Southwest Oncology Group study S0413: a phase II trial of lapatinib (GW572016) as first-line therapy in patients with advanced or metastatic gastric cancer

Drug Delivery Opportunities in Esophageal Cancer: Current Treatments and Future Prospects

With one of the highest mortality rates of all malignancies, the 5-year survival rate for esophageal cancer is under 20%. Depending on the stage and extent of the disease, the current standard of care treatment paradigm includes chemotherapy or chemoradiotherapy followed by surgical esophagogastrectomy, with consideration for adjuvant immunotherapy for residual disease. This regimen has high morbidity, due to anatomic changes inherent in surgery, the acuity of surgical complications, and off-target effects of systemic chemotherapy and immunotherapy. We begin with a review of current treatments, then discuss new and emerging targets for therapies and advanced drug delivery systems. Recent and ongoing preclinical and early clinical studies are evaluating traditional tumor targets (e.g., human epidermal growth factor receptor 2), as well as promising new targets such as Yes-associated protein 1 or mammalian target of rapamycin to develop new treatments for this disease. Due the function and location of the esophagus, opportunities also exist to pair these treatments with a drug delivery strategy to increase tumor targeting, bioavailability, and intratumor concentrations, with the two most common delivery platforms being stents and nanoparticles. Finally, early results with antibody drug conjugates and chimeric antigenic receptor T cells show promise as upcoming therapies. This review discusses these innovations in therapeutics and drug delivery in the context of their successes and failures, with the goal of identifying those solutions that demonstrate the most promise to shift the paradigm in treating this deadly disease.

Characterization of gastric cancer-stimulated signaling pathways and function of CTGF in cancer-associated fibroblasts

BACKGROUND

Cancer-associated fibroblasts (CAFs) are key components of the tumor microenvironment (TME) that play an important role in cancer progression. Although the mechanism by which CAFs promote tumorigenesis has been well investigated, the underlying mechanism of CAFs activation by neighboring cancer cells remains elusive. In this study, we aim to investigate the signaling pathways involved in CAFs activation by gastric cancer cells (GC) and to provide insights into the therapeutic targeting of CAFs for overcoming GC.

METHODS

Alteration of receptor tyrosine kinase (RTK) activity in CAFs was analyzed using phospho-RTK array. The expression of CAFs effector genes was determined by RT-qPCR or ELISA. The migration and invasion of GC cells co-cultured with CAFs were examined by transwell migration/invasion assay.

RESULTS

We found that conditioned media (CM) from GC cells could activate multiple receptor tyrosine kinase signaling pathways, including ERK, AKT, and STAT3. Phospho-RTK array analysis showed that CM from GC cells activated PDGFR tyrosine phosphorylation, but only AKT activation was PDGFR-dependent. Furthermore, we found that connective tissue growth factor (CTGF), a member of the CCN family, was the most pronouncedly induced CAFs effector gene by GC cells. Knockdown of CTGF impaired the ability of CAFs to promote GC cell migration and invasion. Although the PDGFR-AKT pathway was pronouncedly activated in CAFs stimulated by GC cells, its pharmacological inhibition affected neither CTGF induction nor CAFs-induced GC cell migration. Unexpectedly, the knockdown of SRC and SRC-family kinase inhibitors, dasatinib and saracatinib, significantly impaired CTGF induction in activated CAFs and the migration of GC cells co-cultured with CAFs. SRC inhibitors restored the reduced expression of epithelial markers, E-cadherin and Zonula Occludens-1 (ZO-1), in GC cells co-cultured with CAFs, as well as CAFs-induced aggregate formation in a 3D tumor spheroid model.

CONCLUSIONS

This study provides a characterization of the signaling pathways and effector genes involved in CAFs activation, and strategies that could effectively inhibit it in the context of GC. Video Abstract.

EDIL3 is a potential prognostic biomarker that correlates with immune infiltrates in gastric cancer

Background

EDIL3, which contains epidermal growth factor-like repeats and discoidin I-like domains, is a secretory protein that plays an important role in embryonic development and various illnesses. However, the biological function of EDIL3 in gastric cancer (GC) is still unclear. The objective of this research was to explore the role and potential mechanism of EDIL3 in GC.

Methods

In this study, we used the GEPIA, HPA, MethSurv, SMART, STRING, GeneMANIA, LinkedOmics TIMER, TIMER2.0, TISIDB, and RNAactDrug databases to comprehensively analyze the roles of EDIL3 in GC. To validate the in silico findings, EDIL3 expression was measured in our collected GC tissues. Meanwhile, several in vitro experiments were performed to test the function of EDIL3 in GC.

Results

We found that EDIL3 was highly expressed in GC and associated with adverse clinical features. In vitro assays revealed that EDIL3 promoted the proliferation, migration, and invasion of GC cells. The functions of EDIL3 and co-expression genes were significantly associated with extracellular structure organization and matrix receptor interaction. EDIL3 expression was positively associated with numerous tumor-infiltrating immune cells and their biomarkers.

Conclusion

This study determined that EDIL3 may function as an oncogene and is associated with immune infiltration in GC. EDIL3 could be used as a potential therapeutic target for GC.

The impact of violating the independence assumption in meta-analysis on biomarker discovery

With rapid advancements in high-throughput sequencing technologies, massive amounts of "-omics" data are now available in almost every biomedical field. Due to variance in biological models and analytic methods, findings from clinical and biological studies are often not generalizable when tested in independent cohorts. Meta-analysis, a set of statistical tools to integrate independent studies addressing similar research questions, has been proposed to improve the accuracy and robustness of new biological insights. However, it is common practice among biomarker discovery studies using preclinical pharmacogenomic data to borrow molecular profiles of cancer cell lines from one study to another, creating dependence across studies. The impact of violating the independence assumption in meta-analyses is largely unknown. In this study, we review and compare different meta-analyses to estimate variations across studies along with biomarker discoveries using preclinical pharmacogenomics data. We further evaluate the performance of conventional meta-analysis where the dependence of the effects was ignored via simulation studies. Results show that, as the number of non-independent effects increased, relative mean squared error and lower coverage probability increased. Additionally, we also assess potential bias in the estimation of effects for established meta-analysis approaches when data are duplicated and the assumption of independence is violated. Using pharmacogenomics biomarker discovery, we find that treating dependent studies as independent can substantially increase the bias of meta-analyses. Importantly, we show that violating the independence assumption decreases the generalizability of the biomarker discovery process and increases false positive results, a key challenge in precision oncology.

Recent Trends and Advancements in the Diagnosis and Management of Gastric Cancer

Gastric cancer is an enigmatic malignancy that has recently been shown to be increasing in incidence globally. There has been recent progress in emerging technologies for the diagnosis and treatment of the disease. Improvements in non-invasive diagnostic techniques with serological tests and biomarkers have led to decreased use of invasive procedures such as endoscopy. A multidisciplinary approach is used to treat gastric cancer, with recent significant advancements in systemic therapies used in combination with cytotoxic chemotherapies. New therapeutic targets have been identified and clinical trials are taking place to assess their efficacy and safety. In this review, we provide an overview of the current and emerging treatment strategies and diagnostic techniques for gastric cancer.

From Anti-HER-2 to Anti-HER-2-CAR-T Cells: An Evolutionary Immunotherapy Approach for Gastric Cancer

Current Therapeutic modalities provide no survival advantage to gastric cancer (GC) patients. Targeting the human epidermal growth factor receptor-2 (HER-2) is a viable therapeutic strategy against advanced HER-2 positive GC. Antibody-drug conjugates, small-molecule tyrosine kinase inhibitors (TKIs), and bispecific antibodies are emerging as novel drug forms that may abrogate the resistance to HER-2-specific drugs and monoclonal antibodies. Chimeric antigen receptor-modified T cells (CAR-T) targeting HER-2 have shown considerable therapeutic potential in GC and other solid tumors. However, due to the high heterogeneity along with the complex tumor microenvironment (TME) of GC that often leads to immune escape, the immunological treatment of GC still faces many challenges. Here, we reviewed and discussed the current progress in the research of anti-HER-2-CAR-T cell immunotherapy against GC.

