Gastric cancer (GC) represents a global health-care challenge. Recent progress in immunotherapy has elicited attracted considerable attention as a viable treatment option through modulating the host immune system and unleashing pre-existing immunity, which has profoundly revolutionized oncology, especially GC. Nonetheless, low clinical response and intrinsic and acquired resistance remain persistently challenging. The microenvironment of GC comprising multifarious stromal cell types has remarkable immunosuppressive elements that may impact the efficacy of immunotherapy. Immunosenescence is increasingly regarded as a factor that contributes to cancer development, remodels the tumor microenvironment and affects the efficacy of immunotherapy. Natural products are at the forefront of traditional medicine. Senotherapeutics is a class of drugs and natural products capable of delaying, preventing, or reversing the senescence process (i.e., senolytics) or suppressing senescence-associated secretory phenotype (i.e., senomorphics). Emerging evidence supports that natural products can improve the efficacy of existing immunotherapy and expand their indications in GC mainly based upon remodeling the immunosuppressive microenvironment and reversing immunosenescence. The review provides an integrated review of previously reported and ongoing clinical trials with immunotherapeutic regimens in GC and discusses current challenges. Next, we focus on natural compounds that exert anti-GC functions and possess immunomodulatory properties. More attention is paid to the potential of these natural compounds in modulating the immune microenvironment and immunosenescence. Lastly, we discuss the nanomedicine that can overcome the deficiencies of natural products. Altogether, our review suggests the enormous potential of natural compounds in GC immunotherapy, and provides an important direction for future research.

to analyze the most robust research and recommendations that have informed the potential superiority of treatments with anticancer drugs over any type of supportive care for advanced esophageal cancer (EC).

We conducted a critical historical review. First, we identified randomized clinical trials (RCTs) from a previous scoping review conducted by our research group, ASTAC, updating the search strategy. Second, we searched for the most important and recognized international clinical practice guidelines (CPGs) in advanced EC. Finally, we performed a systematic document analysis to compare whether the recommendations proposed in the CPGs were supported by the previously identified relevant evidence.

We identified and assessed 15 RCTs and 11 CPGs from ESMO (eight), ASCO (two), and NICE (one) published over the last 40 years. There is a clear mismatch between these guidelines' recommendations and the available RCTs regarding the efficacy of anticancer drugs compared to best supportive care (BSC).

There is a lack of consistent evidence to support the treatment of advanced EC patients with anticancer drugs, and a notable mismatch exists between the available evidence and the recommendations made by relevant CPGs. As a result, these guidelines may be biased in favoring the use of anticancer drugs over supportive care and in consequence it is advisable to be very prudent when proposing systemic treatments to patients with advanced EC. Further rigorous and independent research is needed to better evaluate the true benefits of anticancer treatments in advanced EC and to update the CPGs accordingly.

Claudin 18 isoform 2 (CLDN18.2) is a potential therapeutic target in gastric cancer (GC). However, combining chemotherapy with anti-CLDN18.2 antibodies has shown limited efficacy in CLDN18.2-positive GC, and chemotherapy-induced changes in the tumor microenvironment (TME) remain unclear.

This study analyzed 37 GC samples, including 11 CLDN18.2-positive cases, using single-cell RNA sequencing and multiplex immunofluorescence to assess chemotherapy-driven TME changes in CLDN18.2-positive GC.

In chemotherapy-treated CLDN18.2-positive GC, cytotoxic natural killer (NK) cells displayed antibody-dependent cytotoxicity (ADCC)-related genes at lower levels than in untreated CLDN18.2-positive GC, while regulatory T cells (Tregs) and tumor-associated macrophages (TAMs) showed TGFB1 expression at higher levels. Additionally, NK cells, Tregs, and TAMs were more abundant in chemotherapy-treated than untreated CLDN18.2-positive GC. These chemotherapy-induced changes were absent in CLDN18.2-negative GC. Cell-cell interaction analysis identified unique interactions in chemotherapy-treated CLDN18.2-positive GC, including CCL5-CCR5 signaling between cytotoxic NK cells (Sender) and effector Tregs (Receptor) and TGFB1-TGFBR signaling between effector Tregs (Sender) and TAMs (Receptor). Cytotoxic NK cells expressed CCL5 at higher levels, CCR5-positive Tregs were more prevalent, and TAMs exhibited higher TGF-β receptor signature scores in chemotherapy-treated than untreated CLDN18.2-positive GC.

Our findings indicate that chemotherapy can drive immunosuppressive TME modifications specific to CLDN18.2-positive GC.

Ramucirumab with either solvent-based or nanoparticle albumin-bound paclitaxel is a standard second-line treatment for advanced gastric cancer. Reportedly, nanoparticle albumin-bound paclitaxel has activated the immune system, but the efficacy of taxane-based agents before nivolumab remains unclear. Therefore, we investigated the prognostic effect of ramucirumab with solvent-based or nanoparticle albumin-bound paclitaxel as second-line therapy, followed by nivolumab as third-line therapy.

This retrospective study enrolled 115 patients with gastric cancer treated with ramucirumab in combination with solvent-based paclitaxel or nanoparticle albumin-bound paclitaxel from 2017 to 2019 at six hospitals. All patients received nivolumab as a third-line therapy. Ramucirumab + solvent-based paclitaxel and ramucirumab + nanoparticle albumin-bound paclitaxel were administered to 57 and 58 patients, respectively.

The progression-free survival of the ramucirumab + solvent-based paclitaxel group was slightly better than that of the ramucirumab + nanoparticle albumin-bound paclitaxel group but with no statistically significant difference (5.3 months vs. 4.2 months). Contrary, the overall survival of the ramucirumab + nanoparticle albumin-bound paclitaxel group was slightly better than the ramucirumab + solvent-based paclitaxel group but with no statistically significant difference (19.0 months vs. 12.5 months). The multivariate analysis of progression-free survival revealed that ramucirumab + nanoparticle albumin-bound paclitaxel was an independent risk factor for poor prognosis, whereas ramucirumab + nanoparticle albumin-bound paclitaxel was an independent factor for good overall survival.

Ramucirumab + nanoparticle albumin-bound paclitaxel may prolong overall survival when administered before nivolumab, despite its limited effect on progression-free survival.

Pembrolizumab, a PD-1 inhibitor, has shown potential for treating advanced gastric and gastroesophageal junction (GEJ) cancer. This meta-analysis evaluates its efficacy and safety, alone or combined with chemotherapy, in this population.

