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PURPOSE: Liver metastasis (LM) is reported in approximately 40% of patients with advanced/metastatic gastric/gastroesophageal junction adenocarcinoma (metastatic esophagogastric adenocarcinoma; mGEA) and is associated with a worse prognosis. This post-hoc analysis from the RAINBOW trial reported the efficacy, safety, and biomarker outcomes of ramucirumab and paclitaxel combination treatment (RAM+PAC) in patients with (LM+) and without (LM-) LM at baseline. MATERIALS AND METHODS: Patients (n=665) were randomly assigned on a 1:1 basis to receive either RAM+PAC (LM+: 150, LM-: 180) or placebo and paclitaxel (PL+PAC) (LM+: 138, LM-: 197). The overall survival (OS) and progression-free survival (PFS) were evaluated using stratified Kaplan-Meier and Cox regression models. The correlation of dichotomized biomarkers (VEGF-C, D; VEGFR-1,2) with efficacy in the LM+ versus LM- subgroups was analyzed using the Cox regression model with reported interaction P-values. RESULTS: The presence of LM was associated with earlier progression than those without LM, particularly in patients receiving PL+PAC (hazard ratio [HR], 1.68). RAM+PAC treatment improved OS and PFS irrespective of LM status but showed greater improvement in LM+ than that in LM- (OS HR, 0.71 [LM+] vs. 0.88 [LM-]; PFS HR, 0.47 [LM+] vs. 0.76 [LM-]). Treatment-emergent adverse events were similar between patients with and without LM. No predictive relationship was observed between biomarker levels (VEGF-C, D; VEGFR-1,2) and efficacy outcome (OS, PFS) (all interaction P-values >0.05). CONCLUSIONS: RAM provided a significant benefit, irrespective of LM status; however, its effect was numerically stronger in patients with LM. Therefore, RAM+PAC is a clinically meaningful therapeutic option for patients with mGEA and LM. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01170663. ispartof: JOURNAL OF GASTRIC CANCER vol:23 issue:2 pages:289-302 ispartof: location:Korea (South) status: published

ObjectivesEpigenomic alterations in cancer interact with the immune microenvironment to dictate tumour evolution and therapeutic response. We aimed to study the regulation of the tumour immune microenvironment through epigenetic alternate promoter use in gastric cancer and to expand our findings to other gastrointestinal tumours.DesignAlternate promoter burden (APB) was quantified using a novel bioinformatic algorithm (proActiv) to infer promoter activity from short-read RNA sequencing and samples categorised into APBhigh, APBint and APBlow. Single-cell RNA sequencing was performed to analyse the intratumour immune microenvironment. A humanised mouse cancer in vivo model was used to explore dynamic temporal interactions between tumour kinetics, alternate promoter usage and the human immune system. Multiple cohorts of gastrointestinal tumours treated with immunotherapy were assessed for correlation between APB and treatment outcomes.ResultsAPBhigh gastric cancer tumours expressed decreased levels of T-cell cytolytic activity and exhibited signatures of immune depletion. Single-cell RNAsequencing analysis confirmed distinct immunological populations and lower T-cell proportions in APBhigh tumours. Functional in vivo studies using ‘humanised mice’ harbouring an active human immune system revealed distinct temporal relationships between APB and tumour growth, with APBhigh tumours having almost no human T-cell infiltration. Analysis of immunotherapy-treated patients with GI cancer confirmed resistance of APBhigh tumours to immune checkpoint inhibition. APBhigh gastric cancer exhibited significantly poorer progression-free survival compared with APBlow (median 55 days vs 121 days, HR 0.40, 95% CI 0.18 to 0.93, p=0.032).ConclusionThese findings demonstrate an association between alternate promoter use and the tumour microenvironment, leading to immune evasion and immunotherapy resistance.

Trial Information Click here to access other published clinical trials. Lessons Learned The recommended S-1 dose was 40 mg/m2, twice daily on Monday, Wednesday, Friday, and Sunday, with oral leucovorin and bevacizumab. Compared with daily administration, the alternate-day administration of S-1 with oral leucovorin may reduce mucositis with promising antitumor activity in refractory metastatic colorectal cancer. Background Daily S-1 plus oral leucovorin administration in a 1-week-on/1-week-off schedule has promising efficacy in gastrointestinal cancer but is associated with high risk of mucositis and diarrhea. Methods This phase Ib, 3+3 dose-escalation trial included patients with chemorefractory metastatic colorectal cancer (mCRC) receiving S-1 (40 mg/m2) and leucovorin (25 mg) orally twice daily (level 1, even-numbered days; level 2, Monday, Wednesday, Friday, and Sunday) and intravenous bevacizumab (5 mg/kg) every 2 weeks. Enrollment continued at the recommended dose level in the expansion cohort. Results We enrolled 21 patients (3 and 18 patients in levels 1 and 2, respectively). Briefly, 12 and 9 patients had Eastern Cooperative Oncology Group (ECOG) performance status of 0 and 1, respectively, and 8 and 13 patients had 1–3 and ≥4 prior treatment lines, respectively. Dose-limiting toxicity (DLT) was not observed, and level 2 was confirmed as the recommended dose. Common grade 3–4 adverse events at level 2 were anemia (22%), anorexia (6%), and diarrhea (6%). In the entire cohort, response rate, disease control rate, and median progression-free survival were 10%, 71%, and 4.2 months, respectively. Conclusion The recommended S-1 dose was 40 mg/m2, twice daily on Monday, Wednesday, Friday, and Sunday, with 25 mg oral leucovorin twice daily and 5 mg/kg bevacizumab every 2 weeks. Compared with the daily administration, alternate-day administration of S-1 plus leucovorin may reduce mucositis with promising antitumor activity in refractory mCRC.

PurposeFluorouracil, leucovorin, and irinotecan (FOLFIRI) plus bevacizumab is the standard second-line chemotherapy for patients with metastatic colorectal cancer (mCRC) who are refractory or intolerant to fluoropyrimidines and oxaliplatin. However, the benefits of incorporating fluoropyrimidines into second-line chemotherapy for patients with mCRC who are refractory to fluoropyrimidines in first-line chemotherapy are unknown.MethodsWe retrospectively evaluated patients with mCRC who were administered irinotecan plus bevacizumab or FOLFIRI plus bevacizumab as second-line chemotherapy at a single institution from January 2010 to April 2020. We compared the efficacy and safety of irinotecan plus bevacizumab (IRI group) with those of FOLFIRI plus bevacizumab (FOLFIRI group).ResultsOf the 255 enrolled patients, 107 (IRI/FOLFIRI group, 31/76 patients) were eligible for analysis. After a median follow-up of 13.1 months (range, 1.2–48.4) and 14.3 months (range, 0.9–46.5) for the IRI and FOLFIRI groups, respectively, the median progression-free survival was 6.4 months and 5.8 months [adjusted hazard ratio (aHR), 0.82; 95% confidence interval (CI), 0.50–1.34, p=0.44] and the median overall survival was 16.6 months and 16.5 months (aHR, 1.01; 95% CI, 0.59–1.69; p=0.97) in the IRI and FOLFIRI groups, respectively. All grade nausea, vomiting, decreased appetite, stomatitis, hand-foot syndrome, neutropenia, thrombocytopenia, increased creatinine, Grade 3/4 neutropenia, and febrile neutropenia occurred more frequently in the FOLFIRI group than in the IRI group.ConclusionOmitting fluorouracil from FOLFIRI plus bevacizumab as second-line chemotherapy may reduce adverse events without affecting antitumor activity in patients with mCRC who are refractory to fluoropyrimidines.

425 Background: Blocking immune checkpoint (IC) pathways, particularly mediated by PD1 and PDL1, has attracted great attention as a promising strategy for treating gastrointestinal cancer. However, the clinical responses are low in many cases, and thus a new treatment strategy and its biomarker are urgently needed for improving the clinical outcome. Blocking other IC molecules, including LAG3, has been evaluated in many clinical trials, while the therapeutic efficacy and the predictive biomarkers remains to be determined due to the same issues as anti-PD1/PDL1 therapy. Methods: We analyzed soluble LAG3 (sLAG3) in sera by ELISA, and LAG3+ cells by flow cytometry, using fresh peripheral blood (PB) obtained from 91 patients with advanced gastric cancer (AGC) before and about one month after nivolumab monotherapy (2 courses) in the WJOG10417GTR study, according to the protocol approved by the IRB (August 2018 - November 2020). Progression-free survival (PFS) and overall survival (OS) were compared between high/low groups divided by the cutoff value determined by visually assessing the continuous trend and change point of log hazard ratios obtained by applying penalized splines to each molecular marker. This study was supported by ONO PHARMACEUTICAL CO., LTD. and Bristol Myers Squibb. Results: Posttreatment values were significantly more associated with patients’ prognosis rather than baseline values, and the sLAG3-high group showed significantly shorter PFS/OS as compared to the low group divided by the median: median PFS (mPFS) 51.5 vs 95.5 days (HR = 2.04, P = 0.002), and median OS (mOS) 188 vs 393 days (HR = 1.81, P = 0.032). Patients with high levels of LAG3+ PBCs after treatment showed worse prognosis as compared to those with low levels divided by the cutoff values: a CD3+CD4+LAG3+ T-cell subset, mPFS 43 vs 72 days (HR = 2.23, P = 0.015) and mOS 178 vs 282 days (HR = 1.56, P = 0.249); a CD3+CD8+LAG3+ T-cell subset, mPFS 57 vs 69 days (HR = 1.89, P = 0.012) and mOS 228 vs 303 days (HR = 1.40, P = 0.233); and a CD56+LAG3+ NK subset, mPFS 57 vs 88 days (HR = 2.15, P = 0.003) and mOS 217 vs 409 days (HR = 1.88, P = 0.031). Patients with sLAG3-high/CD56+LAG3+ NK-high levels showed markedly worse prognosis than those with low/low levels (mPFS-HR = 10.55, P < 0.001; and mOS-HR = 4.59, P < 0.001). Conclusions: Patients with posttreatment high levels of sLAG3 and LAG3+ cells in PB showed poor prognosis of AGC patients after the nivolumab therapy, suggesting that these are useful predictive biomarkers. LAG3 may be a promising target in immunotherapy for AGC. Clinical trial information: UMIN000032686 .

