Therapy For Metastatic Cancer Research Articles

465P Timing of first-line palliative systemic therapy in metastatic Esophagogastric cancer (mEGC): A European Delphi study

465P Timing of first-line palliative systemic therapy in metastatic Esophagogastric cancer (mEGC): A European Delphi study

Phase I study of GUCY2C CAR-T therapy IM96 in patients with metastatic colorectal cancer.

2518 Background: The clinical outcomes of metastatic colorectal cancer (mCRC) therapies are limited, especially for liver metastasis. Guanylyl cyclase 2C (GUCY2C) is ectopically expressed in all stages of CRC and intestinally restricted. GUCY2C-targeted CAR-T (IM96) was developed and phase I study was conducted to evaluate the safety and efficacy (NCT05287165). Methods: In this open-label, 3+3 dose-escalation study, IM96 was evaluated in GUCY2C-positive mCRC patients (pts) failed to ≥3 lines of therapies. Pts were pre-treated with fludarabine and cyclophosphamide, and received a single infusion of IM96 at the dose of 3×108 (DL1), 6×108 (DL2), 12×108 (DL3), or 20×108 (DL4) CAR-T cells. Dose-expansion study was performed at DL3. The primary objectives were safety and toxicity, and the secondary objectives were efficacy and pharmacokinetic profile. Results: As of December 2023, 20 pts were enrolled and infused with IM96. The follow-up time was 7-19 months for all pts. The median age was 52.5, and 11/20 cases were male. Liver metastasis was found in 11/20 cases (55%), proficient mismatch repair (pMMR) in 20/20 pts (100%), KRAS mutation in 12/20 pts (60.0%), NRAS mutation in 1/20 pts (5.0%), and BRAF mutation in 3/20 pts (15.0%). Bridging therapies were used in 19 pts. Only 1/20 pt (5.0%) showed neurotoxicity and ≥grade 3 cytokine release syndromes (CRS). Grade 1-2 CRS occurred in 16/20 pts (80.0%) with dramatic increase of interleukin-6. Grade 1-3 rash was observed in 14/20 pts (70.0%). Grade 3 diarrhea occurred in 11/20 pts (55.0%), and grade 1-3 oral mucositis appeared in 7/20 pts (35.0%), only in DL2, DL3 and DL4 groups. Dose-limiting toxicity and maximum tolerated dose were not achieved. Among 19 evaluable pts, the disease control rate (DCR) was 73.7%, and the objective response rate (ORR) was 26.3%. In DL3 group, pts showed an ORR of 40.0%, nevertheless of liver metastasis or not. The median progression-free survival time was 7 months, and the median duration of response was 10 months in DL3 group. No responding pts showed disease progression within 6 months. Tumor responses were correlated with significant decreases in carcinoembryonic antigen levels among all pts. Conclusions: This study demonstrated that IM96 has durable efficacy with acceptable safety profile in pMMR mCRC pts, in particularly, showing high therapeutic potential in liver metastasis pts. Clinical trial information: NCT05287165 .

Disease Control and Toxicity Outcomes after Stereotactic Ablative Radiation Therapy for Recurrent and/or Metastatic Cancers in Young-Adult and Pediatric Patients.

Pediatric patients with metastatic and/or recurrent solid tumors have poor survival outcomes despite standard-of-care systemic therapy. Stereotactic ablative radiation therapy (SABR) may improve tumor control. We report the outcomes with the use of SABR in our pediatric solid tumor population. This was a single-institutional study in patients < 30 years treated with SABR. The primary endpoint was local control (LC), while the secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity. The survival analysis was performed using Kaplan-Meier estimates in R v4.2.3. In total, 48 patients receiving 135 SABR courses were included. The median age was 15.6 years (interquartile range, IQR 14-23 y) and the median follow-up was 18.1 months (IQR: 7.7-29.1). The median SABR dose was 30 Gy (IQR 25-35 Gy). The most common primary histologies were Ewing sarcoma (25%), rhabdomyosarcoma (17%), osteosarcoma (13%), and central nervous system (CNS) gliomas (13%). Furthermore, 57% of patients had oligometastatic disease (≤5 lesions) at the time of SABR. The one-year LC, PFS, and OS rates were 94%, 22%, and 70%, respectively. No grade 4 or higher toxicities were observed, while the rates of any grade 1, 2, and 3 toxicities were 11.8%, 3.7%, and 4.4%, respectively. Patients with oligometastatic disease, lung, or brain metastases and those who underwent surgery for a metastatic site had a significantly longer PFS. LC at 1-year was significantly higher for patients with a sarcoma histology (95.7% vs. 86.5%, p = 0.01) and for those who received a biological equivalent dose (BED10) > 48 Gy (100% vs. 91.2%, p = 0.001). SABR is well tolerated in pediatric patients with 1-year local failure and OS rates of <10% and 70%, respectively. Future studies evaluating SABR in combination with systemic therapy are needed to address progression outside of the irradiated field.