A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. Databases including PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science were searched up to October 31, 2024. Twelve studies comprising 4,069 patients were included. The primary outcomes were overall survival (OS) and progression-free survival (PFS); secondary outcomes included objective response rate (ORR), adverse events (AEs), and grade ≥ 3 AEs. Effect sizes were calculated using mean differences (MDs) and odds ratios (ORs) with 95% confidence intervals (CIs).

Pembrolizumab combined with chemotherapy significantly improved OS (MD = 1.92 months; 95% CI: 0.94 to 2.91) and ORR (MD = 11.05%; 95% CI: 6.29 to 15.82) compared to chemotherapy alone. Pembrolizumab monotherapy did not show a significant effect on OS (MD = 0.24 months; 95% CI: -1.15 to 1.63) and was associated with a significant reduction in PFS (MD = -2.28 months; 95% CI: -2.85 to -1.71) compared to chemotherapy alone. For safety, pembrolizumab monotherapy significantly reduced the risk of AEs (OR = 0.68; 95% CI: 0.57 to 0.81) and grade ≥ 3 AEs (OR = 0.39; 95% CI: 0.30 to 0.51) compared to chemotherapy. Pembrolizumab combined with chemotherapy did not significantly alter the risk of AEs (OR = 1.01; 95% CI: 0.90 to 1.13) or grade ≥ 3 AEs (OR = 1.12; 95% CI: 0.99 to 1.27) compared to chemotherapy alone.

Pembrolizumab combined with chemotherapy improves survival and response rates with a manageable safety profile in advanced gastric and GEJ cancers. Monotherapy shows limited efficacy, highlighting the need for combination strategies and patient selection.

The therapeutic landscape in nearly every therapeutic line in advanced/metastatic patients with squamous cell carcinoma (SCC) and esophagogastric adenocarcinoma (EGC) is enriched by recent approvals of immune checkpoint inhibitors (ICIs). In curative intended therapy, patients without pathological residual disease of SCC or GEJ (esophagogastric junction) cancer after preoperative chemoradiation and complete resection have access to adjuvant immunotherapy (independent of PD-L1 (programmed cell death protein 1) status, nivolumab, CHECKMATE 577). For metastatic SCC in the first-line, nivolumab combined with chemotherapy or with ipilimumab (TPS (tumor proportion score) ≥1 %, SCC, CHECKMATE 648) are approved, as well as second-line nivolumab alone regardless of PD-L1 status (ATTRACTION 03). For both, locally advanced or metastatic SCC and EGC, chemotherapy with pembrolizumab is available for patients with CPS (combined positive score) ≥10 (KEYNOTE 590) and for adenocarcinoma with nivolumab (CPS ≥5, CHECKMATE 649). Recent added approvals are chemotherapy with pembrolizumab in CPS ≥1 patients (KEYNOTE 859) and the addition of trastuzumab for personalized therapy in HER-2 positive/CPS ≥1 gastric and GEJ patients (KEYNOTE 811).

Microsatellite instability (MSI)-high tumors represent a distinct, small-fraction subtype in esophagogastric junction cancer or gastric cancer (GC), yet their clinical significance remains poorly understood. This study aimed to investigate the prevalence and clinicopathological features of chemotherapy-naïve metastatic or recurrent MSI-high GC as a prescreening study for a phase II trial of nivolumab plus ipilimumab.

Key inclusion criteria included metastatic or recurrent adenocarcinoma of GC, ECOG performance status of 0 or 1, and no prior systemic therapy for metastatic or recurrent disease. MSI status was tested using multiplex PCR fragment analysis (MSI Testing Kit, FALCO). The primary endpoint was the prevalence of MSI-high GC.

Between October 2020 and October 2022, 930 eligible patients from 75 centers in Japan were analyzed. The prevalence of MSI-high GC was 5.6% (95% CI 4.2-7.3). MSI-high GC was more frequently observed in females than males (9.6% vs 3.8%, p < 0.001), patients aged ≥ 70 years compared to those < 70 years (8.0% vs 2.8%, p < 0.001), in the lower stomach than other locations (10.5% vs 3.2%, p < 0.001), HER2-negative tumors than HER2-positive tumors (6.5% vs 1.8%, p = 0.02), and in patients without liver metastasis than those with liver metastasis (6.9% vs 2.2%, p = 0.004).

The prevalence of MSI-high tumors among chemotherapy-naïve patients with unresectable GC was 5.6%. These tumors were associated with female sex, older age, lower stomach, HER2-negative, and absence of liver metastasis. These findings would help assuming MSI-high tumors and may have significant implications for clinical practice and studies targeting this GC subtype.

Gastric cancer ranks among the most prevalent malignancies globally, characterized by limited treatment efficacy and high recurrence rates. Effective management of this disease requires a comprehensive understanding of its underlying pathogenic mechanisms. Galectins have emerged as promising targets in gastric cancer therapy, with Galectin-9 (LGALS9) receiving considerable attention in recent years. However, Galectin-9B (LGALS9B) remains relatively under-explored in gastric cancer research. Our study investigates the role of LGALS9B in gastric cancer progression, demonstrating that its over-expression enhances cellular proliferation, migration, and invasion, while its knockdown inhibits these processes both in vitro and in vivo. We further elucidate that LGALS9B competes with the E3 ligase HERC5 for binding to eukaryotic translation elongation factor 1 delta (EEF1D), thereby preventing its protein degradation. This interaction results in the enrichment of EEF1D, which activates the PI3K/AKT signaling pathway and ultimately promotes gastric cancer progression. These findings highlight the regulatory role of LGALS9B in the pathogenesis of gastric cancer, offering valuable insights into potential novel therapeutic strategies for managing this challenging disease.

Recently, novel molecular targeted therapies have been developed for gastric and esophageal adenocarcinomas. We examined the status of therapeutic target molecules in esophagogastric junction (EGJ) and Barrett's adenocarcinoma.

Tissue microarrays were constructed from 114 cases of non-Barrett's EGJ adenocarcinoma and 30 cases of Barrett's adenocarcinoma. Immunohistochemistry for mismatch repair proteins, PD-L1, HER2, CLDN18, FGFR2b, and EBER-ISH was performed. When HER2 immunohistochemistry was 2 + , gene amplification was examined using in situ hybridization.