331 Background: Anamorelin is a highly selective ghrelin receptor agonist that improves appetite and increases lean body mass in patients (pts) with cachexia. We aimed to investigate the predictors of therapeutic efficacy of anamorelin in pts with gastrointestinal cancer. Methods: This retrospective study included pts with gastric cancer (GC), pancreatic cancer (PC), and colorectal cancer (CRC) treated with anamorelin at our institution between May 2021 and July 2022. Glasgow Prognostic Score (GPS) was defined as follows: GPS 0: CRP≤1.0 (mg/dL) and Alb≥3.5 (g/dL), GPS 1: either CRP>1.0 or Alb1.0 and Alb2. The treatment line for 1st/2nd/≥3rd/others was 51/13/14/22%, respectively. GPS was 0/1/2 in 21/30/49%, respectively. Except for treatment line, there were no significant differences in patient characteristics according to the cancer type. A total of 12 pts discontinued treatment owing to AEs (nausea, 3; epigastric distress, 2; fatigue, 2; poor physical condition, 2; staggering, 1; pulsation, 1; diarrhea, 1 pts). The RR was 42%. Pts with GPS 2 had less improvement in appetite than those with GPS 0 or 1 (26% vs. 56%, adjusted odds ratio [95% confidence interval (95%CI)]:0.22 [0.07–0.69], p=0.009). The RR of pts with GC, PC, and CRC were 44%, 42%, and 41%, respectively. The cumulative incidence of discontinuation of anamorelin after 12 weeks was higher in pts with GPS 2 than in those with GPS 0 or 1 (46% vs. 30%). The TTF in pts with GPS 2 was significantly shorter than that in pts with a GPS 0 or 1 (adjusted subdistributional hazard ratio [95%CI]:2.80 [1.37–5.72], p=0.005). There was no statistically significant difference in TTF by cancer type, although TTF was shorter in GC and PC than in CRC. Other factors, including age, sex, baseline BMI, ECOG PS, lines of therapy, and cancer type did not correlate with RR and TTF. Conclusions: In pts with a GPS of 0 or 1, anamorelin showed better appetite improvement and a longer treatment effect than in those with GPS 2. TTF was shorter in pts with GC and PC; therefore, the timing of use should be carefully considered.

Background/aim Metastatic small bowel adenocarcinoma (SBA) is a rare disease with poor prognosis. This study aimed to explore the efficacy and safety of second-line chemotherapy for patients with SBA. Patients and methods We retrospectively reviewed the clinical characteristics of 27 metastatic patients with SBA after progression on first-line chemotherapy. The patients were divided into Cohort A, receiving second-line chemotherapy, and Cohort B, receiving best supportive care. Results Patients in Cohort B had higher age, worse performance status, and higher neutrophil-to-lymphocyte ratio compared with those in Cohort A. Cohort A showed significantly better overall survival (OS) compared with Cohort B (median OS, 15.6 vs. 3.4 months; p=0.002). Objective response rate, disease control rate, and median progression-free survival (PFS) for Cohort A were 7%, 74%, and 5.0 months, respectively. Patients who underwent irinotecan-based chemotherapy showed longer PFS and OS compared with those who underwent taxane-based chemotherapy. No significant adverse events were reported. Conclusion Second-line chemotherapy for metastatic SBA demonstrated clinical activity with acceptable toxicities.

Background Esophageal cancer is associated with synchronous or metachronous cancer at other primary sites. However, few studies have evaluated the second malignancies after the treatment of esophageal cancer. The present study aimed to clarify the frequency of and risk factors for the second malignancies after definitive therapy for esophageal cancer. Patients and Methods We included patients with esophageal cancer who received definitive therapy between 2000 and 2010. Exclusion criteria were synchronous cancer or a past history of cancer. Standardized incidence rate (SIR) was calculated using age‐ and sex‐specific incidence rates from the cancer registry data. To conduct risk analyses, we used the competing risk regression model, which defined death and the development of second malignancies as competing risks. Results A total of 758 patients were included, with 131 second malignancies occurring in 106 patients (14%), over a median follow‐up of 3.7 years. Cumulative incidences of second malignancies after 3, 5, and 8 years were 4.0%, 7.6%, and 13.8%, respectively. The risk of second malignancy was significantly elevated [SIR = 1.83, 95% confidence interval (CI): 1.50‐2.22]. The most common sites of primary tumor were the head and neck (20%), followed by the lung (17%), stomach (16%), colon and rectum (11%), and urinary tract (9%). Risk analyses revealed that age ≥ 65 years [subdistribution hazard ratio (sHR): 1.51, 95% CI: 1.01‐2.24, vs age, We conducted risk analyses using the competing risk regression model, which defined death and the development of second malignancies as competing risks. Our study revealed that risk of second primary malignancies was significantly higher compared with the general population. Age, clinical stage, and tumor location were identified as significant factors for the development of second primary malignancies.

PURPOSE We previously reported on the pilot study assessing the feasibility of using the Japanese translation of the Comprehensive Score for Financial Toxicity (COST) tool to measure financial toxicity (FT) among Japanese patients with cancer. In this study, we report the results of the prospective survey assessing FT in Japanese patients with cancer using the same tool. PATIENTS AND METHODS Eligible patients were receiving chemotherapy for a solid tumor for at least 2 months. In addition to the COST survey, socioeconomic characteristics were collected by using a questionnaire and medical records. RESULTS Of the 191 patients approached, 156 (82%) responded to the questionnaire. Primary tumor sites were colorectal (n = 77; 49%), gastric (n = 39; 25%), esophageal (n = 16; 10%), thyroid (n = 9; 6%), head and neck (n = 4; 3%), and other (n = 11; 7%). Median COST score was 21 (range, 0 to 41; mean ± standard deviation, 12.1 ± 8.45), with lower COST scores indicating more severe FT. On multivariable analyses using linear regression, older age (β, 0.15 per year; 95% CI, 0.02 to 0.28; P = .02) and higher household savings (β, 8.24 per ¥15 million; 95% CI, 4.06 to 12.42; P < .001) were positively associated with COST score; nonregular employment (β, −5.37; 95% CI, −10.16 to −0.57; P = .03), retirement because of cancer (β, −5.42; 95% CI, −8.62 to −1.37; P = .009), and use of strategies to cope with the cost of cancer care (β, −5.09; 95% CI, −7.87 to −2.30; P < .001) were negatively associated with COST score. CONCLUSION Using the Japanese version of the COST tool, we identified various factors associated with FT in Japanese patients with cancer. These findings will have important implications for cancer policy planning in Japan.

OBJECTIVES Insufficient oral intake in advanced gastric cancer (AGC) limits the use of several drugs. We aimed to determine the oral intake status of patients with AGC during later-line chemotherapy. MATERIALS AND METHODS We retrospectively evaluated data of patients with AGC who experienced disease progression during first-line chemotherapy administered from January 2012 to December 2018 in a single institution. We defined "insufficient oral intake" as requiring daily intravenous fluids or hyperalimentation. Multivariate logistic regression was performed to identify oral intake-related factors. RESULTS Among 589 included patients, at disease progression during first-line, second-line, and third-line chemotherapy, 78.3% (461), 53.3% (314), and 30.4% (179) of patients, respectively, exhibited sufficient oral intake. Fourth-line chemotherapy was initiated for 22.2% (131) of patients, with 20.0% (118) exhibiting sufficient oral intake. During second-line and third-line chemotherapy, 11/67 (16%) and 2/39 (5%) patients, respectively, exhibited improvements in oral intake; 85/428 (19.9%) and 70/259 (27.0%), respectively, exhibited deteriorations in oral intake. Factors correlated to deterioration in oral intake during second-line chemotherapy were poor Eastern Cooperative Oncology Group Performance Status (odds ratio, 4.32; P

Limited data are available regarding the efficacy of nutrition support in advanced gastric cancer (AGC) patients receiving a standard second-line combination chemotherapy. The BALAST study is conducted as a prospective, multicenter observational study to evaluate the efficacy of nutrition support for patients with AGC treated with ramucirumab plus taxane as second-line treatment. As part of the routine care, patients who are malnourished or at risk of malnutrition will receive nutrition support from dietitians. We will enroll a total of 26 patients to estimate weight control rate at 12 weeks as primary end point. This study will generate valuable data reinforcing the role of nutrition support therapy for AGC patients receiving second-line chemotherapy.Lay abstract Various guidelines recommend that nutrition support therapy should be considered if cancer patients are malnourished or at risk of malnutrition. Several studies have revealed that body weight loss, which is an important factor in determining the nutrition status, may predict survival during second-line standard chemotherapy with ramucirumab and a taxane for advanced gastric cancer (AGC) patients. However, limited data are available regarding the efficacy of nutrition support in AGC patients receiving ramucirumab and a taxane. This study is conducted as a prospective, multicenter observational study to evaluate the efficacy of nutrition support for Japanese patients with AGC treated with ramucirumab and a taxane. This study will generate valuable data reinforcing the role of nutrition support therapy for AGC patients in second-line treatment.

