Cetuximab strongly enhances immune cell infiltration into liver metastatic sites in colorectal cancer

A Phase 1b/2 Study of the Anti-CD47 Antibody Magrolimab with Cetuximab in Patients with Colorectal Cancer and Other Solid Tumors

BACKGROUND

Chemotherapy plus epidermal growth factor receptor (EGFR) inhibitors, such as cetuximab, is standard therapy for KRAS wild-type (KRASwt) colorectal cancer (CRC); however, responses are infrequent. Magrolimab is a monoclonal antibody targeting CD47, an antiphagocytic signal overexpressed in solid tumors (STs).

OBJECTIVE

This open-label, multicenter phase 1b/2 study (NCT02953782) aimed to determine the recommended phase 2 dose (RP2D) and evaluate the safety, tolerability, and efficacy of magrolimab + cetuximab in patients with advanced CRC or other STs.

PATIENTS AND METHODS

A total of 78 patients were enrolled at eight study sites in the USA. In phase 1b, patients with advanced STs received weekly maintenance doses of magrolimab at 10-45 mg/kg and cetuximab at 200-250 mg/m2 following 3 + 3 dose-escalation. In phase 2, patients with anti-EGFR-refractory CRC received magrolimab + cetuximab at RP2Ds. Primary endpoints were dose-limiting toxicities, adverse events, and objective response rate (ORR; phase 2).

RESULTS

The maximum tolerated dose was not reached in phase 1b. Two RP2Ds were explored in phase 2: magrolimab at 30 or 45 mg/kg plus cetuximab at 250 mg/m2. Most common treatment-related adverse events (TRAEs) were dermatitis acneiform (35.9%), infusion-related reactions (33.3%), dry skin (32.1%), fatigue (32.1%), and headache (29.5%). Most common grade ≥ 3 TRAEs were anemia (11.5%), increased blood bilirubin (9.0%), and decreased lymphocyte count (9.0%). Discontinuation of any study treatment owing to TRAEs occurred in 3.8% of patients. No deaths occurred due to TRAEs. In phase 2, ORR was 6.3% and 0% in the KRASwt and KRASmt CRC cohorts, respectively; disease control rate was 50.0% and 38.1%, and median overall survival was 9.5 and 7.6 months, respectively.

CONCLUSIONS

These results indicate tolerability and potential antitumor activity when combining anti-CD47 therapy and cetuximab in heavily pretreated patients with CRC.

Current status and future prospects of combined immunotherapy and epidermal growth factor receptor inhibitors in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a malignancy with a poor prognosis, and the majority of patients with HNSCC are diagnosed at later stages owing to its hidden anatomical location and atypical clinical symptoms. It is notably prone to recurrence and metastasis. The traditional treatments include surgery, radiotherapy, chemotherapy, and targeted therapy. Although multiple treatment strategies have been established, the prognosis remains poor because most patients develop resistance to traditional treatments. In recent years, epidermal growth factor receptor (EGFR) inhibitors and immune checkpoint inhibitors (ICIs) have been shown to provide clinical benefits to these patients. Based on the promising results of both anti-EGFR therapy and immunotherapy, as well as the biological rationale for combining immunotherapy with anti-EGFR drugs, numerous preclinical and ongoing or completed clinical trials have explored the use of their synergistic effects. This review summarizes the feasibility of combining immunotherapy with EGFR inhibitors for HNSCC treatment and analyses the relevant biomarkers. It also summarizes the strategies for clinical applications. We found that immunotherapy and EGFR inhibitor combination therapy showed promise in treating patients with HNSCC and exhibited safety with acceptable adverse events. This review may provide valuable insights for the future development of treatments and formulation of therapeutic strategies for HNSCC, as well as useful information for the future design of clinical trials.

Combining Cetuximab and Immunotherapy for Treating MSS/pMMR Colorectal Cancer: Current Evidence and Challenges

Colorectal cancer (CRC) remains a formidable global health challenge, with the majority of patients exhibiting microsatellite stable (MSS) and proficient mismatch repair (pMMR) tumors that are largely unresponsive to immune checkpoint inhibitors (ICIs). The management of MSS/pMMR CRC remains a clinical challenge due to the intrinsic resistance to ICIs. The innovative strategy of combining cetuximab, an EGFR-targeting monoclonal antibody with immunomodulatory properties, offers a promising strategy to enhance the immunotherapeutic response in MSS/pMMR CRC. This combination therapy is rooted in the complementary therapeutic mechanisms of cetuximab and ICIs, which may synergistically improve overall response rates and durability of response. Although some preclinical and clinical data have suggested additional promising results, there are still some challenges and questions that need to be addressed. Further large-scale, randomized, phase III clinical trials are required to confirm the efficacy and safety of this combination therapy. The ongoing clinical trials evaluating the safety and efficacy of cetuximab-ICI combinations are eagerly anticipated to pave the way for a new era in personalized immunotherapy for MSS/pMMR CRC.

Progress of Immune Checkpoint Inhibitors Therapy for pMMR/MSS Metastatic Colorectal Cancer

Immunotherapy is one of the research hotspots in colorectal cancer field in recent years. The colorectal cancer patients with mismatch repair-deficient (dMMR) or high microsatellite instability (MSI-H) are the primary beneficiaries of immunotherapy. However, the vast majority of colorectal cancers are mismatch repair proficient (pMMR) or microsatellite stability (MSS), and their immune microenvironment is characterized by "cold tumors" that are generally insensitive to single immunotherapy based on immune checkpoint inhibitors (ICIs). Studies have shown that some pMMR/MSS colorectal cancer patients regulate the immune microenvironment by combining other treatments, such as multi-target tyrosine kinase inhibitors, anti-vascular endothelial growth factor (VEGF) monoclonal antibodies, chemotherapy, radiotherapy, anti-epithelial growth factor receptor (EGFR) monoclonal antibodies, and mitogen-activated protein kinase (MAPK) signaling pathway inhibitors and oncolytic viruses, etc. to transform "cold tumor" into "hot tumor", thereby improving the response to immunotherapy. In addition, screening for potential prognostic biomarkers can also enrich the population benefiting from immunotherapy for microsatellite stable colorectal cancer. Therefore, in pMMR or MSS metastatic colorectal cancer (mCRC), the optimization of immunotherapy regimens and the search for effective efficacy prediction biomarkers are currently important research directions. In this paper, we review the progress of efficacy of immunotherapy (mainly ICIs) in pMMR /MSS mCRC, challenges and potential markers, in order to provide research ideas for the development of immunotherapy for mCRC.

Consideration on immunotherapy of liver metastases of malignant tumors

In this editorial, we comment on the article "Analysis of the impact of immunotherapy efficacy and safety in patients with gastric cancer and liver metastasis" by Liu et al that was published in the recent issue of the World Journal of Gastrointestinal Surgery. It has prompted us to think and summarize some thoughts on immunotherapy for malignant tumor liver metastasis. Immunotherapy plays a crucial role in the treatment of malignant tumors; however, the presence of liver metastases in advanced tumors may impact its efficacy. Although patients with liver metastases can still benefit from immunotherapy, multiple clinical studies have indicated that, compared to other sites of metastasis, liver metastases may diminish the effectiveness of immunotherapy. The efficacy of immune checkpoint inhibitors in patients with liver metastases often fails to reach the ideal level, primarily due to the liver metastases exploiting the host's peripheral immune tolerance mechanisms to promote systemic CD8(+) T cell exhaustion, resulting in a systemic immune-tolerant environment. This article aims to summarize the reasons for the decreased efficacy of immunotherapy following liver metastasis in various malignant tumors and propose potential clinical strategies for management.

Tislelizumab plus cetuximab and irinotecan in refractory microsatellite stable and RAS wild-type metastatic colorectal cancer: a single-arm phase 2 study

Immunotherapy confers little to no benefit in the treatment of microsatellite stable (MSS) metastatic colorectal cancer (mCRC). Mechanistic insights suggested that epidermal growth factor receptor (EGFR) antibody plus irinotecan might augment the tumor immune response in mCRC. Therefore, we conducted a proof-of-concept, single-arm, phase 2 study (ChiCTR identifier: ChiCTR2000035642) of a combination treatment regimen including tislelizumab (anti-PD-1), cetuximab (anti-EGFR) and irinotecan in 33 patients with MSS and RAS wild-type (WT) mCRC who were previously treated with ≥2 lines of therapy. The primary endpoint was met, with a confirmed objective response rate of 33%. As secondary endpoints, the disease control rate was 79%, and the median progression-free survival and overall survival were 7.3 and 17.4 months respectively. Among the 33 patients, 32 (97.0%) had treatment-related adverse events (AEs). Three (9.1%) reported grade ≥ 3 AEs, including rash (n = 1), neutropenia (n = 2). The post-hoc evaluation of dynamic circulating tumor DNA using next generation sequencing and the analysis of peripheral immune proteomics landscape using Olink revealed that lower variant allele frequency (VAF) at baseline, greater reduction in VAF on treatment, and a hot peripheral macroenvironment were associated with the treatment response independently. Our study showed the antitumor activity of tislelizumab, cetuximab, and irinotecan combination with a tolerable safety profile in previously treated MSS and RAS WT mCRC.

