with PD-L1 expression in ESCC (AUC of ROC curves: 0.886 vs 0.607, respectively P&amp;lt;0.001). Meanwhile, the serum concentrations of TRAIL (measured by ELISA) in pre-NICT ESCC patients were also significantly higher in non-responders (n=58). Conclusions: TRAIL expression in tumor cells is negatively correlated with the response of ESCC to NICT. TRAIL expression may serve as a promising biomarker to predict NICT response and guide NICT selection in ESCC patients. Citation Format: Weixiong Yang, Fang Wang, Jianping Guo, Junchao Cai, Zekang Wang, Yao Liu, Zengli Fang, Wenfang Chen, Lixia Xu, Shuishen Zhang, Bo Zeng, Zhenguo Liu, Sui Peng, Sai-Ching Jim Yeung, Chao Cheng. TRAIL expression in tumor cells predicts and drives poor response to neoadjuvant immunochemotherapy in esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5173.

Abstract 2876: Spatial immune cell atlas predicts the sensitivity to neoadjuvant PD-1 blockade treatment combined with radiotherapy in resectable esophageal squamous cell carcinoma

Abstract Combination of radiotherapy and immunotherapy in neoadjuvant treatment seems a promising approach in resectable esophageal squamous cell squamous (ESCC). The clinical study of radiotherapy combined with PD-1 blockade therapy for neoadjuvant treatment of resectable ESCC shows good result. In order to investigate the underlying mechanism of the effectiveness of radiotherapy combined with immunotherapy in ESCC, we collected the pre and post neoadjuvant therapy samples from 5 responders and 5 non-responders ESCC patients and performed multiplexed tissue imaging using 28 markers. Using the detection measurements exported from QuPath, we performed the unsupervised clustering with Seurat and defined 20 cell types. Scimap was used to calculate the distance between different cell types. We found that CD4+ T, CD8+ T, cytotoxic CD8+ T cells and M1 macrophages showed an increase after treatment in both responders and non-responders. Tregs were decreased after neoadjuvant treatment in responder while there was no significant decrease in non-responder. And the distance between Tregs and cancer cells were increased in responders. Collectively, we provide an approach for investigating the underlying mechanism of the sensitivity to neoadjuvant PD-1 blockade treatment combined with radiotherapy in resectable ESCC using spatial multiplexed imaging. Citation Format: Xiaoyang Yin, Kailun Xu, Shu Zheng, Baosheng Li. Spatial immune cell atlas predicts the sensitivity to neoadjuvant PD-1 blockade treatment combined with radiotherapy in resectable esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2876.

EXTH-07. NEOADJUVANT PD1 BLOCKADE ALTERS THE TUMOR MICROENVIRONMENT POST-SURGERY IN A PRECLINICAL MODEL OF RECURRENT GLIOBLASTOMA

Abstract SIGNIFICANCE Clinical trials investigating neoadjuvant immunotherapy in recurrent glioblastoma patients have shown promising results. In this study, we aimed to assess the impact of neoadjuvant PD1 blockade on the tumor microenvironment after surgery using a relevant murine model of recurrent glioblastoma. OBJECTIVE Our objective was to investigate the effects of neoadjuvant PD1 inhibition on mouse survival and analyze the transcriptome and spatial genomic changes within the intratumoral immune populations following surgery. We compared these changes with those observed in adjuvant anti-PD1 treatment. RESULTS Through our established murine resection model of recurrent KR158 glioblastoma, we demonstrated that neoadjuvant PD1 inhibition prior to tumor debulking significantly improved mouse survival compared to adjuvant treatment. Transcriptome and spatial genomic analyses revealed notable alterations in immune exhaustion and activation pathway genes after neoadjuvant anti-PD1 treatment, distinguishing it from adjuvant anti-PD1 treatment. RNA and protein analyses indicated upregulation of various pathways, including PI3K/AKT, NOTCH, NK cell, MAPK, NF-kB, type II interferon, and TNF, in the neoadjuvant treatment group compared to the adjuvant anti-PD1 treatment group. Single-cell RNA sequencing analyses further revealed an increased proportion of CD8 T, NKT, and NK cells, accompanied by a decreased percentage of CD4 T cells in the neoadjuvant group. Importantly, we observed a significant enhancement in the interaction strength between CD8 T cells and all other immune cells in the neoadjuvant group compared to the adjuvant treatment group. CONCLUSIONS Our findings demonstrate distinct differences in immune cell populations and gene expression profiles between neoadjuvant and adjuvant anti-PD1 therapies in our murine recurrent glioblastoma resection model. These insights provide valuable understanding of the potential mechanisms underlying the divergent efficacy of neoadjuvant and adjuvant anti-PD1 therapies.