EBER positivity, mismatch repair deficiency, PD-L1 combined positive score (CPS) ≥ 1, CLDN18 expression ≥ 75%, FGFR2b expression, and HER2 positivity were observed in 7 (6.1%), 11 (9.6%), 70 (61.4%), 38 (33.3%), 6 (5.3%), and 11 (9.6%) cases of EGJ adenocarcinoma as well as in 0 (0%), 0 (0%), 23 (76.7%), 7 (23.3%), 2 (6.7%), and 6 (20.0%) cases of Barrett's adenocarcinoma, respectively. PD-L1 CPS ≥ 1 cases had longer recurrence-free survival (P = 0.001) and overall survival (P = 0.003) than CPS < 1 cases. Other target molecules were not associated with survival. A total of 93/114 (81.6%) cases of EGJ adenocarcinoma and 26/30 (86.7%) cases of Barrett's adenocarcinomas expressed at least one target molecule.

Most EGJ and Barrett's adenocarcinomas may be eligible for molecular targeted therapy. Appropriate patient stratification based on these molecular tests will be important for precision medicine of the EGJ and Barrett's adenocarcinoma.

The Cancer Genome Atlas (TCGA) classifies gastric cancer (GC) into four molecular subtypes: Epstein-Barr virus-positive, microsatellite instability-high (MSI-H), genomically stable (GS), and chromosomal instability (CIN). This exploratory analysis compared the genomic landscape of late-stage GC from KEYNOTE-059, KEYNOTE-061, and KEYNOTE-062 studies with early-stage GC from TCGA and evaluated the genomic characteristics of late-stage GC in patients of Western and Asian origin.

Using pretreatment tumor samples, bulk DNA was analyzed via whole-exome sequencing (WES; KEYNOTE-059/KEYNOTE-061) and FoundationOneCDx (KEYNOTE-062) to determine TCGA-defined molecular subtypes (only MSI-H is determinable from FoundationOneCDx), genomic alterations, homologous recombination deficiency (HRD), and tumor mutational burden (TMB); gene expression signatures were analyzed using RNA sequencing.

When comparing KEYNOTE-059/061/062 combined WES and FoundationOneCDx data with data from TCGA, the MSI-H subtype prevalence was numerically lower in patients of Western (5% v 22%) and Asian origin (5% v 19%). When comparing KEYNOTE-059/061 WES data with the TCGA data set, the GS subtype prevalence was numerically higher (36% v 21%) in patients of Western or Asian origin. Among subtypes in KEYNOTE-059/061, HRD scores and TMB trended highest in CIN and MSI-H subtypes, respectively. TP53 mutation was the most prevalent genomic characteristic per KEYNOTE-059/061/062 combined analysis in patients of Western or Asian origin. Gene expression signature distributions were generally similar between patients of Western and Asian origin.

Numerical differences in the prevalence of MSI-H and GS subtypes were observed between early-stage and late-stage GC. Genomic characteristics of late-stage GC were generally similar between patients of Western and Asian origin.

Since HER2 and PD-L1 testing are key to selecting drugs for first-line treatments in advanced gastric cancer, evaluating differences in these tests among institutions is necessary to standardize treatment.

A questionnaire survey was conducted targeting institutions certified by the Japanese Gastric Cancer Association.

Responses were obtained from 155 institutions. Most institutions performed HER2 testing in-house, while PD-L1 tests were largely outsourced. HER2 scores and PD-L1 CPS rates showed greater variability across institutions than anticipated. In the pre-analytic phase, 10% neutral buffered formalin was commonly used, with fixation practices generally following guidelines. Overall, the impact of fixation-related factors was limited, but in surgical specimens, longer fixation was associated with a higher proportion of score 0/1+ and a lower proportion of score 3+. When examining HER2 scores by institution, if a particular score had a high (or low) frequency in biopsy, the same trend was also seen in surgical specimens.

These findings suggest that not only factors related to specimen preparation, but also biases in evaluation criteria among pathologists may contribute to the significant variability among institutions. Standardization of pre- and post-analytic phases, coupled with appropriate training, is essential to achieve consistent gastric cancer therapy.

Microsatellite instability-high (MSI-H) cancers are linked to exceptional benefit from immune checkpoint inhibitors (ICIs), but studies on their efficacy across various MSI-H cancer types are limited.

Randomized clinical trials (RCTs) comparing ICIs to chemotherapy in advanced MSI-H/dMMR cancers were systematically reviewed. Eligible studies included 13 RCTs with 1633 MSI-H patients across colorectal, gastric, and endometrial cancers. Data were analyzed using hazard ratios for progression-free survival (PFS) and overall survival (OS), with subgroup analyses by tumor type. Statistical heterogeneity was assessed using Cochrane's Q and I2.

Immunotherapy significantly improved PFS and OS in MSI-H patients, with an HR for OS of 0.35 (95% CI 0.27-0.46; p < 0.00001) versus 0.81 for MSS patients. PFS showed a 64% reduced risk of progression (HR = 0.36, 95% CI 0.28-0.46; p < 0.0001). Subgroup analyses highlighted PFS benefits across tumor types: colorectal (HR = 0.28, 95% CI 0.11-0.73), gastric (HR = 0.43, 95% CI 0.27-0.68), and endometrial cancers (HR = 0.34, 95% CI 0.27-0.42).

This meta-analysis establishes MSI-H as a predictive biomarker for ICIs, supporting its role in therapy selection and underscoring the need for MSI-H/dMMR-focused clinical trials.

Gastric cancer, including gastroesophageal junction cancer, is one of the most commonly diagnosed cancers worldwide, with high mortality. Sugemalimab is a fully human anti-programmed death-ligand 1 (PD-L1) antibody. The combination of sugemalimab and chemotherapy showed promising antitumor activity and safety in a phase 1b study among patients with treatment-naive, unresectable, locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma. This combination was further evaluated in the GEMSTONE-303 phase 3 trial.

To evaluate the efficacy of sugemalimab in combination with capecitabine and oxaliplatin (CAPOX) compared with placebo plus CAPOX as first-line treatment for patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 combined positive score (CPS) of 5 or greater.

GEMSTONE 303 is a phase 3, randomized, double-blind, placebo-controlled study conducted at 54 sites in China that enrolled patients from April 9, 2019, through December 29, 2021, with follow-up to July 9, 2023. A total of 479 eligible patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma with PD-L1 CPS of 5 or greater who did not receive any prior systemic therapy were randomized.

Patients received sugemalimab (1200 mg intravenously) (n = 241) or placebo (n = 238) every 3 weeks for up to 24 months, plus CAPOX every 3 weeks for up to 6 cycles.

Primary outcomes were overall survival and investigator-assessed progression-free survival.

