398 Background: At 4-y follow-up, 1L NIVO + chemo continued to demonstrate clinically meaningful overall survival (OS) and progression-free survival (PFS) benefit vs chemo with acceptable safety in patients (pts) with advanced non-HER2+ GC/GEJC/EAC from CheckMate 649. We report efficacy and safety results of NIVO + chemo vs chemo at 5-y follow-up. Methods: Adults with previously untreated, unresectable, advanced or metastatic, non-HER2+ GC/GEJC/EAC were enrolled, regardless of programmed death ligand 1 (PD-L1) expression. Pts were randomized to NIVO (360 mg Q3W or 240 mg Q2W) + chemo (XELOX Q3W or FOLFOX Q2W), NIVO + ipilimumab, or chemo. Primary endpoints for NIVO + chemo vs chemo were OS and PFS by blinded independent central review (BICR) in pts with PD-L1 combined positive score (CPS) ≥ 5. Results: Pts were randomized to NIVO + chemo (n = 789) or chemo (n = 792). NIVO + chemo continued to show OS and PFS benefit vs chemo in pts with PD-L1 CPS ≥ 5, pts with PD-L1 CPS ≥ 1, and all randomized pts at 60-month (mo) minimum follow-up (Table). OS rates at 60-mo were higher with NIVO + chemo vs chemo in pts with PD-L1 CPS ≥ 5, pts with PD-L1 CPS ≥ 1, and all randomized pts (Table), and OS benefit with NIVO + chemo continued to be observed in most prespecified subgroups. Objective response rates (ORRs) were higher and responses were more durable with NIVO + chemo vs chemo in pts with PD-L1 CPS ≥ 5, pts with PD-L1 CPS ≥ 1, and all randomized pts (Table). No new safety signals were identified. Conclusions: These results represent the first report of 5-y follow-up for anti–PD-1 + chemo combination therapy in GC/GEJC/EAC to our knowledge. NIVO + chemo continued to provide sustained long-term survival vs chemo with an acceptable safety profile after 5 y of follow-up. These data continue to support the use of NIVO + chemo as a standard 1L treatment for advanced GC/GEJC/EAC. Clinical trial information: NCT02872116 . Efficacy PD-L1 CPS ≥ 5 PD-L1 CPS ≥ 1 All randomized NIVO + chemo(n = 473) Chemo (n = 482) NIVO + chemo (n = 641) Chemo (n = 656) NIVO + chemo (n = 789) Chemo (n = 792) mOS (95% CI), mo 14.4 (13.1–16.2) 11.1 (10.1–12.1) 13.8 (12.4–14.8) 11.4 (10.7–12.3) 13.7 (12.4–14.5) 11.6 (10.9–12.5) HR (95% CI) 0.71 (0.61–0.81) 0.76 (0.67–0.85) 0.79 (0.71–0.88) 60-mo OS rate (95% CI), % 16 (12–19) 6 (4–9) 13 (11–16) 5 (4–7) 12 (10–14) 6 (4–8) mPFS a (95% CI), mo 8.3 (7.0–9.4) 6.1 (5.6–6.9) 7.5 (7.0–8.5) 6.9 (6.2–7.1) 7.8 (7.1–8.6) 6.9 (6.7–7.2) HR (95% CI) 0.71 (0.61–0.82) 0.77 (0.68–0.87) 0.79 (0.71–0.89) ORR a,b (95% CI), % 60 (55–65) 45 (40–50) 60 (55–64) 46 (42–51) 58 (54–62) 46 (42–50) mDOR a,c (95% CI), mo 9.6 (8.3–12.4) 7.0 (5.7–8.0) 8.6 (7.9–10.5) 6.9 (5.8–7.6) 8.5 (7.7–9.9) 6.9 (5.9–7.6) a Per BICR. b In pts with measurable target lesions at baseline. c In all measurable responders. DOR, duration of response; m, median.