Biomarkers of Pathologic Complete Response to Neoadjuvant Immunotherapy in Mismatch Repair-Deficient Colorectal Cancer.

Immune checkpoint inhibitors (ICI) have become the standard of care for patients with mismatch repair-deficient/microsatellite instability-high (dMMR/MSI-H) colorectal cancer. However, biomarkers of response to ICI are still lacking. Forty-two patients with dMMR colorectal cancer treated with neoadjuvant PD-1 blockade were prospectively enrolled. To identify biomarkers of pathologic complete response (pCR) to neoadjuvant therapy, we analyzed genomic and transcriptomic profiles based on next-generation sequencing, and immune cell density based on multiplex immunofluorescence (mIF) staining. An integrated analysis of single-cell RNA sequencing from our previous study and GSE178341, as well as mIF was performed to further explore the significance of the tumor microenvironment (TME) on pCR response. The tumor mutation burden of both tumor tissue and plasma blood samples was comparable between the pCR and non-pCR groups, while HLA-DQA1 and HLA-DQB1 were significantly overexpressed in the pCR group. Gene signature enrichment analysis showed that pathways including T-cell receptor pathway, antigen presentation pathway were significantly enriched in the pCR group. In addition, higher pre-existing CD8+ T-cell density was associated with pCR response (767.47 per.mm2 vs. 326.64 per.mm2, P = 0.013 Wilcoxon test). Further integrated analysis showed that CD8+ T cells with low PD-1 expression (PD-1lo CD8+ T cells) expressing high levels of TRGC2, CD160, and KLRB1 and low levels of proliferated and exhausted genes were significantly associated with pCR response. Immune-associated transcriptomic features, particularly CD8+ T cells were associated with pCR response to ICI in dMMR colorectal cancer. Heterogeneity of TME within dMMR colorectal cancer may help to discriminate patients with complete response to neoadjuvant ICI.

Progenitor-like exhausted SPRY1+CD8+ T cells potentiate responsiveness to neoadjuvant PD-1 blockade in esophageal squamous cell carcinoma

Neoadjuvant immune checkpoint blockade (ICB) demonstrates promise in operable esophageal squamous cell carcinoma (ESCC), but lacks available efficacy biomarkers. Here, we perform single-cell RNA-sequencing of tumors from patients with ESCC undergoing neoadjuvant ICB, revealing a subset of exhausted CD8+ Tcells expressing SPRY1 (CD8+ Tex-SPRY1) that displays a progenitor exhausted Tcell (Tpex) phenotype and correlates with complete response to ICB. We validate CD8+ Tex-SPRY1 cells as an ICB-specific predictor of improved response and survival using independent ICB-/non-ICB cohorts and demonstrate that expression of SPRY1 in CD8+ Tcells enforces Tpex phenotype and enhances ICB efficacy. Additionally, CD8+ Tex-SPRY1 cells contribute to proinflammatory phenotype of macrophages and functional state of B cells, which thereby promotes antitumor immunity by enhancing CD8+ Tcell effector functions. Overall, our findings unravel progenitor-like CD8+ Tex-SPRY1 cells' role in effective responses to ICB for ESCC and inform mechanistic biomarkers for future individualized immunotherapy.

Preexisting tumor-resident T cells with cytotoxic potential associate with response to neoadjuvant anti-PD-1 in head and neck cancer.

About 50% of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) experience recurrences after definitive therapy. The presurgical administration of anti-programmed cell death protein 1 (PD-1) immunotherapy results in substantial pathologic tumor responses (pTR) within the tumor microenvironment (TME). However, the mechanisms underlying the dynamics of antitumor T cells upon neoadjuvant PD-1 blockade remain unresolved, and approaches to increase pathologic responses are lacking. In a phase 2 trial (NCT02296684), we observed that 45% of patients treated with two doses of neoadjuvant pembrolizumab experienced marked pTRs (≥50%). Single-cell analysis of 17,158 CD8+ T cells from 14 tumor biopsies, including 6 matched pre-post neoadjuvant treatment, revealed that responding tumors had clonally expanded putative tumor-specific exhausted CD8+ tumor-infiltrating lymphocytes (TILs) with a tissue-resident memory program, characterized by high cytotoxic potential (CTX+) and ZNF683 expression, within the baseline TME. Pathologic responses after 5 weeks of PD-1 blockade were consistent with activation of preexisting CTX+ZNF683+CD8+ TILs, paralleling loss of viable tumor and associated tumor antigens. Response was associated with high numbers of CD103+PD-1+CD8+ T cells infiltrating pretreatment lesions, whereas revival of nonexhausted persisting clones and clonal replacement were modest. By contrast, nonresponder baseline TME exhibited a relative absence of ZNF683+CTX+ TILs and subsequent accumulation of highly exhausted clones. In HNSCC, revival of preexisting ZNF683+CTX+ TILs is a major mechanism of response in the immediate postneoadjuvant setting.