Molecular pathogenesis and emerging targets of gastric adenocarcinoma

Gastric adenocarcinoma (GC) is a devastating disease and is the third leading cause of cancer deaths worldwide. This heterogeneous disease has several different classification systems that consider histological appearance and genomic alterations. Understanding the etiology of GC, including infection, hereditary conditions, and environmental factors, is of particular importance and is discussed in this review. To improve survival in GC, we also must improve our therapeutic strategies. Here, we discuss new targets that warrant further exploration.

Second-Generation JK-206 Targets the Oncogenic Signal Mediator RHOA in Gastric Cancer

Ras homologous A (RHOA), a signal mediator and a GTPase, is known to be associated with the progression of gastric cancer (GC), which is the fourth most common cause of death in the world. Previously, we designed pharmacologically optimized inhibitors against RHOA, including JK-136 and JK-139. Based on this previous work, we performed lead optimization and designed novel RHOA inhibitors for greater anti-GC potency. Two of these compounds, JK-206 and JK-312, could successfully inhibit the viability and migration of GC cell lines. Furthermore, using transcriptomic analysis of GC cells treated with JK-206, we revealed that the inhibition of RHOA might be associated with the inhibition of the mitogenic pathway. Therefore, JK-206 treatment for RHOA inhibition may be a new therapeutic strategy for regulating GC proliferation and migration.

Novel Biomarkers of Gastric Adenocarcinoma: Current Research and Future Perspectives

Simple Summary

Gastric cancer is characterized by poor survival rates despite surgery and chemotherapy. Current research focuses on biomarkers to improve diagnosis and prognosis, and to enable targeted treatment strategies. The aim of our review was to give an overview over the wide range of novel biomarkers in gastric cancer. These biomarkers are targets of a specific treatment, such as antibodies against human epidermal growth factor receptor 2. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are vascular endothelial growth factor, programmed cell death protein 1, and Claudin 18.2. There is a vast number of biomarkers based on DNA, RNA, and protein expression, as well as detection of circulating tumor cells and the immune tumor microenvironment.

Abstract

Overall survival of gastric cancer remains low, as patients are often diagnosed with advanced stage disease. In this review, we give an overview of current research on biomarkers in gastric cancer and their implementation in treatment strategies. The HER2-targeting trastuzumab is the first molecular targeted agent approved for gastric cancer treatment. Other promising biomarkers for targeted therapies that have shown relevance in clinical trials are VEGF and Claudin 18.2. Expression of MET has been shown to be a negative prognostic factor in gastric cancer. Targeting the PD-1/PD-L1 pathway with immune checkpoint inhibitors has proven efficacy in advanced gastric cancer. Recent technology advances allow the detection of circulating tumor cells that may be used as diagnostic and prognostic indicators and for therapy monitoring in gastric cancer patients. Prognostic molecular subtypes of gastric cancer have been identified using genomic data. In addition, transcriptome profiling has allowed a comprehensive characterization of the immune and stromal microenvironment in gastric cancer and development of novel risk scores. These prognostic and predictive markers highlight the rapidly evolving field of research in gastric cancer, promising improved treatment stratification and identification of molecular targets for individualized treatment in gastric cancer.

Design, synthesis and anticancer evaluation of new 4-anilinoquinoline-3-carbonitrile derivatives as dual EGFR/HER2 inhibitors and apoptosis inducers

Dual targeting of EGFR/HER2 receptor is an attractive strategy for cancer therapy. Four series of 4-anilinoquinoline-3-carbonitrile derivatives were designed and prepared by introducing various functional groups, including a polar hydrophilic group (carboxylic acid), a heterocyclic substituent possessing polarity to some extent, and an unpolar hydrophobic phenyl portion, at the C-6 position of the quinoline skeleton. All of the prepared derivatives were screened for their inhibitory activities against EGFR /HER2 receptors and their antiproliferative activities against the SK-BR-3 and A431 cell lines. Compounds 6a, 6 g and 6d exhibited significant activities against the target cell lines. In particular, the antiproliferative activity of 6d (IC₅₀ = 1.930 μM) against SK-BR-3 was over 2-fold higher than that of neratinib (IC₅₀ = 3.966 μM), and comparable to that of Lapatinib (IC₅₀ = 2.737 μM). On the other hand, 6d (IC₅₀ = 1.893 μM) was more active than the reference drug Neratinib (IC₅₀ = 2.151 μM), and showed comparable potency to Lapatinib (IC₅₀ = 1.285 μM) against A431. Cell cycle analysis and apoptosis assays indicated that 6d arrests the cell cycle in the S phase, and it is a potent apoptotic inducer. Moreover, molecular docking exhibited the binding modes of compound 6d in EGFR and HER2 binding sites, respectively. Compound 6d can be considered as a candidate for further investigation as a more potent anticancer agent.

Targeted Therapies in Advanced Gastric Cancer

OPINION STATEMENT

Despite a decreasing incidence in the USA, gastric cancer is highly prevalent worldwide. Furthermore, gastric cancer remains highly lethal with median survival of less than 1 year for metastatic disease. The backbone of therapy against metastatic gastric cancer remains cytotoxic chemotherapy, but recent advances in the molecular understanding of gastric cancer have renewed hope within that targeted agents can be leveraged to improve survival and reduce toxicity. For example, in patients with human epidermal growth factor-2 (HER2)-positive gastric cancer, the addition of trastuzumab to frontline chemotherapy improves survival. In the second line, oncologists can now administer a vascular endothelial growth factor (VEGF) receptor inhibitor, ramucirumab, as a single agent or in combination with chemotherapy, and the immune checkpoint inhibitor pembrolizumab is approved in multiple settings dependent on the Programmed Death Ligand 1 (PD-L1) status. For patients with metastatic disease, our approach to standard of care in the first-line setting is a 5FU/platinum doublet with trastuzumab for HER2-positive tumors. In the second-line setting, most patients receive ramucirumab + paclitaxel, but those that are MSI high receive pembrolizumab. For squamous cell carcinoma of the esophagus with high PD-L1 status (combined positive score (CPS) ≥ 10), we recommend pembrolizumab in the second line. While for PD-L1 ≥ 1% gastroesophageal adenocarcinoma, we do not recommend pembrolizumab before the third-line setting, although this may change in the near future for CPS ≥ 10. The future landscape for targeted therapy in gastric cancer is promising. Numerous clinical trials evaluating the combination immune therapy with molecularly targeted agents are generating much excitement. Moreover, genomic data from The Cancer Center Genome (TCGA) and Asian Cancer Research Group (ACRG) classifications is being used to identify molecular subtypes to enable future clinical trials to include biomarker-enriched patient populations.

Current Molecular Targeted Agents for Advanced Gastric Cancer

Gastric cancer is the third leading cause of malignant tumor-related mortality worldwide. Traditional cytotoxic agents prolong the overall survival and progression-free survival of patients with advanced gastric cancer (AGC) compared to that with best supportive care. Due to the occurrence of serious adverse drug reactions that result in discontinued treatment, the survival benefit in AGC remains unsatisfactory. Systemic chemotherapy regimens have changed greatly, especially since the introduction of trastuzumab. Nevertheless, HER2 positivity is present in only approximately 20% of tumors. Due to the genetic heterogeneity and complexity of patients, there are many studies in progress that are exploring novel targeted drugs as an alternative to chemotherapy or adjuvant treatment in early-stage, progressive, and advanced gastric cancer. On the basis of the differences in gene expression profiles among patients, searching for specific and sensitive predictive biomarkers is important for identifying patients who will benefit from a specific targeted drug. With the development of targeted therapies and available chemotherapeutic drugs, there is no doubt that, over time, more patients will achieve better survival outcomes. Recently, immune checkpoint blockade has been well developed as a promising anticancer strategy. This review outlines the currently available information on clinically tested molecular targeted drugs and immune checkpoint inhibitors for AGC to provide support for decision-making in clinical practice.

Phase I Escalation and Expansion Study of Bemarituzumab (FPA144) in Patients With Advanced Solid Tumors and FGFR2b-Selected Gastroesophageal Adenocarcinoma

PURPOSE

To evaluate the safety, pharmacokinetics, and preliminary activity of bemarituzumab in patients with FGFR2b-overexpressing gastric and gastroesophageal junction adenocarcinoma (GEA).