Immunotherapy for head and neck cancer: Fundamentals and therapeutic development

Squamous cell carcinoma of the head and neck (SCCHN) has been treated by multidisciplinary therapy consisting of surgery, radiotherapy, and cancer chemotherapy, but the recent advent of immunotherapy has produced significant changes in treatment systems and the results of these therapies. Immunotherapy has greatly improved the outcome of recurrent metastatic SCCHN, and the development of new treatment methods based on immunotherapy is now being applied not only to recurrent metastatic cases but also to locally advanced cases. To understand and practice cancer immunotherapy, it is important to understand the immune environment surrounding cancer, and the changes to which it is subject. Currently, the anti-PD-1 antibody drugs nivolumab and pembrolizumab are the only immunotherapies with proven efficacy in head and neck cancer. However, anti-PD-L1 and anti-CTLA-4 antibody drugs have also been shown to be useful in other types of cancer and are being incorporated into clinical practice. In head and neck cancer, numerous clinical trials have aimed to improve efficacy and safety by combining immunotherapy with other drug therapies and treatment modalities. Combinations of immunotherapy with cancer drugs with different mechanisms of action (cytotoxic agents, molecular-targeted agents, immune checkpoint inhibitors), as well as with radiation therapy and surgery are being investigated, and have the potential to significantly change medical care for these patients. The application of cancer immunotherapy not only to daily clinical practice but also to further therapeutic development requires a clear and complete understanding of the fundamentals of cancer immunotherapy, and knowledge of the numerous clinical studies conducted, both past and present. The results of these trials are numerous, both positive and negative, and a comprehensive understanding of this wide range of completed and ongoing clinical trials is critical to a systematic and comprehensive understanding of their scope and lessons learnt. In this article, after outlining the concepts of ``cancer immune cycle,'' ``cancer immune editing,'' and ``tumor microenvironment'' to provide an understanding of the basics of cancer immunity, we summarize the basics and clinical trial data on representative immune checkpoint inhibitors used in various cancer types, as well as recent therapeutic developments in cancer immunotherapy and the current status of these new treatments.

Clinical application of immunogenic cell death inducers in cancer immunotherapy: turning cold tumors hot

Immunotherapy has emerged as a promising cancer treatment option in recent years. In immune "hot" tumors, characterized by abundant immune cell infiltration, immunotherapy can improve patients' prognosis by activating the function of immune cells. By contrast, immune "cold" tumors are often less sensitive to immunotherapy owing to low immunogenicity of tumor cells, an immune inhibitory tumor microenvironment, and a series of immune-escape mechanisms. Immunogenic cell death (ICD) is a promising cellular process to facilitate the transformation of immune "cold" tumors to immune "hot" tumors by eliciting innate and adaptive immune responses through the release of (or exposure to) damage-related molecular patterns. Accumulating evidence suggests that various traditional therapies can induce ICD, including chemotherapy, targeted therapy, radiotherapy, and photodynamic therapy. In this review, we summarize the biological mechanisms and hallmarks of ICD and introduce some newly discovered and technologically innovative inducers that activate the immune system at the molecular level. Furthermore, we also discuss the clinical applications of combing ICD inducers with cancer immunotherapy. This review will provide valuable insights into the future development of ICD-related combination therapeutics and potential management for "cold" tumors.

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.

Study protocol: phase II study to evaluate the effect of cetuximab monotherapy after immunotherapy with PD-1 inhibitors in patients with head and neck squamous cell cancer

Background

Immunotherapy with programmed death receptor-1 (PD-1) inhibitors, as a single agent or in combination with chemotherapy, is the standard first-line treatment for recurrent or metastatic head and neck squamous cell cancer (R/M HNSCC). Unfortunately, there is no established second-line treatment for the many patients who fail immunotherapy. Cetuximab is the only targeted therapy approved in HNSCC but historically has a low response rate of 13%.

Objectives

We hypothesize that cetuximab monotherapy following an immune checkpoint inhibitor (ICI) will lead to increased efficacy due to a potential synergistic effect on the antitumor immune response, as a result of activation effects of both treatments on innate and adaptative immune responses. To the authors' knowledge, this is the only ongoing prospective clinical study that evaluates the combination of cetuximab and ICIs administered sequentially.

Methods and analysis

In this non-randomized, open-label, phase II trial, 30 patients with R/M HNSCC who have previously failed or could not tolerate a PD-1 inhibitor as a single agent or in combination with chemotherapy will subsequently be treated with cetuximab monotherapy. Outcomes of interest include overall response rate, duration of response, progression-free survival, overall survival, and treatment toxicity, as well as treatment outcome measured by a patient-reported outcome questionnaire. Saliva and blood will be collected for correlative studies to investigate the immune response status at the end of therapy with an ICI and the effect of cetuximab on the antitumor immune response. The results will be correlated with the response to cetuximab and the time window between the last administration of an ICI and the loading dose of cetuximab. The clinical study is actively recruiting.

Ethics

This study was approved by the Wake Forest Comprehensive Cancer Center Institutional Review Board: IRB00065239.

Clinical trial registration

This study is registered on ClinicalTrials.gov: NCT04375384.

Phase Ib study of anti-EGFR antibody (SCT200) in combination with anti-PD-1 antibody (SCT-I10A) for patients with RAS/BRAF wild-type metastatic colorectal cancer

OBJECTIVE

This study evaluated the safety and efficacy of an anti-epidermal growth factor receptor (EGFR) antibody (SCT200) and an anti-programmed cell death 1 (PD-1) antibody (SCT-I10A) as third-line or subsequent therapies in patients with rat sarcoma viral oncogene (RAS)/v-raf murine sarcoma viral oncogene homolog B (BRAF) wild-type (wt) metastatic colorectal cancer (mCRC).

METHODS

We conducted a multicenter, open-label, phase Ib clinical trial. Patients with histologically confirmed RAS/BRAF wt mCRC with more than two lines of treatment were enrolled and treated with SCT-I10A and SCT200. The primary endpoints were the objective response rate (ORR) and safety. The secondary endpoints included disease control rate (DCR), progression-free survival (PFS), and overall survival (OS).

RESULTS

Twenty-one patients were enrolled in the study through January 28, 2023. The ORR was 28.57% and the DCR was 85.71% (18/21). The median PFS and OS were 4.14 and 12.84 months, respectively. The treatment-related adverse events (TRAEs) were tolerable. Moreover, compared with the monotherapy cohort from our previous phase I study evaluating SCT200 for RAS/BRAF wt mCRC in a third-line setting, no significant improvements in PFS and OS were observed in the combination group.

CONCLUSIONS

SCT200 combined with SCT-I10A demonstrated promising efficacy in previously treated RAS/BRAF wt mCRC patients with an acceptable safety profile. Further head-to-head studies with larger sample sizes are needed to validate whether the efficacy and safety of combined anti-EGFR and anti-PD-1 therapy are superior to anti-EGFR monotherapy in the third-line setting. (Registration No. NCT04229537).

Anti-EGFR Antibodies in the Management of Advanced Colorectal Cancer

Colorectal cancer is the third most common cancer worldwide, and incidence is rising in younger individuals. Anti-EGFR antibodies, including cetuximab and panitumumab, have been incorporated into standard-of-care practice for patients with advanced disease. Herein, we review the molecular characteristics of these agents and the trials that lead to their approvals. Further, we discuss clinical implications of data regarding biomarkers that dictate treatment selection, different dosing strategies, and side effect management. Finally, we look towards the future and describe contexts in which these agents are currently being investigated clinically with a focus on combinations with MAPK-targeted therapies and immunotherapy. Overall, this review provides historical context, current clinical usage, and future directions for anti-EGFR antibodies in advanced colorectal cancer.

Pharmacogenetics Role of Genetic Variants in Immune-Related Factors: A Systematic Review Focusing on mCRC

Pharmacogenetics plays a key role in personalized cancer treatment. Currently, the clinically available pharmacogenetic markers for metastatic colorectal cancer (mCRC) are in genes related to drug metabolism, such as DPYD for fluoropyrimidines and UGT1A1 for irinotecan. Recently, the impact of host variability in inflammatory and immune-response genes on treatment response has gained considerable attention, opening innovative perspectives for optimizing tailored mCRC therapy. A literature review was performed on the predictive role of immune-related germline genetic biomarkers on pharmacological outcomes in patients with mCRC. Particularly, that for efficacy and toxicity was reported and the potential role for clinical management of patients was discussed. Most of the available data regard therapy effectiveness, while the impact on toxicity remains limited. Several studies focused on the effects of polymorphisms in genes related to antibody-dependent cellular cytotoxicity (FCGR2A, FCGR3A) and yielded promising but inconclusive results on cetuximab efficacy. The remaining published data are sparse and mainly hypothesis-generating but suggest potentially interesting topics for future pharmacogenetic studies, including innovative gene-drug interactions in a clinical context. Besides the tumor immune escape pathway, genetic markers belonging to cytokines/interleukins (IL-8 and its receptors) and angiogenic mediators (IGF1) seem to be the best investigated and hopefully most promising to be translated into clinical practice after validation.

