MODUL-a multicenter randomized clinical trial of biomarker-driven maintenance therapy following first-line standard induction treatment of metastatic colorectal cancer: an adaptable signal-seeking approach

Combining Anti-epidermal Growth Factor Receptor (EGFR) Therapy with Immunotherapy in Metastatic Colorectal Cancer (mCRC)

INTRODUCTION

Monoclonal antibodies binding the EGFR, such as cetuximab and panitumumab, have been extensively used as targeted therapy for the treatment of mCRC. However, in clinical practice, it has been found that these treatment options have some limitations and fail to fully exploit their immunoregulatory activities. Meanwhile, because of the limited effects of current treatments, immunotherapy is being widely studied for patients with mCRC. However, previous immunotherapy trials in mCRC patients have had unsatisfactory outcomes as monotherapy. Thus, combinatorial treatment strategies are being researched.

AREAS COVERED

The authors retrieved relevant documents of combination therapy for mCRC from PubMed and Medline. This review elaborates on the knowledge of immunomodulatory effects of anti-EGFR therapy alone and in combination with immunotherapy for mCRC.

EXPERT OPINION

Although current treatment options have improved median overall survival (OS) for advanced disease to 30 months, the prognosis remains challenging for those with metastatic disease. More recently, the combination of anti-EGFR therapy with immunotherapy has been shown activity with complementary mechanisms. Hence, anti-EGFR therapy in combination with immunotherapy may hold the key to improving the therapeutic effect of refractory mCRC.

Redefining the battle against colorectal cancer: a comprehensive review of emerging immunotherapies and their clinical efficacy

Colorectal cancer (CRC) is the third most common cancer globally and presents a significant challenge owing to its high mortality rate and the limitations of traditional treatment options such as surgery, radiotherapy, and chemotherapy. While these treatments are foundational, they are often poorly effective owing to tumor resistance. Immunotherapy is a groundbreaking alternative that has recently emerged and offers new hope for success by exploiting the body's own immune system. This article aims to provide an extensive review of clinical trials evaluating the efficacy of various immunotherapies, including CRC vaccines, chimeric antigen receptor T-cell therapies, and immune checkpoint inhibitors. We also discuss combining CRC vaccines with monoclonal antibodies, delve into preclinical studies of novel cancer vaccines, and assess the impact of these treatment methods on patient outcomes. This review seeks to provide a deeper understanding of the current state of CRC treatment by evaluating innovative treatments and their potential to redefine the prognosis of patients with CRC.

The next bastion to be conquered in immunotherapy: microsatellite stable colorectal cancer

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide, and its incidence continues to rise, particularly in developing countries. The advent of immune checkpoint inhibitors (ICIs) has represented a significant advancement in CRC treatment. Deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H) serves as a biomarker for immunotherapy, with dMMR/MSI-H CRC exhibiting significantly better response rates to immunotherapy compared to proficient mismatch repair (pMMR)or microsatellite stable (MSS) CRC. While some progress has been made in the treatment of pMMR/MSS CRC in recent years, it remains a challenging issue in clinical practice. The tumor microenvironment (TME) plays a crucial role not only in the development and progression of CRC but also in determining the response to immunotherapy. Understanding the characteristics of the TME in pMMR/MSS CRC could offer new insights to enhance the efficacy of immunotherapy. In this review, we provide an overview of the current research progress on the TME characteristics and advancements in immunotherapy for pMMR/MSS CRC.

