Phase II trial of capecitabine and oxaliplatin (CAPOX) plus cetuximab in patients with metastatic colorectal cancer who progressed after oxaliplatin-based chemotherapy

The impact of combining cetuximab with the traditional chemotherapy regimens on clinical effectiveness in metastatic colorectal cancer: a systematic review and meta-analysis

BACKGROUND

Metastatic colorectal cancer (mCRC) poses a high rate of morbidity and mortality despite various treatment advances. Cetuximab, an anti-EGFR, has shown promising efficacy in improving outcomes when combined with chemotherapy. Understanding its efficacy is essential for optimizing treatment strategies in mCRC. This systematic review and meta-analysis aims to evaluate the effectiveness of combining cetuximab with chemotherapy in mCRC.

METHODS

PubMed and Google Scholar were systematically searched following the benchmarks indicated by PRISMA. The primary outcomes of the study were progression-free survival (PFS) and overall survival (OS). Statistical analyses were executed using Stata version 16.

RESULTS

The meta-analysis encompassed 25 studies involving 3788 mCRC patients. The median age spans from 18 to 77 years. The cetuximab plus chemotherapy exhibited a higher PFS and OS with a significant difference (PFS: HR = 0.79, 95% CI = 0.63-0.96, p < 0.01, I2 = 38% and OS: HR = 0.78, 95% CI = 0.60-0.91, p < 0.01, I2 = 47%) compared to the control group. Subgroup analysis based on randomized controlled trials demonstrated consistent treatment effects for PFS (HR = 0.77, 95% CI = 0.62-0.93) and OS (HR = 0.76, 95% CI = 0.61-0.88) in the cetuximab treatment group.

CONCLUSIONS

Combining cetuximab with chemotherapy offers a potential benefit in improving survival outcomes for metastatic colorectal cancer patients, as indicated by this study. These results suggest that cetuximab may be a valuable addition to mCRC treatment strategies, warranting further clinical investigation and integration into standard care.

Antibody-Loaded Nanoplatforms for Colorectal Cancer Diagnosis and Treatment: An Update

At present, colorectal cancer (CRC) is the second deadliest type of cancer, partly because a high percentage of cases are diagnosed at advanced stages when tumors have already metastasized. Thus, there is an urgent need to develop novel diagnostic systems that allow early detection as well as new therapeutic systems that are more specific than those currently available. In this context, nanotechnology plays a very important role in the development of targeted platforms. In recent decades, many types of nanomaterials with advantageous properties have been used for nano-oncology applications and have been loaded with different types of targeted agents, capable of recognizing tumor cells or biomarkers. Indeed, among the different types of targeted agents, the most widely used are monoclonal antibodies, as the administration of many of them is already approved by the main drug regulatory agencies for the treatment of several types of cancer, including CRC. In this way, this review comprehensively discusses the main drawbacks of the conventional screening technologies and treatment for CRC, and it presents recent advances in the application of antibody-loaded nanoplatforms for CRC detection, therapy or theranostics applications.

LncRNA-NEF suppressed oxaliplatin resistance and epithelial-mesenchymal transition in colorectal cancer through epigenetically inactivating MEK/ERK signaling

A major cause of oxaliplatin chemoresistance in colorectal cancer (CRC) is acquired epithelial-mesenchymal transition (EMT) in cancer cells, making the cancer cells easy to metastasis and recurrence. LncRNA Neighboring Enhancer of FOXA2 (lncRNA-NEF) has been characterized as a tumor suppressor to mediate cancer metastasis in multiple cancer types. However, whether it mediated the drug resistance remains unknown. In the present study, an oxaliplatin-resistant CRC cell line (SW620R) was established and lncRNA-NEF was obviously down-regulated in this resistant cell line. The further loss and gain-of-function studies demonstrated that this lncRNA suppressed oxaliplatin resistance as well as EMT programme in vitro and inhibited metastasis in vivo. Mechanistically, lncRNA-NEF epigenetically promoted the expression of DOK1 (Downstream of Tyrosine kinase 1), a negative regulator of MEK/ERK signaling, by disrupting DNA methyltransferases (DNMTs)-mediated DNA methylation. DOK1, in turn, induced the inactivation of MEK/ERK signaling, forming the lncRNA-NEF/DOK1/MEK/ERK regulatory axis to mediate oxaliplatin resistance in CRC. Collectively, our work reveals the critical function of lncRNA-NEF in mediating the oxaliplatin chemotherapy resistance in CRC, and provides a promising therapeutic strategy for CRC patients with oxaliplatin resistance.

Development and Clinical Indications of Cetuximab

Cetuximab is a chimeric immunoglobulin G1 monoclonal antibody that targets the extracellular domain of the epidermal growth factor receptor (EGFR) with high specificity and affinity. It competitively inhibits endogenous ligand binding and thereby inhibits subsequent EGFR activation. The EGFR signaling pathways regulate cell differentiation, proliferation, migration, angiogenesis and apoptosis, all of which become deregulated in cancer cells. EGFR is an important target for cancer therapy and many studies have demonstrated that cetuximab is active in several types of cancer, particularly colorectal and head and neck cancer. Cetuximab enhances the effects of many standard cytotoxic agents, including irinotecan, and in combination with chemotherapy it can elicit antitumor responses in tumors that previously failed to respond to that chemotherapy. Cetuximab also enhances radiation-induced apoptosis. On the basis of a pivotal European randomized study (the BOND study) and of 2 clinical studies conducted in the USA, cetuximab has been approved in combination with irinotecan for patients affected by EGFR-expressing metastatic colon cancer after failure with irinotecan. There have only been a few small phase II trials on first-line treatment in metastatic colorectal cancer, but the results suggest promising activity of cetuximab together with irinotecan or oxaliplatin. There is some evidence that additive efficacy can be achieved using EGFR inhibitors in combination with vascular endothelial growth factor receptor inhibitors such as bevacizumab. A correlation between response and the main toxicity (acne-like skin reaction) has been observed but is unclear. EGFR status as a specific marker for EGFR inhibitors is controversial. At the moment, EGFR expression does not appear to be a predictive factor for response to EGFR inhibitors.