Targeting Epidermal Growth Factor Receptor in Head and Neck Cancer

ABSTRACT

Head and neck squamous cell carcinomas are rising in incidence worldwide, and despite the advent of improved surgical and radiation techniques, a substantial proportion of patients have disease recurrence, where systemic therapies are the mainstay of management. Recent advances in systemic therapy include the development of epidermal growth factor receptor- and programmed death 1-targeting drugs, which have produced incremental improvements in disease outcomes. However, for most patients, responses to treatment remain elusive because of primary or acquired resistance. Novel drugs and rational drug combinations need to be tested based on biomarker identification and preclinical science that will ultimately advance outcomes for our patients. This review focuses on efforts untaken for epidermal growth factor receptor targeting in head and neck squamous cell carcinoma to date.

Genetic variants involved in the cGAS-STING pathway predict outcome in patients with metastatic colorectal cancer: Data from FIRE-3 and TRIBE trials

BACKGROUND

The activation of stimulator of interferon genes (STING) was reported to enhance cetuximab-mediated natural killer cell activation and dendritic cell maturation. Polymorphisms in genes in the cyclic GMP-AMP synthase (cGAS)-STING pathway may affect innate immune response. Therefore, we hypothesised that genetic variants in the cGAS-STING pathway may predict the efficacy of cetuximab-based treatment in patients with metastatic colorectal cancer.

METHODS

Genomic DNA from blood samples of patients enrolled in FIRE-3 (cetuximab arm, n = 129; bevacizumab arm, n = 107) and TRIBE (bevacizumab arm, n = 215) was genotyped using the OncoArray-500K bead chip panel. Seven selected single nucleotide polymorphisms in 3 genes (cGAS, STING and interferon B1 (IFNB1)) were analysed for the association with overall survival and progression-free survival.

RESULTS

In the cetuximab cohort, patients with STING rs1131769 any T allele showed significantly shorter overall survival (36.3 versus 56.1 months) than carriers of C/C in both univariate [hazard ratio (HR) = 2.08; 95% confidence interval (CI): 1.06-4.07; P = 0.03] and multivariate (HR = 2.98; 95% CI: 1.35-6.6; P = 0.0085) analyses; patients carrying IFNB1 rs1051922 G/A and A/A genotype showed a significantly shorter progression-free survival than carriers of G/G allele in both univariate (G/A versus G/G, 10.2 versus 14.1 months, HR = 1.84; 95% CI 1.23-2.76; A/A versus G/G, 10.7 versus 14.1 months, HR = 2.19; 95% CI 0.97-4.96; P = 0.0077) and multivariate analyses (G/A versus G/G, HR = 2; 95% CI 1.22-3.3; A/A versus G/G, HR = 2.19, 95% CI 0.92-5.26, P = 0.02). These associations were not observed in the bevacizumab arm of FIRE-3 or TRIBE.

CONCLUSION

These results suggest for the first time that germline polymorphisms in STING and IFNB1 genes may predict the outcomes of cetuximab-based treatment in patients with metastatic colorectal cancer.

CAVE-2 (Cetuximab-AVElumab) mCRC: A Phase II Randomized Clinical Study of the Combination of Avelumab Plus Cetuximab as a Rechallenge Strategy in Pre-Treated RAS/BRAF Wild-Type mCRC Patients

Introduction

Immunotherapy has limited efficacy in metastatic colorectal cancer (mCRC). Understanding mechanisms mediating immune resistance in microsatellite stable (MSS) colorectal tumors remains an ongoing challenge. Novel combination immunotherapy-based approaches have been developed under the rationale of overcoming immune resistance and developing effective immune response against colorectal tumor cells. Preclinical studies have demonstrated that cetuximab may modulate immune response to cancer cells. In this scenario, the inhibition of PD-L1 with IgG1 MAb avelumab in combination with anti-EGFR IgG1 monoclonal antibody cetuximab could be a strategy for potentiating antitumor activity. The CAVE phase II single-arm clinical trial provided the first evidence of clinical activity of combining cetuximab plus avelumab in 77 patients with RAS wild-type (WT) mCRC. This combination had a good toxicity profile, with a low rate of common grade 3 adverse events.

Patients and Methods

Based on results obtained with the CAVE clinical trial, here we describe the design and rationale for the phase II, randomized CAVE 2 clinical study of the combination of avelumab plus cetuximab as a rechallenge strategy in pre-treated RAS, BRAF WT mCRC patients treated in first line with chemotherapy in combination with cetuximab and who have had a clinical benefit (complete or partial response) from treatment. A total of 173 patients will be randomized (2:1) to cetuximab + avelumab (115) or cetuximab as a single agent (58). The primary endpoint is overall survival. Key secondary endpoints include overall response rate, progression-free survival, and safety. For each patient, before treatment, a blood sample will be obtained and analyzed for circulating free tumor DNA according to NGS (Foundation/Roche), to identify RAS/BRAF WT patients to be enrolled. The same procedure will be performed at the progression of the disease. Additional blood/plasma, tumor, and fecal samples will be collected and centrally stored for additional translational studies.

Discussion

This study will provide the rationale to test immunotherapy-based combinations in the clinical setting, offering new opportunities for RAS WT mCRC patients.

Clinical Trial Registration

[https://clinicaltrials.gov/ct2/show/NCT05291156], identifier [NCT05291156].

Treatment Sequences in Patients with Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma: Cetuximab Followed by Immunotherapy or Vice Versa

BACKGROUND

The prognosis was poor when patients had recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). Herein, we conducted an observational study of cetuximab followed by immunotherapy (Cet-IO) versus immunotherapy followed by cetuximab (IO-Cet) in patients with R/M HNSCC.

METHODS

Patients who were diagnosed with R/M HNSCC and treated with a sequential cetuximab-containing regimen and immunotherapy-containing regimen were enrolled in our study. Kaplan-Meier curves were estimated for progression-free survival (PFS) and overall survival (OS).

RESULTS

A total of 75 patients were enrolled in our study for oncologic outcomes evaluation, with 40 patients in Cet-IO and 35 patients in IO-Cet. The median PFS1 was 5.1 months in Cet-IO and 4.5 months in IO-Cet (p = 0.777) and the median PFS2 was 16.5 months in Cet-IO and 11.4 months in IO-Cet (p = 0.566). The median OS was 23.7 months versus 22.8 months in Cet-IO and IO-Cet, respectively (p = 0.484). The overall response rate (ORR) were 73% in Cet-IO versus 37% in IO-Cet (p = 0.002). Multivariate analysis demonstrated that the treatment sequences, Cet-IO or IO-Cet, were insignificantly different with survival.

CONCLUSION

Both Cet-IO and IO-Cet are effective in R/M HNSCC patients with insignificant survival differences. The higher ORR of Cet-IO might render it to be considered in patients with large tumor burdens and urgent needs for treatment responses. Further prospective studies are merited to validate our conclusions.

Direct and Indirect Engagement of Dendritic Cell Function by Antibodies Developed for Cancer Therapy

Dendritic cells (DC) are crucial for the priming of T cells and thereby influence adaptive immune responses. Hence, they also represent important players in shaping anti-tumour immune responses. Cancer immunotherapy has been driven over many years by the aim to harness the T-cell stimulatory activity of these crucial antigen-presenting cells (APC). Efficient antigen delivery alone is not sufficient for full engagement of the T-cell stimulatory activity of DC and the inclusion of adjuvants triggering appropriate DC activation is essential to ensure effective anti-tumour immunity induction. While the direct engagement of DC function is a powerful tool for tumour immunotherapy, many therapeutic antibodies, such as antibodies directed against tumour-associated antigens (TAA) and immune checkpoint inhibitors (ICI) have been shown to engage DC function indirectly. The induction of anti-tumour immune responses by TAA-targeting and immune checkpoint inhibitory antibodies is thought to be integral to their therapeutic efficacy. Here, we provide an overview of the immunotherapeutic antibodies in the context of cancer immunotherapy, that has been demonstrated to directly or indirectly engage DC and discuss the current understanding of the functional mechanisms underlying anti-tumour immunity induction by these antibody therapies. In the future, the combination of therapeutic strategies that engage DC function directly and/or indirectly with strategies that allow tumour infiltrating immune effector cells to exert their anti-tumour activity in the tumour microenvironment (TME) may be key for the successful treatment of cancer patients currently not responding to immunotherapeutic antibody treatment.

miR-199b-3p contributes to acquired resistance to cetuximab in colorectal cancer by targeting CRIM1 via Wnt/β-catenin signaling

Background

Despite advances in the development of efficient chemotherapy, the treatment of colorectal cancer (CRC) remains a challenge due to acquired chemoresistance. It has been reported that microRNAs (miRNAs) dysregulation is associated with the development of chemoresistance. Recently, the expression of miR-199b-3p has been found to be significantly different between cetuximab (CTx)-resistant and -sensitive CRC cells. However, its role and the underlying mechanisms in acquired chemoresistance to CTx in CRC are still obscure.

