Immune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade. We enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8+ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD. A total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868-7.440] and overall survival (HR, 5.079; 95% CI, 3.136-8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8+ T lymphocytes, a lower frequency of effector/memory subsets (CCR7-CD45RA- T cells among the total CD8+ T cells) and a higher frequency of severely exhausted populations (TIGIT+ T cells among PD-1+CD8+ T cells) were associated with HPD and inferior survival rate. HPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.

Background: T cells exhibit heterogeneous functional states in the tumor microenvironment. Immune checkpoint inhibitors (ICIs) can reinvigorate only the stem cell-like progenitor exhausted T cells, which suggests that inhibiting the exhaustion progress will improve the efficacy of immunotherapy. Thus, regulatory factors promoting T cell exhaustion could serve as potential targets for delaying the process and improving ICI efficacy. Methods: We analyzed the single-cell transcriptome data derived from human melanoma and non-small cell lung cancer (NSCLC) samples and classified the tumor-infiltrating (TI) CD8⁺ T cell population based on PDCD1 (PD-1) levels, i.e., PDCD1-high and PDCD1-low cells. Additionally, we identified differentially expressed genes as candidate factors regulating intra-tumoral T cell exhaustion. The co-expression of candidate genes with immune checkpoint (IC) molecules in the TI CD8⁺ T cells was confirmed by single-cell trajectory and flow cytometry analyses. The loss-of-function effect of the candidate regulator was examined by a cell-based knockdown assay. The clinical effect of the candidate regulator was evaluated based on the overall survival and anti-PD-1 responses. Results: We retrieved many known factors for regulating T cell exhaustion among the differentially expressed genes between PDCD1-high and PDCD1-low subsets of the TI CD8⁺ T cells in human melanoma and NSCLC. TOX was the only transcription factor (TF) predicted in both tumor types. TOX levels tend to increase as CD8⁺ T cells become more exhausted. Flow cytometry analysis revealed a correlation between TOX expression and severity of intra-tumoral T cell exhaustion. TOX knockdown in the human TI CD8⁺ T cells resulted in downregulation of PD-1, TIM-3, TIGIT, and CTLA-4, which suggests that TOX promotes intra-tumoral T cell exhaustion by upregulating IC proteins in cancer. Finally, the TOX level in the TI T cells was found to be highly predictive of overall survival and anti-PD-1 efficacy in melanoma and NSCLC. Conclusions: We predicted the regulatory factors involved in T cell exhaustion using single-cell transcriptome profiles of human TI lymphocytes. TOX promoted intra-tumoral CD8⁺ T cell exhaustion via upregulation of IC molecules. This suggested that TOX inhibition can potentially impede T cell exhaustion and improve ICI efficacy. Additionally, TOX expression in the TI T cells can be used for patient stratification during anti-tumor treatments, including anti-PD-1 immunotherapy.

Background Regulatory T (T_reg) cells have an immunosuppressive function in cancer, but the underlying mechanism of immunosuppression in the tumor microenvironment (TME) is unclear. Methods We compared the phenotypes of T cell subsets, including T_reg cells, obtained from peripheral blood, malignant effusion, and tumors of 103 cancer patients. Our primary focus was on the expression of immune checkpoint (IC)-molecules, such as programmed death (PD)-1, T-cell immunoglobulin and mucin-domain containing (TIM)-3, T cell Ig and ITIM domain (TIGIT), and cytotoxic T lymphocyte antigen (CTLA)-4, on T_reg cells in paired lymphocytes from blood, peritumoral tissue, and tumors of 12 patients with lung cancer. To identify the immunosuppressive mechanisms acting on tumor-infiltrating T_reg cells, we conducted immunosuppressive functional assays in a mouse model. Results CD8⁺, CD4⁺ T cells, and T_reg cells exhibited a gradual upregulation of IC-molecules the closer they were to the tumor. Interestingly, PD-1 expression was more prominent in T_reg cells than in conventional T (T_conv) cells. In lung cancer patients_, higher levels of IC-molecules were expressed on T_reg cells than on T_conv cells, and T_reg cells were also more enriched in the tumor than in the peri-tumor and blood. In a mouse lung cancer model, IC-molecules were also preferentially upregulated on T_reg cells, compared to T_conv cells. PD-1 showed the greatest increase on most cell types, especially T_reg cells, and this increase occurred gradually over time after the cells entered the TME. PD-1 high-expressing tumor-infiltrating T_reg cells displayed potent suppressive activity, which could be partially inhibited with a blocking anti-PD-1 antibody. Conclusions We demonstrate that the TME confers a suppressive function on T_reg cells by upregulating IC-molecule expression. Targeting IC-molecules, including PD-1, on T_reg cells may be effective for cancer treatment.

