The PD-1 expression balance between effector and regulatory T cells predicts the clinical efficacy of PD-1 blockade therapies.

Immune checkpoint blockade has provided a paradigm shift in cancer therapy, but the success of this approach is very variable; therefore, biomarkers predictive of clinical efficacy are urgently required. Here, we show that the frequency of PD-1+CD8+ T cells relative to that of PD-1+ regulatory T (Treg) cells in the tumor microenvironment can predict the clinical efficacy of programmed cell death protein 1 (PD-1) blockade therapies and is superior to other predictors, including PD ligand 1 (PD-L1) expression or tumor mutational burden. PD-1 expression by CD8+ T cells and Treg cells negatively impacts effector and immunosuppressive functions, respectively. PD-1 blockade induces both recovery of dysfunctional PD-1+CD8+ T cells and enhanced PD-1+ Treg cell-mediated immunosuppression. A profound reactivation of effector PD-1+CD8+ T cells rather than PD-1+ Treg cells by PD-1 blockade is necessary for tumor regression. These findings provide a promising predictive biomarker for PD-1 blockade therapies.

An Oncogenic Alteration Creates a Microenvironment that Promotes Tumor Progression by Conferring a Metabolic Advantage to Regulatory T Cells.

Only a small percentage of patients afflicted with gastric cancer (GC) respond to immune checkpoint blockade (ICB). To study the mechanisms underlying this resistance, we examined the immune landscape of GC. A subset of these tumors was characterized by high frequencies of regulatory T (Treg) cells and low numbers of effector T cells. Genomic analyses revealed that these tumors bore mutations in RHOA that are known to drive tumor progression. RHOA mutations in cancer cells activated the PI3K-AKT-mTOR signaling pathway, increasing production of free fatty acids that are more effectively consumed by Treg cells than effector T cells. RHOA mutant tumors were resistant to PD-1 blockade but responded to combination of PD-1 blockade with inhibitors of the PI3K pathway or therapies targeting Treg cells. We propose that the metabolic advantage conferred by RHOA mutations enables Treg cell accumulation within GC tumors, generating an immunosuppressive TME that underlies resistance to ICB.

The KEYNOTE-811 trial of dual PD-1 and HER2 blockade in HER2-positive gastric cancer.

Human epidermal growth factor receptor 2 (HER2, also known as ERBB2) amplification or overexpression occurs in approximately 20% of advanced gastric or gastro-oesophageal junction adenocarcinomas1-3. More than a decade ago, combination therapy with the anti-HER2 antibody trastuzumab and chemotherapy became the standard first-line treatment for patients with these types of tumours4. Although adding the anti-programmed death 1 (PD-1) antibody pembrolizumab to chemotherapy does not significantly improve efficacy in advanced HER2-negative gastric cancer5, there are preclinical6-19 and clinical20,21 rationales for adding pembrolizumab in HER2-positive disease. Here we describe results of the protocol-specified first interim analysis of the randomized, double-blind, placebo-controlled phase III KEYNOTE-811 study of pembrolizumab plus trastuzumab and chemotherapy for unresectable or metastatic, HER2-positive gastric or gastro-oesophageal junction adenocarcinoma22 ( https://clinicaltrials.gov , NCT03615326). We show that adding pembrolizumab to trastuzumab and chemotherapy markedly reduces tumour size, induces complete responses in some participants, and significantly improves objective response rate.

Whole-transcriptome sequencing in advanced gastric or gastroesophageal cancer: A deep dive into its clinical potential.

Advanced gastric and gastroesophageal junction cancers (GC/GEJCs) harbor diverse molecular signatures, highlighting the need for intricate evaluations to identify potential therapeutic targets. Although whole-transcriptome sequencing (WTS) has emerged as a useful tool for understanding these molecular intricacies, its clinical implications have yet to be fully elucidated. This study evaluated the correlation between immunohistochemistry (IHC) and WTS, compared their clinical significance, and identified potential therapeutic targets undetectable through IHC alone. We enrolled 140 patients with advanced GC/GEJC and assessed them using IHC for six pivotal biomarkers: claudin-18 (CLDN18), human epidermal growth factor receptor 2 (HER2), multiple receptor tyrosine kinases (RTKs), and programmed death ligand 1 (PD-L1). Concurrently, WTS was employed as part of the analyses in MONSTAR-SCREEN-2, a multicenter multiomics study. IHC analysis revealed 16.4% HER2, 39.3% CLDN18 (2+/3 + ≥75%), and 15.8% PD-L1 (combined positive score ≥ 10) positivity, among other molecular markers. Significant correlations were observed between IHC and WTS for all six pivotal biomarkers. Among nineteen HER2 IHC-positive patients treated with anti-HER2 therapeutics, ERBB2 status in WTS was significantly associated with progression-free survival (ERBB2-high vs. -low: median 9.0 vs. 5.6 months, log-rank p = 0.046). IHC-based molecular profiling revealed significantly high expression of CLDN18 in RTK-negative patients, with 78.4% positive for either CLDN18 or PD-L1. Additionally, WTS revealed elevated expression of pivotal biomarkers in patients displaying negative targetable biomarkers via IHC. Our findings highlighted the significant correlation between IHC and WTS, reinforcing the clinical utility of WTS. A subset with IHC-negative but WTS-positive status may benefit from specific biomarker-targeted therapies.