PATIENTS AND METHODS

FPA144-001 was a phase I, open-label, multicenter trial consisting of the following 3 parts: part 1a involved dose escalation in patients with recurrent solid tumors at doses ranging from 0.3 to 15 mg/kg; part 1b involved dose escalation in patients with advanced-stage GEA; and part 2 involved dose expansion in patients with advanced-stage GEA that overexpressed FGFR2b at various levels (4 cohorts; high, medium, low, and no FGFR2b overexpression) and 1 cohort of patients with FGFR2b-overexpressing advanced-stage bladder cancer.

RESULTS

Seventy-nine patients were enrolled; 19 were enrolled in part 1a, 8 in part 1b, and 52 in part 2. No dose-limiting toxicities were reported, and the recommended dose was identified as 15 mg/kg every 2 weeks based on safety, tolerability, pharmacokinetic parameters, and clinical activity. The most frequent treatment-related adverse events (TRAEs) were fatigue (17.7%), nausea (11.4%), and dry eye (10.1%). Grade 3 TRAEs included nausea (2 patients) and anemia, neutropenia, increased AST, increased alkaline phosphatase, vomiting, and an infusion reaction (1 patient each). Three (10.7%) of 28 patients assigned to a cohort receiving a dose of ≥ 10 mg/kg every 2 weeks for ≥ 70 days reported reversible grade 2 corneal TRAEs. No TRAEs of grade ≥ 4 were reported. Five (17.9%; 95% CI, 6.1% to 36.9%) of 28 patients with high FGFR2b-overexpressing GEA had a confirmed partial response.

CONCLUSION

Overall, bemarituzumab seems to be well tolerated and demonstrated single-agent activity as late-line therapy in patients with advanced-stage GEA. Bemarituzumab is currently being evaluated in combination with chemotherapy in a phase III trial as front-line therapy for patients with high FGFR2b-overexpressing advanced-stage GEA.

Administration of Lapatinib with Food Increases Its Plasma Concentration in Chinese Patients with Metastatic Breast Cancer: A Prospective Phase II Study

Lessons Learned

Administration of lapatinib with food significantly increased its plasma concentration in Chinese patients with metastatic breast cancer.

There were no serious adverse events during the study and no significant differences in lapatinib‐related adverse events between the fasted and fed states.

Background

Lapatinib, a small molecular reversible dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and human epidermal growth receptor 2 (HER2), was approved for use in combination with capecitabine to treat metastatic HER2‐positive breast cancer. Administration of lapatinib in the fasted state was recommended; however, our preliminary phase II trial data showed that administration of lapatinib with food increased its concentration.

Methods

This study was a single‐center, open‐label, and prospective self‐controlled clinical study. Ten Chinese patients with metastatic breast cancer were enrolled from June 2017 to April 2018. They were required to receive lapatinib plus physician's choice of chemotherapy. Patients were required to take lapatinib orally on an empty stomach continually for 10 days, and then take lapatinib with food continually for the next 10 days. Plasma concentration was measured by liquid chromatography on the 9th and 10th day of each state.

Results

Area under the concentration‐time curve (AUC) of the fasted state and the fed state was 21.23 ± 8.91 mg*h/L (coefficient of variation (CV)% 42%) and 60.60 ± 16.64 mg*h/L (CV% 27%), respectively. The mean plasma concentration in the fasted state was 0.88 ± 0.39 mg/L (CV% 45%), and that in the fed state was 2.53 ± 0.77 mg/L (CV% 30%). Compared with taking lapatinib on an empty stomach, receiving lapatinib with food significantly increased the plasma concentration of lapatinib (Wilcoxon match‐paired test, p = .005). In addition, there were no serious adverse events during the study or significant difference in lapatinib‐related adverse events between the two states.

Conclusion

Our study shows that receiving lapatinib with food can increase its plasma concentration with no significantly increased drug‐related toxicity. We suggest that a larger‐sample‐size clinical trial is needed to fully understand the effect of administration of lapatinib with food.

EGFRvIII: An Oncogene with Ambiguous Role

Epidermal growth factor receptor variant III (EGFR^vIII) seems to constitute the perfect therapeutic target for glioblastoma (GB), as it is specifically present on up to 28–30% of GB cells. In case of other tumor types, expression and possible role of this oncogene still remain controversial. In spite of EGFR^vIII mechanism of action being crucial for the design of small active anticancer molecules and immunotherapies, i.e., CAR-T technology, it is yet to be precisely defined. EGFR^vIII is known to be resistant to degradation, but it is still unclear whether it heterodimerizes with EGF-activated wild-type EGFR (EGFR^WT) or homodimerizes (including covalent homodimerization). Constitutive kinase activity of this mutated receptor is relatively low, and some researchers even claim that a nuclear, but not a membrane function, is crucial for its activity. Based on the analyses of recurrent tumors that are often lacking EGFR^vIII expression despite its initial presence in corresponding primary foci, this oncogene is suggested to play a marginal role during later stages of carcinogenesis, while even in primary tumors EGFR^vIII expression is detected only in a small percentage of tumor cells, undermining the rationality of EGFR^vIII-targeting therapies. On the other hand, EGFR^vIII-positive cells are resistant to apoptosis, more invasive, and characterized with enhanced proliferation rate. Moreover, expression of this oncogenic receptor was also postulated to be a marker of cancer stem cells. Opinions regarding the role that EGFR^vIII plays in tumorigenesis and for tumor aggressiveness are clearly contradictory and, therefore, it is crucial not only to determine its mechanism of action, but also to unambiguously define its role at early and advanced cancer stages.

The Use of Epidermal Growth Factor Receptor Type 2-Targeting Tyrosine Kinase Inhibitors in the Management of Epidermal Growth Factor Receptor Type 2-Positive Gastric Cancer: A Narrative Review

Gastric cancer (GC), including gastroesophageal junction cancer (GEJC), continues to be one of the most frequently diagnosed neoplasms globally. Moreover, GC/GEJC is a principal cause of neoplasm-related fatalities. Early-stage GC/GEJC has a favorable five-year overall survival (OS) rate with surgical resection. However, the vast majority of patients present with advanced inoperable or metastatic disease with a very unfavorable five-year OS rate. Such patients are left with very limited therapeutic options, such as systemic chemotherapy, targeted therapy, and immunotherapy, all of which can be performed as monotherapy or in various combinations. The molecular profiling of GC has revealed several personalized therapeutic vulnerabilities, one of which is the expression of epidermal growth factor receptor type 2 (EGFR2, also known as HER2). HER2 overexpression or amplification is present in a fair subset of patients with GC/GEJC and has been shown to correlate with poor clinicopathological prognostic outcomes. Generally, treatment schemes to tackle HER2 in HER2-positive GC/GEJC comprise the use of anti-HER2 monoclonal antibodies or HER2-targeting tyrosine kinase inhibitors (TKIs). In this study, we engage in a narrative review of the available phase II and III literature on the efficacy and safety of HER2-targeting TKIs in the management of HER2-positive GC/GEJC.

Pyrotinib treatment on HER2-positive gastric cancer cells promotes the released exosomes to enhance endothelial cell progression, which can be counteracted by apatinib

Aims: Pyrotinib is a newly developed irreversible pan-ErbB receptor tyrosine kinase inhibitor for treatment of human epidermal growth factor receptor 2 (HER2)-positive cancers, and clinic trials of pyrotinib in treatment of HER2-positive gastric cancer (GC) are underway. Exosomes are tiny vesicles secreted by cancer cells and take essential roles in the progression of carcinoma. Whether pyrotinib application has any effect on the cancer cell-released exosomes has not been studied. The aim of our work was to address if pyrotinib treatment impacts the effect of HER2-positive GC cell-derived exosomes on endothelial cell (EC) progression.

Methods: Isolation of exosomes released by HER2-positive NCI-N87 and MKN45 lines after pyrotinib treatment was performed. Then, human umbilical vein endothelial cells (HUVECs) were incubated with different concentrations of exosomes to address their proliferation by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS). Effect of pyrotinib-treated exosomes at concentration of 10 µg/mL was compared to that without pyrotinib treatment over 96-hr time course. Transwell assay and wound-healing assay were carried out by incubating with exosomes released by NCI-N87 and MKN45 cells with/without pyrotinib treatment over 24-hr time course. The aforementioned experiments were done under same conditions in order to evaluate the combined effect of apatinib and pyrotinib on HUVEC motility and invasive capacity.