Abstract B011: Predictable successes: drug additivity explains the efficacy of combination therapies for metastatic urothelial cancer

Abstract Objective: Combination drug regimens have changed the treatment landscape of metastatic urothelial cancer (mUC) and other cancers and are integrated into routine clinical practice. Combination drug regimens may impact cancer outcomes via three major pharmacologic principles: less-than-additive, additive, or more-than-additive efficacy (i.e., synergy). Despite the profound implications of these types of interactions on future drug and biomarker development, as well as on treatment sequencing, these principles have been underexplored in contemporary clinical trials. Here we analyze recent phase 3 trials in locally advanced or metastatic UC to assess whether progression-free survival (PFS) distributions of combination therapies with immune checkpoint inhibitors (ICIs) are lesser than, greater than, or equal to the additive effect expected based on single-agent efficacies. Methods: We analyzed phase 3 trials in locally advanced or metastatic UC including EV302, CheckMate 901, KEYNOTE-361, DANUBE, and IMvigor130. When one monotherapy was not included as an arm in the phase 3 trial, we utilized monotherapy PFS distributions from trials in patients with metastatic UC including EV103, KEYNOTE-045, CheckMate 275, and HCRN-GU17-294. The expected additive effect of a drug combination was calculated by adding the PFS durations of individual drugs, sampled from monotherapy distributions, as recently described for other approved oncology drug combinations (Hwangbo et al, Nature Cancer, 2023). Results: Combination therapies with ICIs were as clinically effective as predicted by additivity, or less so in one case. Specifically, Pembrolizumab plus Enfortumab vedotin (EV302), Nivolumab plus Gemcitabine/Cisplatin (CheckMate 901), Pembrolizumab plus chemotherapy (KEYNOTE-361), and Durvalumab plus Tremelimumab (DANUBE) each exhibited PFS distributions that were statistically indistinguishable from PFS predicted by the additivity model (Cox Proportional Hazards). Atezolizumab plus chemotherapy (IMvigor130) was inferior to additivity. Subgroup analyses by PD-L1 expression and by cisplatin versus carboplatin will be presented. Conclusions: Life-prolonging treatments for mUC have been the result of additive combination therapies, wherein the efficacy of the drug combination is quantitatively explained by the individual efficacies of the component drugs. Additivity in this setting has several potential implications: (1) when a single-agent is principally active in a biomarker-defined subpopulation, the use of that agent in a combination will also principally improve outcomes in that subpopulation; (2) net duration of disease control may be similar between up-front combination and sequential use of the same drugs; assuming that the biology of disease at progression does not preclude the ability to receive subsequent lines of therapy, and (3) future drug development should prioritize combinations based on highly active single agents rather than solely based on hypothesized mechanistic rationale. Citation Format: Noah M. Schlachter, Eric J. Miller, Jonathan F. Anker, Matthew D. Galsky, Adam C. Palmer. Predictable successes: drug additivity explains the efficacy of combination therapies for metastatic urothelial cancer [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B011.