Pembrolizumab plus trastuzumab and chemotherapy for HER2-positive gastric or gastro-oesophageal junction adenocarcinoma: interim analyses from the phase 3 KEYNOTE-811 randomised placebo-controlled trial.

BACKGROUND: Evidence for the efficacy of combined PD-1 and HER2 blockade with chemotherapy on progression-free and overall survival in HER2-positive gastro-oesophageal cancer is scarce. The first interim analysis of the randomised, phase 3 KEYNOTE-811 study showed a superior objective response with pembrolizumab compared with placebo when added to trastuzumab plus fluoropyrimidine and platinum-based chemotherapy. Here, we report results from protocol-specified subsequent interim analyses of KEYNOTE-811. METHODS: The randomised, phase 3 KEYNOTE-811 trial involved 168 medical centres in 20 countries worldwide. Patients aged 18 years or older with locally advanced or metastatic HER2-positive gastro-oesophageal junction adenocarcinoma, without previous first-line treatment, were randomly assigned (1:1) by an integrated interactive voice-response and web-response system to intravenous pembrolizumab 200 mg or placebo, both to be combined with standard chemotherapy (fluoropyrimidine and platinum-based therapy) plus trastuzumab every 3 weeks for up to 35 cycles or until disease progression, unacceptable toxic effects, or investigator or participant-initiated withdrawal. Randomisation used a block size of four and was stratified by region, PD-L1 status, and chemotherapy. Dual primary endpoints were progression-free and overall survival, analysed by intention to treat. Safety was assessed in all randomly assigned patients who received at least one dose of study treatment according to the treatment received. KEYNOTE-811 is registered with ClinicalTrials.gov (NCT03615326) and is active but not recruiting. FINDINGS: Between Oct 5, 2018, and Aug 6, 2021, 698 patients were assigned to pembrolizumab (n=350) or placebo (n=348). 564 (81%) were male and 134 (19%) were female. At the third interim analysis, 286 (82%) of 350 patients in the pembrolizumab group and 304 (88%) of 346 in the placebo group who received treatment had discontinued treatment, mostly due to disease progression. At the second interim analysis (median follow-up 28·3 months [IQR 19·4-34·3] in the pembrolizumab group and 28·5 months [20·1-34·3] in the placebo group), median progression-free survival was 10·0 months (95% CI 8·6-11·7) in the pembrolizumab group versus 8·1 months (7·0-8·5) in the placebo group (hazard ratio [HR] 0·72, 95% CI 0·60-0·87; p=0·0002). Median overall survival was 20·0 months (17·8-23·2) versus 16·9 months (15·0-19·8; HR 0·87 [0·72-1·06]; p=0·084). At the third interim analysis (median follow-up 38·4 months [IQR 29·5-44·4] in the pembrolizumab group and 38·6 months [30·2-44·4] in the placebo group), median progression-free survival was 10·0 months (8·6-12·2) versus 8·1 months (7·1-8·6; HR 0·73 [0·61-0·87]), and median overall survival was 20·0 months (17·8-22·1) versus 16·8 months (15·0-18·7; HR 0·84 [0·70-1·01]), but did not meet prespecified criteria for significance and will continue to final analysis. Grade 3 or worse treatment-related adverse events occurred in 204 (58%) of 350 patients in the pembrolizumab group versus 176 (51%) of 346 patients in the placebo group. Treatment-related adverse events that led to death occurred in four (1%) patients in the pembrolizumab group and three (1%) in the placebo group. The most common treatment-related adverse events of any grade were diarrhoea (165 [47%] in the pembrolizumab group vs 145 [42%] in the placebo group), nausea (154 [44%] vs 152 [44%]), and anaemia (109 [31%] vs 113 [33%]). INTERPRETATION: Compared with placebo, pembrolizumab significantly improved progression-free survival when combined with first-line trastuzumab and chemotherapy for metastatic HER2-positive gastro-oesophageal cancer, specifically in patients with tumours with a PD-L1 combined positive score of 1 or more. Overall survival follow-up is ongoing and will be reported at the final analysis. FUNDING: Merck Sharp & Dohme.