Clinical studies in CRS and HIPEC: Trials, tribulations, and future directions-A systematic review

BACKGROUND

The field of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has suffered from a lack of clinical trials to validate its expanding use.

OBJECTIVE

To evaluate published and ongoing clinical trials seeking to better define role of CRS/HIPEC in the treatment of peritoneal surface malignancies.

METHODS

Systematic review by PubMed search was performed using terms "Clinical trial," "intraperitoneal chemotherapy," and "HIPEC." ClinicalTrials.gov and EudraCT registries were searched for active clinical trials. Eligibility included CRS/HIPEC trials investigating adult patient populations from published clinical reports and/or trials currently accruing or at completion.

RESULTS

Thirteen published trials and 57 active clinical trials were included for review.

CONCLUSIONS

Published and ongoing U.S. and international clinical trials for CRS and HIPEC are defining important parameters that include improving patient selection, strategic sequences of treatment, cytoreductive strategies, chemotherapeutics, optimal hyperthermic temperature and timing, and toxicity profiles. Main barriers or limitations to trial development remain patient enrollment, trial design, and oncologic community collaboration. Overall progress is positive with increasing number of clinical trials throughout the world. Collaboration between surgeons and the wider oncologic community will be crucial to validate this important treatment strategy.

Cetuximab Plus Various Chemotherapy Regimens for Patients with KRAS Wild-Type Metastatic Colorectal Cancer

Background: The aim of this study was to compare the efficacy and hematologic toxicity of cetuximab combined with various types of chemotherapy regimens in patients with KRAS wild-type metastatic colorectal cancer (mCRC). Methods: The response rate, progression-free survival (PFS) and overall survival of the patients were analyzed. Results: In total, 45 patients were included in the study. The overall response rate for the combination of cetuximab and FOLFOX, FOLFIRI and CAPOX was 20, 46 and 30%, respectively, but the differences were not statistically significant. The median PFS for the three groups were 8, 6 and 3.5 months, respectively, but again these differences were not significant. All-grade leukopenia and anemia for the cetuximab plus FOLFOX group were significantly higher than for the other chemotherapy regimens. Conclusion: Our findings suggest that the combination of cetuximab and the three standard chemotherapy regimens resulted in the same outcomes in our patient population of mCRC, with higher hematologic toxicities among the FOLFOX subgroup.

Anti-EGFR monoclonal antibodies for treatment of colorectal cancers: development of cetuximab and panitumumab

Over the last decade, anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs) have been firmly established as essential drugs for the treatment of metastatic colorectal cancer (CRC). Cetuximab and panitumumab have been approved by American and European drug agencies. This review aims at exploring the main outcomes of clinical studies performed during their clinical development, from phase I to III trials, and hence at giving a comprehensive review of the scientific rational and up-to-date evidence sustaining the use of these drugs. Many areas are still under active investigation such as administration schedules, their efficacy in comparison with bevacizumab, their role in adjuvant therapy, molecular predictors, and management of side effects.

Management of advanced colorectal cancer, Part 2

PURPOSE

Important developments in chemotherapy for advanced colorectal cancer over the past 15 years are reviewed, with an emphasis on the most recently published data from clinical trials of newer multidrug regimens, administration techniques, and dosing schedules.

SUMMARY

Eight agents are approved by the Food and Drug Administration (FDA) for use in treating patients with advanced colorectal cancer. Fluorouracil and leucovorin still constitute the foundation of most chemotherapy regimens for this population; combination fluorouracil-leucovorin therapy plus either irinotecan (the FOLFIRI regimen) or oxaliplatin (the FOLFOX regimen) are two firmly established first-line treatments shown to produce similar outcomes. In Phase III trials conducted over the past six to seven years, regimens of capecitabine plus oxaliplatin (CapeOx) were demonstrated to have clinical effectiveness comparable to that of FOLFOX therapy. Response rates of 35-55% and median overall survival of ≥20 months have been documented with some of the newer regimens. Research to define the optimal role of the three monoclonal antibody agents approved by FDA for use in managing advanced colorectal cancer is ongoing; bevacizumab has been shown to confer significant survival benefits when added to certain chemotherapy regimens, and other monoclonal antibodies (cetuximab and panitumumab) also appear to offer significant benefits in select patients as first- or second-line therapies.

CONCLUSION

Over the past 15 years, a shift toward multiagent treatment strategies including a variety of chemotherapy agents and monoclonal antibodies has yielded improved rates of response and prolonged survival among patients with advanced colorectal cancer. The CapeOx, FOLFOX, and FOLFIRI regimens are currently among the most widely used first-line treatments.

Personalized treatment for advanced colorectal cancer: KRAS and beyond

Targeted therapies have improved the survival of patients with advanced colorectal cancer (CRC). However, further improvements in patient outcomes may be gained by the development of predictive biomarkers in order to select individuals who are most likely to benefit from treatment, thus personalizing treatment. Using the epidermal growth-factor receptor (EGFR) pathway, we discuss the existing and potential predictive biomarkers in clinical development for use with EGFR-targeted agents in metastatic CRC. The data and technological issues surrounding such biomarkers as expression of EGFR or its family members or ligands, KRAS-, NRAS-, and BRAF-mutation status, PI3K/PTEN expression, and imaging and clinical biomarkers, such as rash and hypomagnesemia, are summarized. Although the discovery of KRAS mutations has improved patient selection for EGFR-targeted treatments, further biomarkers are required, especially for those patients who exhibit KRAS mutations rather than the wild-type gene.