392 Background: NIVO + chemo demonstrated clinically meaningful survival benefit and an acceptable safety profile vs chemo in previously untreated Chinese pts with advanced GC/GEJC/EAC from CheckMate 649, consistent with the overall study population. 1L NIVO + chemo is currently approved for pts with advanced non-HER2+ GC/GEJC/EAC in China and other countries. We report 5-y results of NIVO + chemo vs chemo in Chinese pts from CheckMate 649. Methods: Adults with previously untreated, unresectable advanced or metastatic, non-HER2+ GC/GEJC/EAC were enrolled regardless of programmed death ligand 1 (PD-L1) expression. Randomized pts received NIVO + chemo, NIVO + ipilimumab, or chemo. Dual primary endpoints for NIVO + chemo vs chemo were overall survival (OS) and progression-free survival (PFS) by blinded independent central review (BICR) in pts with PD-L1 combined positive score (CPS) ≥ 5. Results: 208 Chinese pts were randomized to NIVO + chemo or chemo. At 61-month (mo) minimum follow-up, NIVO + chemo continued to demonstrate OS and PFS benefit vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts (Table). 5-y OS rate was 24% with NIVO + chemo vs 8% with chemo in pts with PD-L1 CPS ≥ 5 and 20% vs 7% in all randomized pts. Objective response rate (ORR) was higher and responses were more durable with NIVO + chemo vs chemo in pts with PD-L1 CPS ≥ 5 and all randomized pts (Table). No new safety signals were identified with longer follow-up. Conclusions: NIVO + chemo continued to demonstrate clinically meaningful long-term survival benefit, more durable responses, and acceptable safety vs chemo in Chinese pts after 5 y of follow-up, consistent with earlier reports and with the overall study population of pts with advanced non-HER2+ GC/GEJC/EAC. These results further support NIVO + chemo as a standard 1L treatment option for Chinese pts. Clinical trial information: NCT02872116 . Efficacy PD-L1 CPS ≥ 5 All randomized NIVO + chemo(n = 75) Chemo (n = 81) NIVO + chemo (n = 99) Chemo (n = 109) mOS (95% CI), mo 15.5(11.9–21.1) 9.6(8.0–12.1) 14.3(11.5–16.5) 10.3(8.1–12.1) HR (95% CI) 0.57 (0.40–0.82) 0.63 (0.46–0.85) mPFS a (95% CI), mo 8.5(6.0–14.0) 4.3(4.1–6.5) 8.3(6.2–12.4) 5.6(4.2–6.8) HR (95% CI) 0.51 (0.34–0.76) 0.57 (0.41–0.80) ORR a,b (95% CI), % 68 (56–79) 48 (36–60) 66 (55–76) 45 (35–56) mDOR a,c (95% CI), mo 12.5 (7.2–23.4) 6.9 (3.9–8.5) 12.5 (7.2–17.7) 5.6 (4.4–8.3) a Per BICR. b In pts with measurable target lesions at baseline. c In responders. DOR, duration of response; m, median.

Background: In metastatic colorectal cancer (mCRC), improvements in survival from combining leucovorin/fluorouracil/oxaliplatin/irinotecan (FOLFOXIRI) with bevacizumab have come at the risk of increased rates of high-grade toxicities. Trilaciclib is indicated to decrease the incidence of chemotherapy-induced myelosuppression in patients receiving standard-of-care chemotherapy for extensive-stage small cell lung cancer. Methods: Patients with untreated mCRC were randomly assigned 1:1 to trilaciclib (n = 164) or placebo (n = 162) prior to FOLFOXIRI/bevacizumab for up to 12 cycles (induction), followed by trilaciclib or placebo prior to fluorouracil/leucovorin/bevacizumab (maintenance). Co-primary endpoints were duration of severe (grade 4) neutropenia (DSN) in cycles 1-4 and occurrence of severe neutropenia (SN) during induction. Secondary endpoints included antitumor efficacy, survival, and safety. Results: The study met its co-primary endpoints. Administering trilaciclib prior to FOLFOXIRI/bevacizumab resulted in significant reductions in DSN in cycles 1-4 vs placebo (mean, 0.1 vs 1.3 days; P < .001) and occurrence of SN during induction (1.3% vs 19.7%; adjusted relative risk [96% CI] = 0.07 [0.0 to 0.3]; P < .001). Grade 3/4 adverse events, including neutropenia, diarrhea, and leukopenia, were less frequent with trilaciclib vs placebo (64.8% vs 73.1%). Trilaciclib was associated with fewer chemotherapy dose reductions and delays and with reduced administration of supportive therapies, compared with placebo. Objective response rate (41.6% vs 57.1%; P = .009) and median progression-free survival (10.3 vs 13.1 months; P < .001) were significantly lower with trilaciclib vs placebo. Conclusions: Administering trilaciclib prior to FOLFOXIRI/bevacizumab protected the neutrophil lineage from the effects of chemotherapy-induced myelosuppression. However, antitumor efficacy endpoints favored placebo.

