Recurrent Gastric Adenocarcinoma Research Articles

Real-world effectiveness and safety of trastuzumab-deruxtecan in Japanese patients with HER2-positive advanced gastric cancer (EN-DEAVOR study).

Trastuzumab-deruxtecan (T-DXd) was approved for the treatment of HER2-positive patients with advanced gastric cancer in Japan based on the results of the DESTINY-Gastric01 trial. This study aimed to collect real-world data and evaluate the effectiveness and safety of T-DXd. Patients aged ≥ 20years at the start of T-DXd administration with a histopathologically confirmed diagnosis of HER2-positive unresectable advanced or recurrent gastric or gastroesophageal junction (GEJ) adenocarcinoma that had worsened after chemotherapy were enrolled in this retrospective cohort study. Key outcomes included T-DXd treatment status, overall survival (OS), real-world progression-free survival (rwPFS), time to treatment failure (TTF), objective response rate and frequency of grade ≥ 3 adverse events (AEs). Of the 312 patients included in the analysis, 75.3% were male, the median (range) age was 70.0 (27.0-89.0) years, 12.2% had an ECOG PS ≥ 2, 43.3% had ascites and the initial T-DXd dose was > 5.4- ≤ 6.4mg/kg in 78.2% of patients. The median (95% confidence interval) OS, rwPFS and TTF (months) was 8.9 (8.0-11.0), 4.6 (4.0-5.1) and 3.9 (3.4-4.2), respectively. The response rate was 42.9% in patients with a target lesion. In total, 48.4% of patients experienced a grade ≥ 3 AE, 2.6% experienced grade 5 AEs and 60.9% experienced AEs leading to T-DXd dose adjustments (reduction: 36.9%, interruption: 34.0% or discontinuation: 23.7%). No new safety signals were detected. T-DXd was effective and had a manageable safety profile as a third- or later-line treatment for patients with HER2-positive gastric or GEJ cancer in Japanese clinical practice. UMIN000049032.

S4986 Recurrent Gastric Adenocarcinoma Presenting as Pseudo-Achalasia

S4986 Recurrent Gastric Adenocarcinoma Presenting as Pseudo-Achalasia

Abstract CT104: Results from a phase 1 study of the anti-immunoglobulin-like transcript 4 (ILT4) monoclonal antibody MK-4830 plus pembrolizumab in patients with previously treated advanced solid tumors

Abstract Background: In the dose escalation phase of a first-in-human phase 1 study (NCT03564691), the anti-ILT4 IgG4 monoclonal antibody MK-4830 + pembrolizumab (pembro) had a manageable safety profile and demonstrated promising antitumor activity in patients (pts) with previously treated advanced solid tumors, including those with PD on immunotherapy. Here, we present safety, efficacy, and biomarker analyses for MK-4830 + pembro for the previously treated pancreatic adenocarcinoma, glioblastoma, head and neck squamous cell carcinoma (HNSCC), and gastric cancer cohorts of the expansion phase. Methods: Eligible pts were aged ≥18 y with metastatic pancreatic adenocarcinoma and 1-3 lines of prior therapy (cohort A), unresectable glioblastoma and 1 prior line of therapy (cohort B), recurrent or metastatic HNSCC that progressed on a platinum-based chemotherapy and PD-(L)1 inhibitor (cohort C), or recurrent or metastatic gastric or gastroesophageal junction adenocarcinoma that progressed on ≥2 prior chemotherapy regimens (cohort I). Pts in cohorts A, B, and I had not previously received a PD-(L)1 inhibitor. All pts received MK-4830 800 mg + pembro 200 mg Q3W for 35 cycles or until PD, unacceptable toxicity, or study withdrawal. Primary objectives were to evaluate safety and ORR per RECIST v1.1 (cohorts A, C, and I) or Response Assessment in Neuro-Oncology (RANO) criteria (cohort B) by investigator assessment. Exploratory objectives included evaluating DOR and PFS per RECIST v1.1 (cohorts A, C, and I) or RANO criteria (cohort B) by investigator assessment. Results: At data cut-off (September 27, 2023), 33 pts were enrolled and received treatment in cohort A, 20 pts in cohort B, 35 pts in cohort C, and 35 pts in cohort I. Median follow-up duration was 38.4 mo (range, 35.5-39.9) in cohort A, 34.1 mo (32.3-36.2) in cohort B, 37.5 mo (33.4-42.1) in cohort C, and 29.5 mo (22.3-36.4) in cohort I. Treatment-related adverse events (TRAEs) occurred in 15 pts (45%) in cohort A, 13 pts (65%) in cohort B, 19 pts (54%) in cohort C, and 16 pts (46%) in cohort I; grade 3 or 4 TRAEs occurred in 3 pts (9%), 0 pts, 2 pts (6%), and 4 pts (11%), respectively. No deaths due to TRAEs occurred. ORR was 6% (95% CI, 1-20) in cohort A, 5% (0-25) in cohort B, 0% (0-10) in cohort C, and 20% (8-37) in cohort I. Median DOR was 14.3 mo (range, 14.0-14.7) in cohort A, 7.4 mo (7.4-7.4) in cohort B, and 9.6 mo (3.0-27.6+) in cohort I. Median PFS was 1.9 mo (95% CI, 1.6-2.0) in cohort A, 1.2 mo (1.1-1.4) in cohort B, 2.2 mo (1.9-4.1) in cohort C, and 1.4 mo (1.3-3.0) in cohort I. Conclusions: In pts with select previously treated advanced or metastatic solid tumors, MK-4830 + pembro had a manageable AE profile but no significant antitumor activity beyond that historically observed with pembro monotherapy. Other treatment options must be explored for these difficult-to-treat tumors. Citation Format: Lillian L. Siu, Marta Gil-Martin, Byoung Chul Cho, Ruth Perets, John Hilton, Ravit Geva, Iwona Lugowska, Martin Gutierrez, Marcelo Bonomi, Rafal Dziadziuszko, Drew Rasco, Eytan Ben-Ami, Cristina P. Rodriguez, Shabana Siddiqi, Nicole Myer, Leah Suttner, Douglas Wilson, Ombololaji O. Akala, Maria de Miguel. Results from a phase 1 study of the anti-immunoglobulin-like transcript 4 (ILT4) monoclonal antibody MK-4830 plus pembrolizumab in patients with previously treated advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT104.