Circulating Tumor DNA to Drive Treatment in Metastatic Colorectal Cancer

In the evolving molecular treatment landscape of metastatic colorectal cancer (mCRC), the identification of druggable alterations is pivotal to achieve the best therapeutic opportunity for each patient. Because the number of actionable targets is expanding, there is the need to timely detect their presence or emergence to guide the choice of different available treatment options. Liquid biopsy, through the analysis of circulating tumor DNA (ctDNA), has proven safe and effective as a complementary method to address cancer evolution while overcoming the limitations of tissue biopsy. Even though data are accumulating regarding the potential for ctDNA-guided treatments applied to targeted agents, still major gaps in knowledge exist as for their application to different areas of the continuum of care. In this review, we recapitulate how ctDNA information could be exploited to drive different targeted treatment strategies in mCRC patients, by refining molecular selection before treatment by addressing tumor heterogeneity beyond tumor tissue biopsy; longitudinally monitoring early-tumor response and resistance mechanisms to targeted agents, potentially leading to tailored, molecular-driven, therapeutic options; guiding the molecular triage towards rechallenge strategies with anti-EGFR agents, suggesting the best time for retreatment; and providing opportunities for an "enhanced rechallenge" through additional treatments or combos aimed at overcoming acquired resistance. Besides, we discuss future perspectives concerning the potential role of ctDNA to fine-tune investigational strategies such as immuno-oncology.

Current status and prospect of immunotherapy for colorectal cancer

PURPOSE

Colorectal cancer is the most common gastrointestinal tumor in China. While significant progress has been achieved in traditional chemotherapy, radiotherapy, and targeted therapy, the prognosis of advanced colorectal cancer is poor, and the five-year survival rate is unsatisfactory. There is an urgent need to explore new treatment modalities. In this review, we examined the latest progress of colorectal cancer immunotherapy and discussed its future prospects.

METHODS

We conducted a literature review to sort out the current status of immunotherapy for different types of colorectal cancer and discussed potential combination therapy options. Results Subsequent line therapy, first-line therapy and neoadjuvant therapy for MSI-H/dMMR colorectal cancer are discussed. In addition, combination therapy options for patients with MSS/pMMR colorectal cancer are presented. Finally, current valuable biomarkers for immunotherapy are highlighted.

RESULTS

Subsequent line therapy, first-line therapy and neoadjuvant therapy for MSI-H/dMMR colorectal cancer are discussed. In addition, combination therapy options for patients with MSS/pMMR colorectal cancer are presented. Finally, current valuable biomarkers for immunotherapy are highlighted.

CONCLUSION

This review discussed the current status of immunotherapy for different types of colorectal cancer and biomarkers for immunotherapy.

Immunocheckpoint Inhibitors in Microsatellite-Stable or Proficient Mismatch Repair Metastatic Colorectal Cancer: Are We Entering a New Era?

Colorectal cancer (CRC) is the third most frequent cancer and the second leading cause of cancer-related deaths in Europe. About 5% of metastatic CRC (mCRC) are characterized by high microsatellite instability (MSI) due to a deficient DNA mismatch repair (dMMR), and this condition has been related to a high sensitivity to immunotherapy, in particular to the Immune Checkpoint Inhibitors (ICIs). In fact, in MSI-H or dMMR mCRC, treatment with ICIs induced remarkable response rates and prolonged survival. However, the majority of mCRC cases are mismatch-repair-proficient (pMMR) and microsatellite-stable (MSS), and unfortunately these conditions involve resistance to ICIs. This review aims to provide an overview of the strategies implemented to overcome ICI resistance and/or define subgroups of patients with MSS or dMMR mCRC who may benefit from immunotherapy.

Implementation of precision medicine in healthcare-A European perspective

The technical development of high-throughput sequencing technologies and the parallel development of targeted therapies in the last decade have enabled a transition from traditional medicine to personalized treatment and care. In this way, by using comprehensive genomic testing, more effective treatments with fewer side effects are provided to each patient-that is, precision or personalized medicine (PM). In several European countries-such as in England, France, Denmark, and Spain-the governments have adopted national strategies and taken "top-down" decisions to invest in national infrastructure for PM. In other countries-such as Sweden, Germany, and Italy with regionally organized healthcare systems-the profession has instead taken "bottom-up" initiatives to build competence networks and infrastructure to enable equal access to PM. In this review, we summarize key learnings at the European level on the implementation process to establish sustainable governance and organization for PM at the regional, national, and EU/international levels. We also discuss critical ethical and legal aspects of implementing PM, and the importance of access to real-world data and performing clinical trials for evidence generation, as well as the need for improved reimbursement models, increased cross-disciplinary education and patient involvement. In summary, PM represents a paradigm shift, and modernization of healthcare and all relevant stakeholders-that is, healthcare, academia, policymakers, industry, and patients-must be involved in this system transformation to create a sustainable, non-siloed ecosystem for precision healthcare that benefits our patients and society at large.