Advanced colorectal cancer (CRC) exhibits weak responses to multiple therapies, primarily due to the presence of cancer stem cells (CSCs), which drive high recurrence rates, metastasis, and drug resistance. We have previously systematically conducted CSC-targeted compound discovery and evaluation studies to inhibit CSC-mediated tumorigenesis and metastasis. Here, we identified ZSH-512, a novel synthetic retinoid that selectively targets retinoic acid receptor (RAR)y, demonstrating its ability to effectively inhibit CRC-CSCs and patient-derived organoids (PDOs) in vitro and significantly reduce CSC-mediated tumor formation and liver metastasis mouse models without noticeable toxicity. Mechanistically, integrated analysis of Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) and RNA sequencing (RNA-seq) revealed that ZSH-512 exerted its effect by modulating the RARy-KDM3A axis to mediate epigenetic programming and broadly suppress stemness-related signaling pathways, including Wnt, Hippo, and Hedgehog. ZSH-512 efficiently inhibited tumorigenesis in CRC-patient-derived tumor xenografts (PDXs) with high KDM3A expression, suggesting KDM3A as a potential predictive biomarker. Collectively, ZSH-512 is a promising therapeutic candidate for targeting CRCCSCs with high efficacy.

Patients with advanced solid tumors have a suboptimal prognosis. This study investigated the safety and feasibility of linperlisib, a selective phosphatidylinositol 3-kinase delta isoform (PI3Kδ) inhibitor, for treating patients with advanced solid tumors. In this phase Ib, single-arm, open-label, multi-center clinical trial, patients with histologically confirmed advanced solid tumors from eight centers in China were enrolled to receive oral linperlisib (80 mg/day). The primary endpoint was safety. Between August 2019 and June 2022, 94 patients were enrolled in the trial and received the study treatment. The most common (≥ 20

PURPOSE:Many cancer patients express interest in using herbal medicine during chemotherapy, but little is known about its benefits and risks. This study aimed to evaluate the effects of the Chinese herbal medicine JianPi-BuShen formula (JPBS) on adjuvant chemotherapy completion in colon cancer patients. PATIENTS AND METHODS:This multi-center, phase III, randomized, placebo-controlled trial included patients with stage II (high risk for recurrence) and stage III colon cancer following surgery, planning to receive CAPOX (capecitabine and oxaliplatin) chemotherapy. Patients were randomized 1:1 to receive either JPBS or a placebo. The primary outcome was the completion rate of planned chemotherapy cycles. Secondary outcomes included relative dose intensity (RDI), chemotherapy-induced toxicities, quality of life (measured by the Edmonton Symptom Assessment System - ESAS), adverse events (AEs), and serious AEs (SAEs). Predefined subgroup analyses were performed by age (>65/≤65) and TNM stage (II/III). RESULTS:A total of 376 participants were analyzed, with a median age of 60.3 years; 56.9 % were male, and 67.6 % had stage III disease. Chemotherapy completion was significantly higher in the JPBS group than in the placebo group (63.0 % vs. 47.6 %, P = 0.003). Oxaliplatin RDI was also higher in the JPBS group (P = 0.049). Subgroup analyses showed JPBS significantly improved completion rates for stage II patients (73.0 % vs. 42.4 %, P = 0.001) and younger patients (66.9 % vs. 48.8 %, P = 0.004). JPBS reduced grade ≥ 2 vomiting (3.8 % vs. 6.4 %, P = 0.007) but increased grade ≥ 2 thrombocytopenia (16.2 % vs. 12.4 %, P = 0.012). Quality of life improved in stage II and younger patients. CONCLUSION:JPBS improved chemotherapy completion rates in stage II and younger colon cancer patients without compromising tolerability. Further research is needed to explore its mechanisms and long-term effects.