Methods

Here we report that miR-199b-3p is significantly up-regulated in both CTx-resistant (CTxR) CRC tissues and cell lines.

Results

Functional assays showed that suppressing miR-199b-3p could improve the sensitivity of CRC-CTxR cells to CTx, thereby reducing cell proliferation, migration and invasion, and enhancing cell apoptosis. Mechanistic studies revealed that CRIM1 is a direct target of miR-199b-3p in CRC-CTxR cells; and the effect of miR-199b-3p on CTx-resistance was exerted by regulating the Wnt/β-catenin signaling pathway via CRIM1. Furthermore, mice xenograft models were established and confirmed that down-regulating miR-199b-3p restores the inhibition effect of CTx on tumor growth in CRC-CTxR. Collectively, our data suggest that silencing miR-199b-3p could enhance the anti-tumor effects of CTx on CTx-resistant CRC in vitro and in vivo by activating Wnt/β-catenin signaling via the down-regulation of CRIM1.

Conclusions

Our findings suggest miR-199b-3p might serve as a promising therapeutic target against CTx resistant CRC, and provide scientific information for exploring novel strategies of improving the efficacy of CTx for CRC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02460-x.

Induction of natural killer antibody-dependent cell cytotoxicity and of clinical activity of cetuximab plus avelumab in non-small cell lung cancer

Background

Antibody-dependent cell-mediated cytotoxicity (ADCC) may mediate antitumour activity of IgG1-isotype monoclonal antibody (mAb), suggesting as potential treatment combination of IgG1-mAbs, anti-epidermal growth factor receptor cetuximab and anti-programmed death-ligand-1 avelumab.

Methods

We evaluated ADCC induction in lung cancer cells by lactate dehydrogenase (LDH) release assay. Antitumour activity and safety of cetuximab plus avelumab were explored in a single-arm proof-of-concept study in pre-treated non-small cell lung cancer (NSCLC) patients (pt) (Cetuximab-AVElumab-lung, CAVE-Lung). Search for predictive biomarkers of response was done.

Results

Avelumab plus cetuximab induced ADCC in NSCLC cells in vitro in presence of natural killers (NK) from healthy donors (HD) or NSCLC pt, as effectors. Sixteen relapsed NSCLC pt were treated with avelumab plus cetuximab. Antitumour activity was observed in 6/16 pt, defined by progression free survival (PFS) ≥8 months, with 4 of them still on treatment at data lock time (range, 14–19 months). Of note, 3/6 responders had received as previous line anti-programmed death-1 therapy. In responders, clinical benefit was accompanied by significant increase in LDH release over baseline at the first radiological evaluation (8 weeks) (p=0.01) and by early skin toxicity; while in the 10 non-responders, that had PFS ≤5 months, LDH release tends to reduce. Baseline circulating DNA levels were higher in non-responders compared with responders and HD (p=0.026) and decrease in responders during therapy. Mutations in DNA damage responsive family genes were found in responders.

Conclusion

Cetuximab and avelumab activates NSCLC pt NK cells. Ex vivo evaluation of ADCC, circulating DNA levels and early skin toxicity may predict response to cetuximab plus avelumab in NSCLC.

EUDRACT 2017-004195-58

Cetuximab Rechallenge Plus Avelumab in Pretreated Patients With RAS Wild-type Metastatic Colorectal Cancer: The Phase 2 Single-Arm Clinical CAVE Trial

Importance

Rechallenge therapy with anti-epidermal growth factor receptor (EGFR) drugs has been suggested in patients with chemo-refractory RAS wild-type (WT) metastatic colorectal cancer (mCRC) after initial response to anti-EGFR-based first-line treatment. The association of treatment with cetuximab plus avelumab with overall survival (OS) may be worthy of investigation in this setting.

Objective

To assess the efficacy and safety of cetuximab rechallenge therapy plus avelumab.

Design, Setting, and Participants

This single-arm, multicenter phase 2 trial enrolled patients from August 2018 to February 2020. Eligible patients with RAS WT mCRC had a complete or partial response to first-line chemotherapy plus anti-EGFR drugs, developed acquired resistance, and failed second-line therapy. Baseline circulating tumor DNA (ctDNA) for KRAS, NRAS, BRAF, and EGFR-S492R mutation analysis was done.

Interventions

Patients received avelumab (10 mg/kg every 2 weeks) and cetuximab (400 mg/m2 and, subsequently, 250 mg/m2 weekly) until disease progression or unacceptable toxic effects.

Main Outcomes and Measures

The primary end point was OS. Secondary end points were progression-free survival (PFS), overall response rate (ORR), and safety.

Results

Seventy-seven patients were enrolled (42 men, 35 women; median age, 63 years); 71 had microsatellite stable tumors (MSS), 3 microsatellite instability-high tumors (MSI-H), 3 unknown. The study met the primary end point, with median OS (mOS) of 11.6 months (95% CI, 8.4-14.8 months). Median PFS (mPFS) was 3.6 months (95% CI, 3.2-4.1 months). Common grade-3 adverse events were cutaneous eruption, 11 (14%), and diarrhea, 3 (4%). For 67 of 77 (87%) patients, baseline analysis of plasma circulating tumor DNA (ctDNA) for KRAS, NRAS, BRAF, and EGFR-S492R variations was feasible. Forty-eight patients had WT disease, whereas 19 had mutations. Patients with RAS/BRAF WT ctDNA had mOS of 17.3 months (95% CI, 12.5-22.0 months) compared with 10.4 months (95% CI, 7.2-13.6 months) in patients with mutated ctDNA (hazard ratio [HR], 0.49; 95% CI, 0.27-0.90; P = .02). The mPFS was 4.1 months (95% CI, 2.9-5.2 months) in RAS/BRAF WT patients compared with 3.0 months (95% CI, 2.6-3.5 months) in patients with mutated ctDNA (HR, 0.42; 95% CI, 0.23-0.75; P = .004).

Conclusions and Relevance

The findings of this single-arm phase 2 trial suggest that cetuximab plus avelumab is an active, well tolerated rechallenge therapy in RAS WT mCRC. Plasma ctDNA analysis before treatment may allow selection of patients who could benefit.

Trial Registration

ClinicalTrials.gov Identifier: NCT04561336.

Irinotecan or Oxaliplatin: Which is the First Move for the Mate?

OBJECTIVES

The aim of the present review is to discuss the potential link between RAS, BRAF and microsatellite instability (MSI) mutational patterns and chemotherapeutic agent efficacy [Irinotecan (IRI) vs. Oxaliplatin (OXA)], and how this can potentially influence the choice of the chemotherapy backbone.

METHODS

Following a review of the research literature, all pertinent articles published in the core journals were selected for the study. The inclusion criteria regarded relevant clinical and pre-clinical studies on the topic of interest (Relationship of OXA and IRI to KRAS/BRAF mutations and MSI).

RESULTS

Excision repair cross complementation group 1 (ERCC1) expression is inhibited by KRAS mutation, making tumor cells more sensitive to OXA. Results from OPUS, COIN and PRIME trials support that no conclusive data are available for BRAF mutant population because of the small number of patients. Enhanced IRI cytotoxicity to MSI cell lines is due to the participation of some of the mismatch repair (MMR) components in various DNA repair processes and their role in the maintenance of the pro-apoptotic effect of IRI and G2/M cell arrest.

CONCLUSION

OXA and IRI are indispensable drugs for mCRC treatment and their selection must be as careful as that of targeted agents. We suggest taking into consideration the interaction between known genomic alterations and OXA and IRI activity to personalize chemotherapy in mCRC patients.

Perspectives on Immunotherapy of Metastatic Colorectal Cancer

Colorectal cancer, especially liver metastasis, is still a challenge worldwide. Traditional treatment such as surgery, chemotherapy and radiotherapy have been difficult to be further advanced. We need to develop new treatment methods to further improve the poor prognosis of these patients. The emergence of immunotherapy has brought light to mCRC patients, especially those with dMMR. Based on several large trials, some drugs (pembrolizumab, nivolumab) have been approved by US Food and Drug Administration to treat the patients diagnosed with dMMR tumors. However, immunotherapy has reached a bottleneck for other MSS tumors, with low response rate and poor PFS and OS. Therefore, more clinical trials are underway toward mCRC patients, especially those with MSS. This review is intended to summarize the existing clinical trials to illustrate the development of immunotherapy in mCRC patients, and to provide a new thinking for the direction and experimental design of immunotherapy in the future.

