Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer

[A review of chemotherapy for metastatic colon cancer]

OBJECTIVE

To report and discuss the results of clinical trials published concerning chemotherapy for metastatic colorectal cancer in order to elucidate and define treatment guidelines.

METHOD

The biomedical and pharmaceutical database EMBASE was searched for phase-II and -III clinical trials or metaanalysis that examined chemotherapy for mCRC (January 1998-January 2006).

RESULTS

5-fluorouracil still maintains its preponderant role after 40 years, and its modulation by adding folinic acid or administering it in more prolonged infusions has managed to slightly increase survival in these patients, as well as to improve the drug s toxicity profile. The development of irinotecan first, and then oxaliplatin has lengthened survival by a few months when in combination with 5-fluorouracil and folinic acid-based regimens. All patients should have access to these two drugs guaranteed during the course of the disease, as it will increase survival. Raltitrexed fails to improve survival, and also diminishes quality of life in these patients; hence its use has been relegated to clinical trials. Bevacizumab, combined with classic chemotherapy regimens, attains slightly longer survivals. Results from studies with cetuximab are not that conclusive, and its use should be restricted to patients with relapsing disease after irinotecan and no other treatment options left.

CONCLUSIONS

New drugs for metastatic colorectal cancer open up new therapy lines allowing increasingly improved survival. However, optimal schemes, as well as their order of administration, have yet to be fully devised.

The new paradigm in the treatment of colorectal cancer: are we hitting the right target?

The treatment of advanced colorectal cancer has definitely advanced in the last 10 years as newer and more active cytotoxic chemotherapy agents have become available. Better understanding of different fundamental molecular changes in carcinogenesis has resulted in the emergence of important therapeutic targets in colon cancer treatment. The era of nihilism has been replaced by a time of optimism with the development of targeted therapy, with the promise of agents with improved activity and a better toxicity profile in the management of colon cancer. This review focuses on novel agents, particularly targeted therapy in both earlier and more advanced phases of clinical investigations.

Biological therapy update in colorectal cancer

Colon and rectal cancer remain the second most common cause of cancer death in the US. Advances in the past 10 years have resulted in improved outcomes for patients. In addition to newer chemotherapeutics agents, the so-called 'targeted' or 'biological' therapies have improved survival in patients with metastatic disease. This review aims to summarize the mechanistic basis for the usefulness of these agents, the key clinical trials demonstrating their efficacy, and the studies now initiated with the hope of further incorporating their use in treating colon and rectal cancer.

Affibody molecules: potential for in vivo imaging of molecular targets for cancer therapy

Targeting radionuclide imaging of tumor-associated antigens may help to select patients who will benefit from a particular biological therapy. Affibody molecules are a novel class of small (approximately 7 kDa) phage display-selected affinity proteins, based on the B-domain scaffold of staphylococcal protein A. A large library (3 x 10(9) variants) has enabled selection of high-affinity (up to 22 pM) binders for a variety of tumor-associated antigens. The small size of Affibody molecules provides rapid tumor localization and fast clearance from nonspecific compartments. Preclinical studies have demonstrated the potential of Affibody molecules for specific and high-contrast radionuclide imaging of HER2 in vivo, and pilot clinical data using indium-111 and gallium-68 labeled anti-HER2 Affibody tracer have confirmed its utility for radionuclide imaging in cancer patients.

Hepatic artery infusion of high-dose melphalan at reduced flow during isolated hepatic perfusion for the treatment of colorectal metastases confined to the liver: a clinical and pharmacologic evaluation

Isolated hepatic perfusion (IHP) offers the advantage of high local drug exposure with limited systemic toxicity. To increase local drug exposure, we administered melphalan at a reduced flow in the hepatic artery during IHP (hepatic artery infusion, hepatic artery-portal vein perfusion, HI-HPP). Between December 2001 and December 2004, 30 patients with colorectal cancer liver metastases underwent HI-HPP with 200mg melphalan. Samples of the perfusate were taken for pharmacokinetic analysis. Patients were monitored for response, toxicity and survival. Perfusion was aborted prematurely in 2 patients due to leakage. During melphalan administration in the hepatic inflow cannula a mean flow rate of 121.3 mL/min and mean pressure of 62.5mm Hg were achieved. One patient died within 30 days after HI-HPP. Four patients developed veno-occlusive disease (VOD), while 2 patients showed signs of VOD. Twelve patients showed hepatic response, with a median duration of response of 11.5 months, according to WHO criteria. Although HI-HPP results in high perfusate melphalan concentration levels, it is associated with a relatively high level of hepatotoxicity and a limited response rate. We believe that the low flow and pressure rates found in this study can result in reduced drug penetration of the tumour and thus limited tumour response.

Vandetanib (ZD6474): an orally available receptor tyrosine kinase inhibitor that selectively targets pathways critical for tumor growth and angiogenesis

Vandetanib (ZD6474; ZACTIMA, AstraZeneca) is a once-daily, orally available agent with potential for use in a number of solid tumor types. Vandetanib targets key signaling pathways in cancer by inhibiting VEGFR-dependent tumor angiogenesis, and EGFR- and RET-dependent tumor cell proliferation and survival. Phase I studies showed vandetanib to be generally well tolerated at doses of < or = 300 mg/day, with a pharmacokinetic profile that supports once-daily oral administration. Phase II evaluation of vandetanib in patients with advanced refractory NSCLC has demonstrated improvements in progression-free survival both as monotherapy (versus gefitinib) and in combination with docetaxel (versus docetaxel alone). These positive outcomes have led to the initiation of Phase III trials of vandetanib in advanced NSCLC. Clinical development is also ongoing in other tumor types and encouraging evidence of antitumor activity has been reported in patients with metastatic hereditary medullary thyroid cancer.