10586 Background: Immune checkpoint inhibitors (ICIs) are effective in multiple tumors. However, about 10% of immune-related adverse events (irAEs) are severe and can have serious or even life-threatening consequences for patients. We investigated whether Human leukocyte antigen (HLA) genes predispose to and thus hold a predictive role of developing of severe irAEs in Chinese population. Methods: In a case/control study, we collected data from patients with metastatic cancer treated with ICIs and developed severe irAEs (Grade ≥3 and required hospitalization). Patients treated with ICIs without any irAEs were used as controls. Data was collected from15th Nov, 2019 until 10th Oct, 2023. HLA typing was performed via next generation sequencing. Results: We enrolled 83 patients with severe irAEs and 286 patients treated with ICIs without any irAEs. We found HLA-B*15:27 (OR=9.1, X21,95 = 7.2, P = 0.008) and HLA-C*04:01 (OR=2.5, X21,95 = 7.0, P =0.008) were significantly associated with severe overall irAEs risk. When assessing irAE individually, a significant association between HLA-B*13:02 and serious myocarditis (OR = 3.4, X21,95 = 6.2, P =0.01) as well as striking enrichment for HLA-A*02:03 haplotypes in severe adrenal insufficiency (OR = 10.0, X21,95 = 19.1, P<0.0001) were observed. Conclusions: Specific HLA alleles were associated with severe irAEs. Consideration of pre-prescription HLA typing and vigilance for serious reactions to ICIs are warranted.

Background:Prognostic factors are complicated and changeable for locally advanced gastric cancer (GC) patients. This study aimed to perform a novel prognostic model on survival for locally advanced GC patients who have received neoadjuvant chemotherapy and radical surgery. Methods:The locally advanced GC patients with neoadjuvant chemotherapy were included in this study from Zhongshan Hospital, Fudan University. A nomogram was developed based on independent prognostic factors identified through a multivariable Cox regression model. Model performance was evaluated in training and independent external cohorts in terms of calibration, discrimination, and clinical usefulness. Results:A total of 273 patients received radical resections. The median progression-free survival (PFS) and overall survival (OS) for all patients were 43.8 and 61.2 months, respectively. Nomogram showed that Lauren type made the greatest contribution to prognosis, followed by ypN. The prognostic nomogram had excellent discriminative ability, with a C-index of 0.689 [95% confidence interval (CI): 0.661-0.716], and an area under the receiver operating characteristic (ROC) curve (AUC) of 0.778, 0.746, and 0.725 for 3-, 5- and 10-year OS, respectively. Similar results were obtained in the external validation cohort. Based on the nomogram, the whole cohort was divided into high-risk and low-risk groups. And risk group classification was significantly associated with clinical characteristics, and produced an AUC value of 0.781, 0.748, and 0.727 for 3-, 5- and 10-year OS, respectively. Furthermore, compared with the tumor-node-metastasis (TNM) staging system (8th edition), Japanese criteria, and German criteria, the decision curve analysis (DCA) graphically demonstrated that the new model had more optimal net benefits in predicting the 3-, 5-, and 10-year OS for GC patients. Both C-index and time-dependent ROC curve demonstrated that the nomogram had a stronger capability for accurately predicting prognosis compared with the other staging system. Conclusions:The nomogram model is an effective support tool to predict OS in GC patients undergoing perioperative chemotherapy followed by radical surgery.