[Chemotherapy for Unresectable Advanced, Metastatic or Recurrent Colorectal Cancer].

Colorectal cancer(CRC)is one of the most commonly diagnosed cancers worldwide. Unresectable advanced, metastatic or recurrent CRC(mCRC)remains incurable for most patients. Systemic chemotherapy is standard treatment for patients with mCRC. The goals of systemic chemotherapy include prolonging survival by stopping cancer progression and palliation. In recent years, advances in the treatment of mCRC have enabled personalized care based on the tumor's molecular profile with improved outcomes for some subtypes. Targeted biologic therapies and immune checkpoint inhibitors have changed the approach to management of uncommon molecularly defined subsets of mCRC. The development of chemotherapy using cytotoxic drugs, biologic monoclonal antibodies, and immune checkpoint inhibitors has prolonged median overall survival up to approximately 30 months. In this report, we describe the evolution of systemic chemotherapy for mCRC, recent advances in standard treatment, and future prospects for the treatment of mCRC.

Phase 1 trial of zolbetuximab in Japanese patients with CLDN18.2+ gastric or gastroesophageal junction adenocarcinoma.

Zolbetuximab is a chimeric monoclonal antibody that targets claudin-18.2, a candidate biomarker in patients with advanced gastric/gastroesophageal cancer. This nonrandomized phase 1 study (NCT03528629) enrolled previously treated Japanese patients with claudin-18.2-positive locally advanced/metastatic gastric/gastroesophageal cancer in two parts: Safety (Arms A and B, n = 3 each) and Expansion (n = 12). Patients received intravenous zolbetuximab 800 mg/m2 on cycle 1, day 1 followed by 600 mg/m2 every 3 weeks (Q3W; Safety Part Arm A and Expansion) or 1000 mg/m2 Q3W (Safety Part Arm B). For the Safety Part, the primary endpoint was safety (i.e., dose-limiting toxicities [DLTs]) and a secondary endpoint was objective response rate (ORR) by investigator. For the Expansion Part, the primary endpoint was ORR by investigator and secondary endpoints included ORR by central review and safety. Additional secondary endpoints for both the Safety and Expansion Parts were disease control rate (DCR), overall survival (OS), progression-free survival (PFS), duration of response, pharmacokinetics, and immunogenicity. In 18 patients, no DLTs (Safety Part) or drug-related treatment-emergent adverse events (TEAEs) grade ≥3 were observed. Most TEAEs were gastrointestinal. In 17 patients with measurable lesions, best overall response was stable disease (64.7%) or progressive disease (35.3%). The DCR was 64.7% (95% confidence interval 38.3-85.8). In Arm A and Expansion combined (n = 15), median OS was 4.4 months (2.6-11.4) and median PFS was 2.6 months (0.9-2.8). In Arm B (n = 3), median OS was 6.4 months (2.9-6.8) and median PFS was 1.7 months (1.2-2.1). Zolbetuximab exhibited no new safety signals with limited single-agent activity in Japanese patients.

HLA Class I Analysis Provides Insight Into the Genetic and Epigenetic Background of Immune Evasion in Colorectal Cancer With High Microsatellite Instability.

BACKGROUND & AIMS: A detailed understanding of antitumor immunity is essential for optimal cancer immune therapy. Although defective mutations in the B2M and HLA-ABC genes, which encode molecules essential for antigen presentation, have been reported in several studies, the effects of these defects on tumor immunity have not been quantitatively evaluated. METHODS: Mutations in HLA-ABC genes were analyzed in 114 microsatellite instability-high colorectal cancers using a long-read sequencer. The data were further analyzed in combination with whole-exome sequencing, transcriptome sequencing, DNA methylation array, and immunohistochemistry data. RESULTS: We detected 101 truncating mutations in 57 tumors (50%) and loss of 61 alleles in 21 tumors (18%). Based on the integrated analysis that enabled the immunologic subclassification of microsatellite instability-high colorectal cancers, we identified a subtype of tumors in which lymphocyte infiltration was reduced, partly due to reduced expression of HLA-ABC genes in the absence of apparent genetic alterations. Survival time of patients with such tumors was shorter than in patients with other tumor types. Paradoxically, tumor mutation burden was highest in the subtype, suggesting that the immunogenic effect of accumulating mutations was counterbalanced by mutations that weakened immunoreactivity. Various genetic and epigenetic alterations, including frameshift mutations in RFX5 and promoter methylation of PSMB8 and HLA-A, converged on reduced expression of HLA-ABC genes. CONCLUSIONS: Our detailed immunogenomic analysis provides information that will facilitate the improvement and development of cancer immunotherapy.