Triple-negative breast cancer: therapeutic options

Triple-negative breast cancers are defined by a lack of expression of oestrogen, progesterone, and ERBB2 receptors. This subgroup accounts for 15% of all types of breast cancer and for a higher percentage of breast cancer arising in African and African-American women who are premenopausal. Because of the absence of specific treatment guidelines for this subgroup, triple-negative breast cancers are managed with standard treatment; however, such treatment leaves them associated with a high rate of local and systemic relapse. Histologically, such cancers are poorly differentiated, and most fall into the basal subgroup of breast cancers, characterised by staining for basal markers (ie, cytokeratin 5/6). Analyses of microarray gene-expression profiling data show that they form a homogeneous group (or so-called cluster) in transcriptional terms and, increasingly, research studies are identifying basal cancers on the basis of exhibiting this distinctive transcriptional profile. Histologically and transcriptionally, triple-negative breast cancers have many similarities to BRCA1-associated breast cancers, which suggests that dysfunction in BRCA1 or related pathways occurs in this subset of sporadic cancers. In this review, we discuss the molecular features of triple-negative breast cancers and consider how the use of existing cytotoxic agents can be optimised for this patient group. We discuss the implications of a possible underlying BRCA1-pathway dysfunction in this subgroup in terms of treatment and we also investigate the predominant proliferative signals and the on-going research addressing the suitability of these signals as therapeutic targets.

A Randomised Phase II Study of Irinotecan in Combination with 5-FU/FA Compared with Irinotecan Alone as Second-Line Treatment of Patients with Metastatic Colorectal Carcinoma

BACKGROUND

We conducted a randomised phase II study to compare irinotecan monotherapy with irinotecan in combination with infusional 5-fluorouracil/folinic acid (5-FU/FA) regarding efficacy and safety of these regimens in second-line therapy after failed fluoropyrimidine therapy in patients with metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

55 patients with mCRC after failure of a first-line therapy were randomised to receive either irinotecan 80 mg/m2 followed by FA 500 mg/m2 and 5-FU 2,000 mg/m2 24 h weekly for 6 weeks, with courses repeated on day 50 (arm A), or irinotecan 125 mg/m2 weekly for 4 weeks, with cycles repeated on day 43 (Arm B).

RESULTS

Both regimens yielded a partial response rate of 11% with identical progression-free survival (3.7 months for both regimens) and similar overall survival (9.5 months for the combination therapy vs. 10.7 months for the monotherapy). Both regimens were very well tolerated, and the combination of irinotecan with 5-FU/FA did not result in increased toxicity.

CONCLUSION

Our study confirms that irinotecan alone or in combination with infusional 5-FU/FA is an effective and safe regimen for CRC patients who failed first-line therapies. However, the role of 5-FU in addition to irinotecan for fluoropyrimidine failures remains unclear. Due to the small sample size, a decision cannot be made which therapy should be preferred, and a significant contribution to the efficacy of single-agent irinotecan is not obvious from this small randomised phase II trial.

Gene expression signature in advanced colorectal cancer patients select drugs and response for the use of leucovorin, fluorouracil, and irinotecan

PURPOSE

In patients with advanced colorectal cancer, leucovorin, fluorouracil, and irinotecan (FOLFIRI) is considered as one of the reference first-line treatments. However, only about half of treated patients respond to this regimen, and there is no clinically useful marker that predicts response. A major clinical challenge is to identify the subset of patients who could benefit from this chemotherapy. We aimed to identify a gene expression profile in primary colon cancer tissue that could predict chemotherapy response.

PATIENTS AND METHODS

Tumor colon samples from 21 patients with advanced colorectal cancer were analyzed for gene expression profiling using Human Genome GeneChip arrays U133. At the end of the first-line treatment, the best observed response, according to WHO criteria, was used to define the responders and nonresponders. Discriminatory genes were first selected by the significance analysis of microarrays algorithm and the area under the receiver operating characteristic curve. A predictor classifier was then constructed using support vector machines. Finally, leave-one-out cross validation was used to estimate the performance and the accuracy of the output class prediction rule.

RESULTS

We determined a set of 14 predictor genes of response to FOLFIRI. Nine of nine responders (100% specificity) and 11 of 12 nonresponders (92% sensitivity) were classified correctly, for an overall accuracy of 95%.

CONCLUSION

After validation in an independent cohort of patients, our gene signature could be used as a decision tool to assist oncologists in selecting colorectal cancer patients who could benefit from FOLFIRI chemotherapy, both in the adjuvant and the first-line metastatic setting.

Clinical relevance of KRAS mutation detection in metastatic colorectal cancer treated by Cetuximab plus chemotherapy

The predictive value of KRAS mutation in metastatic colorectal cancer (MCRC) patients treated with cetuximab plus chemotherapy has recently been suggested. In our study, 59 patients with a chemotherapy-refractory MCRC treated with cetuximab plus chemotherapy were included and clinical response was evaluated according to response evaluation criteria in solid tumours (RECIST). Tumours were screened for KRAS mutations using first direct sequencing, then two sensitive methods based on SNaPshot and PCR-ligase chain reaction (LCR) assays. Clinical response was evaluated according to gene mutations using the Fisher exact test. Times to progression (TTP) were calculated using the Kaplan–Meier method and compared with log-rank test. A KRAS mutation was detected in 22 out of 59 tumours and, in six cases, was missed by sequencing analysis but detected using the SNaPshot and PCR-LCR assays. Remarkably, no KRAS mutation was found in the 12 patients with clinical response. KRAS mutation was associated with disease progression (P=0.0005) and TTP was significantly decreased in mutated KRAS patients (3 vs 5.5 months, P=0.015). Our study confirms that KRAS mutation is highly predictive of a non-response to cetuximab plus chemotherapy in MCRC and highlights the need to use sensitive molecular methods, such as SNaPshot or PCR-LCR assays, to ensure an efficient mutation detection.

The continuum of care: a paradigm for the management of metastatic colorectal cancer

New agents for the treatment of metastatic colorectal cancer have extended median overall survival to more than 20 months, an increase that has changed the view of advanced colorectal cancer from an acute to a chronic condition. This article proposes a shift in treatment strategy from the concept of successive "lines" of therapy, in which chemotherapy is continued until disease progression, to that of a continuum of care, in which the use of chemotherapy is tailored to the clinical setting and includes switching chemotherapy prior to disease progression, maintenance therapy, drug "holidays," and surgical resection of metastases in selected patients. In this approach, the distinction between lines of therapy is no longer absolute. This represents a paradigm shift in the management of metastatic colorectal cancer to that of a continuum of care approach that includes individualized planning, in which patients are given the opportunity to benefit from exposure to all active agents and modalities while minimizing unnecessary treatment and toxicity, with the ultimate goal of improving survival as well as quality of life.