Baseline characteristics were well balanced between the 2 groups. Most patients were male (71.4% in sugemalimab group, 74.8% in placebo group). Median follow-up was 25.1 months in the sugemalimab group and 26.3 months in the placebo group. The sugemalimab group demonstrated significant improvements in overall survival (median, 15.6 months [95% CI, 13.3-17.8] vs 12.6 months [95% CI, 10.6-14.1]; hazard ratio, 0.75 [95% CI, 0.61-0.92]; P = .006) and progression-free survival (median, 7.6 months [95% CI, 6.4-7.9] vs 6.1 months [95% CI, 5.1-6.4]; hazard ratio, 0.66 [95% CI, 0.54-0.81]; P < .001). Grade 3 or higher treatment-related adverse events occurred in 53.9% of patients in the sugemalimab group and 50.6% in the placebo group.

Sugemalimab plus chemotherapy significantly prolonged overall survival and progression-free survival with a manageable safety profile in previously untreated patients with unresectable locally advanced or metastatic gastric or gastroesophageal junction adenocarcinoma.

ClinicalTrials.gov Identifier: NCT03802591.

Gastric cancer (GC) has a high global incidence and mortality rate [...].

We report the case of a 44-year-old male with advanced gastric cancer with distal lymph node metastasis who achieved a pathological complete response to chemotherapy combined with nivolumab. After five months of treatment, the patient underwent total gastrectomy with D2 lymph node dissection, and histological examination revealed the absence of malignant cells not only in the resected specimen but also in the harvested lymph nodes. At present, more than 1 year after the initial surgery, the patient is still alive without any recurrence. This case highlights the potential of chemotherapy combined with nivolumab to induce a complete response in advanced gastric cancer patients.

Understanding the relationship between the Objective Response Rate (ORR) and survival outcomes, notably Progression-Free Survival (PFS) and Overall Survival (OS), is relevant for assessing the efficacy of regimens in oncology. We evaluate the relationship between ORR, PFS and OS in immuno-oncology (IO) trials. Data from 68 clinical trials submitted to the FDA were evaluated, examining immunotherapy regimens, notably immune checkpoint inhibitors such as anti-programmed death (ligand)-1 [anti-PD-(L)1], cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) inhibitors and combination therapies [e.g., IO + IO, anti-PD-L1 + chemotherapy, anti-PD-L1 + CTLA-4, anti-PD-L1 + TKI (tyrosine kinase inhibitors)]. Studies were included based on their reporting of ORR, PFS, and OS. Of the 68 clinical trials reviewed, 55 were included in the analysis. The correlation between ORR and PFS was moderate across most immunotherapy regimens, indicating that ORR can serve as a useful predictor of short-term disease control. However, the correlation between ORR and OS was weaker, especially in trials including combination therapies, indicating that ORR alone may not reliably predict long-term survival outcomes. ORR predicts PFS better in first-line treatment but declines in later lines and remains a weak OS predictor overall. Differing degrees of correlation between ORR and survival metrics, particularly across treatment lines and combinations, are observed. While ORR can serve as a surrogate marker for PFS in IO trials, its utility in predicting OS is restricted and the interpretation of the relationship between ORR and PFS or OS is a key limitation. Rather, a decline in PFS with increasing ORR may reflect trial differences rather than a direct relationship. Future analyses should adopt better methodologies to capture these dynamics and focus on improving surrogate endpoints for immunotherapy to improve clinical trial design and patient outcomes.

The treatment of metastasized gastroesophageal adenocarcinoma largely depends on molecular profiling based on immunohistochemical procedures. Therefore, the examination of HER2, PD-L1, and dMMR/MSI is recommended by the majority of clinical practice guidelines, as positive expression leads to different treatment approaches. Data from large phase-III trials and consequent approvals in various countries enable physicians to offer their patients several therapy options including immunotherapy, targeted therapy, or both combined with chemotherapy. The introduction of novel therapeutic targets such as CLDN18.2 leads to a more complex decision-making process as a significant number of patients show positive results for the co-expression of other biomarkers besides CLDN18.2. The aim of this review is to summarize the current biomarker landscape of patients with metastatic gastroesophageal tumors, its direct clinical impact on daily decision-making, and to evaluate current findings on biomarker co-expression. Furthermore, possible treatment strategies with multiple biomarker expression are discussed.

Gastric cancer (GC) remains a leading cause of morbidity and mortality worldwide. The current standard of care involves neoadjuvant chemotherapy (NACT) followed by radical gastrectomy. This study aims to evaluate the efficacy of neoadjuvant therapy with PD-1/PD-L1 inhibitors in comparison to chemotherapy alone for patients with locally advanced gastric cancer (LAGC).

We conducted a systematic search of PubMed, Web of Science, and Embase to identify studies examining the addition of PD-1/PD-L1 inhibitors to neoadjuvant therapy for LAGC. Odds ratios (OR) were calculated for binary outcomes, such as pathological complete response (pCR), with corresponding 95% confidence intervals (CI).

Seven studies were included, encompassing a total of 1772 patients. Baseline median age ranged from 31 to 75 years. Most patients had an ECOG performance status score of 0 (942 patients), while 294 had an ECOG score of 1. The estimated pCR (OR 5.94, 95% CI 3.98-8.87; p < 0.000001) significantly favored the PD-1/PD-L1 inhibitors combined with chemotherapy over chemotherapy alone. Additionally, the incidence of certain adverse events increased significantly in the intervention group, including any-grade hypothyroidism (OR 4.55, 95% CI 2.27-9.10; p = 0.000019) and rash (OR 1.74, 95% CI 1.10-2.76; p = 0.017). Conversely, the control group showed a statistically significant lower incidence of grade ≥ 3 fatigue (OR 2.80, 95% CI 1.15-6.85; p = 0.024) compared to the intervention group.

This systematic review and meta-analysis indicate that the addition of PD-1/PD-L1 inhibitors to neoadjuvant chemotherapy is associated with a higher pathological complete response rate compared to chemotherapy alone in patients with locally advanced gastric cancer.

Immune checkpoint inhibitors (ICIs), such as pembrolizumab (PEM), are widely recognized for their antitumor efficacy, but they can also lead to various cutaneous adverse events (CAEs). While most CAEs can be managed with topical corticosteroids, severe cases may necessitate halting immunotherapy. The incidence of severe CAEs is notably higher in combination therapies involving ICIs than in monotherapies, emphasizing the need for stringent, long-term management strategies. This includes potential modifications or discontinuations of the combination therapy. PEM, when added to the conventional paclitaxel + cisplatin (or carboplatin) ± bevacizumab regimen, has shown significant improvements in overall and progression-free survival for patients with Stage IVB metastatic or locally uncontrolled recurrent cervical cancer. This case series retrospectively examined the incidence and management of CAEs in 19 female patients treated with this combination therapy between October 2022 and May 2023. Four patients exhibiting CTCAE grade 3 were identified. The four cases of severe CAEs involved erythema multiforme after the initial course of PEM combination chemotherapy. Notably, three patients experienced immediate hypersensitivity reactions, including anaphylaxis, during subsequent treatments. This observation underscores the necessity for rigorous dermatological monitoring of patients undergoing PEM combination chemotherapy. Such vigilance is crucial for early detection of adverse reactions and timely adjustment of treatment regimens, thereby enhancing patient safety.

