Clinical trials of neoadjuvant immune checkpoint inhibitors for early-stage operable colon and rectal cancer

Neoadjuvant Immunotherapy Followed by Surgery Compared with Upfront Surgery Alone in Operable Colon Cancer with Deficient Mismatch Repair: Modeling Oncological Outcomes and Numbers Needed to Treat

BACKGROUND

Trials on neoadjuvant immunotherapy in operable colon cancer with deficient mismatch repair (dMMR) reported high pathological response rates in the surgical specimen, but long-term survival is not known. Neoadjuvant immunotherapy as a stand-alone therapy without subsequent radical surgery is currently not investigated in colon cancer.

OBJECTIVE

The aim of this study was to model outcomes between trial data and real-world patients after surgery.

METHODS

We conducted a comparative modeling study between prospective trial data (NICHE-1) and a prospective, population-derived, translational cohort study (ACROBATICC) of patients with operable colon cancer and microsatellite instability (MSI) status. Comparison was performed across immune-cell infiltrates, stages, MSI, and patient demographics for adverse events, reported oncological outcomes, and modeling numbers needed to treat (NNT) to prevent recurrence.

RESULTS

Patient characteristics between the dMMR tumors in the NICHE-1 (n = 21) and ACROBATICC (n = 43) cohorts differed, with older patients and fewer hereditary dMMRs in the 'real-life' ACROBATICC cohort. Higher expression of CD8+ in dMMR tumors compared with proficient mismatch repair (pMMR) tumors was statistically significant across both cohorts. At long-term follow-up, 2/43 patients with dMMR had died from recurrent colon cancer in the ACROBATICC cohort. Assuming a curative effect of neoadjuvant immunotherapy in addition to surgery in dMMR tumors, the NNT would be >20 patients for any additional survivor.

CONCLUSION

In unselected patients with colon cancer having dMMR, recurrence risk is very low after surgery. Assuming a curative effect of neoadjuvant immunotherapy beyond surgery alone, the NNT would be at least 20 patients to prevent one cancer death over surgery alone.

ICOS+ CD4+ T cells promote antitumor immunity through Akt/STAT1/T-bet axis in MSS/pMMR colorectal cancer

Inducible Co-Stimulator (ICOS), as a T-cell-specific costimulatory receptor that enhances T-cell responses to foreign antigens, plays a crucial role in cancer immunity. However, its role in MSS/pMMR colorectal cancer (CRC) remains unclear. In this study, we demonstrated that ICOS expression decreases as the tumor stages advance and that high ICOS expression is associated with a favorable prognosis in MSS/pMMR CRC. Mechanistically, ICOS promoted the secretion of IFN-γ, TNF-α, and IL-12 in CD4+ T cells through the Akt/STAT1/T-bet axis, leading to the inhibition of MSS/pMMR-CRC-cell proliferation. Importantly, ICOS+ CD4+ T cells enhanced tumor responses to anti-PD-1 therapy in MSS/pMMR CRC. In conclusion, this study revealed that ICOS mediates antitumor immunity by promoting the secretion of cancer-suppressive cytokines. It also suggests that activation of ICOS serves a potential therapeutic strategy for MSS/pMMR CRC.

A constitutive interferon-high immunophenotype defines response to immunotherapy in colorectal cancer

Fewer than 50% of metastatic deficient mismatch repair (dMMR) colorectal cancer (CRC) patients respond to immune checkpoint inhibition (ICI). Identifying and expanding this patient population remains a pressing clinical need. Here, we report that an interferon-high immunophenotype locally enriched in cytotoxic lymphocytes and antigen-presenting macrophages is required for response. This immunophenotype is not exclusive to dMMR CRCs but comprises a subset of MMR proficient (pMMR) CRCs. Single-cell spatial analysis and in vitro cell co-cultures indicate that interferon-producing cytotoxic T cells induce overexpression of antigen presentation in adjacent macrophages and tumor cells, including MHC class II invariant chain CD74. dMMR CRCs expressing high levels of CD74 respond to ICI and a subset of CD74 high pMMR CRC patients show better progression free survival when treated with ICI. Therefore, CD74 abundance can identify the constitutive interferon-high immunophenotype determining clinical benefit in CRC, independently of tumor mutational burden or MMR status.

The role of cGAS-STING signaling pathway in colorectal cancer immunotherapy: Mechanism and progress

Colorectal cancer (CRC) is a common malignant tumor in the gastrointestinal tract, it is known as the "silent killer", which poses a serious threat to the lives of patients. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon gene (STING) signaling pathway responds to DNA by sensing, which plays an important role in anti-infection, autoimmune diseases and anti-tumor immunity. Recent studies have found that the activation of cGAS-STING pathway in CRC can induce the expression and secretion of type I interferon (IFN-I) and a variety of inflammatory factors, further activate anti-tumor CD8+ T cells, exert anti-tumor immune response, and inhibit the progression of CRC. Therefore, targeting the cGAS-STING pathway and developing drugs that can regulate the cGAS-STING pathway are of great significance for improving the therapeutic effect and prognosis of CRC patients. In this review, we introduce the cGAS-STING signaling pathway and the regulatory role of this signaling pathway in CRC immune microenvironment. In addition, we discussed the research progress of cGAS-STING pathway in CRC immunotherapy and the clinical research status of STING agonists developed against this pathway, emphasizing the clinical potential of CRC immunotherapy based on the cGAS-STING signaling pathway.