Tumor microenvironment parameters as a predictor of the duration of clinical effectiveness of immunotargeted therapy in advanced or metastatic endometrial cancer: A pilot multicenter observational study

Background. The inclusion of lenvatinib in the immunotherapy regimen for patients with MSS/pMMR endometrial cancer (EC) is due to its ability to modulate the tumor microenvironment, which allows the use of pembrolizumab in low-immunogenic tumors. However, only 30 % of patients with advanced or metastatic EC have a clinical response when treated with pembrolizumab and lenvatinib. In this regard, there is an obvious need to identify biomarkers that allow accurate selection of candidates for this type of therapy.Aim. To determine the predictive value of subpopulations of lymphocytes and macrophages, their expression of PD-1, expression of estrogen receptors, as well as vessel density in immunotargeted therapy for advanced or metastatic EC.Materials and methods. An open-label non-randomized observational association study was performed, involving a total of 22 patients with advanced or metastatic MSS/pMMR EC treated with pembrolizumab and lenvatinib. Duration of clinical effectiveness was used as a parameter to stratify patients. Using TSA-associated multiplex immunofluorescence, the proportions of CD8+ T lymphocytes, CD20+ B lymphocytes, FoxP3+ T regulatory lymphocytes and CD163+macrophages in tumor samples before the start of immunotargeted therapy were analyzed.Results. Three microenvironmental parameters were found to be associated with duration of clinical efficacy: the proportion of CD20+ B cells, the proportion of FoxP3+ T regulatory lymphocytes, and the ratio of CD8+/CD20+ lymphocytes in the tumor microenvironment. However, the CD8+/CD20+ lymphocyte ratio had the greatest predictive value; a value below 3.219 was associated with long clinical efficacy in patients with advanced or metastatic EC.Conclusion. The ratio of cytotoxic and B-lymphocytes in the microenvironment is a reliable predictor marker of the duration of the period of clinical effectiveness of immunotargeting therapy in advanced or metastatic EC.

Long-Term Follow-Up of Phase I Trial of Oncolytic Adenovirus-Mediated Cytotoxic and Interleukin-12 Gene Therapy for Treatment of Metastatic Pancreatic Cancer.

The long-term follow-up findings of the phase I trial evaluating the efficacy of oncolytic adenovirus-mediated cytotoxic and interleukin-12 gene therapy in metastatic pancreatic cancer (mPC) seem very promising. The study employed a replication-competent Adenovector in combination with chemotherapy in a dose-escalation format. The trial demonstrated a clinically meaningful median overall survival (OS) benefit, with patients in the highest dose cohort exhibiting an impressive median OS of 18.4 months. This contrasts starkly with patients receiving lower doses who experienced a median OS of 4.8 and 3.5 months, respectively. Remarkably, subject number 10, who received the highest dose, demonstrated an extraordinary survival of 59.1 months, presenting a compelling case for further exploration. Additionally, this patient displayed complete responses in lung and liver metastases, a rare occurrence in mPC treatment. Statistical analyses supported the observed survival benefit. The unprecedented OS results emphasize the potential of this treatment strategy and pave the way for future investigations into this promising gene therapy approach.

KEYNOTE-811: Potential to revise first-line therapy for metastatic human epidermal growth factor receptor 2-positive gastric cancer.

The first-line therapy pattern transition of metastatic HER2-positive gastric cancer is shifting. The KEYNOTE-811 study demonstrated that the addition of immunotherapy to the standard treatment of HER2-targeted therapy and chemotherapy showed good results in terms of PFS, especially in subgroup patients with PD-L1 CPS≥1. In the future, the first-line therapy pattern of metastatic HER2-positive gastric cancer will be radically changed based on ongoing randomized controlled clinical trials.

Small Molecule Functional Converter of B-Cell Lymphoma-2 (Bcl-2) Suppresses Breast Cancer Lung Metastasis.

The B-cell lymphoma-2 (Bcl-2) family of proteins plays a vital role in tumorigenesis. Cancer cells utilize the expression of Bcl-2 to evade therapy and develop resistance. Bcl-2 overexpression also causes cancer cells to be more invasive and metastatic. About 80% of cancer deaths are due to metastases, and yet targeted therapies for metastatic cancers are scarce. We discovered a small molecule, BFC1103, which changes the conformation of Bcl-2 to convert the antiapoptotic protein to a proapoptotic protein. BFC1103-induced apoptosis is dependent on the expression levels of Bcl-2, with higher levels causing more apoptosis. BFC1103 suppressed the growth of breast cancer lung metastasis. BFC1103 has the potential for further optimization and development for clinical testing in metastatic cancers that express Bcl-2. This study demonstrates a new approach to target Bcl-2 using a small molecule, BFC1103, to suppress metastatic disease.