Impact of Programmed Death-Ligand 1 Expression on Mismatch Repair Deficiency and Epstein-Barr Virus Status on Survival Outcomes in Patients with Stage II/III Gastric Cancer After Surgery.

BACKGROUND: The aim of this study was to investigate the prognostic impact of mismatch repair (MMR) status, programmed death-ligand 1 (PD-L1) expression, and Epstein-Barr virus (EBV) status in stage II/III gastric cancer after surgery. METHODS: This study included 679 patients diagnosed with pathological stage II/III gastric cancer who underwent curative gastrectomy followed by adjuvant chemotherapy (AC) or observation between 2007 and 2015. Clinical outcomes were retrospectively reviewed and compared with stratification by AC and other clinicopathological factors. RESULTS: Patients were divided into AC (n = 484) or surgery alone (SA; n = 195) groups and were further stratified by MMR and EBV status: MMR-deficient (DMMR) and MMR-proficient (PMMR) groups. Comparing the AC-DMMR group versus the AC-PMMR group, 5-year overall survival was 92.0% versus 74.0% (log-rank p < 0.01), and comparing the SA-DMMR group versus the SA-PMMR group, 5-year overall survival was 71.1% versus 73.7% (log-rank p = 0.89). DMMR (hazard ratio 0.25, 95% confidence interval 0.07-0.81) was identified as an independent prognostic factor in the AC group but not in the SA group. In the subgroup analysis, PD-L1-negative patients among the EBV-positive patients or in the DMMR group had a poor prognosis in both the AC and SA groups. The prognosis of the PMMR and EBV-negative patients was similar regardless of PD-L1 expression. CONCLUSIONS: DMMR was associated with a favorable prognosis in stage II/III gastric cancer after surgery and adjuvant therapy. PD-L1 expression may affect the prognosis of DMMR and EBV-positive gastric cancer.

Efficacy and safety of trifluridine/tipiracil plus ramucirumab in comparison with trifluridine/tipiracil monotherapy for patients with advanced gastric cancer-single institutional experience.

BACKGROUND: Trifluridine/tipiracil plus VEGF inhibition with ramucirumab (RAM) for advanced gastric cancer (AGC) demonstrated clinical activity with an acceptable toxicity profile in previous phase II trial. However, little is known about its efficacy and safety in clinical practice in comparison with trifluridine/tipiracil monotherapy. METHODS: We retrospectively investigated efficacy and safety of trifluridine/tipiracil plus RAM and trifluridine/tipiracil monotherapy as third or later line treatment for AGC patients. RESULTS: Forty-one patients receiving trifluridine/tipiracil plus RAM and 60 patients receiving trifluridine/tipiracil monotherapy were analyzed. The objective response rate (ORR) and the disease control rate (DCR) were 13.5% and 64.9% in the trifluridine/tipiracil plus RAM group, and 3.8% and 42.3% in the trifluridine/tipiracil monotherapy group, respectively (ORR; P = 0.122, DCR; P = 0.052). The median progression-free survival (PFS) and the median overall survival (OS) were 3.0 months and 7.2 months in the trifluridine/tipiracil plus RAM group, and 1.8 months and 3.8 months in the trifluridine/tipiracil monotherapy group, respectively (HR for PFS = 0.66; P = 0.059, HR for OS = 0.50; P = 0.007). Multivariate analysis showed significantly longer PFS (HR = 0.52; P = 0.011) and OS (HR = 0.51; P = 0.031) in the trifluridine/tipiracil plus RAM group compared to the trifluridine/tipiracil monotherapy group. No unexpected adverse events were observed in both groups. CONCLUSIONS: Trifluridine/tipiracil plus RAM might show favorable anti-tumor activity with an acceptable toxicity profile in comparison with trifluridine/tipiracil monotherapy, suggesting one treatment option for AGC patients in salvage line. The combination needs further evaluation in ongoing randomized trials.

Topical corticosteroid therapy for facial acneiform eruption due to EGFR inhibitors in metastatic colorectal cancer patients: a randomized controlled trial comparing starting with a very strong or a weak topical corticosteroid (FAEISS study, NCCH1512, colorectal part).