Methods of overcoming treatment resistance in colorectal cancer

Metastatic colorectal cancer remains a lethal disease with a poor prognosis in the majority of patients. Multiple drug combinations have been developed in recent years that have significantly improved response rates and overall survival however resistance to these drugs is inevitable. Novel agents are currently being developed and participation in clinical trials should be encouraged. In the absence of other treatment options in a patient with good performance status, there is compelling evidence for re-challenging with previously administered agents in different combinations. The aim of this review is to discuss mechanisms of resistance and methods to overcome treatment resistance in patients with metastatic colorectal cancer who are refractory to 5-FU, irinotecan, oxaliplatin, cetuximab and bevacizumab therapy.

The role of personalized medicine in metastatic colorectal cancer: an evolving landscape

Advances in the treatment of metastatic colorectal cancer have led to an improvement in survival from 12 months with fluorouracil monotherapy to approximately 2 years. This is partly as a result of the addition of irinotecan and oxaliplatin, but is also due to the use of monoclonal antibodies against the epidermal growth factor receptor (EGFR) and antiangiogenic drugs such as bevacizumab. However, there are significant molecular differences between tumours which can affect both prognosis and response to treatment. Personalized medicine aims to tailor treatment according to the characteristics of the individual patient and is now a clinical reality as testing for KRAS mutations to guide treatment with the anti-EGFR monoclonal antibodies cetuximab and panitumumab is now part of routine clinical practice. However, not all patients who are KRAS wild type respond to anti-EGFR therapy and a validated biomarker for antiangiogenic therapy is still lacking. Therefore, other biomarkers are needed to assist with predicting response to both existing drugs as well as to drugs currently under investigation. This review summarizes the molecular biology of colorectal cancer, focusing on the genetic features that are currently most clinically relevant. Current and emerging biomarkers are reviewed along with their roles in selecting patients for targeted treatment with currently licensed therapies and drugs being evaluated in clinical trials. The value of predictive biomarkers of chemosensitivity and potential future treatment strategies are also discussed.

Cetuximab therapy in the treatment of metastatic colorectal cancer: the future frontier?

BACKGROUND

To review the outcomes following cetuximab therapy in patients with metastatic colorectal cancer.

METHODS

Relevant articles were reviewed from the published literature using the Medline database. The search was performed using the keywords "colorectal cancer", "cetuximab", "liver metastases", "liver resection" and "hepatectomy".

RESULTS

Cetuximab was first used in the palliative setting and an increase in response rates were seen, however with no improvement in overall survival. Published data have observed that cetuximab may be beneficial as part of a down-staging programme. The addition of cetuximab to chemotherapy regimens in patients with KRAS wild-type colorectal cancer has been shown to increase the response rates and the number of patients being down-staged and offered potentially curative resection. The OPUS and CRYSTAL trials observed good response rates following the addition of cetuximab but low resection rates. The CELIM and POCHER studies reported higher resection rates due to better patient selection and study design. However, the majority of published studies tend to report minimal surgical data and lack short- and long-term outcomes.

CONCLUSION

The use of cetuximab to conventional chemotherapy regimens may improve the efficacy of down-staging programmes, leading to more patients being offered potentially curative resection.

Cetuximab inhibits thymidylate synthase in colorectal cells expressing epidermal growth factor receptor

The monoclonal antibody cetuximab directed against the epidermal growth factor receptor (EGFR) is an attractive agent for targeted therapy in advanced colorectal cancer (CRC), especially when combined with 5-fluorouracil (5-FU)-based chemotherapy. However, the mechanisms of cetuximab activity as chemosensitizer remain poorly understood. Using proteome-fluorescence-based technology, we found that cetuximab is able to suppress the expression of thymidylate synthase (TS), which is involved in the mechanism of 5-FU action. Caco-2, HRT-18, HT-29, WiDr and SW-480 CRC cells were found to express EGFR. SW-620 was used as EGFR-negative cell line. Only in EGFR-expressing cells cetuximab is able to inhibit TS expression. Combined treatment with cetuximab and 5-FU revealed a synergistic anti-tumor response that is closely correlated with functional activity of EGFR/mitogen-activated protein kinase (MAPK) pathway. Moreover, no correlation was seen between constitutive TS protein expression, level of cetuximab-induced TS down-regulation and response either to 5-FU alone or in combination with cetuximab. We demonstrated that only EGFR expression with high functional activity of EGFR/MAPK pathway is important for the synergistic effects between cetuximab and 5-FU in the investigated cell lines.

Systematic review on infusion reactions associated with chemotherapies and monoclonal antibodies for metastatic colorectal cancer

Objective:

The objective of this systematic review is to summarize the literature to date on the rates of infusion reactions (IR) associated with chemotherapies and monoclonal antibody (mAb) drug therapies used for the treatment of metastatic colorectal cancer (mCRC) and the associated clinical and economic impact.

Methods:

This study searched Medline, Medline (R) In-Process, Embase and Cochrane Library databases for studies on IRs associated with chemotherapy and mAbs in mCRC patients from 2000-2011.

Results:

For chemotherapy, the incidence of IRs ranged from 0-71% for all grades and 0-15% for grade 3-4. Rates of all grade IRs associated with cetuximab ranged from 7.6-33% and grade 3-4 IR rates were 0-22%. Rates of all grade IRs associated with panitumumab ranged from 0-4% and rates of grade 3-4 IRs ranged from 0-1%. The overall rate of IRs associated with bevacizumab ranged from 1.6-11%, with a rate of 0-4% for grade 3-4 IRs. A range of 50-100% of patients with grade 3-4 IRs terminated chemotherapy, and 34-100% of cetuximab patients with grade 3-4 IRs discontinued cetuximab therapy. No data were reported for bevacizumab or panitumumab. Only one study evaluated the economic impact of IRs. The study compared cetuximab administrations without an IR to those with an IR requiring resource utilization and found that mean costs were $9308 and $1725 higher for those with an IR requiring an emergency room visit or hospitalization and for those with an IR requiring outpatient treatment, respectively.