The real-world data of immune-checkpoint inhibitor combination therapy for unresectable or metastatic esophageal cancer: a multi-institutional cohort study.

The real-world efficacy, feasibility, and prognostic factors of immune-checkpoint inhibitor combination therapy for unresectable or metastatic esophageal cancer are not fully established. This multi-institutional retrospective cohort study evaluated 71 consecutive patients treated with immune-checkpoint inhibitor combination therapy for esophageal cancer between March 2021 and December 2022. We assessed tumor response, safety, and long-term survival. In patients with measurable lesions, the response rate was 58%, and the disease control rate for all enrolled patients was 80%. Five patients (7.0%) underwent successful conversion surgery. Grade 3 or higher immune-related adverse events occurred in 13% of patients, and one patient (1.4%) died due to cholangitis. Median progression-free survival was 9.7 (95% confidence interval: 6.5-not reached). C-reactive protein levels and performance status were identified as significant predictors of progression-free survival through Cox proportional hazards analysis. Immune-checkpoint inhibitor combination therapy for esophageal cancer demonstrated comparable tumor response, safety, and long-term survival to previous randomized clinical trials. Patients with good performance status and low C-reactive protein levels may be suitable candidates for this treatment.

Early response assessment to targeted therapy in metastatic clear cell renal cancer using 68Ga-PSMA-11 PET/CT and comparison with CECT: a feasibility study

Early response assessment to targeted therapy in metastatic clear cell renal cancer using 68Ga-PSMA-11 PET/CT and comparison with CECT: a feasibility study

Establishment and molecular characterization of HCB-541, a novel and aggressive human cutaneous squamous cell carcinoma cell line

Cutaneous squamous cell carcinoma (cSCC) is a common type of skin cancer that can result in significant morbidity, although it is usually well-managed and rarely metastasizes. However, the lack of commercially available cSCC cell lines hinders our understanding of this disease. This study aims to establish and characterize a new metastatic cSCC cell line derived from a Brazilian patient. A tumor biopsy was taken from a metastatic cSCC patient, immortalized, and named HCB-541 after several passages. The cytokeratin expression profile, karyotypic alterations, mutational analysis, mRNA and protein differential expression, tumorigenic capacity in xenograft models, and drug sensitivity were analyzed. The HCB-541 cell line showed a doubling time between 20 and 30 h and high tumorigenic capacity in the xenograft mouse model. The HCB-541 cell line showed hypodiploid and hypotetraploidy populations. We found pathogenic mutations in TP53 p.(Arg248Leu), HRAS (Gln61His) and TERT promoter (C228T) and high-level microsatellite instability (MSI-H) in both tumor and cell line. We observed 37 cancer-related genes differentially expressed when compared with HACAT control cells. The HCB-541 cells exhibited high phosphorylated levels of EGFR, AXL, Tie, FGFR, and ROR2, and high sensitivity to cisplatin, carboplatin, and EGFR inhibitors. Our study successfully established HCB-541, a new cSCC cell line that could be useful as a valuable biological model for understanding the biology and therapy of metastatic skin cancer.

Abstract 2552: Real-world analysis of biomarker testing and use of targeted therapies in metastatic non-small cell lung cancer (mNSCLC) in the United States (US)