The NCI-MATCH trial: lessons for precision oncology

The NCI-MATCH (Molecular Analysis for Therapy Choice) trial ( NCT02465060 ) was launched in 2015 as a genomically driven, signal-seeking precision medicine platform trial-largely for patients with treatment-refractory, malignant solid tumors. Having completed in 2023, it remains one of the largest tumor-agnostic, precision oncology trials undertaken to date. Nearly 6,000 patients underwent screening and molecular testing, with a total of 1,593 patients (inclusive of continued accrual from standard next-generation sequencing) being assigned to one of 38 substudies. Each substudy was a phase 2 trial of a therapy matched to a genomic alteration, with a primary endpoint of objective tumor response by RECIST criteria. In this Perspective, we summarize the outcomes of the initial 27 substudies in NCI-MATCH, which met its signal-seeking objective with 7/27 positive substudies (25.9%). We discuss key aspects of the design and operational conduct of the trial, highlighting important lessons for future precision medicine studies.

Clinical and exploratory biomarker findings from the MODUL trial (Cohorts 1, 3 and 4) of biomarker-driven maintenance therapy for metastatic colorectal cancer

PURPOSE

MODUL is an adaptable, signal-seeking trial of biomarker-driven maintenance therapy following first-line induction treatment in patients with metastatic colorectal cancer (mCRC). We report findings from Cohorts 1 (BRAF^mut), 3 (human epidermal growth factor 2 [HER2]+) and 4 (HER2‒/high microsatellite instability, HER2‒/microsatellite stable [MSS]/BRAF^wt or HER2‒/MSS/BRAF^mut/RAS^mut).

METHODS

Patients with unresectable, previously untreated mCRC without disease progression following standard induction treatment (5-fluorouracil/leucovorin [5-FU/LV] plus oxaliplatin plus bevacizumab) were randomly assigned to control (fluoropyrimidine plus bevacizumab) or cohort-specific experimental maintenance therapy (Cohort 1: vemurafenib plus cetuximab plus 5-FU/LV; Cohort 3: capecitabine plus trastuzumab plus pertuzumab; Cohort 4: cobimetinib plus atezolizumab). The primary efficacy end-point was progression-free survival (PFS).

RESULTS

Cohorts 1, 3 and 4 did not reach target sample size because of early study closure. In Cohort 1 (n = 60), PFS did not differ between treatment arms (hazard ratio, 0.95; 95% confidence intervals 0.50-1.82; P = 0.872). However, Cohort 1 exploratory biomarker data showed preferential selection for mitogen-activated protein kinase (MAPK) pathway mutations (mainly KRAS, NRAS, MAP2K1 or BRAF) in the experimental arm but not the control arm. In Cohort 3 (n = 5), PFS ranged from 3.6 to 14.7 months versus 4.0 to 5.4 months in the experimental and control arms, respectively. In Cohort 4 (n = 99), PFS was shorter in the experimental arm (hazard ratio, 1.44; 95% confidence intervals 0.90-2.29; P = 0.128).

CONCLUSIONS

Vemurafenib plus cetuximab plus 5-FU/LV warrants further investigation as first-line maintenance treatment for BRAF^mut mCRC. MAPK-pathway emergent genomic alterations may offer novel therapeutic opportunities in BRAF^mut mCRC. Cobimetinib plus atezolizumab had an unfavourable benefit:risk ratio in HER2‒/MSS/BRAF^wt mCRC. New strategies are required to increase the susceptibility of MSS mCRC to immunotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02291289.