Restoring the Immunity in the Tumor Microenvironment: Insights into Immunogenic Cell Death in Onco-Therapies

Immunogenic cell death (ICD) elicited by cancer therapy reshapes the tumor immune microenvironment. A long-term adaptative immune response can be initiated by modulating cell death by therapeutic approaches. Here, the major hallmarks of ICD, endoplasmic reticulum (ER) stress, and damage-associated molecular patterns (DAMPs) are correlated with ICD inducers used in clinical practice to enhance antitumoral activity by suppressing tumor immune evasion. Approaches to monitoring the ICD triggered by antitumoral therapeutics in the tumor microenvironment (TME) and novel perspective in this immune system strategy are also reviewed to give an overview of the relevance of ICD in cancer treatment.

Biomarker-Guided Anti-Egfr Rechallenge Therapy in Metastatic Colorectal Cancer

Simple Summary

The survival of patients with metastatic colorectal cancer (mCRC) has been improved over the years and now reaches 30–40 months. However, few therapeutic options are available after failure of first- and second-line treatments. In fact, prognosis of chemo-refractory mCRC remains poor. Therefore, new therapeutic strategies are needed. Emerging evidence suggest that retreatment with epidermal growth factor (EGFR) inhibitors after a treatment break, in patients that obtained a clinical benefit by previous anti-EGFR, could lead to prolonged survival. The rationale beyond this “rechallenge” strategy is that after a “treatment holiday” EGFR resistant cancer cells decay, restoring the sensibility to EGFR blockade. In this review we analyze the current knowledge of retreatment with EGFR inhibitors, examine the role of novel biomarkers that can guide the appropriate selection of patients. Finally, we discuss future perspectives and on-going clinical trials.

Abstract

The prognosis of patients with metastatic colorectal cancer (mCRC) who progressed to the first and the second lines of treatment is poor. Thus, new therapeutic strategies are needed. During the last years, emerging evidence suggests that retreatment with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (MAbs) in the third line of mCRC patients, that have previously obtained clinical benefit by first-line therapy with anti-EGFR MAbs plus chemotherapy, could lead to prolonged survival. The rationale beyond this “rechallenge” strategy is that, after disease progression to first line EGFR-based therapy, a treatment break from anti-EGFR drugs results in RAS mutant cancer cell decay, restoring the sensitivity of cancer cells to cetuximab and panitumumab. In fact, rechallenge treatment with anti-EGFR drugs has shown promising clinical activity, particularly in patients with plasma RAS and BRAF wild type circulating tumor DNA, as defined by liquid biopsy analysis at baseline treatment. The aim of this review is to analyze the current knowledge on rechallenge and to investigate the role of novel biomarkers that can guide the appropriate selection of patients that could benefit from this therapeutic strategy. Finally, we discuss on-going trials and future perspectives.

Histopathological and Immune Prognostic Factors in Colo-Rectal Liver Metastases

Prognostic studies are increasingly providing new tools to stratify colo-rectal liver metastasis patients into clinical subgroups, with remarkable implications in terms of clinical management and therapeutic choice. Here, the strengths and hurdles of current prognostic tools in colo-rectal liver metastasis are discussed. Alongside more classic histopathological parameters, which capture features related to the tumor component, such as tumor invasion, tumor growth pattern and regression score, we will discuss immune mediators, which are starting to be considered important features. Their objective quantification has shown significant results in prognostication studies, with most of the work focused on adaptive immune cells, namely T cells. As for macrophages, they are only starting to be appreciated and we will present recent advances in evaluation of macrophage morphological features. Deeper knowledge acquired by multiparametric analyses is rapidly uncovering the variety of immune players that should be assessed. The future projection is to implement deep-learning histopathological tools and to integrate histopathological and immune metrics in multiparametric scores, with the ultimate objective to achieve a deeper resolution of the tumor features and their relevance for colo-rectal liver metastasis.

Avelumab and cetuximab as a therapeutic combination: An overview of scientific rationale and current clinical trials in cancer

Treatment outcomes have improved with the advent of immune checkpoint inhibitors and small molecule inhibitors. However, many patients do not respond with single agents. Consequently, ongoing research is focused on the use of combination therapies to increase clinical efficacy by potential synergistic effects. Here, we outline ongoing trials and review the rationale and evidence for the combination of avelumab, an anti-programmed death ligand 1 (PD-L1) immunoglobulin G1 (IgG1) monoclonal antibody (mAb), with cetuximab, an anti-epidermal growth factor receptor (EGFR) IgG1 mAb. Avelumab is approved as a monotherapy for the treatment of Merkel cell carcinoma and urothelial carcinoma, and in combination with axitinib for renal cell carcinoma; cetuximab is approved in combination with chemotherapy for the treatment of squamous cell carcinoma of the head and neck (SCCHN) and RAS wild-type metastatic colorectal cancer, and in combination with radiation therapy for SCCHN. Avelumab binds to PD-L1 expressed on tumor cells and immune regulatory cells, thus blocking its interaction with programmed death 1 and reventing T-cell suppression; cetuximab inhibits the EGFR signaling pathway, inhibiting proliferation and inducing apoptosis. Both therapies have complementary mechanisms of action and may also activate the immune system to induce innate effector function through the binding of their Fc regions to natural killer (NK) cells. Furthermore, cetuximab combined with chemotherapy has been shown to induce immunogenic cell death and leads to an increase in tumor-infiltrating CD8+ T and NK cells, which should synergize with the immunostimulatory effects of avelumab. Prospective studies will investigate this combination and inform future treatment strategies.

Discovery of core gene families associated with liver metastasis in colorectal cancer and regulatory roles in tumor cell immune infiltration

In this study, we aimed to uncover genes that drive the pathogenesis of liver metastasis in colorectal cancer (CRC), and identify effective genes that could serve as potential therapeutic targets for treating with colorectal liver metastasis patients based on two GEO datasets. Several bioinformatics approaches were implemented. First, differential expression analysis screened out key differentially expressed genes (DEGs) across the two GEO datasets. Based on gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, we identified the enrichment functions and pathways of the DEGs that were associated with liver metastasis in CRC. Second, immune infiltration analysis identified key immune signature gene sets associated with CRC liver metastasis, among which two key immune gene families (CD and CCL) identified as key DEGs were filtered by protein-protein interaction (PPI) network. Some of the members in these gene families were associated with disease free survival (DFS) or overall survival (OS) in two subtypes of CRC, namely COAD and READ. Finally, functional enrichment analysis of the two gene families and their neighboring genes revealed that they were closely associated with cytokine, leukocyte proliferation and chemotaxis. These results are valuable in comprehending the pathogenesis of liver metastasis in CRC, and are of seminal importance in understanding the role of immune tumor infiltration in CRC. Our study also identified potentially effective therapeutic targets for liver metastasis in CRC including CCL20, CCL24 and CD70.

Identification of key genes involved in tumor immune cell infiltration and cetuximab resistance in colorectal cancer

Background

The anti-epidermal growth factor receptor (EGFR) antibody introduces adaptable variations to the transcriptome and triggers tumor immune infiltration, resulting in colorectal cancer (CRC) treatment resistance. We intended to identify genes that play essential roles in cetuximab resistance and tumor immune cell infiltration.

Methods

A cetuximab-resistant CACO2 cellular model was established, and its transcriptome variations were detected by microarray. Meanwhile, public data from the Gene Expression Omnibus and The Cancer Genome Atlas (TCGA) database were downloaded. Integrated bioinformatics analysis was applied to detect differentially expressed genes (DEGs) between the cetuximab-resistant and the cetuximab-sensitive groups. Then, we investigated correlations between DEGs and immune cell infiltration. The DEGs from bioinformatics analysis were further validated in vitro and in clinical samples.

Results

We identified 732 upregulated and 1259 downregulated DEGs in the induced cellular model. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, along with Gene Set Enrichment Analysis and Gene Set Variation Analysis, indicated the functions of the DEGs. Together with GSE59857 and GSE5841, 12 common DEGs (SATB-2, AKR1B10, ADH1A, ADH1C, MYB, ATP10B, CDX-2, FAR2, EPHB2, SLC26A3, ORP-1, VAV3) were identified and their predictive values of cetuximab treatment were validated in GSE56386. In online Genomics of Drug Sensitivity in Cancer (GDSC) database, nine of twelve DEGs were recognized in the protein-protein (PPI) network. Based on the transcriptome profiles of CRC samples in TCGA and using Tumor Immune Estimation Resource Version 2.0, we bioinformatically determined that SATB-2, ORP-1, MYB, and CDX-2 expressions were associated with intensive infiltration of B cell, CD4⁺ T cell, CD8⁺ T cell and macrophage, which was then validated the correlation in clinical samples by immunohistochemistry. We found that SATB-2, ORP-1, MYB, and CDX-2 were downregulated in vitro with cetuximab treatment. Clinically, patients with advanced CRC and high ORP-1 expression exhibited a longer progression-free survival time when they were treated with anti-EGFR therapy than those with low ORP-1 expression.