Abstract 5939: Enhancing nab-paclitaxel chemotherapy response in gastric cancer preclinical models through Inhibition of the HGF/c-Met pathway with merestinib

Abstract Background: Current treatments for primary metastatic or recurrent gastric adenocarcinoma (GAC) primarily involve combination chemotherapy, but the median survival time remains under a year. Nab-paclitaxel has displayed significant antitumor activity in preclinical GAC studies. GAC often exhibits overexpression of various growth factors and their receptors, which play a critical role in its pathophysiology. Aberrant activation of the HGF/c-Met pathway has been reported in up to 50% of GAC patients. We investigated the therapeutic potential of merestinib, a novel inhibitor targeting c-Met, along with Axl and DDR1/2 pathways, in combination with nab-paclitaxel in GAC preclinical models. Methods: Animal survival studies were conducted using peritoneal dissemination xenografts in NOD/SCID mice implanted with MKN-45 cells. Tumor growth was assessed in subcutaneous xenografts using MKN-45 and SNU-1 cells in NOD/SCID mice. IHC analyses were performed to evaluate tumor cell proliferation and microvessel density. In vitro cell proliferation and protein expression were assessed using the WST-1 assay and Western blot analysis, respectively. Results: Animal survival significantly improved with nab-paclitaxel (118%) and merestinib (41%) individually. The combination of merestinib with nab-paclitaxel (153%) resulted in further increased animal survival. In MKN-45 xenografts with high c-Met expression, a substantial reduction in tumor growth was observed with nab-paclitaxel and merestinib, showing a synergistic response. The net change in tumor size in the control, nab-paclitaxel, merestinib, and combination groups was 503 mm3, 115 mm3, 91 mm3, and -9.7 mm3 (tumor regression). In low c-Met expressing SNU-1 xenografts, the effect of merestinib and nab-paclitaxel was less pronounced compared to MKN-45 xenografts. The net change in tumor size in the control, nab-paclitaxel, merestinib, and combination groups was 219 mm3, 105 mm3, 131 mm3, and 57 mm3. Tumor cell proliferation and microvessel density corroborated the tumor growth study results. Nab-paclitaxel and merestinib reduced in vitro cell proliferation, with an additive effect in combination. The reduction in cell proliferation by nab-paclitaxel (10 nM), merestinib (100 nM), and their combination was 87%, 82%, and 94% in MKN-45, 59%, 50%, and 82% in SNU-1, and 53%, 19%, and 66% in gastric fibroblasts. In MKN-45 cells, merestinib increased the expression of pro-apoptotic proteins and decreased the expression of phospho-c-Met, phospho-EGFR, phospho-IGF-1R, phospho-ERK, and phospho-AKT. Conclusion:Merestinib has strong antitumor activity in GAC, especially when administered with nab-paclitaxel, demonstrating a synergistic effect. These results provide compelling evidence for the potential clinical relevance of this combination therapy in improving the survival of GAC patients. Citation Format: Quinn Kaurich, Jennifer Huang, Sazzad Hassan, Urs von Holzen, Niranjan Awasthi. Enhancing nab-paclitaxel chemotherapy response in gastric cancer preclinical models through Inhibition of the HGF/c-Met pathway with merestinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5939.

Long-term treatment outcomes in gastric cancer with oligometastasis.

While surgery is essential for curative treatment of gastric cancer with oligometastasis, its target, timing, and possibility of combination with other treatments are unclear. We herein investigated the clinical course and long-term outcomes of gastric cancer with oligometastasis in the real world setting to determine the optimal therapeutic strategy. The present study retrospectively analyzed 992 patients who received any treatment for metastatic or recurrent gastric adenocarcinoma at Tokyo Metropolitan Komagome Hospital between 2007 and 2019. Oligometastasis was defined as any one of the following: liver metastases (HEP) <3; lung metastases (PUL) <3; unilateral adrenal gland metastasis (ADR); para-aortic lymph node metastasis (PALN); or one, distant, lymph node metastasis, excluding the regional lymph nodes (LYM). Overall survival was compared by the characteristics and treatments for the oligometastasis, and univariate and multivariate analyses were used to identify the prognostic factors of overall survival. Ninety-seven patients (9.8%) with the following metastasis sites were enrolled: HEP (n = 27), PUL (n = 2), ADR (n = 3), PALN (n = 55), and LYM (n = 10). The median survival time of the cohort was 22.8 months, and the five-year overall survival rate was 28.4%. On multivariate analysis, chemotherapy for the initial treatment (hazard ratio [HR]: 0.438; p = 0.048), distal gastrectomy and/or metastasectomy (HR: 0.290; p = 0.001), and R0 resection (HR: 0.373; p = 0.005) were identified as independent, positive factors of overall survival. The long-term outcomes of gastric cancer in patients with oligometastasis may improve if treatment is begun with chemotherapy rather than surgery.