Background Nivolumab (NIVO) and irinotecan (IRI) are standard treatments for refractory advanced gastric cancer (AGC); however, it is unclear which drug should be administered first or in which cases. The tumor growth rate (TGR) during preceding treatment is reported to be associated with tumor response in metastatic colorectal cancer patients treated with regorafenib or trifluridine/tipiracil, suggesting that TGR may be useful for drug selection. Therefore, we evaluated the association between TGR during preceding treatment and the tumor response to NIVO or IRI. Patients and methods We retrospectively evaluated consecutive AGC patients treated with NIVO or IRI and divided them into slow-growing (Slow) and rapid-growing (Rapid) groups according to TGR and the presence or absence of new lesions (NL+/NL−, respectively) during preceding treatment (Slow group: NL− with low TGR, Highlights • NIVO and IRI are standard treatments for refractory AGC, although it is unclear which should be administered first. • TGR may be useful for drug selection, therefore we evaluated the association between TGR and the tumor response to NIVO or IRI. • In the Slow group, the response rate (RR) was significantly higher in patients treated with NIVO compared with IRI. • In the Rapid group, there was no significant difference in RR between the NIVO and IRI groups. • TGR and NL emergence during preceding treatment may be useful for drug selection.

Nivolumab is an increasingly used standard care treatment for heavily pretreated patients with advanced gastric cancer, with increasing clinical use in Japan. Data from retrospective studies on various tumors have shown the objective response rate to cytotoxic chemotherapy potentially improves after an exposure to immune checkpoint inhibitors. Based on these data, we conducted the multicenter observational REVIVE study to evaluate the efficacy and safety of cytotoxic chemotherapy in nivolumab-refractory or nivolumab-intolerant patients with advanced gastric cancer. Patients who are refractory or intolerant to nivolumab and scheduled to receive irinotecan monotherapy, oxaliplatin combination treatment or oral trifluridine/tipiracil hydrochloride therapy will be included. The primary end point is overall survival of nivolumab-pretreated patients with advanced gastric cancer after the cytotoxic chemotherapy. Clinical trial registration: UMIN000032182 ( umin.ac.jp )

Background/aim The efficacy of treatment using the anti-programmed cell death-1 (anti-PD-1) antibody for metastatic gastric cancer (mGC) has been established previously. Exploratory analyses in various types of tumours suggest that prior exposure to immune checkpoint inhibitors can enhance the efficacy of subsequent cytotoxic chemotherapy (CTx). Our aim is to evaluate the efficacy and safety of CTx for mGC after progression on anti-PD-(ligand) 1 [anti-PD-(L)1] antibody. Patients and methods We retrospectively evaluated patients with mGC who underwent CTx. The patients received CTx after progression on anti-PD-(L)1 antibody (cohort A) or as a third-line treatment without prior exposure to anti-PD-(L)1 antibody (cohort B). We evaluated: i) clinical characteristics, ii) efficacies, iii) prognoses, and iv) adverse events (AEs). Results In cohorts A and B, 16 and 68 patients fulfilled the criteria, respectively. In the univariate analysis, the overall response rate was significantly higher in cohort A compared to cohort B (31% vs. 10%, respectively; Odds Ratio:3.96, 95% Confidence Interval:1.06-14.8, p=0.040). The multivariate analysis showed a similar trend. Immune-related AEs did not worsen and were manageable, while new immune-related AEs were not observed. Conclusion CTx after progression on anti-PD-(L)1 antibody demonstrated a favourable efficacy in intensively treated patients with mGC.

298 Background: Although FLOT (5-fluorouracil [5-FU]/leucovorin [ l-LV] + oxaliplatin [L-OHP] + docetaxel [DTX]) is globally recognized as the standard treatment for gastric cancer (GC), the safety of FLOT in Japanese patients (pts) is unknown. Moreover, because advanced GC (AGC) pts with severe peritoneal metastasis (SPM) have often been excluded from pivotal clinical trials due to their poor condition, it is necessary to develop standardized treatment for them. Methods: This study is an open-label, multicenter, single-arm, phase I study to determine the recommended phase II dose (RP2D) of FLOT for Japanese AGC pts without (part 1) or with (part 2) SPM using a 3 + 3 design. Main eligibility criteria included histologically confirmed AGC, HER2 negative, and age 20–75 years. In part 2a, pts with ECOG Performance status (PS) 2, who simultaneously had massive ascites and inadequate oral intake, were excluded. Massive ascites was defined as continuous ascites from the pelvic cavity to the upper abdomen, based on computed tomography findings. Inadequate oral intake was defined as the requirement for daily intravenous infusions to supply water or nutrition. The dose limiting toxicity (DLT) was assessed before the start of cycle 2. The fixed dose of L-OHP, l-LV, and 5-FU was 85, 200, and 2600 mg/m2, respectively, and DTX was administered at a dose of 50, 40, and 30 mg/m2 in the level 0, −1, and −2, respectively. Results: In part 1a, one patient died of hemorrhage from the primary tumor on Cycle 1 Day 2 and was replaced. The characteristics were as follows: median age (range), 70 (51–71) years; male/female, 2/1; ECOG PS (0/1), 2/1; histological type (diffuse/intestinal), 3/0; prior gastrectomy (yes/no), 0/3; and measurable lesions (yes/no), 1/2. During DLT evaluation, grade 3 (G3) or higher adverse events (AEs) were neutropenia (n = 1), lymphocytopenia (n = 1), anemia (n = 1), and anorexia (n = 1). During follow-up, the most common G3 or higher AEs included neutropenia (n = 3), lymphocytopenia (n = 1), anemia (n = 1), febrile neutropenia (FN) (n = 1 at cycle 5), diarrhea (n = 1), anorexia (n = 1), fatigue (n = 1), and colonic perforation (n = 1) due to diverticulitis (not treatment-related AE). In part 2a, the characteristics were as follows: median age (range) 64 (49–69) years; male/female, 3/0; ECOG PS (0/1), 0/3; histological type (diffuse/intestinal), 3/0; prior gastrectomy (yes/no), 0/3; and measurable lesions (yes/no), 0/3. Two pts had massive ascites and 1 pt had both massive ascites and inadequate oral intake. During follow-up, only G3 neutropenia (n = 3) was observed. Two pts needed dose modification in cycle 2. Both in part 1a and 2a, no treatment-related deaths and no DLTs were observed and the RP2D was determined in level 0. Conclusions: We determined that DTX 50 mg/m2, L-OHP 85 mg/m2, 5-FU 2600 mg/m2, and l-LV 200 mg/m2 were the RP2D of FLOT for Japanese AGC with/without SPM. Clinical trial information: 041200044.

346 Background: SWI/SNF chromatin-remodeling complex is encoded by multi-gene families that are recurrently mutated in cancer. Previous studies reported that tumors harboring SWI/SNF complex genetic alterations (GA) are sensitive to immune checkpoint inhibitors (ICIs), but the clinical significance of SWI/SNF complex GA in patients with gastrointestinal cancers (GICs) is unclear. Methods: We reviewed patients with metastatic GICs who underwent comprehensive genomic profiling (CGP) and received ICIs at our institution between July 2014–June 2021. SWI/SNF complex GA were defined as ARID1A, ARID1B, ARID2, PBRM1, SMARCA4, and SMARCB1 alterations. Results: Of 292 patients receiving CGP, 136 patients received ICIs, of which 10 (7.4%) had SWI/SNF GA, including 8 ARID1A (5.9%), 1 ARID2 (0.7%) and 2 SMARCA4 (1.5%) alterations. The subjects included 50 esophageal cancers, 84 gastric cancers, and 2 small intestine cancers. The patients with SWI/SNF complex GA had significantly higher proportions of microsatellite instability-high ( p = 0.004) and lower proportions of esophageal cancer ( p = 0.002), compared with patients without SWI/SNF complex GA. During the median follow-up time of 7.5 months (M), the median overall survival (OS), time-to-treatment failure (TTF), and progression-free survival (PFS) in all patients was 13.2 M ([95% confidence interval [CI] 7.7-21.8 M), 2.2 M (95%CI, 1.8-2.5 M), and 2.3 M (95%CI, 1.9-2.8 M), respectively. The patients with SWI/SNF complex GA had better OS (median, not reached vs 10.3 M; hazard ratio [HR], 0.40 [95% confidence interval [CI] 0.19–0.86]; p = 0.019) than those without SWI/SNF complex GA. The patients with SWI/SNF complex GA tended to have longer TTF (median, 4.7 M vs 2.1 M; HR, 0.67 [95%CI 0.38–1.17]; p = 0.16) and PFS (median, 5.4 M vs 2.2 M; HR, 0.70 [95%CI 0.39–1.27], p = 0.24) than those without SWI/SNF GA. The objective response rate (ORR) and disease control rate (DCR) in all patients was 13.2% (95%CI, 8.0-20.1) and 40.4% (95%CI, 32.1-49.2), respectively. The ORR and DCR of patients with SWI/SNF complex GA tended to be higher than those without SWI/SNF complex GA (ORR, 30.0% vs 11.9%; p = 0.13: DCR, 70.0% vs 38.1%; p = 0.09), with 1 complete response and 2 partial responses in the patients with SWI/SNF complex GA. Conclusions: The patients with GICs who had SWI/SNF complex GA were more likely to benefit from ICI therapy, suggesting that novel ICI-containing chemotherapies targeting SWI/SNF complex GA are needed for GICs.[Table: see text]