This study examines the effectiveness of dual-energy CT (DECT) delayed-phase extracellular volume (ECV) fraction in predicting tumor regression grade (TRG) in far-advanced gastric cancer (FAGC) patients receiving preoperative immuno-chemotherapy.

A retrospective analysis was performed on far-advanced gastric adenocarcinoma patients treated with preoperative immuno-chemotherapy at our institution from August 2019 to March 2023. Patients were categorized based on their TRG into pathological complete response (pCR) and non-pCR groups. ECV was determined using the delayed-phase iodine maps. In addition, tumor iodine densities and standardized iodine ratios were meticulously analyzed using the triple-phase enhanced iodine maps. Univariate analysis with five-fold cross-validation and Spearman correlation determined DECT parameters and clinical indicators association with pCR. The predictive accuracy of these parameters for pCR was evaluated using a weighted logistic regression model with five-fold cross-validation.

Of the 88 patients enrolled (mean age 60.8 ± 11.1 years, 63 males), 21 (23.9%) achieved pCR. Univariate analysis indicated ECV's significant role in differentiating between pCR and non-pCR groups (average p value = 0.021). In the logistic regression model, ECV independently predicted pCR with an average odds ratio of 0.911 (95% confidence interval, 0.798-0.994). The model, incorporating ECV, tumor area, and IDAV (the relative change rate of iodine density from venous phase to arterial phase), showed an average area under curves (AUCs) of 0.780 (0.770-0.791) and 0.766 (0.731-0.800) for the training and validation sets, respectively, in predicting pCR.

DECT-derived ECV fraction is a valuable predictor of TRG in FAGC patients undergoing preoperative immuno-chemotherapy.

This study demonstrates that DECT-derived extracellular volume fraction is a reliable predictor for pathological complete response in far-advanced gastric cancer patients receiving preoperative immuno-chemotherapy, offering a noninvasive tool for identifying potential treatment beneficiaries.

Gastric cancer is one of the most common cancers in both Korea and worldwide. Since 2004, the Korean Practice Guidelines for Gastric Cancer have been regularly updated, with the 4th edition published in 2022. The 4th edition was the result of a collaborative work by an interdisciplinary team, including experts in gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology, and guideline development methodology. The current guideline is the 5th version, an updated version of the 4th edition. In this guideline, 6 key questions (KQs) were updated or proposed after a collaborative review by the working group, and 7 statements were developed, or revised, or discussed based on a systematic review using the MEDLINE, Embase, Cochrane Library, and KoreaMed database. Over the past 2 years, there have been significant changes in systemic treatment, leading to major updates and revisions focused on this area. Additionally, minor modifications have been made in other sections, incorporating recent research findings. The level of evidence and grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation system. Key factors for recommendation included the level of evidence, benefit, harm, and clinical applicability. The working group reviewed and discussed the recommendations to reach a consensus. The structure of this guideline remains similar to the 2022 version. Earlier sections cover general considerations, such as screening, diagnosis, and staging of endoscopy, pathology, radiology, and nuclear medicine. In the latter sections, statements are provided for each KQ based on clinical evidence, with flowcharts supporting these statements through meta-analysis and references. This multidisciplinary, evidence-based gastric cancer guideline aims to support clinicians in providing optimal care for gastric cancer patients.

The tumor immune microenvironment is increasingly becoming a key consideration in developing treatment regimens for aggressive cancers, with evidence that regulatory T cells (Tregs) attenuate the antitumor response by interrupting cytotoxic T cells (CD8+). Here, we hypothesized the prognostic relevance of the proportions of Tregs (marked by forkhead box protein 3 [FOXP3]) and CD8+ cells in diffuse, non-Epstein-Barr virus (EBV)/non-microsatellite instability (MSI)-high gastroesophageal adenocarcinomas (GEAs), which are clinically characterized as more aggressive, immunologically inactive tumors as compared with their intestinal counterparts. Cell-count ratios of FOXP3+/CD8+ expression were calculated at the intratumoral region and invasive margin discretely on digital images from 303 chemo-naive non-EBV/non-MSI-high esophagogastric junction (EGJ) adenocarcinomas. A significant modifying prognostic effect of tumor histology was observed between 5-year EGJ cancer-specific survival and the FOXP3+/CD8+ ratio at the invasive margin in pStage I-III tumors (p for interaction = 0.022; hazard ratio [HR] = 8.47 and 95% confidence interval [CI], 2.04-35.19 for high ratio [vs. low] for diffuse; HR = 1.57 and 95% CI, 0.88-2.83 for high ratio [vs. low] for intestinal). A high FOXP3+/CD8+ ratio at the invasive margin was associated with RUNX3 methylation (p = 0.035) and poor prognosis in RUNX3-methylated diffuse histological subtype (5-year EGJ cancer-specific survival, 52.3% for high and 100% for low, p = 0.015). Multiomics data from The Cancer Genome Atlas linked CCL28 with RUNX3-suppressed diffuse histological subtypes of non-EBV/non-MSI-high GEA. Our data suggest that a high FOXP3+/CD8+ ratio at the invasive margin might indicate tumor immune escape via CCL28, particularly in the RUNX3-methylated diffuse histological subtype.

Differences in demographics, medical expertise, and patient healthcare resources across countries have led to significant variations in guidelines. In light of these differences, in this review, we aimed to explore and compare the most recent updates to gastric cancer treatment from five guidelines that are available in English. These English-version guidelines, which have been recently published and updated for journal publication, include those published in South Korea in 2024, Japan in 2021, China in 2023, the United States in 2024, and Europe in 2024. The South Korean and Japanese guidelines provide a higher proportion of content to endoscopic and surgical treatments, reflecting their focus on minimally invasive techniques, function-preserving surgeries, and systemic therapy. The Chinese guidelines provide recommendations addressing not only surgical approaches but also perioperative chemotherapy and palliative systemic therapy. Meanwhile, in the United States and European guidelines, a higher proportion of the content is dedicated to perioperative and palliative systemic therapy, aligning with their approaches to advanced-stage disease management. All guidelines address surgical and systemic chemotherapy treatments; however, the proportion and emphasis of content vary based on the patient distribution and treatment approaches specific to each country. With emerging research findings on gastric cancer treatment worldwide, the national guidelines are being progressively revised and updated. Understanding the commonalities and differences among national guidelines, along with the underlying evidence, can provide valuable insights into the treatment of gastric cancer.