Randomised phase II trial of trifluridine/tipiracil (FTD/TPI) plus ramucirumab (RAM) versus trifluridine/tipiracil for previously treated patients with advanced gastric or esophagogastric junction adenocarcinoma (RETRIEVE study, WJOG15822G)

BackgroundTrifluridine/tipiracil (FTD/TPI) prolongs survival in the third- or later-line treatment for advanced gastric cancer (GC), esophagogastric junction (EGJ) adenocarcinoma, and colorectal cancer. While single-arm phase II trials showed promising outcomes of FTD/TPI plus ramucirumab (RAM) as third- or later-line treatments for advanced GC or EGJ cancer, there have been no clinical trials to directly compare FTD/TPI plus RAM with FTD/TPI monotherapy. Therefore, we have started a randomised phase II trial to evaluate the efficacy and safety of FTD/TPI plus RAM compared with FTD/TPI monotherapy as third- or later-line treatments in patients with advanced GC and EGJ adenocarcinoma.MethodsThis RETREVE trial (WJOG15822G) is a prospective, open-label, randomised, multicentre phase II trial comparing FTD/TPI plus RAM versus FTD/TPI monotherapy in a third- or later-line setting. Eligibility criteria include age of > 20 years; performance status of 0 or 1; unresectable or recurrent gastric or EGJ adenocarcinoma; confirmed HER2 status; refractory or intolerant to fluoropyrimidine, taxane or irinotecan; refractory to RAM (not intolerant); and at least a measurable lesion per RECIST 1.1. FTD/TPI (35 mg/m2 twice daily, evening of day 1 to morning of day 6 and evening of day 8 to morning of day 13) was administered orally every 4 weeks, and RAM (8 mg/kg) was administered intravenously every 2 weeks. The primary endpoint is progression-free survival (PFS), and the secondary endpoints are overall survival, objective response rate, disease control rate, and safety. The expected hazard ratio of PFS is set as 0.7, assuming 4-month PFS rate of 27% in FTD/TPI monotherapy and 40% in FTD/TPI plus RAM. The number of subjects was 110, with a one-sided alpha error of 0.10 and power of 0.70.DiscussionThis study will clarify the additional effect of RAM continuation beyond disease progression on FTD/TPI in the third- or later-line setting for patients with advanced GC or EGJ cancer.Trial registrationjRCTs041220120.

First-line envafolimab plus SOX chemotherapy for PD-L1 positive metastatic or recurrent gastric adenocarcinoma: A multi-centre, single-arm phase II clinical trial.

e16029 Background: Clinical evidence for PD-L1 positive metastatic or recurrent gastric adenocarcinoma patients were relatively limited in clinic, which limited the development of evidence-based medicine for these patients. Immune checkpoint inhibitor (ICI) therapy has been established as the standard treatment for advanced gastric carcinoma patients recently. Envafolimab is the first approved subcutaneous single-domain PD-L1 antibody, which has been commercialized in China for the treatment of MSI-H/dMMR advanced solid tumors. This study aimed to investigate the efficacy and safety of Envafolimab plus SOX chemotherapy for metastatic or recurrent gastric adenocarcinoma, aiming to provide further reference for clinical rational drug use for this population. Methods: This multi-centre, single-arm, open-label study was conducted to evaluate the efficacy and safety of Envafolimab in metastatic or recurrent gastric adenocarcinoma. A total of 38 patients with histologically confirmed advanced gastric adenocarcinoma were enrolled. Patients will receive Envafolimab (300 mg, s.c., day 1) plus chemotherapy (oxaliplatin 130 mg/m2, i.v., day 1, and S-1 40mg, BSA＜1.25 m2、50mg 1.25 m2＜BSA＜1.5 m2、60 mg BSA＞1.5m2, p.o., twice daily, days 1-14) every 3 weeks for 6 cycles, followed by maintenance treatment with Envafolimab plus S-1 until disease progression (PD), unacceptable toxicity, or patient refusal. Eligible patients must be histologically confirmed, advanced metastatic gastric adenocarcinoma or recurrent gastric adenocarcinoma after prior surgical treatment. Other key inclusion criteria were previously untreated, HER2-negative, PD-L1 positive (Combined Positive Score (CPS)≥1), ECOG performance status of 0 or 1, and adequate organ function. Patients with any prior ICI therapy, abnormal AFP elevation, or microsatellite-instability-high (MSI-H) status will be excluded. The primary endpoint was objective response rate (ORR) based on the RECIST version 1.1, and the secondary endpoints were progression-free survival (PFS), overall survival (OS), etc. Adverse events were evaluated using the CTCAE v5.0 criteria. Results: Overall, thirteen patients were consecutively enrolled from March, 2022 to September 2022 and involved in this study. The median age was 62.7 years. At present, eight patients were included for efficacy analysis, and nine for safety evaluation. The ORR was 50%, and DCR was 87.5%, based on RECIST v1.1. Survival data are not mature at present. The most common TRAEs were elevated AST (75%), elevated ALT (65%) and leukopenia (42.5%). No treatment-related deaths occurred. Conclusions: Envafolimab plus chemotherapy is a promising and tolerable therapeutic regimen for patients with metastatic or recurrent gastric adenocarcinoma. Clinical trial information: NCT05237349 .

Efficacy and safety of IBI110 in combination with sintilimab in first-line advanced HER2-negative gastric cancer or gastroesophageal junction cancer: Updated results from a phase Ib study.