Abstract Background: Between 1998 and 2022, over 40% of new oncology drugs approved by the US FDA were precision therapies. In nonsquamous mNSCLC, detecting biomarkers where targeted therapies exist (EGFR, ALK, ROS1, BRAF V600E variant, MET exon 14 skipping variant, RET and PD-L1) has become essential for adequate clinical care. This study investigated real-world use of these biomarker tests, their characteristics, and associated use of targeted therapies in mNSCLC patients in the US. Methods: Adults ≥18 years old with stage IV mNSCLC from the nationwide Flatiron Health electronic health record-derived de identified database (01/2011 - 04/2023). The proportion of patients receiving biomarker tests, timing, characteristics, test type (single, multiple or next-generation sequencing), and proportion of patients receiving guideline recommended associated targeted therapies (i.e. actionable treatment) was assessed. Actionable treatment was defined in study years where at least one actionable therapy was FDA approved (biomarker, therapy, date: ALK, crizotinib, Aug 2011; BRAF V600E, dabrafenib+trametinib, Jul 2015; EGFR, afatinib, Jul 2013; MET exon 14 skipping, capmatinib, May 2020; PD-L1, pembrolizumab, Oct 2015; RET, pralsetinib, Sep 2020; ROS-1, crizotinib, Mar 2016). Results: In 42,037 patients with mNSCLC, the proportion of patients receiving each test were: ALK: 71.6%, BRAF: 48.8%, EGFR: 74.9%, MET: 41.4%, PD-L1: 49.3%, RET: 42.3%, and ROS1: 54.2%. Median (Q1, Q3) time from mNSCLC diagnosis to first biomarker result was 21 (12, 37) days. Tissue was the most common sample type for biomarker testing, although sampling by blood has increased in recent years. Multiple testing methods were more common in ALK and PD-L1 (48.1% and 50.3%, respectively) and next generation sequencing was more common in the other biomarkers (BRAF: 77.7%, EGFR: 57.1%, MET: 74.1%, RET: 70.7%, ROS1: 54.0%). Testing rates increased from 2011 through 2023 for each biomarker, with the highest rates in 2023: ALK (87.7%), BRAF (85.2%), EGFR (88.7%), MET (85.7%), PDL1 (78.7%), RET (84.8%), and ROS1 (86.9%). Testing rates were similar when timing was restricted to a 1-year window from mNSCLC diagnosis. Receipt of actionable treatment varied by biomarker, in order of increasing frequency: RET+ (23.0%), MET+ (34.0%), BRAF+ (42.7%), PDL1+ (56.3%), ROS1+ (59.8%), EGFR+ (70.6%), and ALK+ (89.0%). Generally, across all biomarkers, receipt of actionable therapy increased in more recent years. Conclusion: Current real-world biomarker testing rates and use of actionable treatments may reflect increased adoption of clinical guideline recommendations. Despite increased testing, use of actionable therapy remains low for certain biomarkers. Further improvements in the implementation of robust biomarker testing to use appropriate therapies are needed, which can lead to better patient outcomes. Citation Format: Michael J. Dennis, Devin Abrahami, Maria Cecilia Vieira, Darrin Benjumea, Marley Boyd, Anran Shao, Kirsten Duncan, John Kelton, Sandip P. Patel. Real-world analysis of biomarker testing and use of targeted therapies in metastatic non-small cell lung cancer (mNSCLC) in the United States (US) [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 2552.

Abstract 4132: Low-dose carbon monoxide therapies suppress cancer metastasis

Abstract Metastasis is the primary cause of cancer-related deaths. Novel systemic therapies for metastatic cancer are urgently needed. Carbon monoxide (CO) is an endogenously produced signaling molecule in the human body with demonstrated pharmacological activities, including organ protection and anti-inflammation. We determined the therapeutic effect of low-dose CO and CO prodrugs on cancer progression in this study. We found that low-dose CO inhibits the migration of cancer cell lines including breast, pancreatic, colon, prostate, liver, and lung cancer. We showed that low-dose CO inhibits lung metastasis of breast cancer and liver metastasis of pancreatic cancer in preclinical mouse models. Further, to provide safer and more reliable CO delivery, we developed metal-free, organic CO prodrugs and showed that CO prodrugs inhibit tumor growth and metastasis. We demonstrated that low-dose CO blocks the transcription of heme importers, leading to diminished intracellular heme levels. Altogether, our work lays a strong foundation for the development of CO-based systemic cancer therapies. Citation Format: Tiantian Zhang, Cheryl Zhang, Xiang Chen, Xiaoxiao Yang, Qiyue Mao, George Zhang, Zhengming Chen, Adrian Tan, Jenny Zhaoying Xiang, Erika Hissong, Yao-Tseng Chen, Binghe Wang, Nancy Du. Low-dose carbon monoxide therapies suppress cancer metastasis [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 4132.