Conclusions:

The incidence of IRs varies among different mAbs; and IRs may cause treatment disruption and require costly medical interventions.

Sequential versus combination chemotherapy for the treatment of advanced colorectal cancer (FFCD 2000-05): an open-label, randomised, phase 3 trial

BACKGROUND

The optimum use of cytotoxic drugs for advanced colorectal cancer has not been defined. Our aim was to investigate whether combination treatment is better than the sequential administration of the same drugs in patients with advanced colorectal cancer.

METHODS

In this open-label, randomised, phase 3 trial, we randomly assigned patients (1:1 ratio) with advanced, measurable, non-resectable colorectal cancer and WHO performance status 0-2 to receive either first-line treatment with bolus (400 mg/m(2)) and infusional (2400 mg/m(2)) fluorouracil plus leucovorin (400 mg/m(2)) (simplified LV5FU2 regimen), second-line LV5FU2 plus oxaliplatin (100 mg/m(2)) (FOLFOX6), and third-line LV5FU2 plus irinotecan (180 mg/m(2)) (FOLFIRI) or first-line FOLFOX6 and second-line FOLFIRI. Chemotherapy was administered every 2 weeks. Randomisation was done centrally using minimisation (minimisation factors were WHO performance status, previous adjuvant chemotherapy, number of disease sites, and centre). The primary endpoint was progression-free survival after two lines of treatment. Analyses were by intention-to-treat. This trial is registered at ClinicalTrials.gov, NCT00126256.

FINDINGS

205 patients were randomly assigned to the sequential group and 205 to the combination group. 161 (79%) patients in the sequential group and 161 (79%) in the combination group died during the study. Median progression-free survival after two lines was 10·5 months (95% CI 9·6-11·5) in the sequential group and 10·3 months (9·0-11·9) in the combination group (hazard ratio 0·95, 95% CI 0·77-1·16; p=0·61). All six deaths caused by toxic effects of treatment occurred in the combination group. During first-line chemotherapy, significantly fewer severe (grade 3-4) haematological adverse events (12 events in 203 patients in sequential group vs 83 events in 203 patients in combination group; p<0·0001) and non-haematological adverse events (26 events vs 186 events; p<0·0001) occurred in the sequential group than in the combination group.

INTERPRETATION

Upfront combination chemotherapy is more toxic and is not more effective than the sequential use of the same cytotoxic drugs in patients with advanced, non-resectable colorectal cancer.

FUNDING

Sanofi-Aventis France.

An update on the current and emerging targeted agents in metastatic colorectal cancer

Over the past 8 to 10 years, significant advances have been made in the treatment of metastatic colorectal cancer (mCRC). In particular, the development of the targeted biologic agents bevacizumab, cetuximab, and panitumumab, and their integration with cytotoxic chemotherapy regimens has led to improvements in clinical efficacy. Despite these gains, the overall impact of current targeted agents in the treatment of mCRC has been relatively modest, and while 2-year survival has improved, no gains have been made, as of yet, in 5-year survival. Intense efforts continue to be focused on developing novel targeted agents with a different spectrum of activity. Presently, five novel targeted molecules are in phase III trials, including the antiangiogenesis agents aflibercept and ramucirumab, two novel receptor tyrosine kinase inhibitors, regorafenib and brivanib, and the Akt inhibitor perifosine. There are an additional 52 phase II trials investigating a wide range of other candidate molecules. The potential list of approved targeted agents in mCRC seems likely to increase over the next 5 to 10 years. To maximize their potential clinical impact, however, it will be critically important to introduce efficient molecular diagnostic methodologies into the drug development process for the identification and validation of predictive biomarkers for chemosensitivity. This article reviews the development of targeted agents for the treatment of mCRC, including the three molecules currently approved by the US Food and Drug Administration (FDA), as well as the main non-FDA-approved therapeutics currently undergoing phase II and III clinical testing.

The challenges of integrating molecular imaging into the optimization of cancer therapy

We review novel, in vivo and tissue-based imaging technologies that monitor and optimize cancer therapeutics. Recent advances in cancer treatment centre around the development of targeted therapies and personalisation of treatment regimes to individual tumour characteristics. However, clinical outcomes have not improved as expected. Further development of the use of molecular imaging to predict or assess treatment response must address spatial heterogeneity of cancer within the body. A combination of different imaging modalities should be used to relate the effect of the drug to dosing regimen or effective drug concentration at the local site of action. Molecular imaging provides a functional and dynamic read-out of cancer therapeutics, from nanometre to whole body scale. At the whole body scale, an increase in the sensitivity and specificity of the imaging probe is required to localise (micro)metastatic foci and/or residual disease that are currently below the limit of detection. The use of image-guided endoscopic biopsy can produce tumour cells or tissues for nanoscopic analysis in a relatively patient-compliant manner, thereby linking clinical imaging to a more precise assessment of molecular mechanisms. This multimodality imaging approach (in combination with genetics/genomic information) could be used to bridge the gap between our knowledge of mechanisms underlying the processes of metastasis, tumour dormancy and routine clinical practice. Treatment regimes could therefore be individually tailored both at diagnosis and throughout treatment, through monitoring of drug pharmacodynamics providing an early read-out of response or resistance.

Expression of L1CAM, COX-2, EGFR, c-KIT and Her2/neu in anaplastic pancreatic cancer: putative therapeutic targets?

AIMS

Undifferentiated (anaplastic) pancreatic cancer and undifferentiated pancreatic carcinoma with osteoclast-like giant cells (giant cell tumour) are rare variants of pancreatic ductal adenocarcinoma. Representing biologically highly aggressive neoplasms, they are frequently diagnosed at an advanced stage. The response to established chemo- or radiochemotherapeutic treatment regimens is poor, and undifferentiated pancreatic cancer generally has a dismal prognosis. As additional therapeutic options have not yet been investigated in undifferentiated pancreatic cancer, the aim was to analyse the expression of putative therapeutic targets that have shown promising results in various other neoplasms.