2576 Background: Sintilimab plus oxaliplatin and capecitabine (XELOX) has become the standard of care in patients (pts) with untreated advanced, recurrent, or metastatic gastric or gastroesophageal junction adenocarcinoma (G/GEJ AC) in China. Dual inhibition of PD-1 and lymphocyte-activation gene 3 (LAG-3) may further improve anti-tumor effect. The preliminary safety and efficacy data of IBI110 plus sintilimab and XELOX in pts with first-line G/GEJ AC were previously presented (Chenyu Mao et al. ASCO 2022). Here, we presented updated safety and efficacy results of this study. Methods: This phase Ib study enrolled patients with previously untreated, unresectable, locally advanced or recurrent/metastatic HER2-negative GC/GEJ AC. Pts received IBI110 200mg IV Q3W and sintilimab 200mg IV Q3W plus XELOX (oxaliplatin 130 mg/m2 Q3W and capecitabine 1000mg mg/m2/time twice daily [BID]) until disease progression, unacceptable toxicity or death. The primary objectives were to evaluate the safety, tolerability, and efficacy of the combination therapy per RECIST v1.1. Results: As of data cutoff January 9th 2023, 17 pts were assessed as evaluable (median age: 61 years; ECOG PS=1: 14 pts; all gastric cancer). All pts (17/17, 100%) experienced treatment-related adverse events (TRAEs) of any grade, and the most commonly TRAEs were neutrophil count decreased (64.7%), white blood cell count decreased (52.9%), platelet count decreased (52.9%). Grade ≥ 3 TRAEs occurred in 11 pts (64.7%), the most frequent grade ≥ 3 TRAEs were consistent with TRAEs of any grade. Investigator-assessed immune-mediated adverse events (irAEs) occurred in 10 pts (58.8%). Grade ≥ 3 irAEs occurred in 3 pts (17.6%), all led to discontinuation. No treatment-related death occurred. As data cutoff, among 17 efficacy-evaluable pts, the unconfirmed and confirmed objective response rate (ORR) were 88.2% (95% CI, 63.6-98.5) and 64.7% (95% CI, 38.3-85.8), respectively. The disease control rate (DCR) was 94.1% (95% CI, 71.3-99.9). With a median follow up of 13.1 months (95% CI, 7.1-NC), the median duration of response (DoR) and progression-free survival (PFS) were 11.6 months (95% CI, 2.5-14.4) and 12.9 months (95% CI, 3.8-15.8), respectively. The median overall survival (OS) was not reached, and the 12-months OS rate was 70.6% (95% CI, 43.1-86.6). Conclusions: IBI110 in combination with sintilimab and XELOX demonstrated manageable safety and encouraging efficacy results in patients with first-line gastric adenocarcinoma. This is the first positive trial to show clinical benefits of a LAG3 plus PD-1 inhibitor combined with chemotherapy for this population. Clinical trial information: NCT04085185 .

The Impact of Nutritional Support on Survival Outcomes in Patients with Advanced Gastric Adenocarcinoma Treated with Chemotherapy

Malnutrition and cachexia occur commonly in patients with advanced gastric cancer (AGC). This study elucidated the effect of nutritional support (NS) on survival outcomes among patients with AGC undergoing chemotherapy. We retrospectively evaluated new AGC cases at our institute between January 2015 and January 2021. Inclusion criteria were unresectable or recurrent chemotherapy-treated gastric adenocarcinoma, ECOG performance status (PS) 0–2, and adequate organ function. Time to treatment failure (TTF) and overall survival (OS) were evaluated, and univariate and multivariate analyses identified prognostic factors. A total of 103 eligible patients were separated into groups: 69 patients (67%) into NS and 34 (33%) into routine care (RC). The median follow-up time was 11.0 mo, (0.5–92). NS was offered to patients with poorer PS (p = 0.03), Glasgow prognostic score (GPS) positivity (p = 0.001), and high neutrophil-to-lymphocyte ratios (cut-off ≤ 3, p = 0.02). Median OS and TTF in the RC and NS groups were 11.6 and 10.4 mo, (p = 0.99) and 4.2 and 5.5 mo, (p = 0.07), respectively. Multivariate analyses identified NS (hazard ratio [HR] = 0.53, p = 0.01) and GPS positivity for TTF, and low body mass index (HR = 2.03, p = 0.007) and GPS positivity (HR = 2.25, p = 0.001) for OS as significant prognostic factors. Thus, NS with chemotherapy is a potentially effective intervention for AGC.

Abstract 5092: Predictive biomarkers for the efficacy of PD-1 inhibitors plus chemotherapy for gastric/gastroesophageal junction cancer in first-line setting