The abscopal effect: mechanism of occurrence and prospects of using it in therapy of metastatic cancer

The abscopal effect in oncology has been known for 70 years, but until recently its clinical significance was rather low. The development of immune response checkpoint inhibitors has led to an active study of this phenomenon. There is now evidence of improved survival among patients, in whom the abscopal effect has been documented, opening new perspectives for the treatment of cancers at different stages. This review presents data on the mechanisms of the abscopal effect, experimental and clinical data, current limitations and possible perspectives. The aim of the study was to investigate the current concept of the abscopal effect occurrence and to evaluate the prospects of using the abscopal effect in therapy of metastatic cancer. Material and Methods. We searched publications in Pubmed system from 2010 to 2023. Of 286 publications, 72 were used for writing the review. Results. In the era of widespread use of immune checkpoint inhibitors (ICIs) for cancer therapy, the abscopal effect appears to be an effective therapeutic approach with broad prospects of application in the treatment of patients with metastatic cancer. Conclusion. The incidence of the abscopal effect has increased with the advent of immune therapy, and the use of ICIs with radiation therapy (RT) has shown improved survival even in patients with advanced disease. More research is needed to establish standardized treatment protocols, including the optimal dose and timing of RT, as well as the efficacy and safety of combination therapy with different classes of ICIs. Further search for clinical and laboratory abscopal effect predictors, which could allow personalized treatment approaches, is required.

Safety and Toxicity of Iopofosine I-131 with External Beam Radiation Therapy (EBRT) in Recurrent or Metastatic Head and Neck Cancer (HNC): Results of a Phase 1 Study

Safety and Toxicity of Iopofosine I-131 with External Beam Radiation Therapy (EBRT) in Recurrent or Metastatic Head and Neck Cancer (HNC): Results of a Phase 1 Study

Toward a Template for Synthetic Actin-Targeting Macrolide Analogues That Inhibit Cancer Cell Invasiveness.

Actin barbed end-binding macrolides have been shown to inhibit cancer cell motility and invasion of extracellular matrix (ECM), evoking their potential utility as therapies for metastatic cancers. Unfortunately, the direct use of these compounds in clinical settings is impeded by their limited natural abundance, challenging total synthesis, and detrimental effects on normal tissues. To develop potent analogues of these compounds that are simpler to synthesize and compatible with cell-specific targeting systems, such as antibodies, we designed over 20 analogues of the acyclic side chain (tail) of the macrolide Mycalolide B. These analogues probed the contributions of four distinct regions of the tail towards the inhibition of actin polymerization and ECM invasion by human lung cancer A549 cells. We observed that two of these regions tolerate considerable substituent variability, and we identified a specific combination of substituents that leads to the optimal inhibition of the ECM invasion activity of A549 cells.

Efficacy and safety of anti-programmed death-1 antibody-based combination therapy in advanced or metastatic gastric or gastroesophageal junction cancer in Chinese patients: A real-world study.

Programmed death-1 antibody plus chemotherapy has gained approval for the treatment for (human epidermal growth factor receptor 2 negative locally advanced or metastatic gastric or gastroesophageal junction cancer. This study aims to analyze the efficacy and safety of anti-programmed death-1 antibody combined with chemo- or anti-angiogenesis therapy in Chinese patients with advanced or metastatic gastric or gastroesophageal junction cancer in a real-world setting. In total, 122 patients treated with anti-programmed death-1 antibody-based combination therapy between April 2019 and December 2021 were encompassed. Clinical outcomes and safety profile were measured and analyzed. In the whole cohort, median overall survival was 17.2 months, median progression-free survival was 10.9 months, and median duration of response was 9.4 months. Notably, in the first-line patients, the median overall survival was not reached, median progression-free survival was 14.8 months, objective response rate was 68.4%. In the second-line group, median overall survival, median progression-free survival, median duration of response, and objective response rate were 10.9 months, 5.9 months, 4.5 months, and 41.5%, respectively. Treatment-related adverse events of any grade were observed in 28.2% of the overall cohort, primarily affecting the hematological and liver function. Grade 3 or 4 adverse events were mainly characterized by increased levels of aspartate aminotransferase, alanine aminotransferase, along with decreased lymphocyte and white blood cells, as well as anemia. Patients in our cohort experienced a clinical benefit from anti-programmed death-1 antibody-combined treatment in first-line treatment settings, with acceptable treatment-related adverse events. The benefit of anti-programmed death-1 antibody combined with chemo- or anti-angiogenesis treatment to the second-line patients should be further confirmed by large multi-center randomized, controlled clinical trials.