Conclusions

SATB-2, ORP-1, MYB, and CDX-2 were related to cetuximab sensitivity as well as enhanced tumor immune cell infiltration in patients with CRC.

Current status and perspectives of immune checkpoint inhibitors for colorectal cancer

Immunotherapy, especially immune checkpoint inhibitors, has revolutionized the standard-of-care of multiple types of tumors. For colorectal cancer, the clinical development of immune checkpoint inhibitors is mainly separated according to the status of microsatellite instability or mismatch repair in a tumor. High-level microsatellite instability/deficient mismatch repair metastatic colorectal cancer generally has a tumor microenvironment with infiltration of T cells, associated with a favorable response to immune checkpoint inhibitors. Immune checkpoint inhibitors, including pembrolizumab (anti-PD-1 inhibitor) and nivolumab (anti-PD-1 inhibitor) with or without ipilimumab (anti-CTLA-4 inhibitor), have been integrated into the standard-of-care for high-level microsatellite instability/deficient mismatch repair metastatic colorectal cancer. Conversely, limited T-cell infiltration in the tumor microenvironment of microsatellite stable/proficient mismatch repair metastatic colorectal cancer, which constitutes the majority of metastatic colorectal cancer, is assumed to be a major resistant mechanism to immune checkpoint inhibitors. Currently, clinical trials to improve the clinical activity of immune checkpoint inhibitors by immunomodulation are ongoing for metastatic colorectal cancer. Furthermore, immune checkpoint inhibitors are under development in neoadjuvant and/or adjuvant setting. Here, we review the existing clinical data with ongoing trials and discuss the future perspectives with a focus on the immunotherapy of colorectal cancer.

Polymorphisms within Immune Regulatory Pathways Predict Cetuximab Efficacy and Survival in Metastatic Colorectal Cancer Patients

Cetuximab, an IgG1 EGFR-directed antibody, promotes antibody-dependent cell-mediated cytotoxicity. We hypothesized that single-nucleotide polymorphisms (SNPs) in immune regulatory pathways may predict outcomes in patients with metastatic colorectal cancer treated with cetuximab-based regimens. A total of 924 patients were included: 105 received cetuximab in IMCL-0144 and cetuximab/irinotecan in GONO-ASL608LIOM01 (training cohort), 225 FOLFIRI/cetuximab in FIRE-3 (validation cohort 1), 74 oxaliplatin/cetuximab regimens in JACCRO CC-05/06 (validation cohort 2), and 520 FOLFIRI/bevacizumab in FIRE-3 and TRIBE (control cohorts). Twelve SNPs in five genes (IDO1; PD-L1; PD-1; CTLA-4; CD24) were evaluated by PCR-based direct sequencing. We analyzed associations between genotype and clinical outcomes. In the training cohort; patients with the CD24 rs52812045 A/A genotype had a significantly shorter median PFS and OS than those with the G/G genotype (PFS 1.3 vs. 3.6 months; OS 2.3 vs. 7.8 months) in univariate (PFS HR 3.62; p = 0.001; OS HR 3.27; p = 0.0004) and multivariate (PFS HR 3.18; p = 0.009; OS HR 4.93; p = 0.001) analyses. Similarly; any A allele carriers in the JACCRO validation cohort had a significantly shorter PFS than G/G carriers (9.2 vs. 11.8 months; univariate HR 1.90; p = 0.011; multivariate HR 2.12; p = 0.018). These associations were not demonstrated in the control cohorts. CD24 genetic variants may help select patients with metastatic colorectal cancer most likely to benefit from cetuximab-based therapy.

Modulated Electro-Hyperthermia-Induced Tumor Damage Mechanisms Revealed in Cancer Models

The benefits of high-fever range hyperthermia have been utilized in medicine from the Ancient Greek culture to the present day. Amplitude-modulated electro-hyperthermia, induced by a 13.56 MHz radiofrequency current (mEHT, or Oncothermia), has been an emerging means of delivering loco-regional clinical hyperthermia as a complementary of radiation-, chemo-, and molecular targeted oncotherapy. This unique treatment exploits the metabolic shift in cancer, resulting in elevated oxidative glycolysis (Warburg effect), ion concentration, and electric conductivity. These promote the enrichment of electric fields and induce heat (controlled at 42 °C), as well as ion fluxes and disequilibrium through tumor cell membrane channels. By now, accumulating preclinical studies using in vitro and in vivo models of different cancer types have revealed details of the mechanism and molecular background of the oncoreductive effects of mEHT monotherapy. These include the induction of DNA double-strand breaks, irreversible heath and cell stress, and programmed cells death; the upregulation of molecular chaperones and damage (DAMP) signaling, which may contribute to a secondary immunogenic tumor cell death. In combination therapies, mEHT proved to be a good chemosensitizer through increasing drug uptake and tumor reductive effects, as well as a good radiosensitizer by downregulating hypoxia-related target genes. Recently, immune stimulation or intratumoral antigen-presenting dendritic cell injection have been able to extend the impact of local mEHT into a systemic "abscopal" effect. The complex network of pathways emerging from the published mEHT experiments has not been overviewed and arranged yet into a framework to reveal links between the pieces of the "puzzle". In this paper, we review the mEHT-related damage mechanisms published in tumor models, which may allow some geno-/phenotype treatment efficiency correlations to be exploited both in further research and for more rational clinical treatment planning when mEHT is involved in combination therapies.

Priming the tumor immune microenvironment with chemo(radio)therapy: A systematic review across tumor types

BACKGROUND

Chemotherapy (CT), radiotherapy (RT), and chemoradiotherapy (CRT) are able to alter the composition of the tumor immune microenvironment (TIME). Understanding the effect of these modalities on the TIME could aid in the development of improved treatment strategies. Our aim was to systematically review studies investigating the influence of CT, RT or CRT on different TIME markers.

METHODS

The EMBASE (Ovid) and PubMed databases were searched until January 2019 for prospective or retrospective studies investigating the dynamics of the local TIME in cancer patients (pts) treated with CT, RT or CRT, with or without targeted agents. Studies could either compare baseline and follow-up specimens - before and after treatment - or a treated versus an untreated cohort. Studies were included if they used immunohistochemistry and/or flow cytometry to assess the TIME.

RESULTS

In total we included 110 studies (n = 8850 pts), of which n = 89 (n = 6295 pts) compared pre-treatment to post-treatment specimens and n = 25 (n = 2555 pts) a treated versus an untreated cohort (4 studies conducted both comparisons). For several tumor types (among others; breast, cervical, esophageal, ovarian, rectal, lung mesothelioma and pancreatic cancer) remodeling of the TIME was observed, leading to a potentially more immunologically active microenvironment, including one or more of the following: an increase in CD3 or CD8 lymphocytes, a decrease in FOXP3 Tregs and increased PD-L1 expression. Both CT and CRT were able to immunologically alter the TIME.

CONCLUSION

The TIME of several tumor types is significantly altered after conventional therapy creating opportunities for concurrent or sequential immunotherapy.

Neoadjuvant chemotherapy is associated with a transient increase of intratumoral T-cell density in microsatellite stable colorectal liver metastases

Patients with colorectal liver metastases (CLM) commonly receive neoadjuvant chemotherapy (NACT) prior to surgical resection. NACT may induce immunogenic cell death with subsequent recruitment of T-cells to the tumor microenvironment, which could be exploited by immune checkpoint inhibition (ICI). In theory, this could expand the use of ICI to obtain responses also in microsatellite stable colorectal cancer, but evidence to suggest optimal treatment schedules are lacking. In this study, densities of total-, cytotoxic-, helper- and regulatory T-cells were quantified by immunohistochemistry in resected CLM from 92 patients included in the OSLO-COMET trial (NCT01516710). All but one patient had microsatellite stable tumors (91/92). Associations between T-cell densities and clinicopathological parameters were analyzed. Fluoropyrimidine-based NACT (in most cases with addition of oxaliplatin or irinotecan) was administered to 45 patients completed median 8 weeks prior to surgical resection. No overall association was found between NACT administration and intratumoral T-cell densities. However, within the NACT group, a short time interval (<9.5 weeks) between NACT completion and CLM resection was strongly associated with high intratumoral T-cell densities compared to the long-interval and no NACT groups (medians 491, 236, and 292 cells/mm², respectively; P < .0001). The results from this study suggest that the observed increase in intratumoral T-cells after NACT administration may be transient. The significance of this finding should be further explored to ensure that optimal treatment schedules are chosen for studies combining cytotoxic chemotherapy and ICI.