Results: We showed that HUVEC proliferation, motility and invasive capacity were further enhanced upon incubation with exosomes released by pyrotinib-treated GC cell lines, compared to those without pyrotinib treatment. Significantly, this effect was counteracted by the vascular endothelial growth factor receptor (VEGFR)-2 inhibitor apatinib which inhibits EC progression.

Conclusion: Our study suggests that pyrotinib application on HER2-positive GC produces stronger exosomes that promote the proliferation and motility of vascular ECs, and combination of pyrotinib with apatinib provides potentially better therapy.

Co-operative groups in the development of chemotherapy for gastric cancer

In the multimodality treatment strategy for gastric cancer, chemotherapy has an important role in conferring survival benefit. For the last three decades, great progress has been achieved in adjuvant and palliative chemotherapy. Powerful combination regimens using doublet or triplet cytotoxic agents have been developed and new molecular targeted drugs, including trastuzumab and ramucirumab, have been introduced in clinical practice. These advances have resulted from the accumulation of many clinical trials. A well-designed phase III trial can change standard treatment; however, such a trial is hard to complete due to its huge cost and need to recruit many patients. Some co-operative groups have actively made efforts at fundraising and patient recruitment, which can make implementation of high-quality and large-scale phase III trials possible. This review summarizes the development of chemotherapy for gastric cancer with focus on co-operative groups around the world, considering effective treatment developments in gastric cancer. We studied 11 active co-operative groups, including six in Europe, two in the United States, and three in Japan, that have completed one or more phase III trials cited in the major guidelines. Each co-operative group had its own characteristics and contributed to the establishment of standard treatment in each region. International collaboration in the development of gastric cancer treatment may be difficult due to regional differences in standards of care, particularly for resectable gastric cancer. Whereas, intergroup collaboration within each region is a reasonable method to effectively develop treatments for resectable and advanced gastric cancer.

Differential effects, on oncogenic pathway signalling, by derivatives of the HNF4 α inhibitor BI6015

Background

Gastric cancer (GC) is a highly heterogeneous disease with few “targeted” therapeutic options. Previously, we demonstrated involvement of the transcription factor HNF4α in human GC tumours, and the developmental signal mediator, WNT5A, as a prognostic GC biomarker. One previously developed HNF4α antagonist, BI6015, while not advancing beyond preclinical stages, remains useful for studying GC.

Methods

Here, we characterised the antineoplastic signalling activity of derivatives of BI6015, including transfer of the nitro group from the para position, relative to a methyl group on its benzene ring, to the ortho- and meta positions. We assessed binding efficacy, through surface plasmon resonance and docking studies, while biologic activity was assessed by antimitogenic efficacy against a panel of GC cell lines, and dysregulated transcriptomes, followed by pathway and subpathway analysis.

Results

The para derivative of BI6105 was found substantially more growth inhibitory, and effective, in downregulating numerous oncogenic signal pathways, including the embryonic cascade WNT. The ortho and meta derivatives, however, failed to downregulate WNT or other embryonic signalling pathways, unable to suppress GC growth.

Conclusion

Straightforward strategies, employing bioinformatics analyses, to facilitate the effective design and development of “druggable” transcription factor inhibitors, are useful for targeting specific oncogenic signalling pathways, in GC and other cancers.

[Metastatic stomach cancer: Clinical trials in Asia and in Occident]

Although cytotoxic chemotherapy is the main therapeutic option to treat gastric cancer in the metastatic setting, molecular targeted agents have recently been introduced in an effort to improve survival outcomes which in average do not exceed 1 year. Trastuzumab and ramucirumab, antibodies directed against HER2 and VEGFR2, respectively, may provide clinical benefit for some patients. Results of clinical studies show that Asian patients have increased survival compared to Caucasian patients. Differences between populations, and in particular the presence of polymorphisms capable of influencing the availability of fluorouracil, have been suggested as possible explanations. Other factors including histology, surgical procedures, administration of neoadjuvant chemotherapy in Western countries and screening programs in Asia have also been suggested. However, none of these elements can fully explain this phenomenon. The aim of this article is to present the main protocols used in clinical practice, the perspectives of metastatic gastric cancer treatment and the particularities observed in Asian and Caucasian patients.

Gastric cancer: Basic aspects

Despite major breakthroughs in the field of personalized medicine, gastric cancer (GC) remains a clinically challenging disease, characterized by scarce effective treatment options and the lack of reliable molecular tools for the prediction of patient outcome and response to therapy. The pronounced molecular heterogeneity that dictates the phenotypical aggressiveness of gastric neoplasms severely limits the antitumor efficacy of targeted agents brought to clinical trials, and constitutes a favorable setting for the emergence of refractory tumors exhibiting multidrug resistance. We will review the most recent advances in our understanding of GC biology, which are underlying the development and clinical testing of novel targeted therapeutic agents. We will also emphasize how their efficacy and acquired resistance relate to the aberrant molecular signatures that drive gastric malignancy.

Current Targeted Therapies in HER2-Positive Gastric Adenocarcinoma

Gastric cancer is one of the most common types of cancer in the world, usually diagnosed at an advanced stage. Despite the advances in specific anticancer agents' development, the survival rates remain modest, even in early stages. In 15%-20% of cases, the human epidermal growth factor receptor 2 (HER2) overexpression was identified. We conducted a general review to summarize the progress that has been made in the targeted treatment of HER2-positive esogastric junction or gastric adenocarcinoma. According to our findings, trastuzumab is the only validated anti-HER2 agent in locally advanced or metastatic disease and its adjuvant effectiveness is assessed in a RTOG phase III study. In a previously treated advanced disease, the maytansine derivate TDM 1 failed to be approved as a second-line regimen, and the tyrosine kinase inhibitor, lapatinib, shows modest results. The antiangiogenics have not been analyzed in specific populations and targeting the mesenchymal-epithelial transition factor (MET) receptor, overexpressed in up to 46% of the advanced disease, seems encouraging. Regarding the checkpoint inhibitors, based on KEYNOTE 059 multilevel ongoing trial, stratified according to the HER2 and programmed death-ligand (PD-L) 1 status, pembrolizumab was approved for third-line treatment of gastric or gastroesophageal junction adenocarcinoma.

JWA down-regulates HER2 expression via c-Cbl and induces lapatinib resistance in human gastric cancer cells

Human epidermal growth factor receptor 2 (HER2) targeted therapy is currently considered as the standard treatment for HER2-positive advanced gastric cancer (GC). However, unsatisfactory results of recent phase III clinical trials involving lapatinib suggested biomarkers for selection of patients. The aim of this study was to identify JWA as a biomarker for lapatinib resistance in GC cells and elucidate the underlying mechanisms. Lapatinib was effective to the intrinsic cisplatin-resistant GC cells. JWA activation conferred lapatinib unresponsiveness, but reversed cisplatin resistance in GC cells. Whereas, deletion of JWA significantly restored lapatinib suppression on proliferation and lapatinib-induced apoptosis. JWA-induced down-regulation of HER2 and activation of ERK phosphorylation led to lapatinib resistance. Furthermore, c-Cbl represented a novel mechanism for HER2 degradation enhanced by JWA in GC cells. Taken together, JWA is a potential predictive marker for lapatinib resistance, targeting the patients that may benefit from lapatinib treatment in human GC.

Current therapeutic landscape for advanced gastroesophageal cancers

Treatment of advanced gastroesophageal cancers remains challenging for clinicians, patients, and caregivers alike. Despite considerable research, the therapeutic armamentarium is restricted and hardly personalized. In the first-line setting, trastuzumab with a fluoropyrimidine and platinum agent is the standard-of-care in patients with HER2-positive tumor. For the others, a platinum-based doublet (preferably with oxaliplatin) is recommended. Three-drug cytotoxic regimens should be reserved for exceptional cases where patients have good performance status. Triple combinations produce higher toxicity and provide marginal advantage. In the second line setting, the combination of paclitaxel and ramucirumab is preferred over all others. Currently, nothing is approved in the 3rd or later line. Nivolumab has resulted in an improved benefit in an Asian trial. Early trials of TAS-102, STAT3 inhibitors, anti-claudin 18.2 and other immune checkpoint inhibitors (alone or in combination) are ongoing. However, development of reproducible biomarkers for patient enrichment is critical for future progress.