Gastric carcinoma with lymphoid stroma (GCLS) is characterized by dense intra-and peritumoral lymphocytic infiltration and a high rate of Epstein Barr Virus (EBV) infection, suggesting being a promising candidate for immunotherapy. We investigated correlations between PD-L1 expression and clinicopathologic factors, including EBV positivity and microsatellite instability (MSI) status in GCLSs. The study included resected 214 GCLSs and 300 gastric adenocarcinomas (GACs) for control. Epstein Barr Virus encoding region in situ hybridization (EBER ISH), immunohistochemistry for PD-L1 and HER2, dual-colored in situ hybridization for HER2, and MSI analysis were performed. EBV positivity was found in 181 (85%) of 214 GCLSs. MSI analysis demonstrated that 0.6% of EBV + GCLSs and 54.5% of EBV-GCLSs were MSI-high compared to 7% of EBV-GACs. Approximately 3% and 3.9% of HER2 amplifications were found in EBV- and EBV + GCLSs compared to 13% of EBV-GACs. PD-L1 expression with ≥ 1, ≥ 5, and ≥ 10 combined positive scores (CPS) were observed in 81.8%, 70.2%, and 55.3% of EBV + GCLSs. PD-L1 expression with ≥ 10 CPS was observed in 21.2% of EBV-GCLSs, predominantly in MSI-H tumors (85.7%). EBV positivity and MSI are associated with PD-L1 positivity rates in patients with GCLS who may respond better to PD-1/PD-L1 inhibitors but not anti-HER2 inhibitors.

Recent studies have highlighted the distinct ratio of PD-1 + Treg/PD-1 + CD8 for prognosis prediction. However, it remains unclear about the association of this ratio and tertiary lymphoid structures (TLS) with prognosis and response to neoadjuvant or conversion therapy in advanced gastric cancer.

Firstly, fresh postoperative samples from 68 gastric cancer patients in Renji Hospital were collected. Meanwhile, immune cell infiltration as well as clinical prognosis analysis were conducted. Subsequently, we further systematically evaluated flow cytometry analysis of tumor samples and TLS expression in 38 gastric cancer patients with different response situations after neoadjuvant therapy. Also, a Renji conversion therapy cohort including 10 patients with complete matching samples before and after treatment was established to receive RNA sequencing analysis and multiplex immunohistochemistry (mIHC) tests. The corresponding TLS score and immune cell infiltration were further compared based on therapeutic response variations.

In general, the ratio of PD-1 + Treg/PD-1 + CD8>1 could be regarded as an independent predictor of prognosis in advanced gastric cancer patients. Moreover, PD-1 + Treg/PD-1 + CD8 < 1 and high expression of TLS could indicate better neoadjuvant therapy response and extended survival time in advanved gastric cancer patients. Besides, PD-1 + Treg/PD-1 + CD8 low &TLS high group could predict better progression free survival time (PFS) in complete response (CR) subgroup. In response group after conversion therapy, the number of PD-1 + CD8 + T cells significantly increased, mainly occurring outside the TLSs. Meanwhile, the TLSs were also considerably activated as we could observed.

This study underlined that combining PD-1 + Treg/PD-1 + CD8 ratio and TLS were significantly associated with prognosis and preoperative treatment response in advanced gastric cancer. Inspiringly, these indicators have the potential to elucidate the immune balance of advanced gastric cancer patients and can accurately guide subsequent therapeutic strategies.

Tissue confirmation of pancreatobiliary cancer is often difficult because of the location of the tumor and structure of the surrounding blood vessels. Patient-derived cancer organoids (PDCOs) reflect the genomic characteristics of individual cancers. Although diverse attempts to construct PDCOs for various pancreatobiliary cancer models are ongoing, no research results have yet confirmed the possibility of performing a precise diagnosis on PDCOs derived from pathologically negative patient samples.

We obtained a total of nine samples, including pathologically negative samples, from four patients (three patients with pancreatic cancer and one patient with gallbladder cancer) using different tissue acquisition methods to establish PDCOs (success rate 75%).

We successfully verified whether the constructed PDCOs could represent the tissues of patients with pancreatobiliary cancer at each multi-omics level using tumor panel sequencing, single-cell RNA sequencing, hematoxylin and eosin, and immunohistochemical staining. PDCOs from pathologically negative samples showed expression patterns of malignant ductal cell-related biomarkers similar to those of other pathologically positive samples. Furthermore, the expression patterns at the single-cell level in PDCO from patients ultimately diagnosed with gallbladder cancer after surgery were different from those in patients with pancreatic cancer.

Therefore, our study implicated the potential of PDCOs as diagnostic and research tools, including for case involving limited tissue samples. Based on these results, we anticipate that this could be extended to more advanced studies, such as drug sensitivity testing, through large-scale trials in the near future.

Human epidermal growth factor receptor-2 (HER2), programmed death-ligand 1 (PD-L1), and microsatellite (MS) status are well-established biomarkers in gastroesophageal adenocarcinomas (GEAs). However, it is unclear how the combination of these biomarkers is associated with clinicopathological factors and prognosis. This retrospective study included baseline metastatic GEA patients who were tested for all three biomarkers (HER2, PD-L1, and MS status) at the MD Anderson Cancer Center between 2012 and 2022. Stratification was performed according to the combination of biomarker profiles: triple negative (TN), single positive (SP), and multiple positive (MP). Comparative analyses of clinicopathological factors and survival using combinations of biomarkers were performed. Among the 698 GEA patients analyzed, 251 (36.0%) were classified as TN, 334 (47.9%) as SP, and 113 (16.1%) as MP. The MP group showed a significant association with tumors located in the esophagus (p < .001), well to moderate differentiation (p < .001), and the absence of signet ring cells (p < .001). In the survival analysis, MP group had a significantly longer overall survival (OS) compared to the other groups (MP vs. TN, p < .001 and MP vs. SP, p < .001). Multivariate Cox regression analysis revealed that MP serves as an independent positive prognostic indicator for OS (hazard ratio = 0.63, p < .01). Our findings indicate that MP biomarkers are associated with a favorable prognosis in metastatic GEA. These results are reflective of clinical practice and offer valuable insights into how therapeutics and future biomarkers could influence therapy/prognosis.

