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

Epidermal growth factor receptor (EGFR) status in primary colorectal tumors correlates with EGFR expression in related metastatic sites: biological and clinical implications

BACKGROUND

Epidermal growth factor receptor (EGFR) plays an important role in the pathogenesis of colorectal cancer (CRC). There are several potential strategies to target EGFR. However, monoclonal antibodies and low molecular weight tyrosine kinase inhibitors are the most advanced in clinical development. The majority of studies so far have merely required EGFRs to be expressed by CRC cells. The detection of EGFR expression is usually performed by immunohistochemistry (IHC) in the primary tumor. There are few data regarding the EGFR status in the corresponding distant metastases.

PATIENTS AND METHODS

EGFR status was analyzed by IHC in 80 patients (31 male, 49 female) with CRC (70 colon, 10 rectum) and at least one distant metastatic lesion. Metastatic sites analyzed (n=80) were liver (79 patients) and lung (one patient).

RESULTS

EGFR reactivity was similar in the primary tumor and the related metastases. Among the 80 paired primary/metastatic tumors, only five (6.3%) showed discordance in EGFR status: two cases with EGFR expression in the primary tumor but not in the metastasis, and three samples with EGFR expression in the metastasis but not in the primary tumor.

CONCLUSIONS

Between the paired primary tumors and distant metastatic lesions, 94% of samples had concordant EGFR status when analyzed by IHC.

Role of post-operative chemoradiation in resected gastric cancer

The curative management of gastric adenocarcinoma depends upon complete resection of the primary tumor. In patients with lymph node metastases in the resected specimen, the relapse and death rates from recurrent cancer are at least 70%-80%. There is continued debate over whether more extensive lymph node dissection (D2) improves survival when compared to less extensive operations. Until recently, attempts at preventing recurrence have employed adjuvant chemotherapy and have been ineffective. A large U.S. Intergroup study (INT-0116) demonstrated that combined chemoradiation following complete gastric resection improves median time to relapse (30 vs. 19 months, P < 0.0001) and overall survival (35 vs. 28 months, P = 0.01). The improvements in disease-free and overall survival resulting from post-operative chemoradiation have defined a new standard of care. An update of the results of INT-0116 analysis performed in 2004 with 7 years median follow-up, not only confirms the benefits from post-operative chemoradiation but also shows that chemoradiation does not produce significant long-term toxicity. The recent publication of the first large adequately powered III neoadjuvant chemotherapy trial suggested this technique might down-stage tumors and increase resectability. Future advances in the therapy of resectable gastric cancer may come from studies of pre-operative neoadjuvant chemoradiation and the application of targeted therapies such as growth receptor antagonists and anti-angiogenesis agents.

Molecular determinants of cetuximab efficacy

PURPOSE

To investigate whether mRNA expression levels of cyclin D1 (CCND1), cyclooxygenase 2 (Cox-2), epidermal growth factor receptor (EGFR), interleukin 8 (IL-8), and vascular endothelial growth factor (VEGF), all members of the EGFR signaling pathway, are associated with clinical outcome in patients with EGFR-expressing metastatic colorectal cancer (CRC) treated with cetuximab.

PATIENTS AND METHODS

Thirty-nine patients with metastatic CRC, refractory to both irinotecan and oxaliplatin, were enrolled on IMCL-0144 and treated with single-agent cetuximab. The intratumoral mRNA levels of CCND1, Cox-2, EGFR, IL-8, and VEGF were assessed from paraffin-embedded tissue samples using laser-capture microdissection and quantitative real-time polymerase chain reaction.

RESULTS

There were 21 women and 18 men with a median age of 64 years (range, 35 to 83 years). Higher gene expression levels of VEGF were associated with resistance to cetuximab (P = .038; Kruskal-Wallis test). The combination of low gene expression levels of Cox-2, EGFR, and IL-8 was significantly associated with overall survival (13.5 v 2.3 months; P = .028; log-rank test). Both findings were independent of skin toxicity that was itself significantly correlated to survival. Patients with a lower mRNA amount of EGFR had a longer overall survival compared with patients that had a higher mRNA amount (7.3 v 2.2 months; P = .09; log-rank test). Patients with lower expression of Cox-2 had a significantly higher rate of grade 2 to 3 skin reactions under cetuximab treatment.

CONCLUSION

This pilot study suggests that gene expression levels of Cox-2, EGFR, IL-8, and VEGF in patients with metastatic CRC may be useful markers of clinical outcome in single-agent cetuximab treatment.

Novel targeted therapies in the treatment of gastric and esophageal cancer

Esophageal cancer (EC) and gastric cancer (GC) constitute a major cause of cancer deaths worldwide. Recent improvements in both surgical techniques and adjuvant/neoadjuvant radiotherapy and chemotherapy approaches have increased the survival of patients with loco-regional disease. However, most of the patients with GC or EC have advanced disease either at diagnosis or at follow-up. Despite recent advances in the treatment of advanced disease, these patients still do poorly. An emerging understanding of the molecular pathways that characterize cell growth, cell cycle, apoptosis, angiogenesis and invasion has provided novel targets in cancer therapy. In this review we describe the current status of targeted therapies in the treatment of EC and GC. These therapeutic strategies include EGFR inhibitors, antiangiogenic agents, cell cycle inhibitors, apoptosis promoters and matrix metalloproteinases inhibitors. The emerging data from the clinical development of these compounds has provided novel opportunities in the treatment of EC and GC that will probably translate into efficacy advantage in the treatment of these common malignancies.