Dual or multi-targeting inhibitors: The next generation anticancer agents

Dual-targeting/Multi-targeting of oncoproteins by a single drug molecule represents an efficient, logical and alternative approach to drug combinations. An increasing interest in this approach is indicated by a steady upsurge in the number of articles on targeting dual/multi proteins published in the last 5 years. Combining different inhibitors that destiny specific single target is the standard treatment for cancer. A new generation of dual or multi-targeting drugs is emerging, where a single chemical entity can act on multiple molecular targets. Dual/Multi-targeting agents are beneficial for solving limited efficiencies, poor safety and resistant profiles of an individual target. Designing dual/multi-target inhibitors with predefined biological profiles present a challenge. The latest advances in bioinformatic tools and the availability of detailed structural information of target proteins have shown a way of discovering multi-targeting molecules. This neoteric artifice that amalgamates the molecular docking of small molecules with protein-based common pharmacophore to design multi-targeting inhibitors is gaining great importance in anticancer drug discovery. Current review focus on the discoveries of dual targeting agents in cancer therapy using rational, computational, proteomic, bioinformatics and polypharmacological approach that enables the discovery and rational design of effective and safe multi-target anticancer agents.

Association of Proton Pump Inhibitors and Capecitabine Efficacy in Advanced Gastroesophageal Cancer: Secondary Analysis of the TRIO-013/LOGiC Randomized Clinical Trial

Importance

Capecitabine is an oral cytotoxic chemotherapeutic commonly used across cancer subtypes. As with other oral medications though, it may suffer from drug interactions that could impair its absorption.

Objective

To determine if gastric acid suppressants such as proton pump inhibitors (PPIs) may impair capecitabine efficacy.

Design, Setting, and Participants

This secondary analysis of TRIO-013, a phase III randomized trial, compares capecitabine and oxaliplatin (CapeOx) with or without lapatinib in 545 patients with ERBB2/HER2-positive metastatic gastroesophageal cancer (GEC); patients were randomized 1:1 between CapeOx with or without lapatinib. Proton pump inhibitor use was identified by medication records. Progression-free survival (PFS) and overall survival (OS) were compared between patients treated with PPIs vs patients who were not. Specific subgroups were accounted for, such as younger age (<60 years), Asian ethnicity, female sex, and disease stage (metastatic/advanced) in multivariate Cox proportional hazards modeling. The TRIO-013 trial accrued and randomized patients between June 2008 and January 2012; this analysis took place in January 2014.

Interventions

Patients were divided based on PPI exposure.

Main Outcomes and Measures

Primary study outcome was PFS and OS between patients treated with PPIs vs patients who were not. Secondary outcomes included disease response rates and toxicities.

Results

Of the 545 patients with GEC (median age, 60 years; 406 men [74%]) included in the study, 229 received PPIs (42.0%) and were evenly distributed between arms. In the placebo arm, PPI-treated patients had poorer median PFS, 4.2 vs 5.7 months (hazard ratio [HR], 1.55; 95% CI, 1.29-1.81, P < .001); OS, 9.2 vs 11.3 months (HR, 1.34; 95% CI, 1.06-1.62; P = .04); and disease control rate (83% vs 72%; P = .02) vs patients not treated with PPIs. In multivariate analysis considering age, race, disease stage, and sex, PPI-treated patients had poorer PFS (HR, 1.68; 95% CI, 1.42-1.94; P < .001) and OS (HR, 1.41; 95% CI, 1.11-1.71; P = .001). In patients treated with CapeOx and lapatinib, PPIs had less effect on PFS (HR, 1.08; P = .54) and OS (HR, 1.26; P = .10); however, multivariate analysis in this group demonstrated a significant difference in OS (HR, 1.38; 95% CI, 1.06-1.66; P = .03).

Conclusions and Relevance

Proton pump inhibitors negatively effected capecitabine efficacy by possibly raising gastric pH levels, leading to altered dissolution and absorption. These results are consistent with previous erlotinib and sunitinib studies. Whether PPIs affected lapatinib is unclear given concurrent capecitabine. Given capecitabine's prevalence in treatment breast cancer and colon cancer, further studies are under way.

Trial Registration

clinicaltrials.gov Identifier: NCT00680901.

Cardiac toxicities of lapatinib in patients with breast cancer and other HER2-positive cancers: a meta-analysis

PURPOSE

Lapatinib is a tyrosine kinase inhibitor that targets the human epidermal growth factor receptor 2 (HER2) and the epidermal growth factor receptor (EGFR/HER1), and there are concerns about its cardiac toxicity. Recent studies of lapatinib have reported cardiac adverse events; however, the results have been inconsistent among the studies. The aim of our study was to estimate the cardiac toxicity of lapatinib in patients with breast cancer and other HER2-positive cancers.

METHODS

To evaluate the cardiotoxicity of lapatinib, the results of previous studies were quantitatively integrated using meta-analysis. Forty-five articles regarding cardiac adverse events, including left ventricular dysfunction, left ventricular ejection fraction (LVEF) decrease, arrhythmia, and other cardiac adverse events, were assessed. As a subgroup analysis in patients with breast cancer, 26 studies of lapatinib-induced cardiac adverse events were assessed.

RESULTS

The overall incidence of cardiac adverse events was 2.70% (95% confidence interval [CI] 1.60-4.50%). The incidences of left ventricular dysfunction and LVEF decrease were 1.60% (95% CI 1.30-2.00%) and 2.20% (95% CI 1.30-3.60%), respectively. The overall incidence of cardiac adverse events was 3.00% (95% CI 1.50-6.10%) in patients with breast cancer, which was marginally higher than the rate in patients with all type of cancers.

CONCLUSION

The overall incidence of lapatinib-induced cardiac toxicity was relatively low based on an indirect comparison with trastuzumab. However, careful monitoring of cardiac toxicity is still needed when patients are treated with lapatinib because the related risk factors have not been clearly identified.

Perspectives of HER2-targeting in gastric and esophageal cancer

INTRODUCTION

The blockade of HER2 signaling has significantly improved the outlook for esophagogastric cancer patients. However, targeting HER2 still remains challenging due to complex biology of this receptor in gastric and esophageal cancers. Areas covered: Here, we review complex HER2 biology, current methods of HER2 testing and tumor heterogeneity of gastroesophageal cancer. Ongoing and completed clinical research data are discussed. Expert opinion: HER2 overexpression is a validated target in gastroesophageal cancer, with therapeutic implications resulting in prolonged survival when inhibited in the front-line setting. With standardized HER2 testing in gastro-esophageal cancer, the ongoing trials are testing newer agents and combinations including combination of anti-HER2 antibodies with immunotherapy. Clonal heterogeneity and emergence of resistance will challenge our approach to treating these patients beyond the frontline settings.

Targeted therapies for gastric cancer: failures and hopes from clinical trials

Gastric cancer is the third leading cause of cancer mortality worldwide. As surgery is the only curative treatment strategy and conventional chemotherapy has shown limited efficacy -with a median overall survival of 10 months- new treatments are urgently needed. Trastuzumab and Ramucirumab (targeting HER2 and VEGFR2, respectively) are the only targeted therapies approved so far. Indeed, most Phase III clinical trials evaluating molecular drugs in gastric cancer failed. This review will retrace the relevant clinical trials with molecular therapies performed in gastric cancer patients, discussing the possible reasons for their failure and indicating new perspective for a real improvement of the treatment of this disease.

Evaluation of the Expression of the Human Epithelial Receptor 2 (HER2) in Gastric Carcinoma

Objective. To evaluate the HER2 expression on gastric adenocarcinoma from a Brazilian population and also to analyze the relations between the receptor and clinical characteristics, as well as the survival status. Materials and Methods. A retrospective analysis was conducted from January of 2008 to July of 2012, considering only gastrectomies with curative intent. Tumors were tested for HER2 status using immunohistochemistry. The relation between HER2 status and clinical aspects, surgical findings, and survival were also analyzed. Results. 222 patients with gastric carcinoma were submitted to surgery during that period, but only 121 (54,5%) were with curative intention. The immunohistochemistry revealed that 4 patients (3,3%) were HER2-positive, 6 patients (4,9%) HER2-undetermined, and 111 patients (91,7%) HER2-negative. There was no statistical concordance between HER2 status and survival or the clinical aspects. Conclusion. The HER2 overexpression rate was very low in this Brazilian population sample and cannot be considered as a prognostic factor.