Therapeutic landscape and future direction of metastatic colorectal cancer

In the era of targeted therapy based on genomic alterations, the treatment strategy for metastatic colorectal cancer (mCRC) has been changing. Before systemic treatment initiation, determination of tumour genomic status for KRAS and NRAS, BRAF^V600E mutations, ERBB2, and microsatellite instability and/or mismatch repair (MMR) status is recommended. In patients with deficient MMR and BRAF^V600E mCRC, randomized phase III trials have established the efficacy of pembrolizumab as first-line therapy and the combination of encorafenib and cetuximab as second-line or third-line therapy. In addition, new agents have been actively developed in other rare molecular fractions such as ERBB2 alterations and KRAS^G12C mutations. In March 2022, the combination of pertuzumab and trastuzumab for ERBB2-positive mCRC was approved in Japan, thereby combining real-world evidence from the SCRUM-Japan Registry. As the populations are highly fragmented owing to rare genomic alterations, various strategies in clinical development are expected. Clinical development of a tumour-agnostic approach, such as NTRK fusion and tumour mutational burden, has successfully introduced corresponding drugs to clinical practice. Considering the difficulty of randomized trials owing to cost-benefit and rarity, a promising solution could be real-world evidence utilized as an external control from the molecular-based disease registry.

The role of immunotherapy in microsatellites stable metastatic colorectal cancer: state of the art and future perspectives

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths worldwide, despite several advances has been achieved in last decades. Few prognostic and predictive biomarkers guide therapeutic choice in metastatic CRC (mCRC), among which DNA mismatch repair deficiency and/or microsatellite instability (dMMR/MSI) holds a crucial role. Tumors characterized by dMMR/MSI benefit from immune checkpoint inhibitors. However, most of the mCRC patients (around 95%) are microsatellite stable (MSS), thereby intrinsically resistant to immunotherapy. This represents a clear unmet need for more effective treatments in this population of patients. In this review, we aim to analyze immune-resistance mechanisms and therapeutic strategies to overcome them, such as combinations of immunotherapy and chemotherapy, radiotherapy or target therapies specifically in MSS mCRC. We also explored both available and potential biomarkers that may better select MSS mCRC patients for immunotherapy. Lastly, we provide a brief overview on future perspectives in this field, such as the gut microbiome and its potential role as immunomodulator.

Design and analysis of umbrella trials: Where do we stand?

Background

The efficiencies that master protocol designs can bring to modern drug development have seen their increased utilization in oncology. Growing interest has also resulted in their consideration in non-oncology settings. Umbrella trials are one class of master protocol design that evaluates multiple targeted therapies in a single disease setting. Despite the existence of several reviews of master protocols, the statistical considerations of umbrella trials have received more limited attention.

Methods

We conduct a systematic review of the literature on umbrella trials, examining both the statistical methods that are available for their design and analysis, and also their use in practice. We pay particular attention to considerations for umbrella designs applied outside of oncology.

Findings

We identified 38 umbrella trials. To date, most umbrella trials have been conducted in early phase settings (73.7%, 28/38) and in oncology (92.1%, 35/38). The quality of statistical information available about conducted umbrella trials to date is poor; for example, it was impossible to ascertain how sample size was determined in the majority of trials (55.3%, 21/38). The literature on statistical methods for umbrella trials is currently sparse.

Conclusions

Umbrella trials have potentially great utility to expedite drug development, including outside of oncology. However, to enable lessons to be effectively learned from early use of such designs, there is a need for higher-quality reporting of umbrella trials. Furthermore, if the potential of umbrella trials is to be realized, further methodological research is required.

MODUL cohort 2: an adaptable, randomized, signal-seeking trial of fluoropyrimidine plus bevacizumab with or without atezolizumab maintenance therapy for BRAFwt metastatic colorectal cancer

Background

MODUL is an adaptable, signal-seeking trial designed to test novel agents in predefined patient subgroups in first-line metastatic colorectal cancer (mCRC).

Patients and methods

Patients with measurable, unresectable, previously untreated mCRC received induction with ≤8 cycles of FOLFOX + bevacizumab followed by randomization to maintenance treatment comprising control [fluoropyrimidine (FP)/bevacizumab: 5-fluorouracil 1600-2400 mg/m² 46-h intravenous (i.v.) infusion day 1 q2 weeks plus leucovorin 400 mg/m² 2-h infusion i.v. day 1 q2 weeks or capecitabine 1000 mg/m² b.i.d. orally days 1-14 every 21 days; bevacizumab 5 mg/kg 15-30-min i.v. infusion q2 weeks] or experimental treatment in one of four biomarker-driven cohorts. In patients with BRAF wild-type (BRAF^wt) tumors (cohort 2), experimental treatment was FP/bevacizumab + atezolizumab (800 mg 60-min i.v. infusion q2 weeks). Primary efficacy endpoint was progression-free survival (PFS; intent-to-treat population). Enrollment is complete; efficacy and safety findings from cohort 2 are presented.