Incidence and management of cutaneous toxicities associated with cetuximab

Cetuximab is a human/mouse chimeric monoclonal antibody that binds to the EGF receptor, competitively inhibiting ligand binding, and inducing receptor dimerization and downregulation. Cetuximab has been active in multiple tumors, including colorectal cancer (CRC), head and neck, pancreatic and lung cancers. Cetuximab has been approved by the FDA, in combination with irinotecan, for the treatment of metastatic CRC in patients refractory to irinotecan, and for use as a single agent in the treatment of recurrent metastatic CRC in patients intolerant of irinotecan-based chemotherapy. Most common toxicities are rash, diarrhea, fever, headache, nausea, hypomagnesemia and hypersensitivity reactions. Data from several clinical trials with cetuximab show a positive correlation between rash and response and/or survival. Rash occurred on 90% of patients treated with cetuximab monotherapy and grade 3 or 4 skin reactions occurred on as many as 16% of patients in the trials using cetuximab. A rash usually presents as pustular or maculopapular follicular eruption, often referred to as acneiform. Cetuximab will engage in productive dimerization complexes in human skin causing significant disruption of the normal development and maintenance of the hair follicle, which leads to follicular response and inflammatory response. At this time there are no standard or evidence-based treatment plans for the rash. Most of the evidence is based on institutional or personal experiences. The most commonly used agents are topical antibiotics, oral antibiotics, topical steroids, systemic immunomodulatory agents, topical immunomodulatory agents and anti-inflammatory preparations. As cetuximab is becoming widely used in general oncology practice, it is important to understand the toxicity of rash to develop practice guidelines for their management. This review addresses recommendations for toxicity management of rash caused by cetuximab in treatment of metatstatic CRC.

The role of spermidine/spermine N1-acetyltransferase in determining response to chemotherapeutic agents in colorectal cancer cells

Polyamines have been shown to play a role in the growth and survival of several solid tumors, including colorectal cancer. We identified the polyamine catabolic enzyme spermidine/spermine N(1)-acetyltransferase (SSAT) as being one of the most highly inducible genes in two DNA microarray screens to identify novel determinants of response to chemotherapeutic agents in colorectal cancer. SSAT was shown to be inducible in response to 5-fluorouracil (5-FU) or oxaliplatin in parental and drug-resistant HCT116 cell lines. It was also shown that SSAT mRNA was up-regulated in response to 5-FU or oxaliplatin in a panel of six colorectal cancer cell lines. The polyamine analogue N(1),N(11)-diethylnorspermine (DENSpm) depletes polyamine pools and potently induces SSAT. We evaluated the effect of combining DENSpm with chemotherapeutic agents in HCT116 p53(+/+) cells and in HCT116 drug-resistant daughter cell lines. Western blot analyses showed that SSAT protein expression was dramatically enhanced when DENSpm was combined with oxaliplatin or 5-FU in HCT116 p53(+/+) cells. Using cell viability assays and flow cytometry, synergistic induction of cell death was observed following cotreatment of HCT116 p53(+/+) cells with DENSpm and each chemotherapeutic agent. Of note, this combined therapy increased the chemosensitivity of cells rendered resistant to each of these chemotherapeutic agents. Small interfering RNA-mediated down-regulation of SSAT resulted in loss of synergy between DENSpm and these agents. These results show that SSAT plays an important role in regulating cell death following combined cytotoxic drug and DENSpm treatment. Furthermore, DENSpm sensitizes both sensitive and resistant cells to chemotherapeutic agents. Taken together, these results suggest that SSAT may be an important target for therapeutic intervention in colorectal cancer.

Emerging dermatologic issues in the oncology patient

The spectrum of skin diseases that occurs in the oncology patient differs somewhat from that seen in other immunosuppressed populations. We review the cutaneous manifestations of invasive mold infections in the leukemia/lymphoma population. Aspergillus mold infections are now the leading infectious cause of death in this population. We also review the pustular eruption caused by a new class of chemotherapy for solid malignancies. An update on cutaneous graft-versus-host disease appears elsewhere in this journal. Cutaneous squamous cell carcinomas and basal cell carcinomas occur more frequently in the chronic lymphocytic leukemia and non-Hodgkin's lymphoma population; this is discussed, as is the more aggressive clinical course of these tumors.

Molecular predictors of response to epidermal growth factor receptor antagonists in non-small-cell lung cancer

In the last 5 years the epidermal growth factor receptor (EGFR) has emerged as one of the most important targets for drug development in oncology. Monoclonal antibodies targeting the external domain of EGFR have been shown to have clinical benefit in colorectal and head and neck cancer when combined with chemotherapy and/or radiation. Small molecules that inhibit the tyrosine kinase (TK) domain of EGFR have become critical new weapons in the treatment of non-small-cell lung cancer (NSCLC). The discovery that mutations in the TK domain are associated with dramatic and sustained responses to EGFR TK inhibitors (TKIs) has allowed the design of trials to test these agents as potential first-line therapies and has provided a fascinating window into the future of genotype-directed targeted therapy. Recent advances in understanding the biologic basis of acquired resistance to these agents have great potential to improve the clinical effectiveness of this class of drugs. This review summarizes the biology of EGFR in NSCLC, the clinical and molecular predictors of benefit from treatment with EGFR TKIs, the use of patient-specific molecular profiling, and future directions of clinical and basic scientific research.

Panitumumab: a fully human monoclonal antibody with activity in metastatic colorectal cancer

OBJECTIVE

To review the pharmacology, pharmacokinetics, clinical trials, adverse effects, and drug interactions of panitumumab.

DATA SOURCES

A MEDLINE search was conducted (1966-February 2007) using the search terms panitumumab, ABX-EGF, E7.6.3, monoclonal antibody, colorectal neoplasm, epidermal growth factor receptor, EGFr, and epidermal growth factor receptor signal transduction. Articles and abstracts were further identified from the American Society of Clinical Oncology and the National Comprehensive Cancer Network.

STUDY SELECTION AND DATA EXTRACTION

Clinical trials evaluating panitumumab for solid tumors were selected from the data sources. All published relevant abstracts were included.

DATA SYNTHESIS

The most recent developments in the treatment of metastatic colorectal cancer include the monoclonal antibodies targeted against vascular endothelial growth factor and the epidermal growth factor receptor (EGFr). Panitumumab is the first fully human monoclonal antibody that binds to EGFr. Clinical activity has been demonstrated, most notably in patients with EGFr-positive metastatic colorectal cancer who have failed prior therapy. Phase III study results indicate a 46% reduction in the rate of tumor progression in treated patients compared with those who received best supportive care alone. Panitumumab is well tolerated, with acneiform rash the most common dose-dependent adverse effect. Studies thus far indicate a low rate of infusion-related reactions (1%, grade 3-4).