METHODS AND RESULTS

Fifteen cases of undifferentiated pancreatic cancer (seven containing osteoclast-like giant cells) were investigated clinicopathologically and immunohistochemically for putative therapeutic targets. Whereas L1CAM, cyclooxygenase (COX)-2 and epidermal growth factor receptor (EGFR) were found to be significantly expressed in 80%, 93% and 87% of the investigated tumours, respectively, there was no substantial expression of c-kit (CD117) and there was no detectable expression of Her2/neu.

CONCLUSIONS

The expression of L1CAM, COX-2 and EGFR in the majority of undifferentiated pancreatic carcinomas suggests that they might represent targets for adjuvant therapy in anaplastic pancreatic cancer. On the other hand, c-kit and Her2/neu seem to have no relevance for the therapy of these tumours.

Progress in metastatic colorectal cancer: growing role of cetuximab to optimize clinical outcome

The prognosis of metastatic colorectal cancer remains poor despite advances made in recent years, particularly with new treatments directed towards molecular targets. Cetuximab, a chimeric immunoglobulin (Ig)G1 monoclonal antibody that targets the ligand-binding domain of the epidermal growth factor receptor (EGFR), is active in metastatic colorectal cancer. As an IgG1 antibody, cetuximab may exert its antitumour efficacy through both EGFR antagonism and antibody-dependent cell-mediated cytotoxicity. The benefits of cetuximab in metastatic colorectal cancer are well documented in clinical trials and are acknowledged in the approval and licensing of this agent. There is evidence of the role of cetuximab not only in irinotecan-refractory or heavily pretreated patients, but also of the efficacy and safety of the addition of this agent to FOLFIRI (irinotecan/5-fluorouracil/leucovorin) in first-line metastatic colorectal cancer, with an enhanced effect in 5-fluorouracil patients with Kirsten rat sarcoma (KRAS) wild-type tumours. In these patients, a recent meta-analysis of the pooled Cetuximab Combined with Irinotecan in First-Line Therapy for Metastatic Colorectal Cancer (CRYSTAL) and Oxaliplatin and Cetuximab in First-Line Treatment of mCRC (OPUS) patient populations confirms that the addition of cetuximab to first-line chemotherapy achieves a statistically significant improvement in the best overall response, overall survival time, and progression-free survival (PSF) compared with chemotherapy alone. In nonresectable colorectal liver metastases, cetuximab plus FOLFOX-6 (oxaliplatin/5-fluorouracil/leucovorin) or cetuximab plus FOLFIRI increased significantly resectability of liver metastases, including R0 resections. Also, preliminary data indicate that cetuximab can be administered in a more convenient 2-week schedule in combination with standard chemotherapy. Cetuximab is generally well tolerated. Acne-form rash is the most frequent toxicity. Up to the present time, the results obtained with targeted therapy combinations are not as encouraging as initially expected. The identification of biomarkers associated with disease control, including KRAS and BRAF mutation status in patients treated with cetuximab, is changing the current management of metastatic colorectal cancer. Clinical and molecular predictive markers of response are under active evaluation in order to better select patients who could benefit from cetuximab treatment, with the aim of both optimising patient outcomes and avoiding unnecessary toxicities.

Epirubicin, oxaliplatin, and capecitabine with or without panitumumab for advanced esophagogastric cancer: dose-finding study for the prospective multicenter, randomized, phase II/III REAL-3 trial

PURPOSE

Epirubicin, oxaliplatin, and capecitabine (EOC) is a standard treatment in advanced esophagogastric cancer. Panitumumab (P) is a fully human, immunoglobulin G2 monoclonal antibody targeting epidermal growth factor receptor. Randomized Trial of EOC +/- Panitumumab for Advanced and Locally Advanced Esophagogastric Cancer (REAL-3) will evaluate whether the addition of P to EOC improves survival in patients with advanced esophagogastric adenocarcinoma and undifferentiated carcinoma.

PATIENTS AND METHODS

The original design of REAL-3 added P 9 mg/kg to the standard dose of EOC (dose level [DL] + 1). Due to toxicity, a dose de-escalation was made to EOC + P DL-1 (epirubicin 50 mg/m(2), oxaliplatin130 mg/m(2), capecitabine 1,000 mg/m(2)/d + P 9 mg/kg every 3 weeks). After additional toxicity was observed, the study was amended to include two additional EOC + P dose levels. Using a 3 + 3 design, dose-limiting toxicities (DLTs) were assessed weekly during cycle 1. Patients were randomly assigned 1:1 to EOC +/- P.

RESULTS

Between July 2008 and October 2009, 29 patients were randomly selected for standard-dose EOC (n = 13) or EOC + P (n = 16). Five patients were treated at DL + 1, with grade 3 diarrhea in four of five patients by cycle 4. At DL-1, one patient had grade 3 diarrhea and grade 5 infection. Three patients were treated at DL-3, and then six were treated at DL-2, without DLTs.

CONCLUSION

The recommended dose for EOC + P is epirubicin 50 mg/m(2), oxaliplatin 100 mg/m(2), capecitabine 1,000 mg/m(2)/d, and P 9 mg/kg every 3 weeks. This dose has been selected for the ongoing phase II/III REAL-3 study.

Metastasectomy for stage IV colorectal cancer

Metastatic colorectal cancer traditionally has been considered incurable. Over the past 3 decades, however, resection of low-volume hepatic disease has been recognized as beneficial in some cases. More recently, resection of isolated pulmonary metastases has been shown to offer long-term survival in carefully selected patients. Resection of metastases to more unusual sites (ovary, brain, peritoneal cavity) is more controversial; nevertheless, retrospective data suggest that a few patients may be cured with resection of these tumors. In this article, we review the history and current status of metastasectomy in stage IV colorectal cancer.

EGFR(S) inhibitors in the treatment of gastro-intestinal cancers: what's new?