BACKGROUND: Although pre-emptive therapy with oral tetracycline, moisturizer, sunscreen, and topical corticosteroid is useful for preventing acneiform eruption (AfE) due to epidermal growth factor receptor (EGFR) inhibitors, no studies have examined the efficacy of topical corticosteroids themselves, or investigated the optimal potency of corticosteroid for treating facial AfE (FAfE). PATIENTS AND METHODS: Screened patients with RAS wild-type colorectal cancer started pre-emptive therapy with oral minocycline and moisturizer on initiation of cetuximab or panitumumab therapy. Patients who developed grade 1 or 2 FAfE were randomly allocated to two groups: a ranking-down (RD) group that started with a very strong corticosteroid and serially ranked down every 2 weeks unless FAfE exacerbated; and a ranking-up (RU) group that started with a weak corticosteroid and serially ranked up at exacerbation. FAfE grade, patient quality of life, and adverse events (AEs) with topical corticosteroid were evaluated every 2 weeks. The primary endpoint was the total number of times grade 2 or higher FAfE was identified in the central review of the 8-week treatment period. RESULTS: No significant differences in total numbers of grade 2 or higher FAfE or in AEs caused by topical corticosteroids were observed between groups during the 8 weeks. Incidence of grade 2 or higher FAfE tended to be lower in the RD group during the first 2 weeks. CONCLUSION: Considering the long-term care of FAfE, the RU regimen appears suitable and should be considered the standard treatment for FAfE due to EGFR inhibitor therapy. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN000024113).

Characteristics and clinical outcomes of patients with advanced gastric or gastroesophageal cancer treated in and out of randomized clinical trials of first-line immune checkpoint inhibitors.

BACKGROUND: Although several randomized trials (RCTs) showed survival benefits of immune checkpoint inhibitor (ICI) plus first-line chemotherapy for advanced gastric or gastroesophageal cancer (AGC), these trials could enroll patients who fulfilled the strict eligibility criteria or waited for certain screening period for central assessment of PD-L1 status. METHODS: We retrospectively compared characteristics and clinical outcomes of the patients with AGC who received first-line chemotherapy in control arm of RCTs with ICIs (control group) or clinical practice (practice group) at our institution from February 2016 to April 2019. RESULTS: The control group had a better baseline Eastern Cooperative Oncology Group performance status (PS0, 81.2% vs. 51.4%, p < 0.001) and a longer interval from first visit to first-line chemotherapy initiation (19 days vs. 9 days, p < 0.001) than the practice group. Median overall survival (OS) was 20.3 months in control group and 15.7 months in practice group, with a trend of longer OS in control group than that in practice group (hazard ratio, 0.71; p = 0.062). More patients in control group were treated with subsequent chemotherapy including ICIs. CONCLUSION: Patients with AGC in RCTs of ICIs had a better PS or a higher chance to receive subsequent chemotherapy, resulting in a better prognosis than those treated in clinical practice. This information should be considered when interpreting RCT results and applying new treatments into clinical practice.

PD-1+ regulatory T cells amplified by PD-1 blockade promote hyperprogression of cancer.

PD-1 blockade is a cancer immunotherapy effective in various types of cancer. In a fraction of treated patients, however, it causes rapid cancer progression called hyperprogressive disease (HPD). With our observation of HPD in ∼10% of anti-PD-1 monoclonal antibody (mAb)-treated advanced gastric cancer (GC) patients, we explored how anti-PD-1 mAb caused HPD in these patients and how HPD could be treated and prevented. In the majority of GC patients, tumor-infiltrating FoxP3highCD45RA-CD4+ T cells [effector Treg (eTreg) cells], which were abundant and highly suppressive in tumors, expressed PD-1 at equivalent levels as tumor-infiltrating CD4+ or CD8+ effector/memory T cells and at much higher levels than circulating eTreg cells. Comparison of GC tissue samples before and after anti-PD-1 mAb therapy revealed that the treatment markedly increased tumor-infiltrating proliferative (Ki67+) eTreg cells in HPD patients, contrasting with their reduction in non-HPD patients. Functionally, circulating and tumor-infiltrating PD-1+ eTreg cells were highly activated, showing higher expression of CTLA-4 than PD-1- eTreg cells. PD-1 blockade significantly enhanced in vitro Treg cell suppressive activity. Similarly, in mice, genetic ablation or antibody-mediated blockade of PD-1 in Treg cells increased their proliferation and suppression of antitumor immune responses. Taken together, PD-1 blockade may facilitate the proliferation of highly suppressive PD-1+ eTreg cells in HPDs, resulting in inhibition of antitumor immunity. The presence of actively proliferating PD-1+ eTreg cells in tumors is therefore a reliable marker for HPD. Depletion of eTreg cells in tumor tissues would be effective in treating and preventing HPD in PD-1 blockade cancer immunotherapy.