CONCLUSIONS

Panitumumab is a fully human monoclonal antibody with promising activity in treatment of patients with metastatic colorectal cancer who have failed previous therapy, offering a favorable safety profile.

Forthcoming receptor tyrosine kinase inhibitors

Receptor tyrosine kinases play a significant role in carcinogenesis and have been successfully targeted with monoclonal antibodies and small-molecule inhibitors. There have been recent developments in the understanding of receptor tyrosine kinase signal transduction which have enabled better drug development. The use of receptor tyrosine kinase inhibitors in clinical practice has expanded the knowledge on cancer biology, in particular the understanding of resistant mutations and strategies to overcome such resistance. This has driven drug development from single kinase inhibitors to multi-kinase inhibitors and high-affinity kinase inhibitors. Finally, as the use of receptor tyrosine kinase inhibitors grows in clinical practice, more is learned about appropriate patient selection for such therapies. This is an exciting time in cancer therapeutics, highlighted by the advent of effective targeted therapy with receptor tyrosine kinase inhibitors.

Bevacizumab in the treatment of metastatic colorectal cancer (mCRC) in second- and third-line settings

There are several treatment options for patients with metastatic colorectal cancer (mCRC), including those with disease that has progressed after treatment with chemotherapy. Bevacizumab-containing regimens show good efficacy in patients with previously treated disease. Compared with infused 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX-4), overall survival and progression-free survival are significantly longer with FOLFOX-4 in combination with bevacizumab as second-line treatment in patients with advanced or mCRC. In addition, the response rates and time to progression are greater with the combination of bevacizumab, cetuximab, and irinotecan in patients with irinotecan-refractory mCRC compared with cetuximab and irinotecan therapy. This combination is well tolerated, with no additive toxicities reported. The role of bevacizumab in the treatment of patients with disease refractory to 5-fluorouracil, irinotecan, and oxaliplatin is less clear, owing to inconclusive results in a multicenter study in this population. More research is necessary to determine the efficacy of combinations with bevacizumab in the third- and later-line settings. However, bevacizumab clearly provides significant clinical benefits in previously treated patients with mCRC. On the basis of these benefits and in addition to its approval in the first-line setting, bevacizumab in combination with intravenous 5-fluorouracil-based chemotherapy recently received US Food and Drug Administration approval for the second-line treatment of patients with mCRC.

Future directions in vascular endothelial growth factor-targeted therapy for metastatic colorectal cancer

Bevacizumab, the first approved vascular endothelial growth factor (VEGF)-targeted agent for metastatic colorectal cancer, continues to be developed in phase III trials in other tumor types. Its use is being explored not only in advanced disease, but also in earlier-stage disease in the adjuvant setting. Preclinical and clinical research is also addressing several potential strategies for maximizing the benefits of bevacizumab and other VEGF-targeted agents, including (1) dual inhibition of VEGF and platelet-derived growth factor signaling to target both the endothelial and the pericyte components of tumor vasculature; (2) combining VEGF-targeted agents with other targeted agents, such as inhibitors of HER2 or epidermal growth factor receptor signaling, which affect several angiogenic pathways; and (3) combining VEGF-targeted agents with low-dose, metronomic chemotherapy. The optimal dose and schedule of VEGF-targeted agents is another unanswered question. Further investigation of the mechanism of action and vascular effects of VEGF-targeted agents in humans will help to address these questions. Mechanistic studies in humans will be aided by the development and validation of surrogate clinical end points such as noninvasive assessment of hemodynamics and vascular changes within tumors, using imaging studies.

Targeted agents and esophageal cancer--the next step?

Esophageal cancer (EC) is an aggressive cancer and is a leading cause of cancer-related death worldwide. In the United States and Western Europe, there has been a decline in the incidence of squamous cell carcinomas coupled with a rapid rise in incidence of adenocarcinoma of the esophagus and gastroesophageal junction. Although the 5-year survival rates have slowly increased over time from 4% to 14%, the outcomes are still dismal. The lack of adequate preventative strategies, inadequate screening techniques, early lymphatic and hematogenous spread, and lack of truly effective therapeutic agents all contribute to the poor outcome. This review will highlight the current status of targeted therapies in EC. This will include a review of agents targeting the vascular endothelial growth factor and epidermal growth factor receptor pathways and trials planned or ongoing to incorporate these and other agents into therapy for advanced disease and into combined modality therapy for early-stage tumors. Further work is required regarding the rational integration of these targeted agents and the optimal selection of patients who will most likely benefit.

Colorectal cancer

Cancers of the colon and rectum will affect 1 in 17 North Americans during their lifetime. The progress witnessed in the treatment of these cancers in recent years has been remarkable. Improvements have been realized in surgical technique, radiation therapy, and systemic therapies, particularly with the addition of oxaliplatin and irinotecan to the previously limited armamentarium of fluorouracil alone. Targeted therapies directed at the vascular endothelial growth factor pathway and the epidermal growth factor pathway are now key players in the treatment of colorectal cancer. With current-day therapies, more than 75% of patients with localized disease are recurrence free at 3 years, and up to 50% of patients with advanced unresectable disease are alive at 2 years. This review focuses on the evidence supporting the current role of chemotherapy and radiation therapy in the adjuvant management of colorectal cancers and the strategy of combining chemotherapy and biological therapy in the treatment of metastatic disease.

Cost-effectiveness analysis of cetuximab/irinotecan vs active/best supportive care for the treatment of metastatic colorectal cancer patients who have failed previous chemotherapy treatment

The treatment of colorectal cancer is rapidly becoming a significant financial burden to health-care systems within economically developed nations. A current challenge for oncologists and health-care payers is to integrate new, often high-cost, biologic therapies into clinical practice. Inherent to this process is the consideration of cost-effectiveness. The aim of this study was to compare the cost-effectiveness of cetuximab plus irinotecan with an appropriate comparator from a National Health Service (NHS) perspective. This economic evaluation is a trial-based study of cetuximab vs active/best supportive care. Effectiveness estimates for the treatment groups were modelled from key clinical trials. Cunningham et al (2004) compared cetuximab/irinotecan with cetuximab monotherapy; Cunningham et al (1998) compared irinotecan monotherapy in a second-line setting with supportive care. Modelling was necessary owing to an absence of head-to-head clinical trial data of cetuximab/irinotecan vs current standard care. Costs were calculated for the study drugs received, associated administration, palliative chemotherapy for patients in the standard care arm and other nonchemotherapy resources. The discounted life-expectancy of patients treated with cetuximab/irinotecan was 0.91 life-years, and 0.47 discounted life-years for patients receiving active/best supportive care. Patients treated with cetuximab/irinotecan accumulated mean additional costs of £18 901 per patient relative to the comparator arm, with £11 802 attributable to cetuximab. The incremental cost per life-year gained with cetuximab/irinotecan therapy compared with active/best supportive care was £42 975. The incremental cost per quality adjusted life-year gained was £57 608. The incremental cost per life-year gained for cetuximab/irinotecan is relatively high compared with other health-care interventions. However, this result should be considered in the context of a number of factors specific to the treated patient population.