Results

Four hundred and forty-five patients with BRAF^wt mCRC were randomized (2 : 1) to maintenance in cohort 2. At a median follow-up of 10.5 months, PFS outcome hypothesis was not met [hazard ratio (HR) 0.92; 95% confidence interval (CI) 0.72-1.17; P = 0.48]; overall survival (OS) was immature. At a median follow-up of 20.3 months (2-year survival follow-up), PFS benefit was also not met (HR 0.95; 95% CI 0.77-1.18; P = 0.666); OS HR with nearly two-thirds of patients with events was 0.83 (95% CI 0.65-1.05; P = 0.117). No new safety signals were identified. The most common grade ≥3 treatment-emergent adverse events (TEAEs) for experimental versus control arms were hypertension (6.1% versus 4.2%), diarrhea (3.1% versus 2.1%), and palmar-plantar erythrodysesthesia syndrome (1.0% versus 2.5%). Four patients experienced TEAEs with fatal outcome, two were study treatment-related: hepatic failure (experimental arm) and large intestine perforation (control arm; bevacizumab-related).

Conclusions

Adding atezolizumab to FP/bevacizumab as first-line maintenance treatment after FOLFOX + bevacizumab induction for BRAF^wt mCRC did not improve efficacy outcomes.

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MODUL is an adaptable, signal-seeking trial of novel combinations in predefined subgroups of patients with mCRC.

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In cohort 2 (BRAF^wt mCRC), adding atezolizumab to FP/bevacizumab (bev) first-line maintenance therapy did not improve PFS or OS versus FP/bev.

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ORR and DCR were numerically but not statistically significantly higher with atezolizumab + FP/bev versus FP/bev.

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The safety profile of atezolizumab + FP/bev was consistent with previous findings with no new safety signals identified.

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Findings from MODUL cohort 2 indicate that immunotherapy has limited efficacy in patients with microsatellite stable mCRC.

PD-1/PD-L1 blockade, a novel strategy for targeting metastatic colorectal cancer: A systematic review and meta-analysis of randomized trials

Currently, standard treatment of patients with metastatic colorectal cancer (mCRC) comprises chemotherapy (CT) and/or biological therapy (BT) and/or best supportive care (BSC). The present study performed a meta-analysis on five phase II-III randomized clinical trials, which compared CT/BT/BSC as the control arm with the immune checkpoint inhibitors (ICIs) anti-programmed cell death protein 1 (PD-1) or its ligand (PD-L1) alone or in combination with cytotoxic T lymphocyte antigen 4 or mitogen activated protein kinase kinase inhibitors as the experimental arm, to evaluate whether a standard approach could be overcome using the novel target therapy strategy. Pooled hazard ratio (HR) for progression-free survival was 0.95 in favor of the experimental arm [95% confidence interval (CI), 0.74-1.22; P=0.68]. Heterogeneity was significant: Cochran's Q, 21.0; P=0.0082; I2 index, 76%. Pooled HR for overall survival was 0.88 in favor of the experimental arm (95% CI, 0.75-1.02; P=0.08). Heterogeneity was not significant (Cochran's Q, 6.0; P=0.31; I2 index, 16%). The present meta-analysis demonstrated a trend toward the improvement of survival by PD-1/PD-L1 blockade in mCRC. Further homogeneous studies are necessary to strengthen these results, beyond the known benefits of ICIs in deficient mismatch repair/high microsatellite instability tumors.