Whether pembrolizumab alone or in combination with chemotherapy is superior to chemotherapy in metastatic cancer remains controversial. The study aims to give the effectiveness and safety of pembrolizumab-related interventions compared to chemotherapy in metastatic cancer.

Electronic databases were systematically searched until November 20, 2023, for all randomized controlled trials comparing Pembrolizumab alone or in combination with chemotherapy versus chemotherapy for metastatic cancer. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Hazard ratios (HRs) and odds ratios with 95% confidence intervals (CI) were calculated for OS, PFS, overall response rate, and overall adverse events (AEs) by random effects models.

16 Randomized controlled trials with 9148 patients were included. Compared with chemotherapy, pembrolizumab was associated with longer OS (HR 0.82; 95% CI 0.73-0.91, P = .0004), more immune-mediated AEs, fewer overall AEs, and grade 3 or 4 AEs, however, no significant difference was found in PFS, overall response rate, and events leading to death. Pembrolizumab with chemotherapy was associated with longer OS (HR 0.74; 95% CI 0.61-0.90, P = .002) and PFS (HR 0.63; 95% CI 0.50-0.79, P < .0001), higher overall response rate, and more immune-mediated AEs comparing to chemotherapy alone, however, no significant advantages were observed in disease control rates, overall AEs, grade 3 or 4 AEs and events leading to death. The patients with programmed cell death ligand 1 tumor proportion scores of at least 50% or combined positive scores (CPS) of at least 10 could derive significantly better OS and PFS benefits from pembrolizumab alone or combined with chemotherapy. Similar OS results were found for first-line treatment and lung cancer subgroup analysis.

Pembrolizumab alone or combined with chemotherapy indicates an effective and safe treatment for metastatic cancer. Pembrolizumab alone or combined with chemotherapy provides a better survival advantage under first-line treatment or programmed cell death ligand 1 combined positive scores of at least 10 or programmed cell death ligand 1 tumor proportion scores of at least 50%. However, we found that the specific efficacy of pembrolizumab in unused tumor types could not be effectively evaluated.

Our study aimed to investigate the correlation between hemoglobin A1c (HbA1c), circulating tumor cells (CTCs) and prognosis in advanced gastric cancer (GC) patients who received immunotherapy and explore the potential prognostic predictors to develop a nomogram.

We retrospectively enrolled 259 patients with advanced GC treated at Beijing Friendship Hospital between September 2014 and March 2024. Patients were divided into the immunochemotherapy cohort (ICT) and the chemotherapy (CT) cohort. Survival rate was calculated by Kaplan-Meier survival curve, and the differences were evaluated by log-rank test. The univariate and multivariate Cox proportional hazards regression model was used to identify factors independently associated with survival. A nomogram was developed to estimate 6-, 12-, and 18-month progression-free survival (PFS) probability based on the ICT cohort.

Patients achieved higher PFS in the ICT cohort than the CT cohort. We focused on the ICT cohort and constructed a nomogram based on the multivariate analysis, including five variables: age, PD-L1 expression, HbA1c, CTCs and CEA*. The concordance index value was 0.82 in the training cohort and 0.75 in the validation cohort. Furthermore, we proved the nomogram was clinically useful and performed better than PD-L1 expression staging system. Notably, we found high HbA1c level but not diabetes mellitus significantly affected the efficacy of ICT.

ICT showed better PFS than CT. In addition, HbA1c and CTCs were novel biomarkers to predict PFS in patients treated with ICT. The nomogram could predict PFS of advanced GC patients receiving ICT with increased accuracy and favorable clinical utility.

In gastric cancer treatment, cancer-associated fibroblasts (CAF) may significantly influence the efficacy of immune checkpoint inhibitors by modulating PD-L1 expression. However, the precise mechanisms remain unclear. This study aims to explore the relationship between CAF and PD-L1 expression, providing new insights for improving PD-L1-targeted therapies. Using primary fibroblasts, transcriptome sequencing, ChIP-qPCR, and a lung metastasis model, we discovered that CAF secrete lysyl oxidase (LOX), which activates the TGFβ signaling pathway in gastric cancer cells, thereby promoting insulin-like growth factor 1(IGF1) expression. Upregulation of IGF1 enhances gastric cancer cell migration, epithelial-mesenchymal transition (EMT), and glycolysis. Additionally, we found that lactate accumulation leads to lysine 18 lactylation on histone H3 (H3K18la), which enriches at the PD-L1 promoter region, thus promoting PD-L1 transcription. These findings suggest that CAF may diminish the effectiveness of PD-1/PD-L1 blockade immunotherapy through LOX-induced glycolysis and lactate accumulation. Consequently, we have constructed a model of the interactions among CAF, lactate, and PD-L1 in gastric cancer progression, providing new experimental evidence for PD-L1-based immunotherapy.

The first-line standard therapy for advanced HER2-positive gastric cancer is chemotherapy combined with trastuzumab and pembrolizumab, while pembrolizumab alone does not benefit as a monotherapy in patients with mismatch repair proficiency (pMMR). This case explores the therapeutic potential of adding pembrolizumab to patients who were resistant to trastuzumab, focusing on the synergistic effect of an immune checkmate inhibitor, combined with HER2 antibody.

An 87-year-old metastatic gastric cancer patient, whose medical history was significant for intolerance to chemotherapy and had a poor status of performance. Immunohistochemical staining was presented as HER2 (3+), pMMR, and PD-L1 was 4. Initially treated with trastuzumab monotherapy, the patient showed no response and experienced progressive disease. Subsequently, a combined regimen of trastuzumab and a half-dose of pembrolizumab was administered every 3 weeks. Remarkably, it led to a significant reduction in tumor size, achieving partial remission (PR) after two cycles. This response was sustained over 21 months, as evidenced by the latest CT scans.

The concurrent administration of trastuzumab and pembrolizumab has demonstrated synergistic antitumor activity, achieving clinical efficacy in cases where each agent alone proved ineffective. Preclinical studies illustrated that tumor regression induced by HER2 antibodies requires T cell involvement, and the combination of immune checkpoint inhibitors with trastuzumab augments HER2-specific T cell responses, promotes immune cell recruitment, and induces the expansion of peripheral memory T cells, which showed synergistic rationales for a combination of pembrolizumab and trastuzumab.

The observed synergy between pembrolizumab and trastuzumab highlights a promising treatment avenue that warrants further investigation.

Accurately extrapolating survival beyond trial follow-up is essential in a health technology assessment where model choice often substantially impacts estimates of clinical and cost effectiveness. Evidence suggests standard parametric models often provide poor fits to long-term data from immuno-oncology trials. Palmer et al. developed an algorithm to aid the selection of more flexible survival models for these interventions. We assess the usability of the algorithm, identify areas for improvement and evaluate whether it effectively identifies models capable of accurate extrapolation.