Cetuximab in the treatment of metastatic colorectal cancer: a model-based cost-effectiveness analysis

Cetuximab (Erbitux) has shown activity in patients with metastatic colorectal cancer (mCRC). To evaluate the cost-effectiveness of this drug combined with irinotecan in mCRC, a model-based cost-effectiveness analysis (CEA) was performed. Data on cetuximab obtained from Medline in December 2004 and from the 2004 ASCO-meeting were analyzed for life years gained (LYG) with regard to the use of this monoclonal antibody (MAb). Norwegian prices as of January 2005 were employed. The LYG ranged between 1.7 and 2.0 years. The median cost per patient treated was calculated to 34,256 Euro to 45,764 Euro yielding a cost per LYG in the range between 205,536 Euro and 323,040 Euro. Sensitivity analysis documented price of cetuximab and survival gain to be the major factors influencing the cost-effectiveness ratio. In conclusion, the analysis indicates cetuximab to be a promising, but very expensive antibody.

Phase II study of cetuximab in combination with FOLFIRI in patients with untreated advanced gastric or gastroesophageal junction adenocarcinoma (FOLCETUX study)

BACKGROUND

The purpose of this phase II study was to evaluate the efficacy and safety of cetuximab combined with FOLFIRI as a first-line treatment of advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma.

PATIENTS AND METHODS

Untreated patients with confirmed advanced gastric or gastroesophageal adenocarcinoma received cetuximab at an initial dose of 400 mg/m(2) intravenously (i.v.) followed by weekly doses of 250 mg/m(2), CPT 11 180 mg/m(2) i.v. on day 1, LFA 100 mg/m(2) i.v. followed by 5-FU 400 mg/m(2) i.v. bolus, and 600 mg/m(2) i.v. 22-h continuous infusion on days 1 and 2 (FOLFIRI) every 2 weeks, for a maximum of 24 weeks, then cetuximab alone was allowed in patients with a complete response, partial response, or stable disease. Antitumor activity was assessed by computed tomography (CT) and positron emission tomography (PET) at baseline and after 6 weeks, and further by CT alone or CT and PET every 6 weeks.

RESULTS

Thirty-eight patients were enrolled (median age 63.5 years, range 39-83; median Karnofsky performance status 90, range 70-100; stomach 89.5% and GEJ 10.5%; locally advanced disease 13.2% and metastatic disease 86.8%). All 38 patients were assessed for safety and survival, and 34 patients were assessed for overall response rates (ORR). The ORR was 44.1% [95% confidence interval (CI) 27.5% to 60.9%]. The median time-to-progression was 8 months (95% CI 7-9). At the median follow-up time of 11 months, 55.3% of patients were alive, with a median expected survival time of 16 months (95% CI 9-23). Grade 3-4 toxicity included neutropenia (42.1%), acne-like rash (21.1%), diarrhea (7.9%), asthenia (5.3%), stomatitis (5.3%), and hypertransaminasemia (5.3%). There was one (2.6%) treatment-related death.

CONCLUSIONS

The combination of cetuximab and FOLFIRI is active in gastric and GEJ adenocarcinoma. The higher toxicity appears to be limited to neutropenia.

Evidence of clinical activity for cetuximab combined with irinotecan in a patient with refractory anal canal squamous-cell carcinoma: report of a case

Because of the high cure rate of localized anal cancers from combined modality treatment, there is little that is known for the treatment of patients who progress to have metastatic disease. Treatments currently used are based on activity demonstrated in other cancers with similar histology. Cetuximab, a molecular-targeted therapy, is an antibody directed against epidermal growth factor receptor that has demonstrated anticancer activity in several cancers. We report a female patient with refractory anal cancer who achieved an excellent response to the combination of cetuximab and irinotecan after having failed single-agent irinotecan.

Nail toxicity associated with epidermal growth factor receptor inhibitor therapy

As the use of epidermal growth factor receptor inhibitors becomes more widespread, increasing data are being collected regarding both efficacy and toxicity. Cutaneous toxicities are emerging not only as the most relevant class-related events, but also as potentially important markers of response to therapy. Although a follicular eruption is the most frequent cutaneous manifestation of epidermal growth factor receptor inhibition, ingrown nails, paronychia, and xerosis and desquamation of the digits, all of which occur in a substantial number of patients, require attention from treating oncologists and dermatologists. These nail disorders are mostly mild to moderate in severity, but, if not properly managed, can result in significant pain and interfere with activities of daily living. Descriptions of the nail and periungual toxicities associated with epidermal growth factor receptor inhibitor therapy and prevention and treatment strategies are presented.

Projecting the number of patients with colorectal carcinoma by phases of care in the US: 2000-2020

OBJECTIVE

This study provides projections of colorectal cancer prevalence by phases of care (initial, monitoring, and last year of life) to the year 2020 and describes the estimation method.

METHODS

Cancer prevalence by phase of care was estimated from colorectal cancer incidence and survival from the Surveillance, Epidemiology, and End Results (SEER) Program data, population estimates and projections from the US Census Bureau, and all cause mortality data from the Human Mortality Life Tables. Assumptions of constant incidence and survival were used for projections from 2000 to 2020. Modeled and directly observed patient months by phase of care were compared for 1996 -1998 to provide validation of estimates.

RESULTS

Prevalence of colorectal cancer is estimated to increase from 1,002,786 (0.36%) patients to 1,522,348 (0.46%) patients between 2000 and 2020. The estimated number of person-months in the initial and last year of life phases of care will increase 43%, while the monitoring phase of care will increase 54%. Modeled person-months by phase of care were consistent with directly observed measures of person months by phase of care in 1996-1998.