Remodeling Chondroitin-6-Sulfate-Mediated Immune Exclusion Enhances Anti-PD-1 Response in Colorectal Cancer with Microsatellite Stability

Metastatic microsatellite-stable (MSS) colorectal cancer rarely responds to immune checkpoint inhibitors (ICI). Metabolism heterogeneity in the tumor microenvironment (TME) presents obstacles to antitumor immune response. Combining transcriptome (The Cancer Genome Atlas MSS colorectal cancer, n = 383) and digital pathology (n = 96) analysis, we demonstrated a stroma metabolism-immune excluded subtype with poor prognosis in MSS colorectal cancer, which could be attributed to interaction between chondroitin-6-sulfate (C-6-S) metabolites and M2 macrophages, forming the "exclusion barrier" in the invasive margin. Furthermore, C-6-S derived from cancer-associated fibroblasts promoted co-nuclear translocation of pSTAT3 and GLI1, activating the JAK/STAT3 and Hedgehog pathways. In vivo experiments with C-6-S-targeted strategies decreased M2 macrophages and reprogrammed the immunosuppressive TME, leading to enhanced response to anti-PD-1 in MSS colorectal cancer. Therefore, C-6-S-induced immune exclusion represents an "immunometabolic checkpoint" that can be exploited for the application of combination strategies in MSS colorectal cancer ICI treatment.

Patient Knowledge and Expectations About Return of Genomic Results in a Biomarker-Driven Master Protocol Trial (SWOG S1400GEN)

PURPOSE

Biomarker-driven master protocols represent a new paradigm in oncology clinical trials, but their complex designs and wide-ranging genomic results returned can be difficult to communicate to participants. The objective of this pilot study was to evaluate patient knowledge and expectations related to return of genomic results in the Lung Cancer Master Protocol (Lung-MAP).

METHODS

Eligible participants with previously treated advanced non-small-cell lung cancer were recruited from patients enrolled in Lung-MAP. Participants completed a 38-item telephone survey ≤ 30 days from Lung-MAP consent. The survey assessed understanding about the benefits and risks of Lung-MAP participation and knowledge of the potential uses of somatic testing results returned. Descriptive statistics and odds ratios for associations between demographic factors and correct responses to survey items were assessed.

RESULTS

From August 1, 2017, to June 30, 2019, we recruited 207 participants with a median age of 67, 57.3% male, and 94.2% White. Most participants "strongly/somewhat agreed" with statements that they "received enough information to understand" Lung-MAP benefits (82.6%) and risks (69.5%). In items asking about potential uses of Lung-MAP genomic results, 87.0% correctly indicated that the results help to select cancer treatment, but < 20% correctly indicated that the results are not used to confirm cancer diagnosis, would not reveal risk of developing diseases besides cancer, and would not indicate if family members had increased cancer risk. There were no associations between sociodemographic factors and proportions providing correct responses.

CONCLUSION

In a large National Clinical Trials Network biomarker-driven master protocol, most participants demonstrated incorrect knowledge and expectations about the uses of genomic results provided in the study despite most indicating that they had enough information to understand benefits and risks.

Targeted Immunotherapies in Gastrointestinal Cancer: From Molecular Mechanisms to Implications

Gastrointestinal cancer is a leading cause of cancer-related mortality and remains a major challenge for cancer treatment. Despite the combined administration of modern surgical techniques and chemoradiotherapy (CRT), the overall 5-year survival rate of gastrointestinal cancer patients in advanced stage disease is less than 15%, due to rapid disease progression, metastasis, and CRT resistance. A better understanding of the mechanisms underlying cancer progression and optimized treatment strategies for gastrointestinal cancer are urgently needed. With increasing evidence highlighting the protective role of immune responses in cancer initiation and progression, immunotherapy has become a hot research topic in the integrative management of gastrointestinal cancer. Here, an overview of the molecular understanding of colorectal cancer, esophageal cancer and gastric cancer is provided. Subsequently, recently developed immunotherapy strategies, including immune checkpoint inhibitors, chimeric antigen receptor T cell therapies, tumor vaccines and therapies targeting other immune cells, have been described. Finally, the underlying mechanisms, fundamental research and clinical trials of each agent are discussed. Overall, this review summarizes recent advances and future directions for immunotherapy for patients with gastrointestinal malignancies.