Combination therapy of capecitabine, irinotecan, oxaliplatin, and bevacizumab as a first-line treatment for metastatic colorectal cancer: Safety lead-in results from the QUATTRO-II study.

Background FOLFOXIRI plus bevacizumab is the first-line treatment for metastatic colorectal cancer (mCRC) but demonstrates high neutropenia incidence among Asian patients. Hence, we conducted the randomized phase II QUATTRO-II study (ClinicalTrials.gov identifier: NCT04097444; Japan Registry of Clinical Trials identifier: jRTCs041190072) to evaluate the safety and efficacy of capecitabine, oxaliplatin, and irinotecan (CAPOXIRI) combination plus bevacizumab versus FOLFOXIRI plus bevacizumab, expecting a lower incidence of neutropenia without compromising the efficacy. Methods We investigated the recommended doses (RD) of oxaliplatin and irinotecan as a safety lead-in portion of Step 1 before initiating the randomized portion as Step 2. Four dose levels of CAPOXIRI (fixed dose of capecitabine, 1600 mg/m2; escalated/de-escalated doses of oxaliplatin and irinotecan) plus bevacizumab (7.5 mg/kg) were investigated in a 3 + 3 manner. A dose level of ≤ 2/6 of dose-limiting toxicity (DLT) cases was expected as the RD. Results In Step 1, we included nine patients (three and six in levels 0 and + 1, respectively). Level 0 (irinotecan, 200 mg/m2; oxaliplatin, 100 mg/m2) did not demonstrate DLTs. In level + 1 (irinotecan, 200 mg/m2; oxaliplatin, 130 mg/m2), although one patient experienced grade 4 febrile neutropenia, no further safety concerns were observed. As a preliminary efficacy result, the objective response rate in all nine patients was 89 % (100 and 83 % in levels 0 and + 1, respectively). Conclusions The RD of CAPOXIRI plus bevacizumab was 200, 130, and 1600 mg/m2 for irinotecan, oxaliplatin, and capecitabine, respectively, and 7.5 mg/kg for bevacizumab. The randomized portion is still ongoing.

A multicenter phase II study of TAS-114 in combination with S-1 in patients with pretreated advanced gastric cancer (EPOC1604).

BACKGROUND: This is a phase 2 study aimed at evaluating the efficacy and safety of TAS-114, a novel deoxyuridine triphosphatase inhibitor, combined with S-1 in patients with advanced gastric cancer (AGC). METHODS: Eligible patients had AGC with measurable lesions, according to the Response Evaluation Criteria in Solid Tumors (RECIST, v1.1), with two or more previous chemotherapy regimens including fluoropyrimidines, platinum agents, and taxanes or irinotecan. The primary endpoint was objective response rate (ORR) according to the RECIST, v1.1. Twenty-nine patients were required according to Simon's optimal two-stage design, with one-sided a = 5% and power = 80%. Threshold and expected ORRs were 5% and 25%. Patients received TAS-114 (400 mg/body, twice a day) and S-1 (30 mg/m2, twice a day) for 14 days, followed by 7 days of rest in one 3-week cycle. Protein expression levels of dUTPase and BRCA1 in tumor samples were determined by immunohistochemistry. RESULTS: Accrual was terminated in June 2018 because meeting the predefined efficacy criteria was considered difficult. ORR and disease control rate were 5.0% [95% confidence interval (CI), 0.1-24.9%] and 70.0% (95% CI, 45.7-88.1%), respectively, for all 20 patients enrolled. Median progression-free survival (PFS) and overall survival were 2.4 months (95% CI, 1.2-3.3 months) and 7.1 months (95% CI, 5.2-9.4 months), respectively. Median PFS in the groups with high and low dUTPase protein expression in the cytoplasm was 2.8 months (95% CI, 1.4-3.9) and 1.6 months (95% CI, 0.6-2.4), respectively [hazard ratio, 0.40 (95% CI, 0.16-1.04), log-rank test two-sided p = 0.047]. Grade 3 or higher treatment-related adverse events included anemia (20%), leucopenia (15%), neutropenia (10%), rash (10%), thrombocytopenia (5%), and lymphopenia (5%) CONCLUSIONS: TAS-114 with S-1 showed only modest antitumor activity with acceptable safety profiles for patients heavily pretreated with AGC.

Current status of immunotherapy for advanced gastric cancer.