CONCLUSIONS

Under assumptions of current cancer control strategies we project that colorectal cancer prevalence will increase more rapidly than the US population, largely due to the aging of the US population. This suggests that considerable resources will be needed in the future for initial, continuing and last year of life treatment of colorectal cancer patients unless notable breakthroughs in primary prevention occur in the future years.

Loss of p16 in recurrent malignant mixed müllerian tumors of the uterus

Uterine malignant mixed müllerian tumors (MMMTs) are rare and highly aggressive malignancies with poor clinical prognoses. We examined for differences in the oncoprotein profiles of primary versus recurrent MMMTs. Five cases of recurrent uterine MMMT were examined by paraffin immunohistochemistry for the expression of p53, p16, P-cadherin, and Cerb-B2. P16, p53, and P-cadherin were each expressed in 100%, 80%, and 60% of the primary cases, respectively. Three cases expressed all three oncoproteins. All five cases were negative for Cerb-B2. No difference in antigen expression was seen in the epithelial versus sarcomatous components. Primary and recurrent tumors were concordant for p53, P-cadherin, and Cerb-B2. However, three cases of recurrent tumors were negative for p16 expression. P53, p16, and P-cadherin are common tumor suppressor genes expressed in uterine MMMT. Interestingly, p16 protein expression was lost in some cases of MMMTs when they recurred. This suggests that the oncoprotein and possibly genetic profile of p16 changes over time. We did not observe any difference in antigen expression between areas of epithelial or sarcomatous differentiation, which would support a single pluripotential malignant clone in the histogenesis of these tumors.

EGFR targeting therapies: monoclonal antibodies versus tyrosine kinase inhibitors. Similarities and differences

Current development of targeted therapy in oncology is particularly active and concerns principally two types of agents which are monoclonal antibodies (Mabs) and tyrosine kinase inhibitors (TKIs). Epidermal growth factor receptor (EGFR) signaling pathways play a key role in the regulation of cell proliferation, survival and differentiation. Consequently, EGFR is one of the most-studied ligand-receptor systems and specific EGFR inhibition approaches are currently among the most promising and the most advanced in the clinical setting. Cetuximab (Erbitux), belonging to the Mabs family, gefitinib (Iressa) and erlotinib (Tarceva), belonging to the TKIs family, are among the most advanced anti-EGFR drugs at the clinical level. The aim of this review article is to compare at both experimental and clinical levels the key points which govern the activity of these two types of targeting agents.

Adjuvant chemotherapy improves survival after resection of hepatic colorectal metastases: analysis of data from two continents

BACKGROUND

In the US, systemic chemotherapy is often administered after liver resection for hepatic colorectal metastases, even though no clinical trials data directly support this practice. The bias in America for chemotherapeutic treatment has made studies difficult. Until recently, no well accepted staging systems existed to categorize these patients with liver metastases, who have greatly varied prognoses.

STUDY DESIGN

All liver resections from an American and from a European tertiary care center performed between 1991 and 1998 were assembled from two prospective databases. Of 792 liver resections, the 518 patients treated with no chemotherapy (379 American, 139 European) were compared with 274 patients treated (240 American, 34 European) with 5-FU-based adjuvant chemotherapy. Patients treated by all other treatment regimens, including regional chemotherapy, were excluded, as were patients who died perioperatively. Patient survival analysis was performed by log-rank, with stratification by the clinical risk score (CRS, a staging system grading risk of recurrence by five clinical parameters: node-positive primary, short disease-free interval, large (> 5 cm) liver tumor, multiple liver tumors, and high carcinoembryonic antigen).

RESULTS

Patients subjected to adjuvant chemotherapy had improved survival (p=0.007, log-rank test) even after stratification by clinical risk score (p=0.001, stratified log-rank test). In every clinical risk score category, patients subjected to adjuvant chemotherapy had a higher chance of survival (range 1.3 to 2.0 times). Adjuvant chemotherapy was an independent predictor of outcomes.

CONCLUSIONS

This large study, with patients stratified by risk of recurrence, demonstrates that systemic adjuvant chemotherapy, such as a 5-FU-based regimen, prolongs survival after hepatic resection for colorectal metastases.

Concurrent irinotecan, oxaliplatin and UFT in first-line treatment of metastatic colorectal cancer: a phase I study

The feasibility of combining UFT plus leucovorin (LV) with alternating irinotecan and oxaliplatin was investigated in the first-line treatment of patients with advanced colorectal cancer. Twenty-five patients, median age 63 (range 24–79) years, World Health Organisation performance status 0–2 and median four marker lesions, received irinotecan 180 mg m⁻² on day 1, oxaliplatin 85–100 mg m⁻² on day 15 and UFT 200–300 mg m⁻² day⁻¹ with LV 90 mg day⁻¹, days 1–21 of a 28-day cycle. Patients were treated in cohorts of three. At the highest dose (irinotecan 180 mg m⁻², oxaliplatin 100 mg m⁻² and UFT 300 mg m⁻² day⁻¹), three of four patients experienced grade 3 toxicity. Diarrhoea, lethargy and vomiting were dose-limiting. Three of nine patients had grade 2 toxicities at the maximum tolerated dose (irinotecan 180 mg m⁻², oxaliplatin 100 mg m⁻² and UFT 250 mg m⁻² day⁻¹). There were no grade 3 toxicities in the first month of therapy. The overall response rate was 71% in 21 evaluable patients; progression-free survival was 8.8 months. Alternating irinotecan and oxaliplatin plus UFT is an effective and well-tolerated first-line treatment for patients with advanced colorectal cancer. We recommend a dose of irinotecan 180 mg m⁻² on day 1, oxaliplatin 100 mg m⁻² on day 15 and UFT 250 mg m⁻² day⁻¹ with LV 90 mg day⁻¹ on days 1–21 of a 28-day cycle for future studies.

A novel mechanism of resistance to epidermal growth factor receptor antagonism in vivo

Epidermal growth factor receptor (EGFR) is widely expressed in a number of solid tumors including colorectal cancers. Overexpression of this receptor is one means by which a cell can achieve positive signals for survival and proliferation; another effective means is by constitutive activation of EGFR. We have elucidated the role of constitutive EGFR signaling in malignant progression by stably transfecting colon cancer cells with a human transforming growth factor-alpha cDNA (a ligand for EGFR) under repressible control by tetracycline. We show that constitutive expression of transforming growth factor-alpha and its subsequent constitutive activation of EGFR allows for cancer cell survival in response to environmental stress in vitro and in vivo as well. The reversal of constitutive EGFR activation results in the loss of downstream mitogen-activated protein kinase and Akt activation, and a reduction in xenograft size that is associated with decreased proliferation and increased apoptosis. We used CI-1033, a small molecule antagonist of EGFR, to dissect an activation pathway that shows the ability of ERBb2 to activate Akt, but not Erk in the face of EGFR antagonism. This novel escape mechanism is a possible explanation of why anti-EGFR therapies have shown disappointing results in clinical trials.