257 Background: NIVO therapy is a standard care treatment for heavily pretreated patients with AGC. Improvement in objective response rate (ORR) to CTx after NIVO therapy for various cancer types has been reported. However, the efficacy and safety of CTx for AGC after progression on NIVO remains unclear. Methods: The REVIVE trial was a prospective, multicenter, observational study that evaluated the efficacy and safety of CTx in NIVO-refractory or NIVO-intolerant patients (pts) with AGC (UMIN000032182). The primary endpoint was overall survival (OS) of CTx following NIVO therapy. The median threshold and expected survival times were set as 4.0 and 7.0 months (M). The secondary endpoints are ORR, disease control rate (DCR), progression-free survival (PFS), and incidence of adverse events (AEs), including immune-related adverse events (irAEs). CTx consisted of irinotecan alone (IRI), trifluridine/tipiracil alone (FT), and oxaliplatin-containing regimens (OX). Results: Of 395 pts treated with NIVO who met the eligibility at formal registration from Jun 2018 to Sep 2020, 199 pts who received CTx after NIVO were evaluated. Pt characteristics were as follows: median age, 69 years; male, 70%; ECOG PS 0/1/2, 38/51/12%; histology (diffuse/intestinal), 39/59%; metastatic lesions (peritoneum/liver/lung), 38/34/15%; number of metastatic organ sites (0–1/≥2), 40/60%; measurable lesions, 83%; and CTx regimens (IRI/FT/OX), 64/31/5%. Median OS and PFS were 7.5 M (95%CI, 6.7–9.7) at 145 events for OS and 2.9 M (95%CI, 2.2–3.5) at 184 events for PFS. The ORR and DCR were 17.0% (95%CI, 11.6–23.6) and 46.7% (95%CI, 38.9–54.6). Median OS, median PFS, ORR, and DCR according to CTx regimens (IRI/FT/OX) were 8.1/7.1/6.2 M, 3.3/2.8/2.4 M, 18.9/10.9/25.0%, and 47.8/43.5/50.0%, respectively. At the start of CTx, 42 pts had irAEs due to prior NIVO therapy. The most common any-grade and grade ≥3 AEs during CTx included decreased appetite (46% and 7.5%), fatigue (26% and 2.5%), nausea (24% and 1.5%), constipation (16% and 0%), and diarrhea (28% and 4.0%). No treatment-related deaths were observed. Conclusions: Prior NIVO therapy may lead to improved prognosis after CTx without unexpected AEs in pts with AGC, warranting further investigations after NIVO is approved as first-line treatment.[Table: see text]

Background Anti-HER2 therapy has not demonstrated a survival advantage in the second-line setting of patients with HER2-positive gastric cancer. We conducted this study to assess changes in HER2 status and to identify possible biomarkers for acquired resistance after the use of trastuzumab as the first-line therapy. Patients and methods Patients with advanced or recurrent HER2-positive gastric adenocarcinoma who were diagnosed with progressive disease after the first-line trastuzumab-based therapy and developed pathologically confirmed adenocarcinoma within 3 months after completion of trastuzumab-based therapy were enrolled in this study. We collected re-biopsied samples from the HER2-positive patients who had developed resistance to trastuzumab and re-evaluated their HER2 status. Amplification of EGFR and c-met, as well as PIK3CA mutation, were comparatively analysed when samples were available. Results Among 33 eligible patients, loss of HER2 was identified in 20 patients (60.6%) with refractory disease. Immunohistochemistry showed that the rate of HER2 overexpression was greatly reduced after therapy (pre-HER2 3+: 24 [72.7%] vs. post-HER2 3+: 13 [39.4%]). We found that the use of fixatives other than 10% neutral buffered formalin significantly reduced the HER2-positive rate. EGFR amplification, c-met amplification and PIK3CA mutation before and after trastuzumab-based therapy were observed in 10.3% and 3.8%, 17.9% and 4.2% and 4.0% and 4.2% of cases, respectively. Conclusion Re-evaluation of HER2 status is needed to determine the appropriate use of anti-HER2–targeted therapy after disease progression. Our results also highlight the importance of formalin fixation conditions for HER2 testing.

Accumulating evidence suggests that response-related parameters such as depth of response (DpR) might be associated with survival in colorectal cancer, which has not been shown in gastric cancer. This study aimed to evaluate whether DpR was associated with clinical outcomes in HER2-positive AGC patients treated with trastuzumab-based chemotherapy. Fifty-seven HER2-positive AGC patients who were treated with trastuzumab in combination with fluoropyrimidines plus cisplatin therapy as first-line treatment were retrospectively enrolled. DpR was defined as the percent maximal tumor shrinkage of target lesions observed at the lowest point compared with baseline. The cutoff DpR level to discriminate better survival was based on receiver-operating characteristic curve analysis. Association of DpR with progression-free survival (PFS) and overall survival (OS) was assessed using the multivariable Cox proportional hazards model. Median DpR level was 56.8% (range −37.9 to 100%). In multivariate models adjusted for relevant variables, DpR, as a dichotomized variable with a cutoff level of 50% and a continuous variable, was significantly associated with PFS (hazard ratio [HR] 0.39 and 0.97; 95% confidence interval [CI] 0.22–0.68 and 0.96–0.98) and OS (HR 0.38 and 0.98; 95% CI 0.21–0.70 and 0.97–0.99). Clinically meaningful differences in PFS (median, 9.8 vs. 4.1 months; p

Taxane monotherapy is widely used for advanced gastric cancer (AGC) after failure of standard first-line chemotherapy with fluoropyrimidine and cisplatin. Triplet chemotherapy with docetaxel, cisplatin, and S-1 (DCS) is a promising regimen for first-line chemotherapy of AGC. The aim of this study was to evaluate the efficacy of taxane monotherapy in patients refractory to DCS. We retrospectively evaluated the efficacy and safety of taxane monotherapy in patients with AGC refractory to first-line therapy with DCS between January 2010 and April 2015. Selection criteria were as follows: ECOG PS of 0–2, treatment with taxane monotherapy in second-line or third-line therapy after failure of second-line irinotecan, absence of massive ascites, and adequate organ function. A total of 30 patients were included in this study. Of these, 15 patients received paclitaxel while another 15 received nanoparticle albumin-bound paclitaxel in either second- or third-line treatment. Median age for the second/third-line group was 64.0/62.0 (range 27–75/42–75); 14/13 (93.3/86.7%) had ECOG PS of 0 or 1. No patients achieved complete or partial response and stable disease was observed in 37.5/35.7% of the patients in the second/third line. Median progression-free survival and overall survival were 3.4 and 5.8 months in the second-line group, and 2.0 and 4.5 months in the third-line group, respectively. The incidences of any grade ≥3 adverse events in the second-line group and the third-line group were 60.0 and 33.3%, respectively. There was no treatment-related death. Taxane monotherapy after DCS failure had acceptable toxicities but was ineffective in AGC patients.

There is currently no clinical data regarding the efficacy of trastuzumab treatment for the progression of human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (AGC) occurring during trastuzumab-based chemotherapy. The aim of this study was to retrospectively examine the clinical benefits of trastuzumab for HER2-positive AGC patients who progressed during first-line trastuzumab-based chemotherapy. Among the 108 patients treated with trastuzumab combined with fluoropyrimidine and cisplatin as first-line therapy, 46 HER2-positive AGC patients who received cytotoxic agents with or without trastuzumab subsequent to disease progression were included. Of these, the efficacy and safety outcomes of 26 patients who continued trastuzumab were compared with those of the 20 patients who discontinued trastuzumab. No difference in response rate (18.2 vs. 15.8%, P=1.00) was observed between the two groups. Progression-free survival (PFS) time was numerically longer in the chemotherapy combination with trastuzumab group than in the chemotherapy combination without trastuzumab group (median, 4.0 vs. 2.3 months), with no significance [hazard ratio (HR), 0.63; P=0.14]. In the subset analysis, continuation of trastuzumab significantly improved PFS time in selected subgroups of patients with tumors exhibiting HER2 expression scores of 3+ (HR, 0.41; P=0.04), intestinal-type histology (HR, 0.32; P6 months (HR, 0.44; P=0.04). The survival times for the trastuzumab beyond progression (TBP) and non-TBP groups were similar (HR, 1.06; P=0.88), with equivalent overall survival times in the subgroups with immunohistochemistry scores of 3+ (HR, 0.97; P=0.94), intestinal-type histology (HR, 0.53; P=0.19), and a first PFS time of >6 months (HR, 0.62; P=0.31). There were no differences in the incidence rates of toxicity, including cardiac dysfunction, between the two groups. The study results suggest that selected HER2-positive AGC patients may benefit from trastuzumab continuation during first progression, and further prospective studies are warranted.

Purpose: Regorafenib improves survival in chemorefractory metastatic colorectal cancer (mCRC) patients. However, regorafenib induces various adverse events (AEs) that often impair patients' quality of life. Identification of early predictive markers of the efficacy is warranted. Methods: We retrospectively examined 146 consecutive mCRC patients who received regorafenib. Clinical parameters, including patient background, AEs, and changes in biochemical parameters until day 28, were evaluated to identify efficacy predictors. Results: Median progression-free survival (PFS) was 2.1 months, and median overall survival was 6.6 months. Major AEs in all cycles were hand-foot skin reaction, hypertension, and increased aspartate transaminase. We extracted 121 patients for prognostic analysis. In univariate analysis, decreased carcinoembryonic antigen (HR: 0.570, p = 0.012) and decreased carbohydrate antigen 19-9 (CA19-9) (HR: 0.422, p = 0.0012) were identified as prognostic markers of PFS. Patients in whom serum CA19-9 decreased after regorafenib exhibited significantly better PFS (median 3.7 vs. 2.0 months, p = 0.004) than those in whom serum CA19-9 did not decrease. Multivariate analysis revealed early CA19-9 decrease as an independent predictive factor (HR: 0.415, 95% CI: 0.210-0.818, p = 0.011). Conclusion: Early response of CA19-9 may predict the efficacy of regorafenib. Additional studies are needed for external validation.