Recently, immune checkpoint inhibitors such as anti-programmed cell death-1 (PD-1) or programmed cell death ligand-1 (PD-L1) monoclonal antibodies have improved the overall survival of various types of cancers including advanced gastric cancer (AGC). Until now, two ant-PD-1 inhibitors were approved for AGC in Japan: nivolumab as third- or later-line treatment for AGC and pembrolizumab for previously treated patients with microsatellite instability-high tumours. However, a limited number of patients achieved clinical benefit, highlighting the importance of the better selection of patients or additional treatment to overcome resistance to PD-1/PD-L1 blockade. This review focused on pivotal clinical trials, biomarkers and novel combination therapy of immune checkpoint inhibitors forAGC.

Short-term safety of adjuvant chemoradiotherapy after local resection for patients with high-risk submucosal invasive rectal cancer: a single-arm, multicenter phase II trial.

BACKGROUND: Surgery is recommended for patients with high-risk submucosal invasive rectal cancer (SM-RC) after local resection but affects the quality of life due to stoma placement or impaired anal function; therefore, alternative treatment approaches are needed to prevent local metastasis. The purpose of this study was to assess the short-term safety of adjuvant chemoradiotherapy with capecitabine in patients with high-risk submucosal invasive rectal cancer after local resection. METHODS: This single-arm, multicenter, phase II trial included patients undergoing local resection for high-risk submucosal invasive rectal cancer within 12 weeks prior to enrollment. High-risk submucosal invasive rectal cancer was defined as the presence of at least one of the following factors: poor differentiation of adenocarcinoma, submucosal invasion depth > 1 mm, presence of lymphovascular invasion and grade-2 or -3 tumour budding. Protocol treatment comprised 45.0 Gy radiotherapy with conventional fractionation and 1650 mg/m2 capecitabine given twice daily until radiotherapy completion. The primary endpoint was treatment completion rate with an expected rate of 95% and a threshold of 80%. RESULTS: Twenty-nine patients from six institutions were enrolled between May 2015 and February 2018. One patient was ineligible. Twenty-three patients completed treatment, with a completion rate of 82% (80% confidence interval, 69-91%); the remaining five patients completed treatment with protocol deviation. The median relative dose intensity of capecitabine was 100% (range, 58-100%). Common adverse events included radiation dermatitis (54%), anal pain (39%) and anal mucositis (29%). No grade-3 or higher adverse events were reported. CONCLUSIONS: Adjuvant chemoradiotherapy using capecitabine demonstrated acceptable short-term safety profiles in patients with high-risk submucosal invasive rectal cancer after local resection.

Phase I study of napabucasin in combination with FOLFIRI + bevacizumab in Japanese patients with metastatic colorectal cancer.

BACKGROUND: Napabucasin is an oral NAD(P)H:quinone oxidoreductase 1 bioactivatable agent that generates reactive oxygen species, is hypothesised to affect multiple oncogenic cellular pathways, including STAT-3, and is expected to result in cancer cell death. This phase I study investigated the safety, tolerability, and pharmacokinetics of napabucasin co-administered with fluorouracil, l-leucovorin, and irinotecan (FOLFIRI) chemotherapy plus bevacizumab in Japanese patients with metastatic colorectal cancer (CRC). METHODS: Patients with histologically confirmed unresectable stage IV CRC received oral napabucasin 240 mg twice daily (BID). Intravenous FOLFIRI and bevacizumab therapy was initiated on day 3 at approved doses. Unacceptable toxicity was evaluated over the first 30 days of treatment, after which treatment continued in 14-day cycles until toxicity or disease progression. Endpoints included safety, pharmacokinetics, and tumour response based on RECIST v1.1. RESULTS: Four patients received treatment; three were evaluable during the unacceptable toxicity period. All four patients experienced diarrhoea and decreased appetite (considered napabucasin-related in four and two patients, respectively), and three patients experienced neutrophil count decreased. No unacceptable toxicity was reported during the 30-day evaluation period. No grade 4 events, deaths, or serious adverse events were reported. The addition of FOLFIRI and bevacizumab to napabucasin did not significantly change the pharmacokinetic profile of napabucasin; however, results were variable among patients. The best overall response was stable disease in two patients (50.0%). CONCLUSIONS: Napabucasin 240 mg BID in combination with FOLFIRI and bevacizumab was tolerated, with a manageable safety profile in Japanese patients with metastatic CRC.

Lenvatinib plus pembrolizumab in patients with advanced gastric cancer in the first-line or second-line setting (EPOC1706): an open-label, single-arm, phase 2 trial.