Targeting Metastatic Colorectal Cancer with Immune Oncological Therapies

Metastatic colorectal cancer carries poor prognosis, and current therapeutic regimes convey limited improvements in survival and high rates of detrimental side effects in patients that may not stand to benefit. Immunotherapy has revolutionised cancer treatment by restoring antitumoural mechanisms. However, the efficacy in metastatic colorectal cancer, is limited. A literature search was performed using Pubmed (Medline), Web of Knowledge, and Embase. Search terms included combinations of immunotherapy and metastatic colorectal cancer, primarily focusing on clinical trials in humans. Analysis of these studies included status of MMR/MSS, presence of combination strategies, and disease control rate and median overall survival. Evidence shows that immune checkpoint inhibitors, such as anti-PD1 and anti-PD-L1, show efficacy in less than 10% of patients with microsatellite stable, MMR proficient colorectal cancer. In the small subset of patients with microsatellite unstable, MMR deficient cancers, response rates were 40-50%. Combination strategies with immunotherapy are under investigation but have not yet restored antitumoural mechanisms to permit durable disease regression. Immunotherapy provides the potential to offer additional strategies to established chemotherapeutic regimes in metastatic colorectal cancer. Further research needs to establish which adjuncts to immune checkpoint inhibition can unpick resistance, and better predict which patients are likely to respond to individualised therapies to not just improve response rates but to temper unwarranted side effects.

Augmenting Anticancer Immunity Through Combined Targeting of Angiogenic and PD-1/PD-L1 Pathways: Challenges and Opportunities

Cancer immunotherapy (CIT) with antibodies targeting the programmed cell death 1 protein (PD-1)/programmed cell death 1 ligand 1 (PD-L1) axis have changed the standard of care in multiple cancers. However, durable antitumor responses have been observed in only a minority of patients, indicating the presence of other inhibitory mechanisms that act to restrain anticancer immunity. Therefore, new therapeutic strategies targeted against other immune suppressive mechanisms are needed to enhance anticancer immunity and maximize the clinical benefit of CIT in patients who are resistant to immune checkpoint inhibition. Preclinical and clinical studies have identified abnormalities in the tumor microenvironment (TME) that can negatively impact the efficacy of PD-1/PD-L1 blockade. Angiogenic factors such as vascular endothelial growth factor (VEGF) drive immunosuppression in the TME by inducing vascular abnormalities, suppressing antigen presentation and immune effector cells, or augmenting the immune suppressive activity of regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages. In turn, immunosuppressive cells can drive angiogenesis, thereby creating a vicious cycle of suppressed antitumor immunity. VEGF-mediated immune suppression in the TME and its negative impact on the efficacy of CIT provide a therapeutic rationale to combine PD-1/PD-L1 antibodies with anti-VEGF drugs in order to normalize the TME. A multitude of clinical trials have been initiated to evaluate combinations of a PD-1/PD-L1 antibody with an anti-VEGF in a variety of cancers. Recently, the positive results from five Phase III studies in non-small cell lung cancer (adenocarcinoma), renal cell carcinoma, and hepatocellular carcinoma have shown that combinations of PD-1/PD-L1 antibodies and anti-VEGF agents significantly improved clinical outcomes compared with respective standards of care. Such combinations have been approved by health authorities and are now standard treatment options for renal cell carcinoma, non-small cell lung cancer, and hepatocellular carcinoma. A plethora of other randomized studies of similar combinations are currently ongoing. Here, we discuss the principle mechanisms of VEGF-mediated immunosuppression studied in preclinical models or as part of translational clinical studies. We also discuss data from recently reported randomized clinical trials. Finally, we discuss how these concepts and approaches can be further incorporated into clinical practice to improve immunotherapy outcomes for patients with cancer.