Objective: Anti-epidermal growth factor receptor (EGFR) antibodies and bevacizumab are commonly used, sequentially, as palliative chemotherapies for patients with metastatic colorectal cancer. However, little is known about the efficacy of second-line treatments containing bevacizumab after first-line treatment with an anti-EGFR antibody. Methods: We retrospectively reviewed 128 patients who received second-line bevacizumab-containing chemotherapy and evaluated the effect of prior use of anti-EGFR antibody on the efficacy of the second-line treatment. Results: As first-line treatments, 35 of these patients received only cytotoxic chemotherapy (cohort A), 58 received bevacizumab-containing chemotherapy (cohort B), and 35 received anti-EGFR-containing chemotherapy (cohort C). The median progression-free survival (PFS) with the second-line bevacizumab-containing therapy was 8.3 months in cohort C, 6.9 months in cohort A (hazard ratio [HR], 1.43; 95% confidence interval [CI], 0.83-2.51), and 5.6 months in cohort B (HR, 1.95; 95% CI, 1.18-3.22). Multivariate analysis showed that PFS in cohort C was the same as that in cohort A, but better than that in cohort B. The overall response rate in cohort C (25.7%) was also similar to that in cohort A (20.0%), but better than that in cohort B (10.3%). Conclusions: Prior use of anti-EGFR antibody did not adversely affect the efficacy of subsequent bevacizumab-containing chemotherapy.

Background Disseminated intravascular coagulation (DIC) is a rare complication of advanced gastric cancer (AGC). Despite reports of the efficacy of chemotherapy for AGC with DIC, little is known of platinum-based doublet therapy. Patients and methods We conducted a single-institute, retrospective chart review of 500 consecutive chemotherapy-naive patients with advanced gastric adenocarcinoma (recurrent or metastatic) from November 2010 to November 2015. Results Six patients were diagnosed with AGC with DIC (1.2%); five (1.0%; 3 men, 2 women) received platinum-based doublet chemotherapy. All patients exhibited improved DIC and thrombocytopenia and survived for >100 days (range=114-313) with no therapy-related mortality. Grade ≥3 adverse effects included neutropenia, anemia, hyponatremia, catheter-related infection and diarrhea (maximum: 2 patients each). Conclusion Fluoropyrimidine plus platinum combination therapy was effective against DIC and yielded acceptable survival outcomes. Combination chemotherapy should be considered as a primary therapy for AGC with DIC.

e16045 Background: The ATTRACTION-3 trial showed that nivolumab (Nivo) significantly improved overall survival (OS) of patients (pts) with previously treated advanced esophageal squamous cell carcinoma (ESCC) regardless of tumor programmed cell death ligand-1 (PD-L1) expression assessed with tumor proportion score (TPS). On the other hand, pembrolizumab prolonged OS in advanced esophageal carcinoma pts with combined positive score (CPS) of ≥ 10 in the KEYNOTE-181 trial. Whether CPS can predict clinical outcome of Nivo in advanced ESCC pts remains unclear. Methods: We retrospectively evaluated advanced ESCC pts who received Nivo at a single institution between January 2014 and September 2020. The main eligibility criteria were as follows: refractory or intolerant to fluoropyrimidines and platinum, no prior anti-PD-1/PD-L1 antibody treatment, no comorbid malignancies, and available tissue specimens obtained before initiation of Nivo. PD-L1 immunostaining was performed using PD-L1 IHC 22C3 pharmDx assay, and the tumors were classified into three groups depending on CPS (≥ 10, 1–10, < 1). The adjusted hazard ratios (aHRs) for progression-free survival (PFS) and OS were calculated using a multivariate Cox model that contained variables with p values < 0.05 in the univariate analysis. Results: Among 69 pts, 50 were eligible (CPS ≥ 10/CPS 1–10/CPS < 1, 23/18/9). Patient characteristics were as follows (CPS ≥ 10/CPS 1–10/CPS < 1): age, ≥ 65, 70/67/67%; male, 83/67/78%; PS ≥ 1, 61/72/44%; second-line treatment, 65/61/56%; disease status, recurrent, 61/33/78%; prior esophagectomy, 65/33/44%; prior radiotherapy, 57/56/56%; prior taxane, 52/28/44%; the number of metastatic sites, ≥ 2, 48/61/89%; lymph node metastasis, 78/83/89%, lung metastasis, 26/22/56%; liver metastasis, 17/17/44%. Among 42 pts (84%) with disease progression after Nivo treatment, 24 pts received salvage-line chemotherapy. The adjustment factor for PFS was liver metastasis, while that for OS was not detected. The median PFS was 4.1 months (mo) in CPS ≥ 10 and 2.5 mo in CPS 1–10 (HR vs. CPS ≥ 10, 1.06; 95% CI, 0.51–2.17; p = 0.864; aHR, 1.15; 95% CI, 0.54–2.36; p = 0.713), and 1.4 mo in CPS < 1 (HR vs. CPS ≥ 10, 3,78; 95% CI, 1.53–8.92; p = 0.005; aHR, 1.91; 95% CI, 0.67–5.39; p = 0.223). The median OS was 12.3 mo in CPS ≥ 10, 10.2 mo in CPS 1–10 (HR vs. CPS ≥ 10, 1.72; 95% CI, 0.75–4.00; p = 0.201), and 9.0 mo in CPS < 1 (HR vs. CPS ≥ 10, 2.31; 95% CI, 0.92–5.69; p = 0.075). Objective response rate (CPS ≥ 10/CPS 1–10/CPS < 1) in 40 pts who had measurable lesions were 32/25/0%, respectively. Conclusions: The pts with CPS of < 1 did not respond to Nivo. Our study suggests that CPS is useful for predicting response to Nivo in pts with advanced ESCC.[Table: see text]

234 Background: Nivolumab (Nivo) is a standard therapy after ramucirumab (RAM)-based second-line chemotherapy in patients (pts) with advanced gastric cancer (AGC). However, the relationship between angiogenesis-related factors and the efficacies of immune-checkpoint inhibitors after anti-angiogenic chemotherapy is unclear. Methods: We retrospectively evaluated pts with AGCs who received Nivo after RAM-based second-line chemotherapy at a single institution from Nov 2017 to Aug 2019. Clinical benefit of Nivo was defined as CR, PR, or >4 months of SD and non-CR/non-PD. In addition, preserved serum samples at time points of pre-RAM, pre-Nivo, and post-Nivo (within 12 weeks from the start of Nivo) were analyzed by using the designated panel, containing vascular endothelial growth factor-A/D (VEGF-A/D), placental growth factor (PlGF), soluble vascular endothelial growth factor receptor-1/2/3 (sVEGFR-1/2/3), Interleukin-6/8 (IL-6/8), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), tissue inhibitor of metalloproteinase-1 (TIMP-1), angiopoietin-2, hepatocyte growth factor (HGF), interferon gamma (INF-γ), osteopontin (OPN), soluble neuropilin-1, and thrombospondin-2 (TSP-2). We investigated the association between angiogenesis-related factors and clinical outcomes with Nivo. Results: We evaluated 167 samples from 58 pts, including 10 pts (17.2%) exhibiting clinical benefit. Characteristics of pts were as follows: median age, 68; male, 74%; PS, 0/1-2, 17/83%; HER2 positive, 16%; prior gastrectomy, 40%; histology, intestinal/diffuse, 16/84%; disease status, metastatic/recurrent, 69/31%; lung metasstasis, 14%; liver metasstasis, 26%; peritoneum metastasis, 67%; lymph node metastasis, 31%. The median progression-free survival (PFS) and overall survival (OS) of Nivo were 1.7 and 6.2 months, respectively, with a median follow-up of 5.0 months. There were no correlations between pre-Nivo levels of angiogenesis-related factors and clinical benefit; however, the median post-Nivo/pre-Nivo VEGF-A ratio was significantly lower in pts with clinical benefit than in those without clinical benefit (0.44 versus 0.94, p = 0.008). By multivariate analysis using characteristics of pts and data from pre-Nivo samples, VEGF-A above the median level of 1400 pg/mL and sVCAM-1 below the median level of 1640000 pg/mL were independent prognostic factors for poor PFS (hazard ratio, 1.90, p = 0.033) and OS (hazard ratio, 2.02, p = 0.037), respectively. Conclusions: Our study suggests that rapid decline of serum VEGF-A level after Nivo and higher VEGF-A before Nivo were respectively associated with the clinical benefit of Nivo and poor survival in pts with AGC treated with Nivo after RAM-based second-line chemotherapy.