Novel targets for anticancer treatment development in colorectal cancer

Despite recent advances in the treatment of metastatic colorectal cancer (CRC), the prognosis of patients with this malignancy remains poor. An emerging understanding of the molecular pathways that characterize cell growth, cell cycle, apoptosis, angiogenesis, and invasion has provided novel targets in cancer therapy. Numerous proteins have been implicated as having a crucial role in CRC. There are different targets according to their cellular localization such as membrane receptor targets, intracellular signaling targets, and other protein kinases that regulate cell division. Emerging data from the clinical development of new drugs directed to these targets are providing novel opportunities in the treatment of patients with CRC that will probably translate into an efficacy advantage in the years to come. In this article, we review the current developmental status of some of the most advanced targeted therapies in the treatment of CRC.

A simple and reproducible scoring system for EGFR in colorectal cancer: application to prognosis and prediction of response to preoperative brachytherapy

The aim of this study was to determine the predictive and prognostic value of epidermal growth factor receptor (EGFR) expression in rectal cancers treated with preoperative high-dose rate brachytherapy and in mismatch-repair (MMR)-proficient colorectal cancers (CRCs), respectively. We validate the use of receiver operating characteristic (ROC) curve analysis to select cutoff scores for EGFR overexpression for the end points studied. Immunohistochemistry (IHC) for EGFR was performed on 82 rectal tumour biopsies and 1197 MMR-proficient CRCs using a tissue microarray. Immunoreactivity was scored as the percentage of positive tumour cells by three pathologists and the inter-observer reliability was assessed. ROC curve-derived cutoffs were used to analyse the association of EGFR overexpression, tumour response and several clinicopathological features including survival. The scoring method was found to be reproducible in rectal cancer biopsies and CRCs. The selected cutoff scores from ROC curve analysis for each clinicopathological feature were highly consistent among pathologists. EGFR overexpression was associated with response to radiotherapy (P-value <0.001) and with worse survival time (P-value <0.001). In multivariate analysis, EGFR overexpression was independently associated with adverse prognosis (P-value <0.001). Epidermal growth factor receptor is a predictive marker of response to preoperative radiotherapy and an independent adverse prognostic factor CRC.

Cost of cancer care: issues and implications

Medical technology is increasingly costly in most fields of clinical medicine. Oncology has not been spared from issues related to cost, in part resulting from the tremendous scientific progress that has lead to new tools for diagnosis, treatment, and follow-up of our patients. The increasing cost of health care in general (and cancer care in particular) raises complex questions related to its effects on our economy and the citizens of our society. This article reviews the macroeconomic principles and individual behaviors that govern medical spending, and examines how cost disproportionately affects various populations. Our overall goal is to frame debate about health policy concerns that influence the clinical practice of oncology.

Therapeutic Options in the Management of Colon Cancer: 2005 Update

Recently, major developments in the treatment of colon cancer have emerged. These developments include improvements in surgical technique and staging and the introduction of new molecularly targeted pharmacologic agents. Improvements in surgical management involve enhanced staging techniques, allowing more accurate determination of risk of recurrence. Newer agents, such as oxaliplatin, cetuximab, and bevacizumab, now are approved for the treatment of colon cancer. The data associated with use of oxaliplatin in adjuvant and metastatic settings continue to mature; survival benefits are expected to become more fully apparent in the next two years. Bevacizumab, a monoclonal antibody that neutralizes vascular endothelial growth factor, when combined with irinotecan, 5-fluorouracil, and leucovorin (IFL), was superior to IFL alone in achieving median and progression-free survival. Cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor, when given in combination with irinotecan, achieved an increased objective response and increased time to progression, compared with cetuximab alone, in patients refractory to irinotecan-containing regimens. In addition to surgical and pharmacologic developments, the recognition that genetics and molecular markers play an important role in carcinogenesis has heightened research to integrate this knowledge into practice. Nurses play a pivotal role in the care of patients with colon cancer and must be conversant in the new advances in treatment.

Chronomodulated irinotecan, oxaliplatin, and leucovorin-modulated 5-Fluorouracil as ambulatory salvage therapy in patients with irinotecan- and oxaliplatin-resistant metastatic colorectal cancer

PURPOSE

To evaluate the activity and tolerability of salvage chronomodulated chemotherapy combining irinotecan (I), 5-fluorouracil/leucovorin (5-FU/LV), and oxaliplatin (O) (chronoIFLO) in patients with metastatic colorectal cancer (MCRC) and prior progression on four drugs.

PATIENTS AND METHODS

Seventy-seven nonhospitalized MCRC patients received chronoIFLO every 3 weeks, with day 1: I (180 mg/m2 over 6 hours, with peak infusion rate at 05:00) and days 2-5: 5-FU/LV (700/300 mg/m2 per day over 12 hours, with peak flow rate at 04:00), and O (20 mg/m2 per day over 12 hours, with peak flow rate at 16:00). Toxicity and response were assessed every 3 weeks and every 2 months, respectively. RESULTS. Three or more prior chemotherapy lines were given to 75% of the patients. Two or more organs had metastatic disease in 65% of the patients. A median number of six courses of chronoIFLO was given. The main grade 3-4 toxicities were diarrhea (39% of the patients, 9% of the courses) and neutropenia (30% of the patients and 7% of the courses). Grade 3 peripheral sensory neuropathy occurred in 14% of the patients. Two patients achieved a partial response and 61 had stable disease, resulting in disease control for 82% of the patients. The median time to progression (TTP) was 5.5 months (95% confidence interval, 3.7-6.0). The median overall survival time was 14.2 months (9.8-17.3). Baseline performance status, serum carcinoembryonic antigen (CEA) level, and CEA doubling time were independent prognostic factors of TTP.

CONCLUSIONS

ChronoIFLO safely and durably halted tumor progression in most extensively pretreated MCRC patients.