Trastuzumab in the management of gastroesophageal cancer: patient selection and perspectives

The addition of trastuzumab to the treatment of a subset of patients with advanced gastric and gastroesophageal junction cancers showing HER2 positivity has been shown to confer clinical benefit; however, questions remain over the optimal methods for defining and selecting such patients. This review provides an overview of current standards for assessing HER2 positivity, the evolving treatment landscape for HER2-positive gastric and esophageal cancers and the challenges and potential future directions in optimal patient selection for HER2-targeted therapy.

Lapatinib resistance in HER2+ cancers: latest findings and new concepts on molecular mechanisms

In the era of new and mostly effective molecular targeted therapies, human epidermal growth factor receptor 2 positive (HER2+) cancers are still intractable diseases. Lapatinib, a dual epidermal growth factor receptor (EGFR) and HER2 tyrosine kinase inhibitor, has greatly improved breast cancer prognosis in recent years after the initial introduction of trastuzumab (Herceptin). However, clinical evidence indicates the existence of both primary unresponsiveness and secondary lapatinib resistance, which leads to the failure of this agent in HER2+ cancer patients. It remains a major clinical challenge to target the oncogenic pathways with drugs having low resistance. Multiple pathways are involved in the occurrence of lapatinib resistance, including the pathways of receptor tyrosine kinase, non-receptor tyrosine kinase, autophagy, apoptosis, microRNA, cancer stem cell, tumor metabolism, cell cycle, and heat shock protein. Moreover, understanding the relationship among these mechanisms may contribute to future tumor combination therapies. Therefore, it is of urgent necessity to elucidate the precise mechanisms of lapatinib resistance and improve the therapeutic use of this agent in clinic. The present review, in the hope of providing further scientific support for molecular targeted therapies in HER2+ cancers, discusses about the latest findings and new concepts on molecular mechanisms underlying lapatinib resistance.

The genomics and therapeutics of HER2-positive gastric cancer-from trastuzumab and beyond

Gastric cancer is a biologically heterogeneous tumor. The identification of human epidermal growth factor receptor-2 (HER2) biomarker overexpression in gastric cancer represented a significant step towards unraveling the molecular complexity of this disease. Trastuzumab in combination with chemotherapy, in the first-line setting of patients with metastatic, HER2-positive gastric and gastroesophageal, represents the first targeted therapeutic to demonstrate improvement in response rate and survival in gastric cancer. However, not all patients with HER2-positive gastric cancer respond to trastuzumab and the majority of patients who do initially benefit from trastuzumab develop resistance to it. Advances in molecular oncology and cancer genomics have helped to classify gastric cancer into molecularly distinct subtypes. This information informs research efforts investigating the etiology of mechanisms of resistance to HER2-directed therapy and guides clinical investigation in methods to overcome this resistance. This article reviews anti-HER2-therapies that are currently used as standard of care in advanced, HER2-positive, breast cancer and are now under investigation as monotherapy and in combination with chemotherapy and/or a second HER2-directed agent in advanced HER2-positive gastric cancer. The future directions of clinical investigation in HER2-positive gastric cancer are also discussed including: novel HER2-directed therapies, the pharmacokinetics and pharmacodynamics of anti-HER2-therapies, the role of functional imaging, the potential of patient derived xenograft preclinical models and the importance of tumor genomic sequencing.

Molecular-targeted first-line therapy for advanced gastric cancer

BACKGROUND

Gastric cancer is the fifth most common cancer and third leading cause of cancer-related deaths worldwide. Complete resection of the whole tumor remains the only approach to treat this malignant disease. Since gastric cancer is usually asymptomatic in its early stages, many people are diagnosed at an advanced stage when the tumor is inoperable. In addition, because other conventional treatments (radiotherapy and chemotherapy) have only modest efficacy for those with advanced/metastatic gastric cancer, the prognosis in such cases is poor. Recently, trials have provided some promising results regarding molecular-targeted therapy, raising the possibility that the development of these agents could be a fruitful approach. However, the benefit of molecular-targeted therapy for advanced gastric cancer remains inconclusive.

OBJECTIVES

To evaluate the efficacy and safety of molecular-targeted therapy , either alone or in combination with chemotherapy, in people with advanced gastric cancer.

SEARCH METHODS

We searched the following databases (from inception to December 2015): the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and CINAHL. In addition, we searched the reference lists of included trials and contacted experts in the field.

SELECTION CRITERIA

We searched for randomized controlled trials (RCTs) in adults (aged 18 years or older) with histologically-confirmed advanced adenocarcinoma of the stomach/gastro-esophageal junction. Trials of participants with esophageal adenocarcinoma were also considered to be eligible. The eligible trials should aim to evaluate the effects of molecular-targeted agents on participants' prognosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed selection of eligible trials, assessment of trial quality, and data extraction. We used methods of survival analysis and expressed the intervention effect as a hazard ratio (HR) when pooling time-to-event data, and calculated the odds ratio (OR) for dichotomous data and mean differences (MDs) for continuous data, with 95% confidence intervals (CI).

MAIN RESULTS

We included 11 studies randomizing 4014 participants to molecular-targeted therapy plus conventional chemotherapy or chemotherapy alone. Five were at low risk of bias, and we considered the risk of bias in the other six studies to be high, mainly due to their open-label design. All identified studies reported data regarding survival. We found low-quality evidence that molecular-targeted may have a small effect on mortality (HR 0.92, 95% CI 0.80 to 1.05, 10 studies) compared with conventional chemotherapy alone. Similarly, it may have little effect on progression-free survival when compared with conventional chemotherapy alone (HR 0.90, 95% CI 0.78 to 1.04, 11 studies; low-quality evidence). We did not find evidence from subgroup analysis that survival outcomes differed by type of molecular-targeted agent (EGFR- or VEGF-targeting agents) or tumor type, meaning that we were unable to explain the variation in effect across the studies by the presence or absence of prognostic biomarkers or type of molecular-targeted agent. From 11 eligible trials, we were able to use data from 3723 participants with measurable tumors. We found low-quality evidence that molecular-targeted therapy may increase tumor response (OR 1.24, 95% CI 1.00 to 1.55, low-quality evidence). Data from one small trial were too limited to determine the effect of treatment on quality of life (very low-quality evidence). The addition of targeted therapy to chemotherapy probably increases the risk of adverse events (OR 2.23, 95% CI 1.27 to 3.92, 5 trials, 2290 participants, moderate-quality evidence) and severe adverse event (OR 1.19, 95% CI 1.03 to 1.37, 8 trials, 3800 participants), compared with receiving chemotherapy alone.

AUTHORS' CONCLUSIONS

There is uncertainty about the effect of adding targeted therapy to chemotherapy on survival outcomes in people with advanced gastric cancer, with very little information on its impact on quality of life. There is more certain evidence of increased risk of adverse events and serious adverse events. The main limitation of the evidence for survival outcomes was inconsistency of effects across the studies, which we could not explain by prespecified subgroups in terms of the type of therapy or tumor type. Ongoing studies in this area are small and unlikely to improve our understanding of the effects of targeted therapy, and larger studies are needed.

A Phase II Biomarker-Embedded Study of Lapatinib plus Capecitabine as First-line Therapy in Patients with Advanced or Metastatic Gastric Cancer

An exploratory phase II biomarker-embedded trial (LPT109747; NCT00526669) designed to determine the association of lapatinib-induced fluoropyrimidine gene changes with efficacy of lapatinib plus capecitabine as first-line treatment for advanced gastric cancer or gastroesophageal junction adenocarcinoma independent of tumor HER2 status. Tumor biopsies obtained before and after 7-day lapatinib (1,250 mg) to analyze changes in gene expression, followed by a 14-day course of capecitabine (1,000 mg/m(2) twice daily, 14/21 days) plus lapatinib 1,250 mg daily. Blood samples were acquired for pharmacokinetic analysis. Primary clinical objectives were response rate (RR) and 5-month progression-free survival (PFS). Secondary objectives were overall survival (OS), PFS, time to response, duration of response, toxicity, and identification of associations between lapatinib pharmacokinetics and biomarker endpoints. Primary biomarker objectives were modulation of 5-FU-pathway genes by lapatinib, effects of germline SNPs on treatment outcome, and trough steady-state plasma lapatinib concentrations. Sixty-eight patients were enrolled; (75% gastric cancer, 25% gastroesophageal junction). Twelve patients (17.9%) had confirmed partial response, 31 (46.3%) had stable disease, and 16 (23.9%) had progressive disease. Median PFS and OS were 3.3 and 6.3 months, respectively. Frequent adverse events included diarrhea (45%), decreased appetite (39%), nausea (36%), and fatigue (36%). Lapatinib induced no changes in gene expression from baseline and no significant associations were found for SNPs analyzed. Elevated baseline HER3 mRNA expression was associated with a higher RR (33% vs. 0%; P = 0.008). Lapatinib plus capecitabine was well tolerated, demonstrating modest antitumor activity in patients with advanced gastric cancer. The association of elevated HER3 and RR warrants further investigation as an important player for HER-targeted regimens in combination with capecitabine. Mol Cancer Ther; 15(9); 2251-8. ©2016 AACR.