76 Background: FOLFIRI + bevacizumab (FOLFIRI + BEV) is a standard second-line chemotherapy (Cx) for metastatic colorectal cancer (mCRC) patients (pts) who are refractory or intolerant to fluoropyrimidines (FPs) and oxaliplatin (OX). However, the efficacy of continuing FPs as second-line Cx for pts who are refractory to FPs in first-line Cx remains unclear. Methods: We retrospectively evaluated mCRC pts who received irinotecan (IRI) + BEV or FOLFIRI + BEV as second-line Cx at a single institution from Jan 2010 to Apr 2020. The main eligibility criteria were ECOG performance status (PS) of 0-2, known KRAS status, a standard initial dose of fluorouracil (5-FU) (bolus 400 mg/m2, infusional 2400 mg/m2) in FOLFIRI + BEV and IRI (150 mg/m2), refractory to FPs, no prior use of IRI, and prior use of OX. We compared the efficacy and safety of IRI + BEV with those of FOLFIRI + BEV. The adjusted hazard ratios (aHRs) for progression-free survival (PFS) and overall survival (OS) were calculated using a multivariate Cox model that contained variables with p < 0.05 in the univariate analysis to reduce the imbalance between both the treatments. Results: Among the 261 pts, 107 were eligible (IRI + BEV/FOLFIRI + BEV, 31/76 pts). Pt characteristics were as follows (IRI + BEV/FOLFIRI + BEV): median age, 67/62; ECOG PS, 1–2, 55/46%; KRAS mutant, 45/50%; BRAF V600E mutant, 6/11%; right-sided tumor, 19/43%; lactate dehydrogenase (LDH) ≥ 400 U/L, 13/12%; PFS of first-line Cx < 6 month (m), 39/30%; prior use of BEV, 84/63%. Relative dose intensity (RDI) (IRI + BEV/FOLFIRI + BEV) of IRI and BEV was similar in the groups; median RDI (range) of IRI, 80 (44–100) /83 (49–100) %; p = 0.560; median RDI of BEV, 86 (35–100) /83 (20–100) %; p = 0.681. Efficacies (IRI + BEV/FOLFIRI + BEV) after a median follow-up of 13.1/14.3 m were as follows: median PFS, 6.4/5.8 m (HR, 0.90; 95% CI, 0.57–1.38; p = 0.64; aHR, 0.82; 95% CI, 0.50-1.34; p = 0.44); median OS, 16.6/16.5 m (HR, 0.83; 95% CI, 0.51-1.32; p = 0.44; aHR, 1.01; 95% CI, 0.59-1.69; p = 0.97); objective response rate, 25.9/11.3%. Adjustment factors for PFS were prior colorectomy, number of metastatic sites, ECOG PS, liver metastasis, and the level of LDH, while those for OS were prior colorectomy, number of metastatic sites, liver metastasis, peritoneal metastasis, and the level of LDH. All subgroup analyses for PFS and OS according to the pt characteristics also showed no significant differences in the groups. All grade nausea (32/58%) and stomatitis (13/36%) and grade 3–4 neutropenia (23/58%) and febrile neutropenia (0/3%) were less common in the IRI + BEV than in the FOLFIRI + BEV group. Conclusions: Our study suggests that omitting 5-FU from FOLFIRI + BEV as second-line Cx for mCRC pts who are refractory to FPs may lower the occurrence of adverse events without impairing the treatment efficacy.

e16560 Background: Trifluridine/tipiracil, an oral drug, was approved in Japan for patients (pts) with advanced gastric cancer (AGC). Insufficient oral intake (INSUF) is one of the most common complications. We evaluated the clinical characteristics and impact of oral intake during 2nd line chemotherapy (CT). Methods: We retrospectively evaluated AGC pts receiving 2nd line CT from January 2012 to December 2018 at a single institution. We defined “INSUF” as a requirement for daily intravenous fluids or hyperalimentation and “improvement of oral intake (IMP)” as no such requirement for > 1 week. Exacerbation (EXA) was defined as a change from “sufficient oral intake (SUF)” to INSUF. Results: We enrolled 495 pts, of which 67 (13%) and 428 (87%) pts had INSUF and SUF at the start of 2nd line CT, respectively. Patient characteristics are summarized in the Table. There was no difference in the cytotoxic drugs of 2nd line CT. The causes of INSUF were peritoneal metastases (79%), cachexia (15%), and primary complications (3%). The objective response rates of INSUF and SUF pts were 9% and 26%, respectively. INSUF pts had poorer progression-free survival (PFS) (1.7 vs. 3.7 months [M]; adjusted HR [aHR], 1.51; p < 0.001) and overall survival (3.2 vs. 10.1 M; aHR, 2.01; p < 0.001) than SUF pts. At the end of 2nd line CT, 147 (32%) and 314 (68%) pts had INSUF and SUF, respectively. In SUF pts, the factors correlated with EXA were poor ECOG PS (odds ratio [OR], 5.26; p < 0.001), massive or moderate ascites (OR, 2.04; p = 0.031), palliative operation history (OR, 2.90; p = 0.007), and ramucirumab use (OR, 0.50; p = 0.034). Median PFS was shorter after CT in pts with EXA than in those without (1.7 vs. 4.2 M; aHR, 2.05; p < 0.001). Among INSUF pts, 11 pts (16%) achieved IMP; the rate of IMP did not differ according to regimen. Median PFS was shorter in pts without IMP than in pts with IMP (1.1 vs. 3.3 M; aHR, 4.97; p = 0.001). Subsequent CT was administered to 29% and 71% of INSUF and SUF pts, respectively. Conclusions: INSUF at the start of 2nd line CT was a poor prognostic factor. For appropriate use of oral drugs, CT should be changed in SUF pts with factors associated with EXA. [Table: see text]

126 Background: Sarcopenia and muscle loss during chemotherapy (Cx) have a poor prognosis in metastatic colorectal cancer (mCRC). It is unclear whether cachexia during Cx has a survival impact. Methods: mCRC patients (pts) receiving first-line Cx at a single institution between Jan 2010 and Jun 2018 were retrospectively evaluated. Pts receiving doublet Cx with bevacizumab or anti-EGFR agents, ECOG Performance Status (PS) 0–2, and abdominal computed tomography (CT) before and after initiating first-line Cx at least once were included and classified pts into those with (cachexia group) or without (non-cachexia group) cachexia. The skeletal muscle index (SMI) was calculated from the CT cross-section area at L3 divided by the length squared. Muscle loss was defined as a < 5% reduction in the SMI. The association between muscle loss and cachexia during Cx, time to treatment failure (TTF) and overall survival (OS) was determined by univariate and multivariate analysis including muscle loss, primary tumor location, ECOG PS, number of metastatic sites, ALP, WBC, LDH, KRAS status, and BRAF status as independent variables. Results: Of 562 included pts, 185 were eligible and 69 (37%) experienced cachexia. Differences in all patient characteristics such as muscle loss, ECOG PS 2, KRAS mutant, and BRAF mutant (28%, 8%, 32%, and 10% with cachexia group and 27%, 3%, 32%, and 8% with non-cachexia group) were not significant. Median follow-up was 26.8 months. Muscle loss was not associated with TTF (13.3 vs. 15.5 months, HR = 1.05; 95% CI: 0.76–1.45, p = 0.76). OS was shorter (24.4 vs. 29.9 months, HR = 1.23; 95% CI: 0.86–1.76, p = 0.25), but the difference was not significant in univariate and multivariate analysis. However, cachexia group presented significantly shorter TTF [median TTF 11.9 vs. 16.9 m; HR 1.52, 95% CI: 1.12-2.07, p < 0.01; adjusted HR (aHR) 1.53, 95% CI: 1.12-2.11, p < 0.01] and shorter OS (median OS 21.4 vs. 34.1 m; HR 1.81, 95% CI: 1.29-2.55, p < 0.01; aHR 1.97, 95% CI: 1.38-2.81, p < 0.01) than non-cachexia group. Conclusions: Cachexia during Cx may have a negative impact on survival in pts with mCRC.

396 Background: Although nivolumab (NIVO) and irinotecan (IRI) are currently used as third- or later-line therapy for advanced gastric cancer (AGC), few direct comparisons between them have been available. The present study therefore aims to compare the efficacy and safety of NIVO with IRI and explore clinical factors that predict efficacy. Methods: Patients with AGC who underwent NIVO or IRI treatment between November 2016 and June 2018 at three institution were retrospectively examined, subsequently evaluating response rates (RR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs). The main inclusion criteria were patients pretreated with fluoropyrimidines and taxanes, Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0–2, and no previous NIVO or IRI treatment. Results: A total of 71 and 61 patients received NIVO and IRI, respectively, with both groups having similar baseline characteristics, except for gender. Efficacies were as follows (NIVO/IRI): RR, 20%/6% (p = 0.17); median PFS, 1.6 months (m)/1.8 m (HR 0.93, p = 0.67); median OS, 6.4 m/6.4 m (HR 0.91, p = 0.61); 1-year survival rate, 24.9%/19.3% (p = 0.61), respectively. Interaction analysis found no significant interaction between drugs and various factors such as ECOG PS (p = 0.59) and neutrophile/lymphocyte ratio (p = 0.33) related to OS. Subsequent chemotherapy agents were administered to 32 patients (45%) in the NIVO group (17 patients out of them received IRI) and 36 patients (59%) in the IRI group (23 patients out of them received NIVO) (p = 0.12). NIVO tended to have lower grade 3 or more AEs than IRI, especially neutropenia (3% vs. 28%, respectively; p < 0.01) and febrile neutropenia (1% vs. 8%, respectively; p = 0.09), as well as neutropenia, nausea, diarrhea, constipation, fatigue, and anorexia of any grade. Five patients developed immune-related adverse events in the NIVO group: pneumonitis (n = 1) and rash (n = 4). Conclusions: Although no remarkable differences in efficacy were found between NIVO and IRI for AGC, NIVO had a better safety profile compared to IRI. This study found no clinical factors that predicted efficacy.

BACKGROUND/AIM Anti-EGFR antibodies or bevacizumab comprise first-line treatment for patients with RAS wild-type colorectal liver metastases (CLM). Which marker better predicts efficacy, early tumor shrinkage or morphologic response, still remains unclear. PATIENTS AND METHODS We retrospectively evaluated 155 patients with KRAS exon 2 wild-type CLM treated with bevacizumab (BEV group) or anti-EGFR antibodies (EGFR group). Three radiologists independently assessed early tumor shrinkage (ETS) and early optimal morphologic response (EOMR) from baseline and first follow-up CT scan. RESULTS Patients with ETS had longer progression-free survival (PFS) than those without ETS [hazard ratio (HR)=0.69] and ETS tended to be observed in the EGFR group, while patients with EOMR had longer PFS than those without EOMR (HR=0.64) and EOMR tended to be observed in the BEV group. CONCLUSION Among patients with KRAS exon 2 wild-type CLM, EOMR and ETS may predict better PFS, especially in patients treated with bevacizumab and anti-EGFR antibodies, respectively.