The future of colorectal cancer research: an interview with Hans Schmoll

Hans Schmoll speaks to Rachel Jenkins, Managing Commissioning Editor. Over four decades of professional activity, Hans has become one of the most highly esteemed and influential medical oncologists in Germany. As Editor of the German standard reference book for medical and multidisciplinary oncology (6000 pages) [1], he has defined treatment standards and education in medical oncology in the German speaking countries. His work as a research scientist has covered numerous fields in medical oncology, in particular, genitourinary and gastrointestinal cancers, where he has defined worldwide standards for the management of germ-cell cancer and early and late stages of colon cancer. Within the European Society of Medical Oncology, he served on the Executive Board as founding chair of the Multidisciplinary Oncology Committee and as scientific chair of the Istanbul European Society of Medical Oncology Congress 2006.

HER2 in Colorectal Carcinoma: Are We There yet?

HER2 (ERBB2) is a member of the ERBB family of receptor tyrosine kinases and functions to drive signaling in the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways. Overall, approximately 2-3% of CRCs exhibit ERBB2 amplification. Multiple phase II clinical trials have now shown that ERBB2 amplification can be predictive of response to anti-ERBB2 targeted therapy. Consequently, recently released guidelines from the National Comprehensive Cancer Network recommend treatment with anti-ERBB2 targeted therapy for RAS wild-type, ERBB2-amplified metastatic CRC. While circumspection is still needed, ERBB2 amplification has now emerged as the next standard-of-care biomarker for metastatic CRC, expanding targeted therapy options for these patients.

LncRNA TINCR/microRNA-107/CD36 regulates cell proliferation and apoptosis in colorectal cancer via PPAR signaling pathway based on bioinformatics analysis

The present study aims to determine the potential biomarkers and uncover the regulatory mechanisms of the long-noncoding RNA (lncRNA) TINCR/miR-107/CD36 axis in colorectal cancer (CRC). Aberrantly-expressed lncRNAs and differential-expressed genes were identified by analyzing the dataset GSE40967. Gene set enrichment analysis was employed, and Cytoscape software helped in establishing the co-expression network between lncRNAs and genes. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis contributes to examining the expression levels of lncRNA TINCR, miR-107 and CD36. The dual luciferase assay was used to validate the association between miR-107 and lncRNA TINCR or CD36. The EdU incorporation assay was employed, and flow cytometry was employed to detect cell apoptosis with the tumor xenograft model being utilized. Significantly dysregulated lncRNAs and mRNAs were identified. The peroxisome proliferator-activated receptor (PPAR) signaling pathway in CRC tissues was down-regulated. The loss of TINCR expression was associated with CRC progression. The expression levels of the TINCR and CD36 were down-regulated. We identified miR-107 as an inhibitory target of TINCR and CD36. Overexpression of TINCR could inhibit cell proliferation and promote apoptosis. MiR-107 overexpression in CRC cells induced proliferation and impeded apoptosis. A regulatory function of the lncRNA TINCR/miR-107/CD36 axis in CRC was revealed. LncRNA TINCR overexpression exerted suppressive influence on CRC progression through modulating the PPAR signaling pathway via the miR-107/CD36 axis.

HER2-targeted therapy: an emerging strategy in advanced colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is one of the most common malignant tumors; it is a focus of research globally, but the identification of clinically actionable oncogenic drivers remains elusive. Human epidermal growth factor receptor 2 (HER2) activation is present in approximately 5% of CRC and has acquired resistance to epidermal growth factor receptor (EGFR)-targeted therapy. Early clinical trials suggest an emerging role for personalized HER2-targeted therapy in a subset of metastatic CRC.

AREAS COVERED

This manuscript reviews the relevance of HER2 activation in CRC and its potential role as a target for therapy. A literature search was conducted in June 2018 of MEDLINE and EMBASE databases for published preclinical and clinical studies; abstracts of international cancer meetings (AACR, ASCO, and ESMO) were also reviewed.

EXPERT OPINION

HER2 is activated in a small but relevant proportion of CRC patients (particularly left-side, RAS wild-type, anti-EGFR resistant tumors). Dual HER2 blockade with monoclonal antibodies (mAbs) (trastuzumab and pertuzumab) or the combination of mAbs with tyrosine kinase inhibitors (trastuzumab and lapatinib) induces durable tumor responses in about one-third of HER2-positive CRC refractory to standard systemic therapy. Although immature, these results are remarkable and anticipate an expanding role for HER2 as a therapeutic target in CRC.