We applied the Palmer algorithm to the CheckMate-649 trial, which investigated nivolumab plus chemotherapy versus chemotherapy alone in patients with gastroesophageal adenocarcinoma. We evaluated the algorithm's performance by comparing survival estimates from identified models using the 12-month data cut to survival observed in the 48-month data cut.

The Palmer algorithm offers a systematic procedure for model selection, encouraging detailed analyses and ensuring that crucial stages in the selection process are not overlooked. In our study, a range of models were identified as potentially appropriate for extrapolating survival, but only flexible parametric non-mixture cure models provided extrapolations that were plausible and accurately predicted subsequently observed survival. The algorithm could be improved with minor additions around the specification of hazard plots and setting out plausibility criteria.

The Palmer algorithm provides a systematic framework for identifying suitable survival models, and for defining plausibility criteria for extrapolation validity. Using the algorithm ensures that model selection is based on explicit justification and evidence, which could reduce discordance in health technology appraisals.

Advanced gastroesophageal cancers are still associated with poor outcomes. We aim to study PD-1/PD-L1 inhibitors in phase III clinical trials that have compared them to chemotherapy in gastric, gastroesophageal junction (GEJ), and esophageal adenocarcinoma.

On March 28, 2024, we searched: PubMed, Embase, Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov. We only included randomized clinical trials for PD-1/PD-L1 inhibitors alone or with chemo vs chemotherapy in advanced gastric, GEJ, or esophageal adenocarcinoma. The primary endpoints were overall survival and progression-free survival. A subgroup analysis was conducted for the following variables: treatment line, type of intervention, age group, gender, ECOG Performance Status, combined positive scores (CPS), microsatellite instability (MSI) status, liver metastasis, and primary tumor location.

Only 10 out of 8,942 articles were included, involving 6,782 patients. PD-1/PD-L1 inhibitors showed a significant improvement in the overall survival compared to chemotherapy alone (hazard ratio (HR): 0.86, 95% CI: 0.80-0.93; p = 0.0002). Combining PD-1/PD-L1 inhibitors with chemotherapy significantly improved overall and progression-free survival compared to monotherapy (combined therapy HR 0.80; p < 0.00001 vs. monotherapy HR 0.98; p = 0.77). CPS ≥1 had an HR of 0.78 (95% CI: 0.73-0.84; p < 0.00001), CPS ≥10 had an HR of 0.67 (95% CI: 0.59-0.76; p < 0.00001), and MSI-high status had an HR of 0.35 (95% CI: 0.24-0.52; p < 0.00001). Esophageal adenocarcinoma, reported in three trials, did not show significant improvement in the overall survival (HR 0.89; 95% CI: 0.69-1.14; p = 0.37).

PD-1/PD-L1 inhibitors have significantly improved overall survival, and combining them with chemotherapy is more effective than monotherapy. Both CPS ≥10 and MSI-H showed an added benefit to overall survival and should be included in biomarker investigations. Clinical trials are needed for second-line treatments and esophageal adenocarcinoma.

The accelerated approval (AA) pathway was established by the United States Food and Drug Administration (FDA) to provide earlier access to therapies for patients with serious medical conditions and unmet medical needs. Since its inception, the AA pathway has been used for novel treatments across different therapeutic areas, but most prominently in oncology, including the immune checkpoint inhibitor class. This review article describes the history of regulatory approvals for pembrolizumab, an immunotherapy agent targeting programmed death receptor-1 (PD-1), and use of the AA pathway and the corresponding regulatory decisions made by the FDA. From its first AA in September 2014 to February 2024, pembrolizumab has used the accelerated pathway for roughly 40% of the approved indications listed in the US Prescribing Information and was the first oncology therapy to receive an AA for an alternate dosing regimen and a tissue-agnostic indication. As of February 2024, 14 of the 18 indication-specific AAs and 1 post-marketing requirement (PMR) for the alternate dosing regimen AA were converted to traditional approvals. Accelerated approvals for two indications were withdrawn, and the remaining ongoing PMRs are not due until later in 2024 or 2025. The median conversion time from AA to traditional approval was 2.6 years, which is roughly 6 months earlier than the median time reported for oncology AAs. While FDA was the first agency to establish an expedited approval pathway, regulators from other countries have established similar pathways. For pembrolizumab, approximately half of the datasets that supported US AAs also supported expedited approval, or sometimes full approval, in Canada, EU, Australia or Japan. Ultimately, the AA pathway balances the provision of earlier access to therapies with overcoming uncertainty about potential effectiveness, and therefore it is important to confirm treatment benefit and withdraw indications that do not confirm benefit in a timely manner. The regulatory strategy and use of this expedited program for pembrolizumab highlights the importance of the AA pathway in providing oncology patients with earlier access to life-saving medications.

The response rate to immune checkpoint inhibitor (ICI) therapy is limited. Further, there is a need to discover biomarkers to predict therapeutic efficacy. The vascular endothelial growth factor (VEGF) is strongly associated with intra-tumoral immunity; however, its utility as a marker remains unknown. Therefore, our objectives were to examine the isoforms of VEGF and determine whether VEGF levels predict ICI efficacy.

Levels of VEGF isoforms VEGF-A121 and VEGF-A165 were measured in stored serum samples obtained from 30 patients with advanced or recurrent gastric cancer who received nivolumab monotherapy at Kagoshima University Hospital, and the association with prognosis and treatment efficacy was retrospectively analyzed.

The serum levels of the total VEGF, VEGF-A121, and VEGF-A165 were not significantly associated with prognosis. However, the ratio of VEGF-A121/VEGF-A165 (VEGF-A121/165) exhibited a statistically significant (p = 0.0088) difference in progression-free survival (PFS) with the low-ratio group having a 67-day prolonged median PFS time. Under univariable analysis, only VEGF-A121/165 values exhibited reduced progression-free survival with statistical significance. When comparing treatment responses in the low (n = 15) and high (n = 15) serum VEGF-A-121/165 groups, RECIST evaluation was 3 to 0 for complete response (CR), 2 to 0 for partial response (PR), 3 to 2 for stable disease (SD), and 3 to 10 for progressive disease (PD). Patients with clinically unsettled PR or SD were classified as non-CR/non-PD (4 vs. 3), with a disease control rate of 80% vs. 33%.

The serum VEGF-A121/165 ratio may represent a new, easily measured biomarker for predicting the therapeutic response to ICIs.