A CT-based novel model to predict pathological complete response of locally advanced esophageal squamous cell carcinoma to neoadjuvant PD-1 blockade in combination with chemotherapy

PurposeTo develop a novel CT-based model to predict pathological complete response (pCR) of locally advanced esophageal squamous cell carcinoma (ESCC) to neoadjuvant PD-1 blockade in combination with chemotherapy. Methods117 consecutive patients with locally advanced ESCC were stratified into training cohort (n = 82) and validation cohort (n = 35). All patients underwent non-contrast and contrast-enhanced thoracic and upper abdominal CT before neoadjuvant PD-1 blockade in combination with chemotherapy (CTpre), and after two cycles of the therapy before esophagectomy (CTpost), respectively. Univariate analyses and binary logistic regression analyses of ESCC quantitative and qualitative CT features were performed to determine independent predictors of pCR. Prediction performance of the model developed with independent predictors from training cohort was evaluated by receiver operating characteristic (ROC) analysis, and validated by Kappa test in validation cohort. ResultsIn training cohort, the difference in CT attenuation between tumor and background normal esophageal wall obtained from CTpre (ΔTNpre), tumoral increased CT attenuation after contrast-enhanced scan from CTpost images (ΔTpost) and gross tumor volume (GTV) from CTpre were independent predictors of pCR (odds ratio = 1.128 (95% confidence interval (CI): 0.997–1.277), 1.113 (95%CI: 0.965–1.239) and 1.133 (95%CI: 1.043–1.231), respectively, all P-values < 0.05). Logistic regression model equation (0.121 × ΔTNpre + 0.107 × ΔTpost + 0.125 × GTV − 9.856) to predict pCR showed the best performance with an area under the ROC of 0.876, compared with each independent predictor. The good performance was confirmed by the Kappa test (K-value = 0.796) in validation cohort. ConclusionsThis novel model can be reliable to predict pCR to neoadjuvant PD-1 blockade in combination with chemotherapy in locally advanced ESCC.

China special issue on gastrointestinal tumor-radiological features of pathological complete response in mismatch repair deficient colorectal cancer after neoadjuvant PD-1 blockade: A post hoc analysis of the PICC phase II trial.

Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy.

Intensive cycles of neoadjuvant camrelizumab combined with chemotherapy in locally advanced esophageal squamous cell carcinoma: a single-arm, phase II trial

BackgroundTwo cycles of neoadjuvant PD-1 blockade plus chemotherapy induced favorable pathological response and tolerant toxicity in patients with locally advanced esophageal squamous cell carcinoma (ESCC). However, approximately 25% of patients relapsed within 1 year after surgery, indicating that a short course of treatment may not be sufficient. Therefore, exploring the effects of intensive treatment is needed for optimal clinical outcomes.MethodsLocally advanced ESCC patients were administered three cycles of camrelizumab plus nab-paclitaxel and capecitabine, followed by thoracoscopic esophagectomy. The primary endpoint was pathologic response. Secondary endpoints included safety, feasibility, radiologic response, survival outcomes, and immunologic/genomic correlates of efficacy.ResultsForty-seven patients were enrolled in the study. Forty-two patients received surgery, and R0 resection was achieved in all cases. The complete and major pathological response rates were 33.3% and 64.3%, respectively, and the objective response rate was 80.0%. Three cycles of treatment significantly improved T down-staging compared to two cycles (P = 0.03). The most common treatment-related adverse events were grades 1–2, and no surgical delay was reported. With a median follow-up of 24.3 months, the 1-year disease-free survival and overall survival rates were both 97.6%, and the 2-year disease-free survival and overall survival rates were 92.3% and 97.6%, respectively. Three patients experienced disease recurrence or metastasis ranging from 12.5 to 25.8 months after surgery, and one patient died 6 months after surgery due to cardiovascular disease. Neither programmed death-ligand 1 expression nor tumor mutational burden was associated with pathological response. An increased infiltration of CD56dim natural killer cells in the pretreatment tumor was correlated with better pathological response in the primary tumor.ConclusionsIt seems probable that intensive cycles of neoadjuvant camrelizumab plus nab-paclitaxel and capecitabine increased tumor regression and improved survival outcomes. Randomized controlled trials with larger sample sizes and longer follow-up periods are needed to validate these findings.Trial registration Chinese Clinical Trial Registry, ChiCTR2000029807, Registered February 14, 2020, https://www.chictr.org.cn/showproj.aspx?proj=49459.