Immunotherapy with immune checkpoint inhibitors in colorectal cancer: what is the future beyond deficient mismatch-repair tumours?

Following initial success in melanoma and lung tumours, immune checkpoint inhibitors (ICIs) are now well recognized as a major immunotherapy treatment modality for multiple types of solid cancers. In colorectal cancer (CRC), the small subset that is mismatch-repair-deficient and microsatellite-instability-high (dMMR/MSI-H) derive benefit from immunotherapy; however, the vast majority of patients with proficient MMR (pMMR) or with microsatellite stable (MSS) CRC do not. Immunoscore and the consensus molecular subtype classifications are promising biomarkers in predicting therapeutic efficacy in selected CRC. In pMRR/MSS CRC, biomarkers are also needed to understand the molecular mechanisms governing immune reactivity and to predict their relationship to treatment. The continuous development of such biomarkers would offer new perspectives and more personalized treatments by targeting oncological options, including ICIs, which modify the tumour-immune microenvironment. In this review, we focus on CRC and discuss the current status of ICIs, the role of biomarkers to predict response to immunotherapy, and the approaches being explored to render pMMR/MSS CRC more immunogenic through the use of combined therapies.

Perspectives on Treatment of Metastatic Colorectal Cancer with Immune Checkpoint Inhibitor Therapy

Despite lengthening survival, death rates from metastatic colorectal cancer (CRC) remain unacceptably high, with a bright spot being the demonstration of durable responses in patients with CRC who have mismatch repair-deficient (dMMR) and/or microsatellite instability-high (MSI-H) tumors and are treated with immune checkpoint inhibitor therapy. Nivolumab and pembrolizumab, as well as nivolumab in combination with low-dose ipilimumab-all checkpoint inhibitors-are currently approved by the U.S. Food and Drug Administration (FDA) for patients with MSI-H/dMMR metastatic CRC that progressed following treatment with a fluoropyrimidine, oxaliplatin, and irinotecan. Nonetheless, there are a number of questions and considerations in the use of these checkpoint inhibitor therapies. Using a question-and-answer format, this review summarizes the scientific rationale for immune checkpoint inhibitor therapy in CRC, including the effects of tumor factors such as genetic aberrations and mutational load on the immune response, particularly in patients with MSI-H/dMMR disease. We discuss response patterns, response criteria, and immune-related adverse events using findings from published efficacy and safety data of immune checkpoint inhibitor therapy in metastatic CRC. We also discuss issues surrounding treatment sequencing, incorporating approved checkpoint inhibitors into the current treatment paradigm, and the multiple investigational strategies that may optimize immunotherapy for advanced CRC in the future, including novel combination therapies. IMPLICATIONS FOR PRACTICE: Colorectal cancer (CRC) is the third most common cancer in the U.S. Despite advances in chemotherapy, survival remains poor for patients with metastatic CRC. Certain immunotherapy agents have demonstrated long-lasting responses in previously treated patients with immune-responsive microsatellite instability-high/mismatch repair-deficient metastatic CRC, leading to U.S. Food and Drug Administration approval of the immune checkpoint inhibitors nivolumab (with or without low-dose ipilimumab) and pembrolizumab in this population. Combination therapy (e.g., nivolumab with low-dose ipilimumab) has demonstrated numerically higher response rates and improved long-term clinical benefit relative to anti-programmed death-1 monotherapy. Ongoing trials are evaluating immunotherapy in the broader CRC population and novel combinations to optimize immunotherapy for advanced CRC.

Distinguishing Features of Cetuximab and Panitumumab in Colorectal Cancer and Other Solid Tumors

Cetuximab and panitumumab are two distinct monoclonal antibodies (mAbs) targeting the epidermal growth factor receptor (EGFR), and both are widely used in combination with chemotherapy or as monotherapy to treat patients with RAS wild-type metastatic colorectal cancer. Although often considered interchangeable, the two antibodies have different molecular structures and can behave differently in clinically relevant ways. More specifically, as an immunoglobulin (Ig) G1 isotype mAb, cetuximab can elicit immune functions such as antibody-dependent cell-mediated cytotoxicity involving natural killer cells, T-cell recruitment to the tumor, and T-cell priming via dendritic cell maturation. Panitumumab, an IgG2 isotype mAb, does not possess these immune functions. Furthermore, the two antibodies have different binding sites on the EGFR, as evidenced by mutations on the extracellular domain that can confer resistance to one of the two therapeutics or to both. We consider a comparison of the properties of these two antibodies to represent a gap in the literature. We therefore compiled a detailed, evidence-based educational review of the known molecular, clinical, and functional differences between the two antibodies and concluded that they are distinct therapeutic agents that should be considered individually during treatment planning. Available data for one agent can only partly be extrapolated to the other. Looking to the future, the known immune activity of cetuximab may provide a rationale for this antibody as a combination partner with investigational chemotherapy plus immunotherapy regimens for colorectal cancer.

Vitamin D Deficiency has a Negative Impact on Cetuximab-Mediated Cellular Cytotoxicity against Human Colon Carcinoma Cells

BACKGROUND

Hypovitaminosis D is associated with an adverse prognosis in colon cancer patients, possibly due to the effects of the vitamin on the immune system. Antibody-dependent cell-mediated cytotoxicity (ADCC) significantly contributes to the anti-tumor effects of monoclonal antibodies, including cetuximab, an epidermal growth factor receptor (EGFR)-targeted monoclonal antibody that is frequently added to chemotherapy in the treatment of colon cancer.

OBJECTIVE

The present study evaluates the association between vitamin D serum levels and the ability of ex vivo NK cells to support cetuximab-mediated ADCC in colon cancer cell lines.

METHODS

Blood samples were obtained from 124 healthy volunteers and serum vitamin D was determined by RIA. NK cells were isolated from each sample and added to human colorectal carcinoma cells with or without cetuximab, and ADCC was assessed using a colorimetric lactate dehydrogenase assay.

RESULTS

Correlation analysis indicates a significant, gender- and age-independent association between vitamin D levels and cetuximab-induced ADCC on HT29 cells, where NK cells from samples with vitamin D < 20 ng/mL are significantly less efficient in inducing ADCC. A confirmatory study on two additional colon cancer cell lines yielded similar results.

CONCLUSIONS

These data suggest that vitamin D supplementation in vitamin-deficient/insufficient colorectal cancer patients could improve cetuximab-induced ADCC.

miR-31-3p Expression and Benefit from Anti-EGFR Inhibitors in Metastatic Colorectal Cancer Patients Enrolled in the Prospective Phase II PROSPECT-C Trial

PURPOSE

Anti-EGFR mAbs are effective in the treatment of metastatic colorectal cancer (mCRC) patients. RAS status and tumor location (sidedness) are predictive markers of patients' response to anti-EGFR mAbs. Recently, low miR-31-3p expression levels have been correlated with clinical benefit from the anti-EGFR mAb cetuximab. Here, we aimed to validate the predictive power of miR-31-3p in a prospective cohort of chemorefractory mCRC patients treated with single-agent anti-EGFR mAbs.

EXPERIMENTAL DESIGN

miR-31-3p was tested by in situ hybridization (ISH) in 91 pretreatment core biopsies from metastatic deposits of 45 patients with mCRC. Sequential tissue biopsies obtained before treatment, at the time of partial response, and at disease progression were tested to monitor changes in miR-31-3p expression overtreatment. miR-31-3p expression, sidedness, and RAS status in pretreatment cell-free DNA were combined in multivariable regression models to assess the predictive value of each variable alone or in combination.

RESULTS

Patients with low miR-31-3p expression in pretreatment biopsies showed better overall response rate, as well as better progression-free survival and overall survival, compared to those with high miR-31-3p expression. The prognostic effect of miR-31-3p was independent from age, gender, and sidedness. No significant changes in the expression of miR-31-3p were observed when sequential tissue biopsies were tested in long-term or poor responders to anti-EGFR mAbs. miR-31-3p scores were similar when pretreatment biopsies were compared with treatment-naïve archival tissues (often primary colorectal cancer).

CONCLUSIONS

Our study validates the role of miR-31-3p as potential predictive biomarker of selection for anti-EGFR mAbs.