In the past 10 to 15 years, a considerable progress has been made in the treatment of gastrointestinal (GI) related malignancies, as number of agents expanded from only one in 1995 to seven in 2006. Current review describes the recent role of targeted therapies, specifically EGFR inhibitors in the treatment of GI cancers. Importance of dietary agents in the treatment and prevention of GI cancers is also reviewed.

Cetuximab in combination therapy: from bench to clinic

Cetuximab, a chimeric IgG(1) monoclonal antibody directed against the ligand-binding domain of the epidermal growth factor receptor, offers a paradigm for the combination of molecularly targeted therapies with cytotoxic agents. In preclinical models, the addition of cetuximab to chemotherapy or radiation therapy enhances antitumor activity. Proposed mechanisms include reducing tumor cell proliferation, angiogenesis, and DNA repair capacity; increasing apoptosis; and inducing cell cycle arrest at treatment-sensitive points. These effects may enhance and restore tumor sensitivity to cytotoxic therapies. In clinical trials, the addition of cetuximab to chemotherapy improves outcomes of patients who had previously failed such agents, as illustrated in irinotecan-resistant and oxaliplatin-refractory metastatic colorectal cancer. As initial therapy, the addition of cetuximab to chemotherapy extends survival in colorectal cancer, lung cancer, and head and neck cancer. Combining cetuximab with radiation therapy extends survival in locally advanced head and neck cancer. As predictive biomarkers are identified, it may become possible to select patients most likely to benefit from such combinations.

Cetuximab and circadian chronomodulated chemotherapy as salvage treatment for metastatic colorectal cancer (mCRC): safety, efficacy and improved secondary surgical resectability

BACKGROUND

Circadian rhythm disruption was linked to high serum levels of Transforming Growth Factor Receptor α, an Epidermal Growth Factor Receptor (EGFR) ligand and poor survival in patients with metastatic colorectal cancer (mCRC). We hypothesized that EGFR blockade with cetuximab would enhance the activity of chronotherapy as a result of improved circadian coordination.

METHODS

All the patients with mCRC referred to our unit for progression on prior chemotherapy over a 30-month-period received weekly cetuximab and fortnightly chronotherapy.

RESULTS

Fifty-six patients were treated with a median of six courses of fluoropyrimidine-based chemotherapy and irinotecan (61%), oxaliplatin (25%) or both (14%) after a median of three prior regimens. We found no EFGR amplification by FISH in the tumor of 27 consecutive patients. Acneiform rash and diarrhea were the most common toxicities. Objective response rate was 32.1% and positively correlated with rash grade (p = 0.025). None of the responders had K-Ras mutation in their tumor. Median progression-free and overall survival were 4.6 and 13.7 months, respectively. Complete macroscopic resections of metastases in liver, lung or other abdominopelvic sites were performed following tumor downstaging by the treatment regimen in 11 patients (21%), 8 of whom being alive at 3 years. These figures are twice as high as those reported for first-line combination of cetuximab with conventional chemotherapy or for third line chronotherapy.

CONCLUSIONS

The addition of cetuximab to chronotherapy allowed safe and effective therapeutic control of metastases, including their complete resection, despite previous failure of several treatment regimens.

Association of cetuximab with adverse pulmonary events in cancer patients: a comprehensive review

Compounds derived from biologic sources, or biologicals, are increasingly utilized as therapeutic agents in malignancy. Development of anti-cancer targeted therapies from biologics is increasingly being utilized. Cetuximab, a chimeric monoclonal antibody, is one such anti-cancer targeted therapeutic that has shown efficacy in quelling the rate of patient decline in colorectal, head/neck, and non-small cell lung cancer. However, due to the relatively recent addition of biologic compounds to the therapeutic arsenal, information related to adverse reactions is less well known than those seen in traditional chemotherapeutics. Dermatologic reactions have been demonstrated as the most frequent side effect cited during cetuximab therapy for malignancy; however, other effects may lead to greater morbidity. In general, pulmonary complications of therapeutics can lead to significant morbidity and mortality. The purpose of this review is to compile the various pulmonary side effects seen in patients treated with cetuximab for various malignancies, and to compare the incidence of these adverse reactions to standard therapies.

Alternative dosing schedules for cetuximab: a role for biweekly administration?

The anti-epidermal growth factor receptor targeted monoclonal antibody (MoAb) cetuximab has established efficacy as a single agent and in combination with other modalities (chemotherapy, radiation therapy) in head and neck cancer and metastatic colorectal cancer. The agent is typically administered weekly; however, the development of a biweekly dosing regimen for cetuximab would provide treatment flexibility when combined with biweekly or longer chemotherapy regimens. The feasibility for biweekly dosing with cetuximab is supported by several factors. Biweekly dosing with MoAbs has been effective in multiple tumor types. Although cetuximab is currently administered on a weekly schedule, pharmacokinetic data demonstrate that cetuximab has a long terminal half-life, allowing administration of a biweekly schedule. Results from phase I studies show that a biweekly schedule of cetuximab is well tolerated, exhibits similar pharmacokinetics and pharmacodynamics to conventional weekly dosing, and does not seem to compromise efficacy. Additional studies are therefore warranted to further evaluate biweekly dosing for cetuximab in order to optimize treatment outcomes and convenience for patients.

Clinical use of anti-epidermal growth factor receptor monoclonal antibodies in metastatic colorectal cancer

Abstract Cetuximab and panitumumab, monoclonal antibodies used to target the epidermal growth factor receptor (EGFR), were recently approved by the United States Food and Drug Administration for use as single agents or in combination with other chemotherapy drugs in the treatment of metastatic colorectal cancer. The anti-EGFR monoclonal antibodies, either as single agents or in combination with chemotherapy, have demonstrated clinical activity in this setting. When combined with standard cytotoxic chemotherapy or other targeted agents (e.g., bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody), anti-EGFR monoclonal antibodies have been well tolerated and produced minimal toxicities. However, cetuximab and panitumumab appear to benefit only select patients. Predictive markers of efficacy, including EGFR overexpression, development of skin rash, and the absence of a K-ras mutation, have been evaluated in clinical studies to identify patients likely to respond to anti-EGFR monoclonal antibody therapy. This review discusses recent clinical studies of anti-EGFR monoclonal antibodies in the treatment of metastatic colorectal cancer, predictive markers of their efficacy, and common toxicities associated with their use.