Adding first-line PD-1 inhibition to anti-VEGF and XELOX in pMMR metastatic colorectal cancer: Steppingstones, stumbling blocks, and next phase

In the randomized, double-blind, multicenter study by Wang et al.,1 the addition of serplulimab (a PD-1 antibody) to anti-VEGF (HLX04; a bevacizumab biosimilar) together with chemotherapy (XELOX) was deemed to be tolerable and safe and may improve progression-free survival. However, even if adverse events were comparable, oncological endpoints including survival need to be confirmed in the next phase 3 study.

Comprehensive analysis of bulk and single-cell RNA sequencing data reveals Schlafen-5 (SLFN5) as a novel prognosis and immunity

Recent advancements have elucidated the multifaceted roles of the Schlafen (SLFN) family, including SLFN5, SLFN11, SLFN12, SLFN13, and SLFN14, which are implicated in immunological responses. However, little is known about the roles of this gene family in relation to malignancy development. The current study aimed to explore the diagnostic and prognostic potential of Schlafen family genes in colorectal adenocarcinoma (COAD) through bioinformatics analysis. Leveraging advanced bioinformatics tools of bulk RNA-sequencing and single-cell sequencing, we conducted in-depth analyses of gene expressions, functional enrichment, and survival patterns of patients with colorectal cancer compared to normal tissue. Among Schlafen family genes, the transcription levels of SLFN5 in COAD tissues were significantly elevated and correlated with poor survival outcomes. Furthermore, SLFN5 regulated the immune response via Janus kinase (JAK)/signal transduction and activator of transcription (STAT)/interferon (IFN)-alpha/beta signaling. These chemokines in inflammation are associated with diabetes and metabolism, suggesting their involvement in altered cellular energetics for COAD progress. In addition, an immune cell deconvolution analysis indicated a correlation between SLFN5 expression and immune-related cell populations, such as regulatory T cells (Tregs). These findings highlighted the potential clinical significance of SLFN5 in COAD and provided insights into its involvement in the tumor microenvironment and immune regulation. Meanwhile, the drug discovery data of SFLN5 with potential targeted small molecules suggested its therapeutic potential for COAD. Collectively, the current research demonstrated that SFLN5 play crucial roles in tumor development and serve as a prospective biomarker for COAD.

Advancements in neoadjuvant immune checkpoint inhibitor therapy for locally advanced head and neck squamous Carcinoma: A narrative review

The prevalent treatment paradigm for locally advanced head and neck squamous carcinoma (HNSCC) typically entails surgery followed by adjuvant radiotherapy and chemotherapy. Despite this, a significant proportion of patients experience recurrence and metastasis. Immune checkpoint inhibitors (ICIs), notably pembrolizumab and nivolumab, have been established as the first and second lines of treatment for recurrent and metastatic HNSCC (R/M HNSCC). The application of ICIs as neoadjuvant immunotherapy in this context is currently under rigorous investigation. This review synthesizes data from clinical trials focusing on neoadjuvant ICIs, highlighting that the pathological responses elicited by these treatments are promising. Furthermore, it is noted that the safety profiles of both monotherapy and combination therapies with ICIs are manageable, with no new safety signals identified. The review concludes by contemplating the future direction and challenges associated with neoadjuvant ICI therapy, encompassing aspects such as the refinement of imaging and pathological response criteria, selection criteria for adjuvant therapies, evaluation of the efficacy and safety of various combination treatment modalities, and the identification of responsive patient cohorts.

Programmed death ligand-1 (PD-L1) clone 22C3 expression in resected colorectal cancer as companion diagnostics for immune checkpoint inhibitor therapy: A comparison study and inter-rater agreement evaluation across proposed cut-offs and predictive (TPS, CPS and IC) scores

BACKGROUND

Expression of programmed death ligand-1 (PD-L1) guides the use of immune checkpoint inhibitors (ICI) in several cancers. In colorectal cancer (CRC), ICI are only approved for metastatic CRC, while several studies suggest high efficacy even in operable CRC. The aim of this study was to investigate the inter-rater agreement of PD-L1 as a companion diagnostic marker.

METHODS

Specimens from resected stage I-III CRC (n = 166 tumors) were stained with PD-L1 22C3 clone. PD-L1 expression was scored by two pathologists as tumor proportion score (TPS), combined positive score (CPS) and immune cell score (IC). Inter-rater agreement was tested using three different agreement coefficients.

RESULTS

Raw scores of the two pathologists had 'good' to 'excellent' correlation. Spearman's rho for TPS=0.917 (95 %CI 0.839-0.995), for CPS=0.776 (95 %CI 0.726-0.826) and IC=0.818 (95 %CI 0.761-0.875). For TPS, kappa (κ)-agreements for both the ≥1 % and ≥10 % cutoffs had excellent correlation. For CPS the ≥1 % and ≥10 % cutoffs demonstrated κ=0.32 (95 %CI 0.12-0.51) and κ=0.36 (95 %CI 0.25-0.48) respectively. Cutoffs for IC showed κ=0.53 (95 %CI 0.18-0.79) for the ≥1 % cutoff, and κ=0.61 (95 %CI 0.48-0.73) for the ≥10 % cutoff. Gwet's agreement coefficient (AC1) showed higher agreement coefficients than κ-values for most, but not all cut-offs.

CONCLUSION

Agreement for PD-L1 was good to excellent for raw scores. Agreement variation across several criteria and cut-offs suggests the need for more robust criteria for PD-L1 as a companion diagnostic marker.