Background Financial toxicity (FT) has a negative impact on the quality of life and survival of patients with cancer. The comprehensive score for FT (COST) questionnaire is a tool to measure FT which has already been validated in patients with cancer in the United States. However, the feasibility and validity of assessing FT using the COST questionnaire have not been established in non-US healthcare settings, including that in Japan. Methods This is a prospective pilot survey to ascertain the feasibility of using the COST questionnaire to evaluate FT in Japanese patients with advanced solid cancer who had been receiving chemotherapy for at least 2 months. The COST questionnaire was translated into Japanese using Functional Assessment of Chronic Illness Therapy methodology. Results Of the 12 patients approached, 11 (92%) responded to the questionnaire. The median COST score was 22 (range, 6-29; mean ± SD, 20.18 ± 8.17). Five (45%) and two (18%) patients suffered grade 1 (COST score 14-25) and grade 2 (COST score 1-13) FT, respectively. The COST measure demonstrated good internal consistency with a Cronbach α of 0.87. Conclusions The COST measure demonstrated good feasibility in measuring FT in the Japanese healthcare setting. Despite the existing universal health insurance system and ceiling amount for high-cost medical expenses, some Japanese patients experienced meaningful FT during chemotherapy. A prospective study is already underway to confirm the preliminary results (UMIN: 000025043).

To investigate the influence of addition of docetaxel to neoadjuvant chemotherapy (NAC) with cisplatin plus 5-fluorouracil (CF) in patients with clinical stage III or T3 esophageal squamous cell carcinoma. Information about 209 esophageal cancer patients with stage III or T3 disease, who underwent NAC consisting of CF with or without docetaxel, was reviewed. The survival outcomes were analyzed using the Kaplan–Meier method and propensity score-adjusted Cox proportional hazards models. The relevant variables were included in the propensity score model. NAC was administered to 149 patients in the CF group and 60 patients in the docetaxel plus CF (DCF) group. Overall, 129 patients treated with CF and 58 patients treated with DCF underwent surgery after NAC. The overall response rate was significantly higher in the DCF group compared with the CF group (61.0 vs. 43.2 %, p = 0.021). After matching, recurrence-free survival did not differ statistically between the CF and DCF groups [hazard ratio (HR) 0.83, 95 % confidence interval (CI) 0.50–1.37, p = 0.46]. After matching, the improvement in overall survival in the DCF group reached statistical significance (HR 0.49, 95 % CI 0.24–0.999, p = 0.050). No significant differences in rate of locoregional or distant recurrences were observed between the CF and DCF groups (53.0 vs. 48.3 %, p = 0.54). NAC with DCF is superior to CF in patients with clinical stage III or T3 esophageal squamous cell carcinoma.

Although nivolumab showed survival benefit in patients with advanced gastric cancer (AGC) progressing after standard chemotherapy, there is a lack of data regarding oxaliplatin-based chemotherapy in this clinical setting. We retrospectively evaluated the efficacy and safety of oxaliplatin with l-leucovorin and bolus/continuous infusion of 5-fluorouracil as salvage treatment in patients with AGC refractory or intolerant to fluoropyrimidines, cisplatin, taxanes, and irinotecan. Overall, 50 patients treated between December 2009 and December 2013 were included in this analysis. The overall response rate (ORR) was 21.2% among 33 patients with measurable disease. The median time to treatment failure (TTF) and overall survival (OS) were 2.4 and 4.2 months. In multivariate analysis, factors associated with OS included poor performance status [hazard ratio (HR) 3.20; 95% confidence interval (CI) 1.55–6.60], shorter time from the start of first-line therapy (HR 2.20; 95% CI 1.18–4.12), and higher neutrophil/lymphocyte ratio value (HR 4.87; 95% CI 2.32–10.25). In patients (n = 35) with at most one risk factor, the ORR, median TTF, and OS were 26.1%, 3.6, and 6.7 months, respectively. The most common grade 3 or 4 adverse events were neutropenia (30%), anemia (22%), febrile neutropenia (8%), and peripheral neuropathy (8%). Initial and subsequent dose reduction was performed in 18 (36%) and 23 (46%) patients. There was one treatment-related death caused by septic infection. Salvage chemotherapy with the combination of oxaliplatin, leucovorin, and 5-fluorouracil has a potential activity and is tolerable for heavily treated AGC with appropriate dose modification and patient selection.

Background/aim Severe peritoneal metastasis (PM) from advanced gastric cancer (AGC) causes massive ascites and inadequate oral intake. Because patients with severe PM are often not included in clinical trials, little is known regarding the efficacy and safety of oxaliplatin with l-leucovorin and bolus/continuous infusion of 5-fluorouracil (FOLFOX) for them. Patients and methods We retrospectively studied AGC patients with massive ascites and/or inadequate oral intake due to severe PM treated with FOLFOX as the first-line treatment. Results Only 39 (10%) of 378 AGC patients had severe PM; 10 received FOLFOX. The median progression-free and overall survivals were 7.5 and 13.2 months, respectively. Ascites decreased in seven of nine patients with ascites, and oral intake improved in four of seven patients with an inadequate oral intake. Common grade 3-4 adverse events included neutropenia and anemia. Conclusion This study suggests that FOLFOX is effective and manageable for AGC patients with severe PM.

3528 Background: Anti-EGFR therapy (tx) in RAS wild-type (wt) metastatic colorectal cancer (mCRC) induces resistance through acquired genomic alterations. We aimed to define such alterations in Nationwide Cancer Genome Screening Project tissue and blood specimens, using next generation sequencing (NGS). Methods: Tumor specimens in patients (pts) with RAS wt mCRC were obtained from SCRUM-Japan GI-SCREEN (tissue) and GOZILA (circulating tumor DNA [ctDNA] from blood). Genomic alterations were compared using the Oncomine Comprehensive Assay (SCRUM) and Guardant360 (GOZILA), before anti-EGFR tx and after progression. Results: 373 total actionable alterations were identified in 71 pts with available matched tissue and ctDNA; 255 (68%) were acquired after anti-EGFR tx progression. Frequently seen acquired oncogenic alterations included KRAS mutations (27%) and amplifications (amps) of EGFR (41%), CDK6 (24%), BRAF (20%), MYC (17%), MET (14%), PIK3CA (11%), FGFR1 (11%), and KRAS (10%). Fusions of RET, ALK, and FGFR3 were newly acquired in 1-4%. Acquired alterations co-arose in multiple pathways, including the cell cycle, PI3K-AKT, and MAPK, although 29% of pts had none. Acquired mutations were less frequently clonal versus primary mutations (p7) adjusted plasma copy numbers (ApCN). Acquired ERBB2 amps were identified in 3 pts (4%) with a median ApCN of 4, one of whom (ApCN=4.2), treated with dual HER2 blockade, progressed after 2 cycles. Conclusions: Our integrated analysis revealed that anti-EGFR tx of pts with RAS WT mCRC led to acquired genomic alterations in multiple oncogenic pathways. Although most acquired alterations were subclonal, a subset of oncogenic alterations had relatively high clonality and ApCN, suggesting potential targets for overcoming acquired resistance to anti-EGFR tx. Early progression in a pt with an ApCN of 4.2 suggests low-level/subclonal acquired alterations may not be effective treatment targets.

e15106 Background: Tumor mismatch repair (MMR) predicts benefit of immune checkpoint inhibitors (ICIs) in metastatic colorectal cancer (mCRC). We conducted a large-scale prospective observational trial on microsatellite instability (MSI) status in mCRC: SCRUM-Japan GI-SCREEN CRC-MSI. Methods: mCRC patients (pts) appropriate for systemic chemotherapy were eligible. Paired tumor and normal DNA extracted from FFPE samples were analyzed by the MSI Analysis System, which includes 5 mononucleotide markers. Tumors exhibiting ≥2 unstable markers were defined as MSI-H, while those with ≤1 were labelled MSI-L/MSS. Results: From 2/2016 to 3/2018, 1,711 pts were enrolled, and 1,696 samples were submitted. MSI status was determined in 1,676 pts (98.8%); 51 pts (3.0%) were MSI-H. For MSI-H vs. MSI-L/MSS pts: Median age (years) 64/64; male gender (%) 51.0 vs. 43.8, p=0.31; right-sided primary (%) 70.6 vs. 25.0, p20 mt/Mb, was observed in 27/29 (93.1%) MSI-H pts. The frequency of representative gene mutations (%) for MSI-H vs. MSI-L/MSS pts were: TP53 17.2 vs. 66.1, p

TPS178 Background: Immune checkpoint inhibitors are drugs that block specific proteins produced by the immune system cells, such as T-cells; these proteins prevent T-cells from killing cancer cells. NIV is a standard care for pretreated mGC patients (pts), with increasing clinical use in Japan. Data from retrospective studies on various tumors have shown that after exposure to immune checkpoint inhibitors, the objective response rate to CTx potentially improves; however, enough data have not been accumulated. Although there are no recommended CTx regimen following NIV therapy, in a clinical setting, an irinotecan or oxaliplatin combination regimen (limited to cisplatin-refractory or cisplatin-intolerant pts) is frequently used as post-NIV CTx. This multicenter observational study aims to evaluate the efficacy and safety of CTx in NIV-refractory or NIV-intolerant mGC pts. Methods: We prospectively collect clinical and imaging data from NIV-pretreated mGC pts; these pts will be treated with cytotoxic agents. Pts who meet inclusion criteria A (histologically proven mGC pretreated with NIV, prior administration of a combination therapy of fluoropyrimidine plus platinum and taxanes, and written informed consent) at primary registration are registered. After primary registration, pts who meet inclusion criteria B [Eastern Cooperative Oncology Group Performance Status (ECOG PS 0-2), refractory or intolerant to NIV; prior administration of irinotecan monotherapy or oxaliplatin combination regimens and prior use of cisplatin; evaluable lesions according to RECIST ver. 1.1] at formal registration are registered. The primary endpoint is overall survival of NIV-pretreated mGC pts after CTx. For this study, we require 146 pts, with bilateral alpha = 0.05 and beta = 0.10, with a median threshold survival of 4.0 months and an expected median survival of 6.0 months. Therefore, we plan to enroll 200 pts, considering exclusions from the analysis; since May 2018, we have enrolled 27 pts. Clinical trial information: UMIN000032182.