Combinatorial immune checkpoint blockade increases myocardial expression of NLRP-3 and secretion of H-FABP, NT-Pro-BNP, interleukin-1β and interleukin-6: biochemical implications in cardio-immuno-oncology.

Immune checkpoint blockade in monotherapy or combinatorial regimens with chemotherapy or radiotherapy have become an integral part of oncology in recent years. Monoclonal antibodies against CTLA-4 or PD-1 or PDL-1 are the most studied ICIs in randomized clinical trials, however, more recently, an anti-LAG3 (Lymphocyte activation gene-3) antibody, Relatlimab, has been approved by FDA in combination with Nivolumab for metastatic melanoma therapy. Moreover, Atezolizumab is actually under study in association with Ipilimumab for therapy of metastatic lung cancer. Myocarditis, vasculitis and endothelitis are rarely observed in these patients on monotherapy, however new combination therapies could expose patients to more adverse cardiovascular events. Human cardiomyocytes co-cultured with human peripheral blood lymphocytes (hPBMCs) were exposed to monotherapy and combinatorial ICIs (PD-L1 and CTLA-4 or PD-1 and LAG-3 blocking agents, at 100 nM) for 48 h. After treatments, cardiac cell lysis and secretion of biomarkers of cardiotoxicity (H-FABP, troponin-T, BNP, NT-Pro-BNP), NLRP3-inflammasome and Interleukin 1 and 6 were determined through colorimetric and enzymatic assays. Mitochondrial functions were studied in cardiomyocyte cell lysates through quantification of intracellular Ca++, ATP content and NADH:ubiquinone oxidoreductase core subunit S1 (Ndufs1) levels. Histone deacetylases type 4 (HDAC-4) protein levels were also determined in cardiomyocyte cell lysates to study potential epigenetic changes induced by immunotherapy regimens. Both combinations of immune checkpoint inhibitors exert more potent cardiotoxic side effects compared to monotherapies against human cardiac cells co-cultured with human lymphocytes. LDH release from cardiac cells was 43% higher in PD-L1/CTLA-4 blocking agents, and 35.7% higher in PD-1/LAG-3 blocking agents compared to monotherapies. HDAC4 and intracellular Ca++ levels were increased, instead ATP content and Ndufs1 were reduced in myocardial cell lysates (p < 0.001 vs. untreated cells). Troponin-T, BNP, NT-Pro-BNP and H-FABP, were also strongly increased in combination therapy compared to monotherapy regimen. NLRP3 expression, IL-6 and IL-1β levels were also increased by PDL-1/CTLA-4 and PD-1/LAG-3 combined blocking agents compared to untreated cells and monotherapies. Data of the present study, although in vitro, indicate that combinatorial immune checkpoint blockade, induce a pro- inflammatory phenotype, thus indicating that these therapies should be closely monitored by the multidisciplinary team consisting of oncologists, cardiologists and immunologists.

Real-world treatment patterns, testing patterns, and clinical outcomes of first-line (1L) therapy for metastatic gastric cancer, gastroesophageal junction cancer, or esophageal adenocarcinoma (mGC/GEJC/EAC).