Role of oxaliplatin in the treatment of colorectal cancer

Oxaliplatin is a third-generation platinum compound that has shown a definite role in the management of colorectal cancer (CRC). Oxaliplatin in combination with fluorouracil and leucovorin in the FOLFOX4 regimen represents a new standard of treatment in the adjuvant setting as well as for the metastatic disease. The combination of oxaliplatin with capecitabine in the XELOX regimen has been demonstrated to be not inferior to FOLFOX4 in metastatic patients, and it is under evaluation, with or without bevacizumab, in the post-surgical management of resected patients. FOLFOX4 and XELOX regimens represent a backbone on which to add new targeted drugs. Indeed, the combination of bevacizumab with either FOLFOX4 or XELOX significantly prolonged the progression-free survival and overall survival in comparison with FOLFOX4 or XELOX combined with placebo in metastatic CRC patients, while FOLFOX4 plus cetuximab produced a significantly greater activity than FOLFOX4 alone in metastatic CRC patients with K-RAS wild type.

Toxicity associated with combination oxaliplatin plus fluoropyrimidine with or without cetuximab in the MRC COIN trial experience

We present the preliminary toxicity data from the MRC COIN trial, a phase III randomised controlled trial of first-line therapy in advanced colorectal cancer, with particular reference to the addition of cetuximab to an oxaliplatin-fluoropyrimidine combination. A total of 804 patients were randomised between March 2005 and July 2006 from 78 centres throughout the United Kingdom. Patients were allocated to oxaliplatin plus fluoropyrimidine chemotherapy with or without the addition of weekly cetuximab. The choice of fluoropyrimidine (either 5-fluorouracil (5FU) or capecitabine) was decided by the treating physician and patient before randomisation. Toxicity data were collected from all patients. Two hundred and three patients received 5FU plus oxaliplatin (OxMdG, 25%), 333 oxaliplatin+capecitabine (Xelox, 41%), 102 received OxMdG+cetuximab (OxMdG+C, 13%) and 166 Xelox+cetuximab (21%). Percent grade 3/4 toxicities included diarrhoea 6, 15, 13 and 25%, nausea/vomiting 3, 7, 7 and 14% for OxMdG, Xelox, OxMdG+C and Xelox+C, respectively. Sixty-day all-cause mortality was 6, 5, 5 and 7%. Statistically significant differences were evident for patients receiving Xelox+cetuximab vs Xelox alone: diarrhoea relative risk (RR) 1.69 (1.17, 2.43, P=0.005) and nausea/vomiting RR 2.01 (1.16, 3.47, P=0.012). The excess toxicity observed in the oxaliplatin-, capecitabine-, cetuximab-treated patients led the trial management group to conclude that a capecitabine dose adjustment was required to maintain safety levels when using this regimen.

Expression pattern and functional relevance of epidermal growth factor receptor and cyclooxygenase-2: novel chemotherapeutic targets in pancreatic endocrine tumors?

OBJECTIVES

Pancreatic endocrine tumors represent morphologically and biologically heterogeneous neoplasms. Well-differentiated endocrine tumors (benign or of uncertain behavior) can be distinguished from well-differentiated and poorly differentiated endocrine carcinomas. Although many well-differentiated endocrine carcinomas show rather low rates of tumor growth, more than two-thirds of pancreatic endocrine carcinomas display distant metastases at the time of diagnosis. As the currently applied therapies beyond surgery only achieve partial or complete response rates of approximately 15%, additional chemotherapeutic targets are needed, especially in the therapy of inoperable and progressive pancreatic endocrine carcinomas.

METHODS

The expression of epidermal growth factor receptor (EGFR) and cyclooxygenase (COX)-2 were investigated in 110 clinically and pathomorphologically well-characterized pancreatic endocrine tumors, using immunohistochemistry and immunoblot analyses. Functional tests were performed using the human pancreas carcinoid cell line BON and the mouse insulinoma cell line beta-TC-3.

RESULTS

The expression of EGFR correlated significantly with the grade of malignancy, increasing from low rates of expression in benign tumors and tumors of uncertain behavior to high rates of expression in well- and poorly differentiated endocrine carcinomas. The expression of COX-2 was independent of the malignant potential, but was more frequently expressed in primary tumors than in metastases. The treatment of the human pancreas carcinoid cell line BON and the mouse insulinoma cell line beta-TC-3 with EGFR and COX-2 inhibitors (monotherapy and combined therapy) resulted in a significant, dose-dependent reduction of cell viability coupled with increased apoptosis.

CONCLUSIONS

Our results suggest that EGFR and COX-2 may represent useful additional chemotherapeutic targets in pancreatic endocrine tumors.

A phase I study of gefitinib, capecitabine, and celecoxib in patients with advanced solid tumors

This phase I study was designed to determine the maximum tolerated dose (MTD) and toxicity profile of the combination of gefitinib, capecitabine, and celecoxib in patients with advanced solid tumors. Patients were treated with escalating doses of gefitinib once daily, capecitabine twice daily (14 of 28 days), and celecoxib twice daily. Plasma samples for biomarkers were obtained at baseline and weekly for the first 2 cycles. Pharmacokinetic variables were correlated with toxicity and presence of biological effect. Tumor biopsies from 5 patients were analyzed for changes in tumor metabolic activity by nuclear magnetic resonance spectroscopy. [18F]fluorodeoxyglucose positron emission tomography was done as a correlate in 6 patients at the MTD. Thirty-nine patients received 168 cycles of therapy. The dose-limiting toxicities observed included nausea, dehydration and nausea, diarrhea, and stomatitis. The MTD was 250 mg/d gefitinib (days 1-14) and 2,000 mg/m2/d capecitabine divided twice daily (days 8-21) every 28 days. Celecoxib was eliminated due to concerns of increased risk for cardiovascular toxicity, although no patients in this study had cardiac events. One patient with cholangiocarcinoma had a confirmed partial response. Fourteen of 39 (36%) patients maintained prolonged stable disease for a median of 4 months (range, 3-24 months). [18F]fluorodeoxyglucose positron emission tomography scan and metabolomic analyses revealed differences in metabolic response to gefitinib versus capecitabine. The combination of gefitinib and capecitabine is well tolerated and appears to have activity against certain advanced solid tumors, providing a rationale for further evaluation in advanced solid malignancies.