Abstract Background: Biomarkers that could predict the beneficial effects of immune checkpoint inhibitors (ICIs) in combination with chemotherapy in treatment-naive advanced or recurrent gastric or gastroesophageal junction (G/GEJ) adenocarcinoma patients are lacking. Methods: We conducted a retrospective analysis of patients with G/GEJ adenocarcinoma who had undergone first-line treatment with programmed death-1 (PD-1) inhibitor plus chemotherapy between October 2017 and July 2021. Comparative analysis of the objective response rate (ORR) was performed using the Chi-square or Fisher’s exact tests. Survival curves were plotted by the Kaplan-Meier analysis and compared for significance with a log-rank test. Univariate and multivariate Cox proportional hazard models were established for evaluating the prognostic value of clinicopathological factors. Results: Of the 172 enrolled patients, 142 showed measurable lesions. The ORR was 52.8%. Higher response rates were observed in patients with age greater than or equal to 60 (p = 0.013), non-diffuse type (p &amp;lt; 0.001), synchronous metastasis (p = 0.029), distant lymph node metastasis (p = 0.002), non-peritoneal metastasis (p= 0.002), HER2 positivity (p = 0.002), and PD-L1 CPS greater than or equal to 5 (p = 0.017). Through univariate analysis, age, histology, number of metastatic sites, and peritoneal metastasis were found to be associated with progression-free survival (PFS). Through multivariate analysis, peritoneal metastasis occurrence was the only identified independent indicator of poor PFS (HR 2.768, 95% CI 1.184-6.472, p = 0.019). Additionally, multi-factor combination results showed that patients with at least one of the following: mismatch repair-deficient (D-MMR)/microsatellite instability-high (MSI-H), HER2 (+), EBV (+), and/or PD-L1 CPS greater than or equal to 5, exhibited higher response rates and longer PFS as compared to those lacking these factors; this benefit was consistent after excluding PD-L1 expression. Among the clinical combinatorial factors, significantly poor ORRs and lower PFS were observed in patients with age &amp;lt; 60, diffuse type, and peritoneal metastasis as compared to those without any of these factors. Conclusions: Peritoneal metastasis was an independent biomarker of poor efficacy to immunotherapy combined with chemotherapy in G/GEJ cancer patients in first-line setting. Some combination factors could be beneficial for efficacy prediction. Citation Format: Yu-Ting Sun, Shi-Xun Lu, Ming-Yu Lai, Xia Yang, Wen-Long Guan, Li-Qiong Yang, Yu-Hong Li, Feng-Hua Wang, Rui-Hua Xu, Miao-Zhen Qiu. Predictive biomarkers for the efficacy of PD-1 inhibitors plus chemotherapy for gastric/gastroesophageal junction cancer in first-line setting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5092.

A multicenter randomized phase III study of albumin-bound paclitaxel combined with S-1 (AS) versus oxaliplatin combined with S-1 (SOX) for first-line treatment of advanced gastric cancer (GAPSO study).

282 Background: Albumin-bound paclitaxel has been proven to be an active agent in advanced gastric cancer, and was approved by PMDA Japan for use as a second-line treatment of advanced gastric cancer. The aim of this study was to evaluated the efficacy and safety of AS and SOX in the first-line treatment of advanced gastric cancer. Methods: Patients diagnosed with unresectable locally advanced, recurrent or metastatic human epidermal growth factor receptor type 2 (HER2)-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma were randomized (1:1) to either AS group (albumin-bound paclitaxel 260mg/m2 d1 or 130mg/m2 d1, 8; S-1 40 mg [BSA &lt; 1.25 m2], 50 mg [1.25 ≤ BSA &lt; 1.50 m2] and 60 mg [BSA ≥1.50 m2] b.i.d. d1-14, every 3wks) or SOX group (oxaliplatin 130mg/m2 d1; S-1 40 mg [BSA &lt; 1.25 m2], 50 mg [1.25 ≤ BSA &lt; 1.50 m2] and 60 mg [BSA ≥1.50 m2] b.i.d. d1-14, every 3wks). Primary endpoint was progression-free survival (PFS), secondary endpoints included overall survival (OS), objective response rate (ORR) and safety. Results: Between March 2019 and March 2021, 96 patients were enrolled and 85 patients (AS group, n = 43; SOX group, n = 42) who received at least one dose of study drug and had at least one postbaseline efficacy evaluation were included in the final analysis. 34 (79.0%) patients in the AS group and 35 (83.3%) in the SOX group had discontinued treatment. Of these 85 patients, 78.8% had two or more organs involved, 61.2% had peritoneal dissemination, and more than 1/4 had massive ascites. Patient demographics and disease characteristics were generally balanced between arms. With median follow-up 15.4 months (95% CI, 8.8-21.9), the median PFS of AS group vs. SOX group was 9.2 vs.5.1 months (HR = 0.58 [95% CI 0.36-0.96], p = 0.034); and the median OS was 14.4 vs. 15.4 months (HR = 0.73 [95%CI 0.40-1.34], p = 0.375). Tumor response was assessable in 33 patients according to RECIST V1.1 in both cohorts, the ORR and DCR were similar in AS vs. SOX arm (ORR: 54.5% vs. 51.5%, P = 0.805; DCR: 78.8% vs. 78.8%, P = 1.000). The main grade 3 or worse treatment-related adverse events were neutropenia (30.2% vs 23.8%), Leucopenia (11.6% vs 11.9%) and peripheral sensory neuropathy (4.7% vs 7.1%) in AS and SOX group. The study was planned to be adjusted, due to the widespread use of immunotherapy in first-line treatment of gastric cancer. Conclusions: The results of this study indicated that in previously untreated patients with unresectable locally advanced, recurrent or metastatic HER2-negative gastric or GEJ adenocarcinoma, AS achieved better PFS than SOX, with an inadequate power. The toxicities were controllable and consistent with previously reported. Clinical trial information: NCT03801668.

Comparison of 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT in the staging and restaging of gastric adenocarcinoma.