275 Background: GC/GEJC/EAC are among the leading causes of cancer-related morbidity and mortality worldwide. Nivolumab + fluoropyrimidine- + platinum-containing chemotherapy (NIVO+chemo) has demonstrated superior efficacy in patients with advanced non-HER2-positive (HER2-) GC/GEJC/EAC versus chemo alone in the CheckMate 649 trial. The objective of this study was to characterize real-world treatment and PD-L1 testing patterns in the 1L setting for mGC/GEJC/EAC since the FDA approval of NIVO+chemo on April 16, 2021. Methods: This retrospective observational study used the electronic medical record data from the ConcertAI Patient360 database. Adult patients with HER2- mGC/GEJC/EAC and 1L initiation date (index date) between April 16, 2021 and October 31, 2022 were included. PD-L1 testing patterns and 1L regimens were described overall and stratified by PD-L1 testing. The analyses of clinical outcomes are currently ongoing. Results: A total of 161 patients with mGC/GEJC/EAC met the inclusion criteria. The median age at index was 67.0 years, 76.4% were male, and the median follow-up time from index date was 6.7 months. 81 (50.3%) patients had evidence of receiving at least one PD-L1 test (median [interquartile range] time from first test to 1L initiation: 0.4 [-0.1, 1.0] months) among whom 28 (34.6%) had the first test documented after 1L initiation. Overall, 1L immunotherapy-based regimens were received by 63 (39.1%) patients, with NIVO+chemo being the most common (n = 47; 29.2%). 1L fluoropyrimidine- + platinum-containing chemotherapy and other chemotherapies were received by 51 (31.7%) and 42 (26.1%) patients, respectively. Among patients with evidence of PD-L1 testing, 31 (38.3%) received NIVO+chemo, and 37 (45.7%) received chemotherapy alone. Among those without evidence of PD-L1 testing, 56 (70.0%) received chemotherapy alone, and 16 (20.0%) received NIVO+chemo. Conclusions: These preliminary findings show an early uptake of NIVO+chemo in the advanced or metastatic GC/GEJC/EAC patient population. With a majority of PD-L1 untested patients receiving chemotherapy only as 1L therapy, there is an opportunity for these patients to potentially benefit from immuno-oncology containing regimens. Further analyses are needed to characterize the chemotherapy only treated patient population.

HGCSG 1803: Single-arm phase II study evaluating efficacy of oxaliplatin, irinotecan and S-1 combination therapy (OX-IRIS) in metastatic pancreatic cancer as first line treatment.

647 Background: Combination chemotherapy with oxaliplatin, irinotecan, fluorouracil and leucovorin (FOLFIRINOX) showed improved survival compared to gemcitabine monotherapy for patients with metastatic pancreatic cancer and has become the one of the standard regimens. Despite of its clinical benefit, FOLFIRNIOX needs continuous infusion of 5-FU for 46 hours, which impairs patient’s quality of life. In other gastrointestinal cancer, infusion pump free regimens, in which oral 5-FU drug replace the continuous infusion of 5-FU, have developed as alternative regimen by its convenience. Therefore, we planned to develop new combination chemotherapy with oxaliplatin, irinotecan and S-1 (OX-IRIS) for metastataic pancreatic cancer. Methods: HGCSG1803 study has conducted as a multicenter, non-randomized, single arm, phase II study in Japan. The chemotherapy-naïve patients with metastatic pancreatic cancer were eligible. S-1 (40 mg/m2) orally intake twice daily for 14-day followed by a 14-day rest, and intravenous 65 mg/m2 of L-OHP and 100 mg/m2 of IRI on day 1 and day 15 every four weeks were continued until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by RECIST ver1.1, with a threshold of 10% and an expected value of 30%. The secondary endpoints were overall survival (OS), progression-free survival (PFS), and safety. Results: Between Jan 2020 and May 2022, forty patients were enrolled and 39 patients were included in full analysis set (one patient were excluded because of consent withdrawal). Median age was 66 (range, 41-75), female/male were 16/23, ECOG PS 0/1; 32/7, UGT1A1 wild /heterozygous for *6 or *28 allele 27/12, liver/lung/peritoneal metastasis 28/9/11, respectively. The median relative dose intensities of S-1, irinotecan, and oxaliplatin were 76%, 72%, and 70%, respectively. Objective response rate and disease control rate were 43.6% (95%CI 27.8-60.4%) and 76.9% (95%CI 60.4-89.1%), respectively. In the median follow-up time was 13.7 months, median progression free survival and overall survival were 4.3 months (95%CI 2.5-6.2 months) and 11.1 months (95%CI 7.2-14.9 months), respectively. Four patients discontinued protocol therapy due to adverse events (AE) without disease progression. Grade 3 or higher AE that occurred in more than 5% of patients were leucopenia (21%), hypokalemia (21%), neutropenia (18%), anemia (15%), hyponatremia (15%), ALT elevation (10%), anorexia (8%), nausea (5%), and febrile neutropenia (5%). One patient died due to protocol therapy (drug induced pneumonitis). Conclusions: OX-IRIS showed high response rate with manageable safety, and the primary endpoint was met. This new triplet regimen could be a useful first line treatment option for patients with metastatic pancreatic cancer. Clinical trial information: jRCTs011190008 .