Genomic Alterations and Targeted Therapy in Gastric and Esophageal Adenocarcinoma

PURPOSE

Gastric and esophageal adenocarcinomas are common and aggressive malignancies. Systemic therapy for these tumors is based primarily on cytotoxic chemotherapy, but outcomes remain poor. Precision medicine, where treatments are tailored to specific molecular abnormalities of tumors, holds great promise for improving outcomes in this disease.

METHODS

A search was performed in PubMed to identify studies that have characterized the molecular basis of gastric and esophageal adenocarcinoma, as well as clinical trials exploring targeted therapies in this disease.

FINDINGS

Recent genomic studies have identified potentially targetable genomic alterations in gastroesophageal adenocarcinoma. Specifically, The Cancer Genome Atlas study defined 4 subgroups of gastric cancer, each harboring distinct genomic features. However, development of targeted therapies for gastroesophageal cancer has been challenging. The only biomarker-driven therapy in clinical practice, trastuzumab for the ~15% of patients with human epidermal growth factor receptor 2-positive disease, is modestly effective, extending median overall survival by 2.7 months. Clinical trials of other targeted therapies, including epidermal growth factor receptor, fibroblast growth factor receptor 2, and MET inhibitors, have had disappointing results so far.

IMPLICATIONS

The availability of genomic tools provides an unprecedented opportunity to develop new rational therapeutic strategies. New trial designs of targeted therapies in biomarker-selected patient populations have the potential to improve outcomes in this lethal disease. As these clinical trials are being developed, it is increasingly important to incorporate correlative studies that will allow us to identify biomarkers of response or resistance to targeted therapies.

Risk of Gastrointestinal Events During Lapatinib Therapy: A Meta-Analysis From 12,402 Patients With Cancer

Lapatinib, a tyrosine kinase inhibitor used as an anticancer therapeutic agent, has adverse events associated with treatment resulting in noncompliance and withdrawal from the therapy. Here, we performed meta-analysis of published clinical trials to determine relative risk (RR) and incidence of gastrointestinal events during lapatinib therapy in patients with cancer. A comprehensive literature search was performed and summary incidence, RR, and 95% confidence intervals (CI) were calculated using fixed-effects or random-effects models, depending on the heterogeneity of trials. Thirty-six trials with 12,402 patients were included; summary incidences of all-grade gastrointestinal events in patients with cancer were diarrhea 57.8%, nausea 30.8%, and vomiting 19.6%. Lapatinib combination with chemotherapy or any anti-HER2 mAbs were associated with significant risk of all-grade diarrhea [(RR 3.64, 95% CI, 2.96-4.49), (RR 2.89, 95% CI, 2.21-3.79), respectively] and high-grade diarrhea [(RR 11.25, 95% CI, 7.31-17.33), (RR 9.96, 95% CI, 7.23-13.72), respectively], and lapatinib combination with chemotherapy group showed a significantly increased risk of all-grade nausea (RR 1.54, 95% CI, 1.25-1.89). Lapatinib combination with chemotherapy or any anti-HER2 mAbs were associated with significant risk of all-grade vomiting [(RR 1.47, 95% CI, 1.12-1.93), (RR 1.30, 95% CI, 1.11-1.52), respectively]. Lapatinib combination with any anti-HER2 mAbs was associated with a significant risk of high-grade vomiting (RR 2.25, 95% CI, 1.41-3.61). This study revealed a significantly increased risk of diarrhea, nausea, and vomiting in patients with cancer receiving lapatinib, suggesting that appropriate clinical intervention and gastrointestianal protective agents should be emphasized.

Lapatinib in Combination With Capecitabine Plus Oxaliplatin in Human Epidermal Growth Factor Receptor 2–Positive Advanced or Metastatic Gastric, Esophageal, or Gastroesophageal Adenocarcinoma: TRIO-013/LOGiC—A Randomized Phase III Trial

Purpose

To evaluate the efficacy of adding lapatinib to capecitabine and oxaliplatin (CapeOx) in patients with previously untreated human epidermal growth factor receptor 2 (HER2) –amplified advanced gastroesophageal adenocarcinoma.

Patients and Methods

Patients with HER2-positive advanced gastroesophageal adenocarcinoma were randomly assigned at a one-to-one ratio to CapeOx plus lapatinib 1,250 mg or placebo daily. Primary end point was overall survival (OS) in patients with centrally confirmed HER2 amplification in the primary efficacy population.

Results

A total of 545 patients were randomly assigned, and 487 patients comprised the primary efficacy population. Median OS in the lapatinib and placebo arms was 12.2 (95% CI, 10.6 to 14.2) and 10.5 months (95% CI, 9.0 to 11.3), respectively, which was not significantly different (hazard ratio, 0.91; 95% CI, 0.73 to 1.12). Median progression-free survival in the lapatinib and placebo arms was 6.0 (95% CI, 5.6 to 7.0) and 5.4 months (95% CI, 4.4 to 5.7), respectively (hazard ratio, 0.82; 95% CI, 0.68 to 1.00; P = .0381). Response rate was significantly higher in the lapatinib arm: 53% (95% CI, 46.4 to 58.8) compared with 39% (95% CI, 32.9 to 45.3) in the placebo arm (P = .0031). Preplanned exploratory subgroup analyses showed OS in the lapatinib arm was prolonged in Asian and younger patients. No correlation was observed between HER2 immunohistochemistry status and survival. There were increased toxicities in the lapatinib arm, particularly diarrhea.

Conclusion

Addition of lapatinib to CapeOx did not increase OS in patients with HER2-amplified gastroesophageal adenocarcinoma. There were clear differences in the effect of lapatinib depending on region and age. Future studies could examine this correlation.

Changing strategies for target therapy in gastric cancer

In spite of a worldwide decrease in the incidence of gastric cancer, this malignancy still remains one of the leading causes of cancer mortality. Great efforts have been made to improve treatment outcomes in patients with metastatic gastric cancer, and the introduction of trastuzumab has greatly improved the overall survival. The trastuzumab treatment took its first step in opening the era of molecular targeted therapy, however several issues still need to be resolved to increase the efficacy of targeted therapy. Firstly, many patients with metastatic gastric cancer who receive trastuzumab in combination with chemotherapeutic agents develop resistance to the targeted therapy. Secondly, many clinical trials testing novel molecular targeted agents with demonstrated efficacy in other malignancies have failed to show benefit in patients with metastatic gastric cancer, suggesting the importance of the selection of appropriate indications according to molecular characteristics in application of targeted agents. Herein, we review the molecular targeted agents currently approved and in use, and clinical trials in patients with metastatic gastric cancer, and demonstrate the limitations and future direction in treatment of advanced gastric cancer.

Targeted therapies in gastric cancer and future perspectives

Advanced gastric cancer (AGC) is associated with a high mortality rate and, despite multiple new chemotherapy options, the survival rates of patients with AGC remains poor. After the discovery of targeted therapies, research has focused on the new treatment options for AGC. In the last two decades, many targeted molecules were developed against AGC. Currently, two targeted therapy molecules have been approved for patients with AGC. In 2010, trastuzumab was the first molecule shown to improve survival in patients with HER2-positive AGC as part of a first-line combination regimen. In 2014, ramucirumab was the second targeted molecule to improve survival rates and was suggested as treatment for patients with AGC who had progressed after first-line platinum plus fluoropyrimidine with or without anthracycline chemotherapy. Ramucirumab was the first targeted therapy acting as a single agent in patients with advanced gastroesophageal cancers. Although these two molecules were introduced into clinical use, many other promising molecules have been tested in phase I-II trials. It is obvious that in the near future many different targeted therapies will be in use for treatment of AGC. In this review, the current status of targeted therapies in the treatment of AGC and gastroesophageal junction tumors, including HER (2-3) inhibitors, epidermal growth factor receptor inhibitors, tyrosine kinase inhibitors, antiangiogenic agents, c-MET inhibitors, mammalian target of rapamycin inhibitors, agents against other molecular pathways fibroblast growth factor, Claudins, insulin-like growth factor, heat shock proteins, and immunotherapy, will be discussed.