Immunotherapy-based combination strategies for treatment of gastrointestinal cancers: current status and future prospects

Strategies in comprehensive therapy for gastrointestinal (GI) cancer have been optimized in the last decades to improve patients' outcomes. However, treatment options remain limited for late-stage or refractory diseases. The efficacy of immune checkpoint inhibitors (ICIs) for treatment of refractory GI cancer has been confirmed by randomized clinical trials. In 2017, pembrolizumab was approved by the US Food and Drug Administration as the first agent for treatment of metastatic solid tumors with mismatch repair deficiency, especially for colorectal cancer. Given the different mechanisms, oncologists have focused on determining whether ICIs-based combination strategies could achieve higher efficacy than conventional therapy alone in late-stage or even front-line treatment of GI cancer. This review discusses the current status of combining immune checkpoint inhibitors with molecular targeted therapy, chemotherapy, or radiotherapy in GI cancer in terms of mechanisms, safety, and efficacy to provide basis for future research.

Nouvelles stratégies innovantes en immunothérapie

NOVEL STRATEGY IN ONCOIMMUNOLOGY

Recent advances in immuno-oncology with the development of anti-PD1/PD-L1 antibodies are revolutionizing oncological management. Immuno-oncology I currently developing in most histological types of cancer. However, the rate of success of anti-PD1/PD-L1 antibodies in monotherapy is limited by a limited to a subpopulation of patients accounting for about 25-30 % of patients in most indications. The development of new strategies is based on this observation with the aim to predict response or enhancing response rate. Thus, we note the development of different strategies aimed at better selecting patients or combining inhibitory checkpoints with other therapies in order to increase their effectiveness. This review will study therapeutic test strategies to validate these new associations.

RAS status and neoadjuvant chemotherapy impact CD8+ cells and tumor HLA class I expression in liver metastatic colorectal cancer

Background

T lymphocytes and HLA expression on tumor cell both influence prognostic of localized colorectal cancer, but their role following chemotherapy in patients with liver metastatic colorectal cancer (mCRC) was not addressed.

Methods

One hundred fourteen patients treated in curative intend of liver mCRC were included in this retrospective study. Patients were either untreated or treated with neoadjuvant therapy containing an anti-EGFR, bevacizumab or oxaliplatin. Immune densities were quantified in the tumor core and in invasive margin of metastases, using Qupath software or a pathologist’s quantification. CD8, NKp46, Foxp3, CD163, HLA, PD-L1 were analyzed and were correlated with progression free survival (PFS) and overall survival (OS) using multivariable Cox proportional hazards models.

Results

In the whole cohort only a high CD8+ cells infiltrate, a high HLA-I expression and wild-type RAS/RAF status were associated with a better overall survival in both univariate and multivariate model. Moreover, CD8+ cells immune infiltrate at invasive margin combined to HLA expression in cancer cell could increase patient’s outcome prediction. RAS status but not immune cell infiltrate was associated with HLA expression on tumor cells. In comparison to untreated patients, neoadjuvant chemotherapy induced CD8+ cells recruitment and increased PD-L1 staining in immune infiltrates only for WT RAS patients. In this context, anti-EGFR and oxaliplatin based chemotherapy are the most powerful to induce CD8+ cells mobilization within the metastatic site.

Conclusions

While CD8 infiltrate and HLA expression appear to be prognostic for mCRC, CD8 and PD-L1 infiltrate are enhanced by neoadjuvant chemotherapy in mCRC under RAS status dependence.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0438-3) contains supplementary material, which is available to authorized users.

Depicting Changes in Tumor Biology in Response to Cetuximab Monotherapy or Combination Therapy by Apoptosis and Proliferation Imaging Using 18F-ICMT-11 and 18F-FLT PET

Imaging biomarkers must demonstrate their value in monitoring treatment. Two PET tracers, the caspase-3/7-specific isatin-5-sulfonamide 18F-ICMT-11 (18F-(S)-1-((1-(2-fluoroethyl)-1H-[1,2,3]-triazol-4-yl)methyl)-5-(2(2,4-difluoro-phenoxymethyl)-pyrrolidine-1-sulfonyl)isatin) and 18F-FLT (3'-deoxy-3'-18F-fluorothymidine), were used to detect early treatment-induced changes in tumor biology and determine whether any of these changes indicate a response to cetuximab, administered as monotherapy or combination therapy with gemcitabine. Methods: In mice bearing cetuximab-sensitive H1975 tumors (non-small lung cancer), the effects of single or repeated doses of the antiepidermal growth factor receptor antibody cetuximab (10 mg/kg on day 1 only or on days 1 and 2) or a single dose of gemcitabine (125 mg/kg on day 2) were investigated by 18F-ICMT-11 or 18F-FLT on day 3. Imaging was also performed after 2 doses of cetuximab (days 1 and 2) in mice bearing cetuximab-insensitive HCT116 tumors (colorectal cancer). For imaging-histology comparison, tumors were evaluated for proliferation (Ki-67 and thymidine kinase 1 [TK1]), cell death (cleaved caspase-3 and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling [TUNEL]), and target engagement (epidermal growth factor receptor expression) by immunohistochemistry, immunofluorescence, and immunoblotting, respectively. Tumor and plasma were analyzed for thymidine and gemcitabine metabolites by liquid chromatography-mass spectrometry. Results: Retention of both tracers was sensitive to cetuximab in H1975 tumors. 18F-ICMT-11 uptake and ex vivo cleaved caspase-3 staining notably increased in tumors treated with repeated doses of cetuximab (75%) and combination treatment (46%). Although a single dose of cetuximab was insufficient to induce apoptosis, it did affect proliferation. Significant reductions in tumor 18F-FLT uptake (44%-50%; P < 0.001) induced by cetuximab monotherapy and combination therapy were paralleled by a clear decrease in proliferation (Ki-67 decrease, 72%-95%; P < 0.0001), followed by a marked tumor growth delay. TK1 expression and tumor thymidine concentrations were profoundly reduced. Neither imaging tracer depicted the gemcitabine-induced tumor changes. However, cleaved caspase-3 and Ki-67 staining did not significantly differ after gemcitabine treatment whereas TK1 expression and thymidine concentrations increased. No cetuximab-induced modulation of the imaging tracers or other response markers was detected in the insensitive model of HCT116. Conclusion:18F-ICMT-11 and 18F-FLT are valuable tools to assess cetuximab sensitivity depicting distinct and time-variant aspects of treatment response.

Current status of immunotherapy against gastrointestinal cancers and its biomarkers: Perspective for precision immunotherapy

Immunotherapy has shown encouraging results for some types of tumor. Although enormous efforts have been made toward the development of specific immunotherapeutic strategies against gastrointestinal cancers, such as adoptive T-cell transfer, peptide vaccines, or dendritic cell vaccines, the efficacy of immunotherapies prior to the introduction of immune checkpoint inhibitors was not substantial. This article reviews immunotherapy for gastrointestinal malignancies, including cell therapy, peptide vaccine, and immune checkpoint inhibitors, and attempts to resolve the immunosuppressive conditions surrounding the tumor microenvironment, and to construct novel combination immunotherapies beyond immune checkpoint inhibitors.

Strategy to targeting the immune resistance and novel therapy in colorectal cancer

Assessing the CRC subtypes that can predict the outcome of colorectal cancer (CRC) in patients with immunogenicity seems to be a promising strategy to develop new drugs that target the antitumoral immune response. In particular, the disinhibition of the antitumoral T‐cell response by immune checkpoint blockade has shown remarkable therapeutic promise for patients with mismatch repair (MMR) deficient CRC. In this review, the authors provide the update of the molecular features and immunogenicity of CRC, discuss the role of possible predictive biomarkers, illustrate the modern immunotherapeutic approaches, and introduce the most relevant ongoing preclinical study and clinical trials such as the use of the combination therapy with immunotherapy. Furthermore, this work is further to understand the complex interactions between the immune surveillance and develop resistance in tumor cells. As expected, if the promise of these developments is fulfilled, it could develop the effective therapeutic strategies and novel combinations to overcome immune resistance and enhance effector responses, which guide clinicians toward a more “personalized” treatment for advanced CRC patients.

NHERF1 Between Promises and Hopes: Overview on Cancer and Prospective Openings

Na+/H+ exchanger regulatory factor 1 (NHERF1) is a scaffold protein, with two tandem PDZ domains and a carboxyl-terminal ezrin-binding (EB) region. This particular sticky structure is responsible for its interaction with different molecules to form multi-complexes that have a pivotal role in a lot of diseases. In particular, its involvement during carcinogenesis and cancer progression has been deeply analyzed in different tumors. The role of NHERF1 is not unique in cancer; its activity is connected to its subcellular localization. The literature data suggest that NHERF1 could be a new prognostic/predictive biomarker from breast cancer to hematological cancers. Furthermore, the high potential of this molecule as therapeutical target in different carcinomas is a new challenge for precision medicine. These evidences are part of a future view to improving patient clinical management, which should allow different tumor phenotypes to be treated with tailored therapies. This article reviews the biology of NHERF1, its engagement in different signal pathways and its involvement in different cancers, with a specific focus on breast cancer. It also considers NHERF1 potential role during inflammation related to most human cancers, designating new perspectives in the study of this "Janus-like" protein.