In this study, we aimed to evaluate the diagnostic sensitivities of 68Ga-FAPI-04 PET/CT and 18F-FDG PET/CT in the primary tumor, and nodal, peritoneal and distant organ metastases of primary and recurrent gastric adenocarcinoma (GAc) with patient and lesion-based comparison. Twenty-one patients with histopathologically proven newly diagnosed or recurrent GAc who underwent 18F-FDG and 68Ga-FAPI-04 imaging were included in the study. Both imaging techniques were evaluated visually according to the intensity of organ-based uptake. SUVmax and tumor-to-background ratio (TBR) values obtained from primary tumor/relapse and metastatic organs were compared statistically. 68Ga-FAPI-04 uptake was positive in all 15 newly diagnosed patients, while two patients among them who had mucinous and signet ring cell carcinoma did not exhibit 18F-FDG uptake. The sensitivity and specificity of 68Ga-FAPI-04 PET/CT in detecting primary gastric were 100%, while the sensitivity and specificity of 18F-FDG were 86.6 and 100%, respectively. 68Ga-FAPI-04 imaging revealed diffuse stomach uptake in seven patients, while 18F-FDG could only show two of them. The sensitivity and specificity of in-patient-based detection of lymph node metastases were 100 and 95.2%, respectively, while these values were 71.4 and 93.7%, respectively, for 18F-FDG. For peritoneal involvement 68Ga-FAPI-04 had a sensitivity and specificity of 100%, whereas 18F-FDG had a sensitivity of 40% and a specificity of 100%. 68Ga-FAPI-04 PET/CT is an imaging modality with the potential of yielding more sensitive and specific findings 18F-FDG PET/CT. This modality may help avoid invasive diagnostic procedures that may be frequently required in GAc.

Abstract 1043: Enhancing cytotoxic chemotherapy effects by nintedanib in gastric cancer preclinical models

Abstract Background: Gastric adenocarcinoma (GAC) remains the 3rd most common cause of cancer mortality in the world. Systemic chemotherapy is a preferred treatment option for advanced and recurrent GAC, but response rates and survival extension remain limited. Tumor angiogenesis plays a critical role in GAC growth, invasion and metastasis. In this study, we determined the antitumor efficacy of nintedanib, a potent triple angiokinase inhibitor for VEGFR-1/2/3, PDGFR-α/β and FGFR-1/2/3, alone or in combination with chemotherapy, in preclinical models of GAC. Methods: Animal survival and tumor growth studies were performed in 4-6 week-old female NOD/SCID mice with human GAC cell xenografts (MKN-45, KATO-III, SNU-5). The mechanistic evaluation involved Immunohistochemistry and Immunoblot analyses of subcutaneous tumors. In vitro cell viability assays were performed using colorimetric WST-1 reagent. Results: In MKN-45 cell-derived peritoneal dissemination xenografts, animal survival was improved by nintedanib (33%), docetaxel (100%) or irinotecan (181%), while oxaliplatin, 5-FU and epirubicin had no effect. The addition of nintedanib to docetaxel (157%) or irinotecan (214%) led to a further extension in animal survival. In KATO-III cell-derived xenografts carrying FGFR2 gene amplification, nintedanib monotherapy extended survival much more (209%). Docetaxel and irinotecan effects were again further enhanced by nintedanib. In MKN-45 subcutaneous xenografts, nintedanib, epirubicin, docetaxel or irinotecan reduced tumor growth (range: 68-87%), while 5-FU and oxaliplatin had a smaller effect (40%). The addition of nintedanib to all chemotherapy groups demonstrated a further reduction in tumor growth. Subcutaneous tumor analysis revealed that nintedanib attenuated tumor cell proliferation, reduced tumor vasculature and increased tumor cell death. Nintedanib (10 μM) inhibited in vitro cell proliferation of mutationally different GAC cells by 25% (MKN-45), 75% (KATO-III) or 82% (SNU-5), and confirmed additive inhibitory effects in combinations with chemotherapy agents. Conclusion: Nintedanib showed notable antitumor efficacy and significantly improved taxane or irinotecan chemotherapy responses. Combination regimens with nintedanib have the potential for improving clinical GAC therapy. Citation Format: Niranjan Awasthi, Margaret A. Schwarz, Frank Hilberg, Roderich E. Schwarz. Enhancing cytotoxic chemotherapy effects by nintedanib in gastric cancer preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1043.

P-56 A multicenter prospective translational study using circulating tumor DNA to identify acquired genomic alterations in recurrent gastric or gastroesophageal junction adenocarcinoma in patients who received curative-intent treatment (Liquid-GEAR)

For many patients with cancer recurrence after curative-intent therapy for early stage disease, genomic testing of the archived primary tumor sample is performed because tissue biopsy of recurrent lesions may be technically difficult or pose unacceptable risks. However, the molecular profile of cancer at the time of recurrence may have evolved since the original diagnosis. Evaluation of circulating tumor DNA (ctDNA) in patients with recurrent cancers may overcome the technical challenges of tissue biopsy and provide novel findings regarding the mechanism of recurrence and information to guide treatment decisions.

Camrelizumab combined with SOX regimen in the first-line treatment of unresectable advanced or recurrent gastric cancer: A single-arm, prospective, open clinical study.