BACKGROUND: Pembrolizumab, an anti-PD-1 antibody, results in tumour response in around 15% of patients with advanced gastric cancer who have a PD-L1 combined positive score of at least 1. Lenvatinib, a multikinase inhibitor of VEGF receptors and other receptor tyrosine kinases, substantially decreased tumour-associated macrophages and increased infiltration of CD8 T cells, resulting in enhanced anti-tumour activity of PD-1 inhibitors in an in-vivo model. We aimed to assess the combination of lenvatinib plus pembrolizumab in patients with advanced gastric cancer in a phase 2 study. METHODS: This study was an open-label, single-arm, phase 2 trial undertaken at the National Cancer Center Hospital East (Chiba, Japan). Eligible patients were aged 20 years or older and had metastatic or recurrent adenocarcinoma of the stomach or gastro-oesophageal junction, an Eastern Cooperative Oncology Group performance status of 0 or 1, and measurable disease according to the Response Evaluation Criteria in Solid Tumors (RECIST version 1.1), irrespective of the number of previous lines of treatment. Patients received 20 mg oral lenvatinib daily plus 200 mg intravenous pembrolizumab every 3 weeks until disease progression, development of intolerable toxicity, or withdrawal of consent. The primary endpoint was objective response rate according to RECIST, analysed in all patients who were eligible and received protocol treatment at least once. The safety analysis included all those who received protocol treatment at least once, regardless of eligibility. This study is registered at ClinicalTrials.gov, NCT03609359, and enrolment is complete. FINDINGS: Between Oct 15, 2018, and March 25, 2019, 29 patients were enrolled in the first-line or second-line settings. At data cutoff (March 20, 2020), the median follow-up was 12·6 months (IQR 10·5-14·3). 20 (69%, 95% CI 49-85) of 29 patients had an objective response. The most common grade 3 treatment-related adverse events were hypertension (in 11 [38%] patients), proteinuria (five [17%]), and platelet count decrease (two [7%]). No grade 4 treatment-related adverse events, serious treatment-related adverse events, or treatment-related deaths occurred. INTERPRETATION: Lenvatinib plus pembrolizumab showed promising anti-tumour activity with an acceptable safety profile in patients with advanced gastric cancer. On the basis of these results, a confirmatory trial will be planned in the future. FUNDING: Merck Sharp & Dohme.

Retrospective cohort study of nanoparticle albumin-bound paclitaxel plus ramucirumab versus paclitaxel plus ramucirumab as second-line treatment in patients with advanced gastric cancer.

BACKGROUND: Nanoparticle albumin-bound paclitaxel (nab-PTX) has shown non-inferiority to paclitaxel (PTX) as second-line therapy for advanced gastric cancer (AGC) with fewer infusion-related reactions. The efficacy and safety of nab-PTX plus ramucirumab (RAM) was reported in a phase II trial; however, there is no randomized trial comparing this regimen with PTX plus RAM in patients with AGC. This retrospective study aimed to investigate the efficacy and safety of nab-PTX plus RAM versus PTX plus RAM in patients with AGC. METHODS: This study included patients with AGC who received nab-PTX plus RAM from September 2017 to January 2019 or PTX plus RAM from June 2015 to August 2017 as second-line chemotherapy in our hospital. RESULTS: A total of 113 and 138 patients who received nab-PTX plus RAM and PTX plus RAM, respectively, were analyzed. Median progression-free survival (PFS) was 3.9 months (95% confidence interval [CI]: 3.4-4.3) in the nab-PTX plus RAM group and 3.9 months (95% CI: 3.1-4.7) in the PTX plus RAM group (hazard ratio [HR]: 1.08; 95% CI: 0.83-1.40; P = 0.573). Median overall survival (OS) was 10.9 months (95% CI: 9.3-12.7) in the nab-PTX plus RAM group and 10.3 months (95% CI: 8.5-12.0) in the PTX plus RAM group (hazard ratio: 0.82; 95% CI: 0.61-1.10; P = 0.188). In patients with moderate/massive ascites, favorable outcomes for progression-free survival were observed in the nab-PTX plus RAM group compared with the PTX plus RAM group. Although anemia and fatigue (any grade) were more frequent in the nab-PTX plus RAM group, discontinuation of study treatment was not increased in the nab-PTX plus RAM group. There was no occurrence of hypersensitivity reaction in the nab-PTX plus RAM group, while two patients (1.4%) experienced grade 3 hypersensitivity reactions in the PTX plus RAM group. CONCLUSIONS: The combination of nab-PTX plus RAM showed a similar efficacy and safety profile to PTX plus RAM as second-line treatment for patients with AGC.