Purpose Immune checkpoint inhibitors (ICI) have shown marked responses in patients with non-small cell lung cancer (NSCLC) in clinical trials. However, because such trials comprise cohorts selected based on specific criteria, it is unclear if their results represent routine clinical practice. Methods We examined 155 patients with advanced NSCLC who were administered either nivolumab or pembrolizumab at Yonsei Cancer Center, Korea between March 2014 and January 2019. Patient characteristics, EGFR/ALK mutation status, metastatic locations, response to ICIs, and adverse events were retrospectively analyzed. Results The median age was 64 years and 72.9% of patients were male; former or current smokers constituted 67.1% of the subjects. Adenocarcinoma was predominant (67.7%), and 50.3% of the patients underwent ≥ 2 previous treatments. Twenty-three patients (14.8%) were EGFR mutation- or ALK rearrangement-positive. The objective response rate (ORR) was 23.9% [95% confidence interval (CI) 17.4–31.4%]; the median progression-free survival (PFS) and overall survival (OS) were 3.06 (95% CI 1.893–4.21) and 10.25 (95% CI 5.39–15.11) months, respectively. Multivariate analysis identified ECOG performance status, EGFR mutation/ALK rearrangement status, liver metastasis and PD-L1 proportion as independent predictors of OS. Furthermore, 61.9% of the patients had adverse events of any grade; 38.1% had immune-related adverse events that were associated with PFS and OS on multivariate analysis. Conclusions The real-world ORR, PFS, OS, and adverse event profiles were comparable to previous clinical trials despite the patients’ different baseline characteristics. Our findings can aid in establishing effective immunotherapeutic management of NSCLC in routine clinical practice.

Radical lymph node dissection (LND) along the left recurrent laryngeal nerve (RLN) is surgically demanding and can be associated with substantial postoperative morbidity. The question of whether robot-assisted esophagectomy (RE) might be superior to video-assisted thoracoscopic esophagectomy (VATE) for performing LND along the RLN in patients with esophageal squamous cell carcinoma (ESCC) remains open. We will conduct a multicenter, open-label, randomized controlled trial (Robotic-assisted Esophagectomy vs Video-Assisted Thoracoscopic Esophagectomy (REVATE)) enrolling patients with ESCC scheduled to undergo LND along the RLN. Patients will be randomly assigned to either RE or VATE. The primary outcome measure will be the rate of unsuccessful LND along the left RLN, which will be defined as: failure to remove lymph nodes along the left RLN (i.e., no identifiable nodes on pathology reports); or occurrence of permanent (duration > 6 months) left RLN palsy following LND. Secondary outcomes will include the number of successfully removed RLN nodes, postoperative recovery, length of hospital stay, 30-day and 90-day mortality, quality of life, and oncological outcomes. The REVATE study provides an opportunity to explore whether RE could facilitate LND along the left RLN—a complex surgical procedure that, as of now and with the use of VATE, remains difficult to perform and associated with a significant burden of morbidity. ClinicalTrials.gov, NCT03713749 . Registered on 22 October 2018.