e16017 Camrelizumab combined with SOX regimen in the first-line treatment of unresectable advanced or recurrent gastric cancer£ºA single-arm, prospective, open clinical study. Background: Gastric cancer is one of the most common malignant tumors of the digestive system. In China, 80% of patients with gastric cancer are already in advanced or locally advanced stage at the time of detection. Even after receiving radical gastrectomy, more than half of patients will have local recurrence or distant metastasis, and the 5-year survival rate of patients with gastric cancer with metastasis is less than 10%.In recent years, more and more evidence supports the application of immune checkpoint inhibitors in advanced gastric cancer.In 2020, PD-1 was approved for advanced gastric cancer receiving second-line or above treatment in China, which is an affirming of the efficacy of PD-1 in the clinical treatment of gastric cancer. Immunotherapy combined with conventional chemotherapy, this study aims to explore the efficacy and safety of PD1 combined with chemotherapy in the treatment of first-line gastric cancer. Methods: This was a single center, prospective clinical study conducted at the Affiliated Hospital of Xuzhou Medical University, Jiangsu Province.Patients with newly treated unresectable advanced or recurrent gastric or gastroesophageal junction adenocarcinoma were enrolled.All enrolled subjects were treated with camrelizumab combined with SOX regimen every 3 weeks.The primary endpoint was progression-free survival (PFS).Secondary endpoints were overall survival (OS), objective response rate (ORR), disease control rate (DCR), and safety.This study was registered at Chictr.org.cn with the number Chictr2000029691. Results: The study plans to enroll 30 patients, and 16 patients have been included in the study from March 2020 to December 2020. Among them, 7 patients can be evaluated, 14 males, 2 females, ECOG score 0 or 1. Of the 7 patients who can be evaluated for efficacy, 1 achieved PR and 5 achieved SD, ORR was 14.29%, and DCR was 85.71 %. This is the early stage of data analysis, PFS has not yet reached, and the side effects are mild, mainly with grade 1 adverse reactions. The most common AEs are neutropenia (3/7) and decreased appetite (2/7). There were no treatment-related deaths. Conclusions: This study provides preliminary evidence for the first-line treatment of unresectable advanced or recurrent gastric or gastroesophageal junction adenocarcinoma with camrelizumab combined with chemotherapy. The current number of enrolled cases is small, but the preliminary effect of immunotherapy combined with chemotherapy in first-line patients with advanced gastric cancer can still be seen. This trial will further explore the clinical efficacy and safety of immunotherapy in the first-line gastric cancer. Clinical trial information: ChiCTR2000029691.

Trastuzumab ± Capecitabine Maintenance After the First-Line Treatment of HER2-Positive Advanced Gastric Cancer: Retrospective Observational Real-Life Data of Turkish Oncology Group.

In the ToGA trial for HER2-positive advanced gastric cancer, cisplatin plus fluoropyrimidine was given for 6 cycles; trastuzumab was given until disease progression. However, there is a lack of real-life data about trastuzumab maintenance after 6 cycle chemotherapy. This study aims to present real-life data of trastuzumab ± capecitabine maintenance after 6 cycles of platinum, fluoropyrimidine, and trastuzumab in non-progressive patients. This is a retrospective multicenter study of the Turkish Oncology Group. A total of 35 HER2-positive, inoperable locally advanced, recurrent, or metastatic gastric adenocarcinoma patients being non-progressive at the end of 6 cycle chemotherapy and being given trastuzumab ± capecitabine as maintenance treatment were included from sixteen oncology centers. Baseline characteristics, objective tumor responses, progression free and overall survival data, and toxicities were determined. About 68% of the patients were given CF, and 32% were given FOLFOX with trastuzumab as the first-line treatment. The best response in 6 cycle chemotherapy was complete 8 (22%), partial 24 (68%), and stable disease 3 (8%). All patients had trastuzumab maintenance (median cycle 13; range 7-51), and 49% of the patients had capecitabine with trastuzumab (median capecitabine cycle 6; range 2-30). The median PFS of the patients was 12.0months (95% CI 10.3-13.7), and median OS was 17.4months (95% CI 15.2-19.5). There were 2 patients with grade 1 cardiotoxicity. Trastuzumab maintenance ± capecitabine after 6 cycles of trastuzumab plus combined chemotherapy treatment revealed efficacy and safety in non-progressive HER2-positive advanced gastric cancer.

Phase II study of cabozantinib (cabo) combined with pembrolizumab (pembro) in metastatic or recurrent gastric and gastroesophageal adenocarcinoma (GEC) to overcome resistance to checkpoint inhibitors.

TPS253 Background: GEC is the third leading cause of cancer mortality and the fifth most common malignancy worldwide. Fluoropyrimidine and platinum-based combinations are the most commonly used 1L treatment regimens. There are few standard treatment options after 1st line regimens. In the 3L+ GEC Keynote-059 trial, objective response rate (ORR) with Pembro was 15.5% in PD-L1(+) vs. 6.4% in PD-L1(-) tumors. While the responses were durable, the 6-months PFS (6-PFS) was only 14.1% and the median PFS was 2.0 mo. This highlights the remaining unmet need for the majority of patients who either are refractory or develop disease progression following treatment with PD-1 inhibitors in GEC. Cabo plus checkpoint inhibitors have shown clinical benefit in various cancers including hepatocellular, renal cell (RCC), urothelial and castration-resistant prostate cancers. In the CheckMate-9ER trial, Cabo+Nivolumab improved both OS and PFS vs sunitinib in 1L RCC. In patients with RCC who had progression on anti-PD1 inhibitor treatment, Cabo showed promising activity with an ORR of 33% and DCR of 79% (ESMO 2018, abstract 3793). Hypothesis: Based on preclinical and clinical observations, Cabo might contribute to overcoming primary or secondary resistance to PD-1 blockade in GEC. Methods: Prospective, open label, non-randomized phase 2 trial. Eligibility: Diagnosis of GEC, 2+ line of treatment including previous fluoropyrimidine/platinum, ECOG 0-2, adequate organ function, prior checkpoint inhibitor if tumor PD-L1 CPS≥10%. Treatment: Cabozantinib 40mg PO daily, Pembrolizumab 200 mg IV on day 1 of 21d cycle. Primary objective: Feasibility of the combination and estimate of efficacy. Primary endpoint:PFS-6. Secondary objectives: OS, ORR, adverse events. Total number of patients to be enrolled N = 27. Current enrollment (Sep 2020) N = 10. Statistics: If the PFS-6 is &gt; 25%, the study would be regarded as positive, in which case it is planned to expand patient enrollment into a larger single arm phase 2 trial with additional sites to establish the efficacy of the regimen. Clinical trial information: NCT04164979.