245 Background: Inhibition of TIGIT, a novel checkpoint inhibitor, may further amplify immune responses by complementing the PD-L1/PD-1 pathway. Anti-tumor activity has been demonstrated with cancer immunotherapy in ESCC. SKYSCRAPER-08 (NCT04540211) is evaluating the efficacy and safety of tira (anti-TIGIT) + atezo (anti-PD-L1) in combination with CT compared with placebo + CT as 1L treatment (tx) in an Asian population with unresectable locally advanced (LA), unresectable recurrent, or metastatic (R/M) ESCC. Methods: Eligible pts (confirmed LA or R/M ESCC; ECOG PS 0–1; no prior systemic tx) were randomized 1:1 to receive tira 600mg + atezo 1200mg + CT (paclitaxel 175mg/m2 + cisplatin 60–80mg/m2, local standard of care) or placebo + CT on Day 1 of each 21-day cycle (cycles 1–6); followed by tira + atezo or placebo maintenance until loss of clinical benefit/unacceptable toxicity. Primary endpoints: independent review facility (IRF)-assessed progression-free survival (PFS) and overall survival (OS). Secondary endpoints: investigator (INV)-assessed PFS, objective response rate (ORR), duration of response (DoR), and safety. Results: Overall, 461 pts were randomized (tira + atezo + CT, n= 229; placebo + CT, n=232). Pt characteristics were generally balanced between arms. As of 15 June 2022 (minimum survival follow-up 6.5 months [mo]; PFS primary analysis), median IRF-assessed PFS was 6.2 mo for tira + atezo + CT vs 5.4 mo for placebo + CT (HR 0.56; 95% CI: 0.45, 0.70; P<0.0001). As of 13 Feb 2023 (minimum survival follow-up 14.5 mo; OS final analysis), median OS was 15.7 mo for tira + atezo + CT vs 11.1 mo for placebo + CT (HR: 0.70; 95% CI: 0.55, 0.88; P= 0.0024). INV-assessed PFS, IRF-assessed ORR and DoR are presented in Table. Treatment-related adverse events (TRAEs) occurred in 98.2% of pts (both arms); Grade 3/4 TRAEs in 59.6% (tira + atezo + CT) and 56.4% (placebo + CT) of pts; Grade 5 TRAEs in 2.6% (tira + atezo + CT) and 0.9% (placebo + CT) of pts. Conclusions: The study met both primary endpoints of IRF-assessed PFS and OS, demonstrating statistically significant and clinically meaningful improvements in PFS and OS for tira + atezo + CT over placebo + CT. Generally consistent benefit was observed across subgroups, including PD-L1 status. The safety profile was consistent with the known risks of the individual tx. Clinical trial information: NCT04540211 . [Table: see text]

Background:Immune checkpoint inhibitors (ICIs) are emerging as important drugs for patients with locally advanced esophageal cancer (EC). Yet, immune-related adverse events (irAEs) may be a major obstacle for these population. Multidisciplinary team (MDT) is an efficient way to deal with such conditions. The aim of this study is to report a case of a stage III esophageal squamous cell carcinoma (ESCC) patient who achieved long-term survival through comprehensive treatment and MDT management, despite multiple irAEs. Case Description:A 67-year-old man was diagnosed with stage III ESCC (cT4N1M0) in January 2021. After 2 cycles of initial immuno-chemotherapy with good efficiency, he suffered from grade 3 immune-related hepatitis (IRH) and recovered after steroid therapy. Then radical radiotherapy began as planned. However, he got pneumonia and common antibiotics and steroid showed no effect. Finally, NGS-based pathogen detection identified cytomegalovirus (CMV) infection in his sputum. Ganciclovir was prescribed to him and his condition turned better soon. During a five-month period of anti-infectious therapy and follow-up, there was no anti-tumor treatment. However, the patient's esophageal lesion was evaluated as having a partial response (PR) on computed tomography (CT) scan and cancer cells transformed to high-grade intraepithelial neoplasia through gastroscopy. He underwent endoscopic submucosal dissection (ESD) and began a five-month follow-up period. When dysplasia recurred locally, the MDT members carefully restarted ICIs since he had fully recovered from previous irAEs and we believed he benefited from long-term responses to ICIs. Despite experiencing a third irAE, that is, adrenocortical insufficiency with mild symptoms, the patient still greatly benefited from ICIs. After being diagnosed as stage III EC for about 35 months, the patient's disease was still evaluated as clinical no evidence of disease (NED). Conclusions:EC patients with irAEs who are well managed benefited from ICIs. MDT is crucial in the management of comprehensive treatment for EC.

AbstractInfigratinib, an FGFR1‐3 selective oral tyrosine kinase inhibitor, has shown clinical activity in cancers with FGFR alterations. The pharmacokinetics (PK) of infigratinib and its major metabolites have been characterized in global populations. This study examined the PK profile of infigratinib and its metabolites in Chinese patients. In this phase II, open‐label, single‐arm study in China, patients with advanced gastric cancer (GC) or gastroesophageal junction adenocarcinoma (GEJ) harboring FGFR2 gene amplification received 125 mg infigratinib orally once daily in a “3 weeks on, 1 week off” schedule for 28‐day cycles. Plasma PK parameters were calculated with a non‐compartmental model. Data were available from 21 patients (19 GC and two GEJ). After a single dose, peak infigratinib plasma concentration was reached at a median time of 3.1 h, with geometric mean Cmax of 85.9 ng/mL and AUC0‐t of 637 h*ng/mL. After 21‐day dosing, geometric mean infigratinib Cmax,ss of 204 ng/mL was reached at a median of 4.0 h; geometric mean AUC0‐24,ss was 3060 h*ng/mL. The geometric mean Rac,Cmax (%CV) and Rac,AUC0‐24 (%CV) of infigratinib was 2.5 (113.8) and 5.1 (138.2), respectively. A steady state of infigratinib was reached after continuous dosing for 15 days. The metabolites accounting for >10% of infigratinib were BHS697 and CQM157. The PK profiles of infigratinib and its metabolites in Chinese patients with GC or GEJ were largely consistent with known PK profiles of infigratinib from global populations.