Targeting HER 2 and angiogenesis in gastric cancer

Gastric cancer is one of the most commonly diagnosed and the second leading cause of cancer death worldwide. Surgery combined with multimodal therapy remains the only curative therapy. However, local relapse or distant metastases occur in more than 50% of radically resected patients. Due to molecular therapies, targeting HER2 and angiogenesis, major advances in the treatment of gastric cancer could be achieved. Nevertheless, development of resistance to monoclonal antibodies, such as trastuzumab, is arising. Currently a number of promising new therapeutic are under investigation, combining chemotherapy with newly developed agents to overcome cancer resistance. In this review we report current clinical applications of targeted therapies and overview ongoing trials, investigating the use of monoclonal antibodies in (HER2 positive) gastric cancer.

Molecular targeted therapy in gastric cancer

Gastric cancer is one of the most common malignant tumors in China. Traditional treatments such as surgery, radiotherapy and chemotherapy not only have side effects, but the treatment efficiency is also poor. Molecular targeted therapy, due to its high efficiency, low toxicity, and high orientation, has been widely used in the treatment of gastric cancer. Targets applied in molecular targeted therapy of gastric cancer are mainly related to the cytokine and receptors that contribute to gastric cancer cell growth, including epidermal growth factor and its receptors, vascular endothelial growth factor and its receptors, epithelial cell adhesion molecules, insulin-like growth factor and its receptors, and molecules related to the cell cycle. This review focuses on molecular targeted treatment in gastric cancer.

Molecular effects of Lapatinib in the treatment of HER2 overexpressing oesophago-gastric adenocarcinoma

BACKGROUND

Lapatinib, a dual EGFR and HER2 inhibitor has shown disappointing results in clinical trials of metastatic oesophago-gastric adenocarcinomas (OGAs), and in vitro studies suggest that MET, IGFR, and HER3 confer resistance. This trial applied Lapatinib in the curative neoadjuvant setting and investigated the feasibility and utility of additional endoscopy and biopsy for assessment of resistance mechanisms ex vivo and in vivo.

METHODS

Patients with HER2 overexpressing OGA were treated for 10 days with Lapatinib monotherapy, and then in combination with three cycles of Oxaliplatin and Capecitabine before surgery. Endoscopic samples were taken for molecular analysis at: baseline including for ex vivo culture +/- Lapatinib to predict in vivo response, post-Lapatinib monotherapy and at surgery. Immunohistochemistry (IHC) and proteomic analysis was performed to assess cell kinetics and signalling activity.

RESULTS

The trial closed early (n=10) due to an anastomotic leak in two patients for which a causative effect of Lapatinib could not be excluded. The reduction in Phosphorylated-HER2 (P-HER2) and P-EGFR in the ex vivo-treated biopsy demonstrated good correlation with the in vivo response at day 10. Proteomic analysis pre and post-Lapatinib demonstrated target inhibition (P-ERBB2, P-EGFR, P-PI3K, P-AKT, and P-ERK) that persisted until surgery. There was also significant correlation between the activation of MET with the level of P-Erk (P=0.0005) and P-PI3K : T-PI3K (total PI3K) ratio (P=0.0037). There was no significant correlation between the activation status of IGFR and HER3 with downstream signalling molecules.

CONCLUSIONS

Additional endoscopy and biopsy sampling for multiple biomarker endpoints was feasible and confirmed in vitro data that MET is likely to be a significant mechanism of Lapatinib resistance in vivo.

Advancing pharmacological treatment options for advanced gastric cancer

INTRODUCTION

Gastric cancer is the third most common cause of cancer-related deaths worldwide. Improvement of conventional chemotherapy has been modest in the past decades.

AREAS COVERED

We review recent important studies of metastatic or recurrent gastric cancer. For human epidermal growth factor receptors 2 (HER2) negative cancer, standard treatments are combinations of fluoropyrimidine and platinum with or without epirubicin or docetaxel in first-line therapy. Controversy exists regarding the use of triplet chemotherapies due to their toxicity. For HER2 positive cancer, standard treatments are combinations of fluoropyrimidine and cisplatin with trastuzumab. As second- or third-line treatment, taxanes or irinotecan prolonged survival compared with best supportive care alone, but the extension of overall survival was only 1 - 2 months. A recent study demonstrated that ramucirumab plus paclitaxel improved survival as a second-line therapy.

EXPERT OPINION

Most trials have failed to demonstrate a benefit of targeted agents. It is important to identify predictive biomarkers to enrich an appropriate patient population for targeted agents such as HER2 status for trastuzumab.

Current and Future Therapies for Advanced Gastric Cancer

The treatment of patients with advanced gastric cancer remains a challenging area of oncology. Extensive trials of differing chemotherapy regimens have yielded no international consensus on the optimal combination, and overall survival with chemotherapy alone remains poor. Recently an improved understanding of the molecular drivers of the disease has opened up promising new avenues of treatment through the use of biological targeted agents. The anti-HER2 monoclonal antibody trastuzumab was the first targeted agent to significantly prolong survival in the first-line treatment of a molecularly-selected subgroup of patients. More recently the anti-vascular endothelial growth factor receptor 2 monoclonal antibody ramucirumab has demonstrated a modest survival benefit in previously treated patients as both a monotherapy and in combination with chemotherapy. Immunotherapy and the use of checkpoint inhibitors are a further exciting area of development with promising preliminary results for the activity of the anti-Programmed Death 1 Receptor antibody pembrolizumab and ongoing trials of a number of immune-modulating agents. Continuing research to identify novel targets and therapies aims to make further incremental gains in survival. In this review we outline the evidence base supporting current chemotherapy regimens and describe the latest advances in the development and use of molecularly targeted and immune-modulating agents.

HER2 directed therapy for gastric/esophageal cancers

OPINION STATEMENT

The majority of patients with esophagogastric cancer present with advanced disease, which is incurable. Systemic chemotherapy can lead to a decrease in cancer-related symptoms and prolongs survival. However, even with treatment, the prognosis remains poor; most patients with advanced disease have a median overall survival less than one year. Molecularly targeted therapies, such as those targeting human epidermal growth factor receptor 2 (HER2), are anticipated to improve the current status of systemic treatment beyond conventional cytotoxic therapy. Trastuzumab in combination with chemotherapy in patients is the first molecular agent in metastatic HER2 positive gastric and gastroesophageal adenocarcinomas to result in improvements in response rates, time to progression and survival. Trastuzumab is now being investigated in the neoadjuvant and adjuvant setting. Unfortunately, as with breast cancer, many esophagogastric patients will develop resistance to trastuzumab. Several promising therapies are currently under investigation as monotherapy and in combination with chemotherapy in the first and second line setting.

Targeted therapy in gastric cancer

Gastric cancer is often diagnosed at an advanced stage. Although chemotherapy prolongs survival and improves quality of life, the survival of gastric cancer patients with advanced disease is short. Thanks to recent insights into the molecular pathways involved in gastric carcinogenesis, new targeted treatment options have become available for gastric cancer patients. Trastuzumab, an antibody targeted to HER-2, was shown to improve survival of advanced gastric cancer patients harboring HER-2 overexpression due to gene amplification in their tumor cells, and is currently also explored in adjuvant and neoadjuvant settings. Another agent with promising results in clinical trials is ramucirumab, an antibody targeting VEGFR-2. No clear survival benefit, however, were experienced with agents targeting EGFR (cetuximab, panitumumab), VEGF-A (bevacizumab), or mTOR (everolimus). Drugs targeting c-MET/HGF are currently under investigation in biomarker-selected cohorts, with promising results in early clinical trials. This review will summarize the current status of targeted treatment options in gastric cancer.