A phase Ib multicenter study of trifluridine/tipiracil (FTD/TPI) in combination with irinotecan (IRI) in patients with advanced recurrent or unresectable gastric and gastroesophageal adenocarcinoma (aGEC) after at least one line of treatment with a fluoropyrimidine and platinum containing regimen.

TPS251 Background: In 2L+ aGEC, taxanes +/- ramucirumab or IRI are recommended treatment options. IRI has been tested in multiple single arm and randomized trials in second line (2L)+ aGEC, with reported objective response rates (ORR) in the 15-29% range and median progression-free survival (PFS) of &lt;3 months (mo). Outcomes for aGEC remain poor with a median overall survival (OS) of 9.6 mo and PFS at 6 mo (PFS6) of only 36%. The TAGS trial in third line (3L)+ aGEC showed a significant improvement in OS from 3.6 mo to 5.7 mo with FTD/TPI over placebo. A 2L treatment with taxanes after 1L platinum containing regimens is currently associated with worsening peripheral neuropathy, which often leads to dose reductions, treatment delays, and a reduced quality of life for patients. The feasibility of FTD/TPI combined with IRI (+/- bevacizumab) in a modified 14-day schedule has been published for advanced colon cancer (PMID: 31924737) with no new safety signals while also encouraging activity in a cohort of heavily pretreated patients. Methods: Hypothesis:The combination of FTD/TPI with IRI in 2L+ aGEC is feasible, clinically active, and provides a treatment option which is not associated with development of peripheral neuropathy. Trial Design: 2-center, prospective, open label, non-randomized phase 1b trial. Eligibility: Diagnosis of aGEC, 1+ line of treatment including a fluoropyrimidine/platinum, ECOG 0-2, adequate organ function. Treatment:FTD/TPI 25mg/m2 on days 1-5 and IRI 180mg/m2 on day 1 every 14 days. G-CSF in allowed as needed. Primary objective: Feasibility of the regimen and estimate of efficacy. Primary endpoint: PFS6. Secondary objectives: OS, ORR, adverse events. Total number of pts to be enrolled N=20. Current enrollment (September 2020) N=14. Clinical trial information: NCT04074343.

Performances of Prognostic Models in Stratifying Patients with Advanced Gastric Cancer Receiving First-line Chemotherapy: a Validation Study in a Chinese Cohort.

PurposeWhile several prognostic models for the stratification of death risk have been developed for patients with advanced gastric cancer receiving first-line chemotherapy, they have seldom been tested in the Chinese population. This study investigated the performance of these models and identified the optimal tools for Chinese patients.Materials and MethodsPatients diagnosed with metastatic or recurrent gastric adenocarcinoma who received first-line chemotherapy were eligible for inclusion in the validation cohort. Their clinical data and survival outcomes were retrieved and documented. Time-dependent receiver operating characteristic (ROC) and calibration curves were used to evaluate the predictive ability of the models. Kaplan-Meier curves were plotted for patients in different risk groups divided by 7 published stratification tools. Log-rank tests with pairwise comparisons were used to compare survival differences.ResultsThe analysis included a total of 346 patients with metastatic or recurrent disease. The median overall survival time was 11.9 months. The patients were different into different risk groups according to the prognostic stratification models, which showed variability in distinguishing mortality risk in these patients. The model proposed by Kim et al. showed relative higher predicting abilities compared to the other models, with the highest χ2 (25.8) value in log-rank tests across subgroups, and areas under the curve values at 6, 12, and 24 months of 0.65 (95% confidence interval [CI]: 0.59–0.72), 0.60 (0.54–0.65), and 0.63 (0.56–0.69), respectively.ConclusionsAmong existing prognostic tools, the models constructed by Kim et al., which incorporated performance status score, neutrophil-to-lymphocyte ratio, alkaline phosphatase, albumin, and tumor differentiation, were more effective in stratifying Chinese patients with gastric cancer receiving first-line chemotherapy.

Combination of trastuzumab and taxane-containing intensified chemotherapy in first-line treatment of HER2-positive advanced gastric cancer.

Taxane-containing combinations are recommended for the first-line therapy of advanced gastric cancer. It is not known which chemotherapy regimen is the best with trastuzumab for HER2-positive patients. The aim of this study was to compare taxane-containing intensified chemotherapy versus standard chemotherapy in combination with trastuzumab in the first-line treatment of HER2-positive advanced gastric adenocarcinoma. This study is a retrospective multicenter study of the Turkish Oncology Group. A total of 130 HER2-positive patients with inoperable locally advanced, recurrent, or metastatic gastric adenocarcinoma being given chemotherapy plus trastuzumab as the first-line treatment were included from 16 different oncology centers. Trastuzumab combination with intensified chemotherapy including taxane or standard chemotherapy was compared in terms of progression-free survival (PFS), overall survival (OS), and toxicity. There were 108 patients in the standard and 22 patients in the intensified chemotherapy group. PFS of the standard and intensified group were 5.6 months (95% confidence interval [CI] 4.8-6.4) and 5.3 months (95% CI 2.6-8), respectively (p = 0.70). OS of the standard and intensified group were 11.1 months (95% CI 8.3-13.9) and 15.2 months (95% CI 12.7-17.7), respectively (p = 0.03). Repeated analysis excluding patients given any previous therapy revealed similar results. The intensified group had more fever and febrile neutropenia. Trastuzumab combination with intensified chemotherapy provides better OS in first-line treatment of HER2-positive advanced gastric cancer. Further large-scale studies should be performed in HER2-positive patients.