Advanced Colorectal Cancer: Current Treatment and Nursing Management With Economic Considerations

Colorectal cancer is one of the most common cancers affecting men and women in the United States. In 2005, 10% of all new cancer cases in men will be colorectal; for women, 11% of new cases will be colorectal. The disease is the third most frequent cancer occurring in both sexes. Colorectal cancer also is the third most frequent cause of death for men and women, and more than 56,000 cancer deaths in 2005 will be attributed to colorectal cancer. Chemotherapy options for treatment of the disease remained relatively stagnant until the approval of irinotecan in 1996 followed by capecitabine, oxaliplatin, and the new targeted agents. The new agents have improved efficacy of treatment for colorectal cancer and the lives of patients with advanced disease. With the new options for treatment come increased nursing and patient-teaching responsibilities, as well as increased costs associated with the newer drugs in the armamentarium of chemotherapy agents. Formulary budgets are seeing dramatic rises in expenditures for the new, targeted therapy treatments; discussion of the most appropriate therapies may be considered. This article will discuss epidemiology of colorectal cancer, treatment options in advanced colorectal cancer, and nursing care crucial to patients undergoing chemotherapy. Discussion of economic impact also will be presented.

Classification and management of skin, hair, nail and mucosal side-effects of epidermal growth factor receptor (EGFR) inhibitors

Inhibitors of epidermal growth factor receptor (EGFR) are commonly used as therapeutic agents in oncology. In contrast to currently used oncological treatments, these inhibitors almost always cause skin- and skin adnex toxicity. About 85% of treated patients develop to a more or lesser extent an acneiform eruption. Xerosis cutis and painful nail disorders occur in, respectively, 35% and 10-15% of all treated patients. Also hair and mucosal changes have been reported, although to a lesser extent. These skin- and skin adnex toxicities are reversible after withdrawal of treatment, but are seldom a reason to stop or interrupt therapy. This review outlines the classification, the pathogenesis and therapy of these skin, hair, nail and mucosal changes due to EGFR inhibition. Informing the patient and management of these side-effects is very important to reduce discomfort and as such to increase compliance to therapy.

Cetuximab in the treatment of head and neck cancer

Approaches to the treatment of locally advanced and recurrent and/or metastatic squamous cell carcinoma of the head and neck (SCCHN) have been limited by their toxicity. Effective, better tolerated approaches are urgently required. Cetuximab is an immunoglobulin G(1) monoclonal antibody that specifically targets the epidermal growth factor receptor (EGFR), which is commonly expressed in a number of solid tumors, including SCCHN, where it is associated with poor prognosis. Cetuximab is approved in 56 countries for use in the treatment of EGFR-expressing metastatic colorectal cancer that has progressed on irinotecan-containing therapy and has recently received approval in Europe and the USA for use in the treatment of SCCHN. A randomized Phase III study has demonstrated that cetuximab plus radiotherapy can significantly improve locoregional control and prolong overall survival compared with radiotherapy alone. Cetuximab has also been confirmed to be effective as monotherapy in recurrent and/or metastatic SCCHN that has progressed on platinum-containing therapy. Clinical studies have demonstrated that cetuximab is well tolerated and does not significantly increase the side effects associated with radiotherapy or chemotherapy. This article presents the rationale for EGFR inhibition in the management of head and neck cancers, and the preclinical and clinical evidence for the use of cetuximab in the treatment of SCCHN.

Molecular markers that predict response to colon cancer therapy

Progress in the treatment of colon cancer depends on the development of target-based molecules built on an improved understanding of the molecular biology of the disease. Defining end points for chemotherapy resistance is needed as drug resistance develops quickly and patients demonstrate variation in response to chemotherapy. Many techniques that measure a marker's preponderance have been developed including biochemical, immunohistochemical, genomics, proteomics or a combination thereof. However, standardization of these techniques that measure either genes or their protein products is urgently needed. This article reviews several markers (TS,TP, DPD, FT, EGFR, VEGF, CD44v6, TRAIL, microsatellite instability, allelic deletions, oncogenes and suppressor genes [c-myc, Ki-Ras, p53, p21, Topo I, Topo IIalpha, Fos, hMLH1, Bcl-2/Bax and MDR1], MDR-related proteins [Pgp, MRP and LRP], genomic polymorphisms [XPD, ERCC1, GSTP1 and TS 3 -UTR] and COX-;2) that influence DNA metabolism, DNA damage, programmed cell death, the immune or vascular system, or lead to mutations. When combined together and tested by newly developed genomic and proteomic approaches, many of these markers provide a more sensitive indicative predictor of response than when evaluated separately or by older biochemical, immunohistologic or morphologic methods. A global approach involving the simultaneous testing of several predictive multimarkers will provide critical information for improving chemotherapy to alleviate suffering from this disease.

Panitumumab the first fully human monoclonal antibody: from the bench to the clinic

Panitumumab (formerly known as ABX-EGF) is the first fully human monoclonal antibody to epidermal growth factor receptor to enter clinical trials for the treatment of solid tumors. Like cetuximab (Erbitux; BMS), it is directed against the extracellular ligand-binding domain of the receptor and results in blockade of the essential downstream signaling pathways that are known to govern apoptosis, proliferation and differentiation of both normal and neoplastic cell types in a wide array of tissues. It has a very high affinity for epidermal growth factor receptor and has been generally well tolerated and associated with very few infusion reactions. As a fully human agent, panitumumab has not been associated with the formation of any antibodies directed against it that has been evidenced by a very reliable pharmacokinetic profile with possible dosing schedules ranging from 1 to 3 weeks. Similar to other agents targeting the epidermal growth factor receptor pathway, a rash has been the primary toxicity and is dose dependent up to 2.5 mg/kg at which dose 100% of all patients have been affected. The anti-tumor activity of panitumumab has been tested in vitro and in vivo, and inhibition of tumor growth has been observed in numerous cancer models, particularly lung, kidney and colorectal. It has been efficacious and well tolerated both as monotherapy and in combination with other chemotherapeutic agents. Several phase I trials, two phase II trials and most recently a phase III trial in pretreated colorectal cancer have been carried out to date. Currently, there is also a randomized phase III trial (Panitumumab Advanced Colorectal Cancer Evaluation Study) investigating the role of panitumumab in the first-line treatment of colorectal cancer. No unfavorable drug-drug interactions have been observed nor has there been any effect on the pharmacokinetics of drugs with which it is being used. Recent progress in preclinical and clinical studies of panitumumab is reviewed.