Objective: Esophageal cancer (EC) ranks eighth among cancers in cancer-related deaths globally, and ~44% of new cases occur in China. We sought to describe the clinical characteristics and treatment landscape of EC in China before the approval of immunotherapy in 2020. Methods: CHANNEL was a large, retrospective study using patient-level data from 14 hospitals/cancer centers across China, including adults initiating therapy for newly diagnosed EC (January to December 2018). Demographics, clinicopathologic characteristics, and treatment patterns over 6 months were descriptively summarized. Results: Of 3,493 patients, 75.7% were men, the mean age was 64.1 years, and 75.0% had no family history of cancer. Most (92.8%) had squamous cell carcinoma, with a primary lesion in the middle esophagus (56.4%). Among patients with resectable EC, 92.9% received initial surgery, and 7.1% received neoadjuvant therapy, primarily chemotherapy (85.5% platinum-taxane). Among patients with unresectable early or locally advanced EC, 50.8% and 49.2% received palliative and radical therapy, respectively, as the initial treatment, primarily chemotherapy (66.5% platinum-taxane) and chemoradiotherapy (50.8% platinum-taxane), respectively. Adjuvant therapy was administered to 22.9% of patients undergoing initial surgery, and 2.4% receiving neoadjuvant therapy and surgery. Among patients with advanced EC, 84.6% received systemic therapy as an initial treatment, primarily chemotherapy (61.5% platinum-taxane). Conclusions: Before the approval of immunotherapy in China, most patients with resectable early or locally advanced EC underwent radical surgery without preoperative treatment, whereas most patients with advanced EC received platinum-taxane chemotherapy. These findings highlight the need for novel EC treatments before immunotherapy was introduced, and provide a baseline for evaluating the benefits of immunotherapy, now that this treatment is widely used in this setting.

BACKGROUND:It remains unclear whether intensification of the chemotherapy backbone in tandem with an anti-EGFR can confer superior clinical outcomes in a cohort of RAS/BRAF wild-type colorectal cancer (CRC) patients with initially unresectable colorectal liver metastases (CRLM). To that end, we sought to comparatively evaluate the efficacy and safety of cetuximab plus FOLFOXIRI (triplet arm) versus cetuximab plus FOLFOX (doublet arm) as a conversion regimen (i.e., unresectable to resectable) in CRC patients with unresectable CRLM. METHODS AND FINDINGS:This open-label, randomized clinical trial was conducted from April 2018 to December 2022 in 7 medical centers across China, enrolling 146 RAS/BRAF wild-type CRC patients with initially unresectable CRLM. A stratified blocked randomization method was utilized to assign patients (1:1) to either the cetuximab plus FOLFOXIRI (n = 72) or cetuximab plus FOLFOX (n = 74) treatment arms. Stratification factors were tumor location (left versus right) and resectability (technically unresectable versus ≥5 metastases). The primary outcome was the objective response rate (ORR). Secondary outcomes included the median depth of tumor response (DpR), early tumor shrinkage (ETS), R0 resection rate, progression-free survival (PFS), overall survival (not mature at the time of analysis), and safety profile. Radiological tumor evaluations were conducted by radiologists blinded to the group allocation. Primary efficacy analyses were conducted based on the intention-to-treat population, while safety analyses were performed on patients who received at least 1 line of chemotherapy. A total of 14 patients (9.6%) were lost to follow-up (9 in the doublet arm and 5 in the triplet arm). The ORR was comparable following adjustment for stratification factors, with 84.7% versus 79.7% in the triplet and doublet arms, respectively (odds ratio [OR] 0.70; 95% confidence intervals [CI] [0.30, 1.67], Chi-square p = 0.42). Moreover, the ETS rate showed no significant difference between the triplet and doublet arms (80.6% (58/72) versus 77.0% (57/74), OR 0.82, 95% CI [0.37, 1.83], Chi-square p = 0.63). Although median DpR was higher in the triplet therapy group (59.6%, interquartile range [IQR], [50.0, 69.7] versus 55.0%, IQR [42.8, 63.8], Mann-Whitney p = 0.039), the R0/R1 resection rate with or without radiofrequency ablation/stereotactic body radiation therapy was comparable with 54.2% (39/72) of patients in the triplet arm versus 52.7% (39/74) in the doublet arm. At a median follow-up of 26.2 months (IQR [12.8, 40.5]), the median PFS was 11.8 months in the triplet arm versus 13.4 months in the doublet arm (hazard ratio [HR] 0.74, 95% CI [0.50, 1.11], Log-rank p = 0.14). Grade ≥ 3 events were reported in 47.2% (35/74) of patients in the doublet arm and 55.9% (38/68) of patients in the triplet arm. The triplet arm was associated with a higher incidence of grade ≥ 3 neutropenia (44.1% versus 27.0%, p = 0.03) and diarrhea (5.9% versus 0%, p = 0.03). The primary limitations of the study encompass the inherent bias in subjective surgical decisions regarding resection feasibility, as well as the lack of a centralized assessment for ORR and resection. CONCLUSIONS:The combination of cetuximab with FOLFOXIRI did not significantly improve ORR compared to cetuximab plus FOLFOX. Despite achieving an enhanced DpR, this improvement did not translate into improved R0 resection rates or PFS. Moreover, the triplet arm was associated with an increase in treatment-related toxicity. TRIAL REGISTRATION:ClinicalTrials.gov Identifier: NCT03493048.