Biweekly cetuximab and irinotecan in advanced colorectal cancer patients progressing after at least one previous line of chemotherapy: results of a phase II single institution trial

This is a phase II institutional exploratory trial of biweekly irinotecan and cetuximab administration regimen in metastatic colorectal cancer patients progressing to at least one previous chemotherapy line. A total of 40 patients were treated between November 2005 and November 2007 with irinotecan 180 mg m⁻² and cetuximab 500 mg m⁻² q2w (every 2 weeks), in every 21-day cycles, until unacceptable toxicity or progressive disease. An overall response rate of 22.5% was obtained (two complete and seven partial responses). The disease control rate was 60%. The time to progression was 3.4 months and the overall survival was 8 months. The toxicity compared very favourably to weekly cetuximab combination schedules. Grade 3/4 adverse effects were observed in 12 patients. Overall, our results turn up very similar both in terms of toxicity and efficacy to those obtained by weekly and biweekly administration regimens.

EGFR and HER2 expression in primary cervical cancers and corresponding lymph node metastases: implications for targeted radiotherapy

Background

Proteins overexpressed on the surface of tumor cells can be selectively targeted. Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are among the most often targeted proteins. The level and stability of expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target for imaging in nuclear medicine and for various forms of therapy. So far, the expression of EGFR and HER2 has only been determined in primary cervical cancers, and we have not found published data regarding the receptor status in corresponding metastatic lesions. The goal of this study was to evaluate whether any of these receptors are suitable as target for clinical diagnosis and therapy.

Methods

Expression of EGFR and HER2 was investigated immunohistochemically in both lymph node metastases and corresponding primary cervical cancers (n = 53). HER2 and EGFR expression was scored using HercepTest criteria (0, 1+, 2+ or 3+).

Results

EGFR overexpression (2+ or 3+) was found in 64% (35/53) of the primary cervical tumors and 60% (32/53) of the corresponding lymph node metastases. There was a good concordance between the primary tumors and the paired metastases regarding EGFR expression. Only four patients who had 2+ or 3+ in the primary tumors changed to 0 or 1+ in lymph node metastases, and another two cases changed the other way around. None of the primary tumors or the lymph node metastases expressed HER2 protein.

Conclusion

The EGFR expression seems to be common and stable during cervical cancer metastasis, which is encouraging for testing of EGFR targeted radiotherapy. HER2 appears to be of poor interest as a potential target in the treatment of cervical cancer.

Synergy between cetuximab and chemotherapy in tumors of the gastrointestinal tract

Cetuximab is a recently approved monoclonal antibody that targets the epidermal growth factor receptor, a receptor tyrosine kinase involved in the development and progression of colorectal cancer (CRC) and other solid tumors. Cetuximab, as a single agent or in combination with chemotherapy, has demonstrated significant clinical efficacy against CRC. Combinations of cetuximab with chemotherapy have proven to be well tolerated, with minimal overlap of toxicities between agents; and the anticancer synergy between cetuximab and traditional chemotherapy agents has made cetuximab a vital treatment for patients who are no longer responsive to chemotherapy alone. The U.S. Food and Drug Administration approved cetuximab in combination with irinotecan for the treatment of irinotecan-refractory metastatic CRC or as monotherapy for treating patients intolerant to irinotecan. Combination chemotherapies involving cetuximab as well as combinations involving cetuximab and other targeted agents, such as bevacizumab, an anti-vascular endothelial growth factor monoclonal antibody, constitute powerful new treatment options for the management of CRC. This review discusses recent clinical studies that have further defined this synergy, focusing primarily on tumors of the gastrointestinal tract.

Loading doses for costly cancer biologicals: sound pharmacology or unnecessary extravagance?

The rising cost of new molecularly-targeted anticancer drugs has become a major issue in oncology. One small but significant factor contributing to this problem is the routine co-administration of loading doses, which may inflate the cost of the first treatment by as much as US$1000. Here, we question the cost-effectiveness of this practice in cancer patients on several grounds, including non-urgent pace of disease, lack of evidence for survival benefit, weak dose-dependency of biopharmaceutical efficacy in cancer and the unproven validity of the 'volume of distribution' concept applied to target-specific drugs.

Epidermal growth factor receptor inhibitors in colorectal cancer treatment: what's new?

Colorectal cancer constitutes one of the most common malignancies and the second leading cause of death from cancer in the western world representing one million new cases and half a million deaths annually worldwide. The treatment of patients with metastatic colon cancer comprises different regimens of chemotherapeutic compounds (fluoropyrimidines, irinotecan and oxaliplatin) and new targeted therapies. Interestingly, most recent trials that attempt to expose patients to all five-drug classes (fluoropyrimidines, irinotecan, oxaliplatin, bevacizumab and cetuximab) achieve an overall survival well over 2 years. In this review we will focus on the main epidermal growth factor receptor inhibitors demonstrating clinical benefit for colorectal cancer mainly cetuximab, panitumumab, erlotinib and gefitinib. We will also describe briefly the molecular steps that lie beneath them and the different clinical or molecular mechanisms that are reported for resistance and response.