Lessons Learned A shortened infusion of ramucirumab (from 60 to 20 minutes) was safe and feasible without infusion-related reactions. Twenty-minute infusions of ramucirumab can be an option for patients with no infusion-related reactions during the first 60-minute treatment. Background Ramucirumab is usually administered over 60 minutes, during which it is unlikely to cause infusion-related reactions (IRRs). This prospective study evaluated the safety of a shortened infusion of ramucirumab. Methods Patients who received their first dose of ramucirumab in a 60-minute infusion without developing IRRs were eligible and received their second ramucirumab dose for 20 minutes. The primary study endpoint was incidence of IRR during the first short-term infusion, and the secondary endpoints were incidence of IRR at any time and adverse events other than IRR. Results Of the 40 patients enrolled (median age, 68.5 years), 20 (55%) were male, 27 (67.5%) had stage IV gastric cancer, 25 (62.5%) received ramucirumab in combination with taxane-based chemotherapy, and 24 (60%) received only a single administration of ramucirumab prior to their enrollment. Notably, no IRR was observed during the first short-term infusion (IRR rate, 0%; 95% confidence interval [CI], 0%–0.72%). Among the 149 short-term infusions performed, there were no instances of IRRs or unexpected adverse events related to the treatment (Table 1). Conclusion For patients without development of IRRs upon the first ramucirumab administration, shortening infusion time (from 60 to 20 minutes) is safe and feasible.

4038Background: Addition of trastuzumab to cisplatin and fluoropyrimidine-based doublet chemotherapy is the standard first-line treatment for patients with human epidermal growth factor receptor 2 ...

e22128Background: Financial toxicity (FT) has negative impact on quality of life and survival of patients with cancer. COST is a well validated tool to measure FT in US. However, FT using COST ques...

12094Background: Tumor mutation burdens (TMBs) in advanced gastrointestinal (GI) malignancies have not been well-characterized. We analyzed TMB in tissue samples from advanced GI malignancies using...

152 Background: The efficacy of anti-PD-1 antibody for metastatic gastric cancer (mGC) was revealed. In non-small cell lung cancer (NSCLC), it was reported that overall response rate (ORR) in patients (pts) treated with chemotherapy (CTx) after immunotherapy exposure was higher than historical data from the pre-anti-PD-(L)1 era. The purpose of this retrospective study was to evaluate whether CTx improved efficacy outcomes after exposure anti-PD(L)1 antibody in mGC. Methods: We investigated retrospectively clinical characteristics at baseline of mGC pts who received CTx after progression of anti-PD-(L)1 antibody between April 2014 and August 2017. Anti-PD-(L)1 antibody was adapted as third- or later-line therapy. Pts fulfilled following criteria: histologically proven adenocarcinoma; ECOG PS 0-2; adequate organ functions; and received CTx including fluoropyrimidines (FU), platinum, and taxane or irinotecan. We evaluated efficacy outcomes, including ORR, disease control rate (DCR), time to treatment failure (TTF), and overall survival (OS). Results: Out of 40 treated with anti-PD-(L)1 antibody, 15 pts were included. Patient characteristics were as follows: median age (range), 67 (46-83) years; male/female, 13/2; ECOG PS (0/1/2), 5/8/2; HER2 positive, 8; histology (differentiated/undifferentiated), 10/5; metastatic lesions (peritoneum/liver/lung), 4/8/3; number of metastatic sites (1/≥2), 2/13; number of prior CTx regimens (3/4/5), 2/9/4; median period (range) from first line CTx, 30.7 (12.7-68.1) months; and CTx regimens (FU+oxaliplatin/taxane/irinotecan), 10/3/2. ORR, DCR, median TTF, and OS were 33% (95% CI, 15.2-58.3), 87% (95% CI, 62.1-96.3), 3.5 (95% CI, 1.6-4.4) months, and 7.6 (95% CI, 4.4-8.5) months, respectively. There were no predictive and prognostic factors associated with ORR, TTF, and OS on univariate analysis. At the beginning of CTx, 4 pts had immune-related adverse events (irAEs), but these were manageable and no new irAEs appeared during CTx. Conclusions: Our data support further evaluation of the use of CTx after progression of anti-PD-L 1 antibody, even in heavily pretreated mGC pts. Updated results will be presented.

856 Background: The FOLFOXIRI regimen (irinotecan, oxaliplatin, 5-fluorouracil and leucovorin) improves the response rate and overall survival compared to FOLFIRI in pts with metastatic colorectal cancer (mCRC), and addition of cetuximab to chemotherapy increases efficacy in pts with RAS wild-type mCRC. We conducted a phase 1 study of FOLFOXIRI plus cetuximab to determine the maximum-tolerated dose (MTD) and recommended dose (RD) and to assess its safety and efficacy in Japanese pts with RAS wild-type mCRC. Methods: Main eligibility criteria were: histologically confirmed colorectal adenocarcinoma; KRAS and NRAS wild-type status; measurable metastatic disease according to Response Evaluation Criteria in Solid Tumors version 1.1; age 20-74 years; Eastern Cooperative Oncology Group performance status 0 or 1. Pts with UDP-glucuronosyltransferase 1A1*6/*6, *28/*28 and *6/*28 genotypes were excluded. Pts received an escalating dose of intravenous irinotecan (100, 120, and 150 mg/m2 in the dose levels 0, 1, and 2, respectively) and a fixed dose of intravenous oxaliplatin (85 mg/m2), continuous infusion 5-fluorouracil (2400 mg/m2) plus l-leucovorin (200 mg/m2), and cetuximab (an initial dose of 400 mg/m2 followed by 250 mg/m2 per week). Results: A total of 9 Japanese pts were treated (3 and 9 in the dose levels 1 and 2, respectively). No patients experienced a dose-limiting toxicity (the MTD was not reached), and the dose level 2 (irinotecan 150 mg/m2) was established as the RD. With a median 8 cycles per patient, the most common grade 3 or 4 adverse events included neutropenia (44%), paronychia (22%), and acne-like rash (11%). No febrile neutropenia and treatment-related death were observed. Among 9 pts, 1 pt had complete response, 7 pts had partial response, and 1 pt had progressive disease, for an overall response rate of 89%. As of September 24, 2017, median progression free survival was 14.0 (95% CI 7.2-20.7) months. Conclusions: The combination of cetuximab and FOLFOXIRI has shown a favorable toxicity profile and promising antitumor activity in pts with RAS wild-type mCRC. Clinical trial information: UMIN000018217.

Background Both bevacizumab and anti-epithelial growth factor receptor (EGFR) agents (e.g. cetuximab and panitumumab) are sequentially used for metastatic colorectal cancer (mCRC). Their co-administration as a first-line treatment does not improve outcome, indicating that there are negative interactions between these agents. A long-term pharmacokinetics study demonstrated serum persistence of bevacizumab following termination of bevacizumab 6 months after the last administration. This prompted us to investigate the impact of short intervals between bevacizumab and anti-EGFR antibody on the efficacy of subsequent anti-EGFR therapy. Methods We retrospectively reviewed consecutive patients with KRAS exon 2 wild-type mCRC who underwent anti-EGFR therapy after the failure of fluoropyrimidines, oxaliplatin and irinotecan. We divided patients into two groups (Group A: the interval between bevacizumab and anti-EGFR agent 6 months). Results Of the 114 included patients (median age, 63 years), 78 (68%) were male. Most patients (88%) were treated with cetuximab plus irinotecan. Groups A and B consisted of 74 and 40 patients, respectively. There were no significant differences in patient characteristics. Group B patients had significantly longer progression-free survival (4.2 vs. 6.6 months; HR, 0.65; 95% CI, 0.43-0.98; P = 0.038) and longer overall survival (11.6 vs. 14.3 months; HR, 0.63; 95% CI, 0.41-0.98, P = 0.039). The response rate was 24.3% in Group A and 47.5% in Group B (P = 0.012). Conclusion A short interval between bevacizumab and anti-EGFR antibody treatment may interfere with the efficacy of subsequent anti-EGFR therapy.

3051 Background: Anti-PD-1 monotherapy has proven effective for the patients (pts) with MGC. However, the identification of biomarkers for predicting clinical outcomes remain as critical needs. We aimed to identify baseline characteristics associated with time to treatment failure (TTF) or overall survival (OS) for anti-PD-1/PD-L1 monotherapy as second- or later-line therapy in MGC. Methods: Routine blood count parameters and clinical characteristics at baseline were retrospectively investigated in 31 pts with MGC in Aichi Cancer Center Hospital. Endpoints were TTF and OS following anti-PD-1/PD-L1 monotherapy. Kaplan-Meiyer and Cox regression analysis were applied for survival analyses. Results: Patient characteristics were as follows: median age (range), 68 (47–83); ECOG performance status (PS) 0/1, 21/10; PM +ve/-ve, 12/19; No. of metastatic sites 1–2/≥3, 18/13; No. of prior chemotherapy regimens 1–2/≥3, 11/20; and absolute eosinophil count (AEC)