Background:Immune checkpoint inhibitors (ICIs) have significant clinical benefit for a subset of patients with gastrointestinal cancers (GICs) including esophageal cancer, gastric cancer and colorectal cancer. However, it is difficult to predict which patients will respond favorably to immune checkpoint blockade therapy. Thus, this study was initiated to determine if peripheral T-cell receptor (TCR) repertoire profiling could predict the clinical efficacy of anti-programmed death 1 (PD-1) treatment.Methods:Blood samples from 31 patients with GICs were collected before anti-PD-1 antibody treatment initiation. The clinical significance of the combinatorial diversity evenness of the TCR repertoire [the diversity evenness 50 (DE50), with high values corresponding to less clonality and higher TCR diversity] from peripheral blood mononuclear cells (PBMCs) was evaluated in all the enrolled patients. A highly predictive nomogram was set up based on peripheral TCR repertoire profiling. The performance of the nomogram was assessed by receiver operating characteristic (ROC) curve, concordance index (C-index), and calibration curves, and decision curve analysis (DCA) was used to assess its clinical applicability.Results:Compared to non-responders [progression disease (PD)], the DE50 scores were significantly higher in responders [stable disease (SD) and partial response (PR)] (P=0.018). Patients with a high DE50 score showed better progression-free survival (PFS) than those with a low DE50 score (P=0.0022). The multivariable Cox regression demonstrated that high DE50 and low platelet-lymphocyte ratio (PLR) were significant independent predictors for better PFS when treated with anti-PD-1 antibody. Furthermore, a highly predictive nomogram was set up based on peripheral TCR repertoire profiling. The area under the curves (AUCs) of this system at 3-, 6- and 12-month PFS reached 0.825, 0.802, and 0.954, respectively. The nomogram had a C-index of 0.768 [95% confidence interval (CI): 0.658-0.879]. Meanwhile, the calibration curves also demonstrated the reliability and stability of the model.Conclusions:High DE50 scores were predictive of a favorable response and longer PFS to anti-PD-1 treatment in GIC patients. The nomogram based on TCR repertoire profiling was a reliable and practical tool, which could provide risk assessment and clinical decision-making for individualized treatment of patients.

Objective:The open-label, phase II RATIONALE-209 study evaluated tislelizumab (anti-programmed cell death protein 1 antibody) as a tissue-agnostic monotherapy for microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) tumors. Methods:Adults with previously treated, locally advanced unresectable or metastatic MSI-H/dMMR solid tumors were enrolled. Patients received tislelizumab 200 mg intravenously every 3 weeks. Objective response rate (ORR; primary endpoint), duration of response (DoR), and progression-free survival (PFS) were assessed by independent review committee (Response Evaluation Criteria in Solid Tumors v1.1). Results:Eighty patients were enrolled and treated; 75 (93.8%) patients had measurable disease at baseline. Most had metastatic disease and received at least one prior therapy for advanced/metastatic disease (n=79; 98.8%). At primary analysis (data cutoff July 8, 2021; median follow-up 15.2 months), overall ORR [46.7%; 95% confidence interval (95% CI), 35.1-58.6; one-sided P<0.0001] and ORR across tumor-specific subgroups [colorectal (n=46): 39.1% (95% CI, 25.1-54.6); gastric/gastroesophageal junction (n=9): 55.6% (95% CI, 21.2-86.3); others (n=20): 60.0% (95% CI, 36.1-80.9)] were significantly greater with tislelizumab vs. a prespecified historical control ORR of 10%; five (6.7%) patients had complete responses. Median DoR, PFS, and overall survival were not reached with long-term follow-up (data cutoff December 5, 2022; median follow-up 28.9 months). Tislelizumab was well tolerated with no unexpected safety signals. Treatment-related adverse events (TRAEs) of grade ≥3 occurred in 53.8% of patients; 7.5% of patients discontinued treatment due to TRAEs. Conclusions:Tislelizumab demonstrated a significant ORR improvement in patients with previously treated, locally advanced unresectable or metastatic MSI-H/dMMR tumors and was generally well tolerated.

Background: RMX1002 (grapiprant) is a selective E-type prostanoid receptor 4 (EP4) antagonist and a promising candidate for cancer therapy, potentially enhancing anti-tumor immune responses. This study aimed to evaluate the safety, pharmacokinetics, pharmacodynamics, and efficacy of RMX1002 as monotherapy and in combination with anti-PD-1 antibody toripalimab for advanced solid tumors. Patients and Methods: This multicenter, phase I trial enrolled patients with histologically or cytologically confirmed advanced solid tumors. This study included three phases: Ia (dose-escalation of RMX1002 monotherapy from 200 to 650mg BID), Ib (dose-escalation from 500 to 650mg BID in combination with toripalimab), and Ic (dose-expansion of 500mg BID with toripalimab). Safety, pharmacokinetics, pharmacodynamics, and efficacy were assessed. Results: A total of 45 patients were enrolled (17 in phase Ia, 12 in phase Ib, and 16 in phase Ic). No dose-limiting toxicity was reported, and the MTD was not reached. Overall, 21 patients experienced RMX1002-related adverse events with CTCAE grade ≥3. Pharmacokinetics revealed rapid absorption of RMX1002 with the maximum concentration (Cmax) reached within 2 to 5 hours, and dose-dependent increases in Cmax and area under the concentration-time curve. The increase in urinary metabolite of PGE2 suggested the inhibition of EP4 signaling pathway. The best response of stable disease was reported in 64.7%, 28.6%, and 18.8% of patients in phase Ia, Ib, and Ic, respectively. Conclusion: RMX1002 was well tolerated at the tested doses and showed signs of antitumor activity. RMX1002 500 mg BID with toripalimab 240 mg biweekly was selected as the recommended dose for future clinical trials.

In recent years, immunotherapy, particularly PD-1 antibodies, have significantly enhanced the outcome of gastric cancer patients. Despite these advances, some patients do not respond well to treatment, highlighting the need to understand resistance mechanisms and develop predictive markers of treatment effectiveness. This study retrospectively analyzed data from 106 patients with stage IV gastric cancer who were treated with first-line immunotherapy in combination with chemotherapy. By comparing plasma cytokine levels between patients resistant and sensitive to PD-1 antibody therapy, the researchers identified elevated IL-4 expression in the resistant patients. Mechanical investigations revealed that IL-4 induces metabolic changes in macrophages that activate the PI3K/AKT/mTOR pathway. This alteration promotes ATP production, enhances glycolysis, increases lactic acid production, and upregulates FcγRIIB expression in macrophages. Ultimately, these changes lead to CD8+ T cell dysfunction and resistance to PD-1 antibody therapy in gastric cancer. These findings highlight the role of IL-4-induced macrophage polarization and metabolic reprogramming in immune resistance and verify IL-4 as potential targets for improving treatment outcomes in gastric cancer patients.