Chemotherapy for colorectal cancer--an overview of current management for surgeons

BACKGROUND

The role of systemic chemotherapy in the management of colorectal cancer has been re-evaluated with the advent of newer agents. The results of published trials are reviewed in this article and the protocols of some of the major ongoing trials outlined.

METHODS

A medline based literature search was performed for articles relating to clinical trials using systemic chemotherapy in the management of colorectal cancer in the advanced and adjuvant setting. Additional original papers were obtained from citations in those identified by the initial search.

RESULTS

The combination of irinotecan or oxaliplatin with 5-fluorouracil (5-FU) based chemotherapy regimens for advanced cancer demonstrates better response rates when compared with 5-FU and folinic acid (FA). Although this translates into a modest survival benefit, it may increase resectability rates in patients with hepatic metastasis. Adjuvant chemotherapy in stage III cancer has been established to improve long-term survival although it is benefit for patients with stage II disease remains less clear.

CONCLUSION

Evaluation of the various combinations of chemotherapeutic agents that are most effective and the clinical situations for which they are best suited is ongoing and will improve the current outlook for those with colorectal cancer.

Prognostic impact of epidermal growth factor receptor (EGFR) expression on loco-regional recurrence after preoperative radiotherapy in rectal cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) represents a major target for current radiosensitizing strategies. We wished to ascertain whether a correlation exists between the expression of EGFR and treatment outcome in a group of patients with rectal adenocarcinoma who had undergone preoperative radiotherapy (RT).

METHODS

Within a six-year period, 138 patients underwent preoperative radiotherapy and curative surgery for rectal cancer (UICC stages II-III) at our institute. Among them, 77 pretherapeutic tumor biopsies were available for semi-quantitative immunohistochemical investigation evaluating the intensity and the number (extent) of tumor stained cells. Statistical analyses included Cox regression for calculating risk ratios of survival endpoints and logistic regression for determining odds ratios for the development of loco-regional recurrences.

RESULTS

Median age was 64 years (range: 30-88). Initial staging showed 75% and 25% stage II and III tumors, respectively. RT consisted of 44-Gy pelvic irradiation in 2-Gy fractions using 18-MV photons. In 25 very low-rectal-cancer patients the primary tumor received a boost dose of up to 16 Gy for a sphincter-preservation approach. Concomitant chemotherapy was used in 17% of the cases. All patients underwent complete total mesorectal resection. Positive staining (EGFR+) was observed in 43 patients (56%). Median follow-up was 36 months (range: 6-86). Locoregional recurrence rates were 7 and 20% for EGFR extent inferior and superior to 25%, respectively. The corresponding locoregional recurrence-free survival rate at two years was 94% (95% confidence interval, CI, 92-98%) and 84% (CI 95%, 58-95%), respectively (P = 0.06). Multivariate analyses showed a significant correlation between the rate of loco-regional recurrence and three parameters: EGFR extent superior to 25% (hazard ratio = 7.18, CI 95%, 1.17-46, P = 0.037), rectal resection with microscopic residue (hazard ratio = 6.92, CI 95%, 1.18-40.41, P = 0.032), and a total dose of 44 Gy (hazard ratio = 5.78, CI 95%, 1.04-32.05, P = 0.045).

CONCLUSION

EGFR expression impacts on loco-regional recurrence. Knowledge of expression of EGFR in rectal cancer could contribute to the identification of patients with an increased risk of recurrences, and to the prediction of prognosis.

Dual inhibition of epidermal growth factor receptor and vascular endothelial growth factor receptor phosphorylation by AEE788 reduces growth and metastasis of human colon carcinoma in an orthotopic nude mouse model

We studied growth factors and their receptors in tumor cells and tumor-associated endothelial cells as the therapeutic targets in colon cancer. Immunohistochemical analysis of 13 surgical specimens of human colon adenocarcinoma revealed that both tumor cells and tumor-associated endothelial cells in 11 of the 13 specimens expressed the epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), EGF receptor (EGFR), phosphorylated EGFR (pEGFR), vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR), and phosphorylated VEGFR (pVEGFR). HT29 human colon cancer cells growing orthotopically in the cecum of nude mice expressed a high level of EGF, EGFR, pEGFR, VEGF, VEGFR, and pVEGFR. Double-immunofluorescence staining found that tumor-associated mouse endothelial cells also expressed pEGFR and pVEGFR. Tumors in mice treated for 5 weeks with oral AEE788 (an inhibitor of EGFR and VEGFR tyrosine kinase) as a single agent or with CPT-11 alone were smaller (>50%) than those in control mice. Mice treated with the combination of AEE788 and CPT-11 had significantly smaller tumors (P < 0.01) and complete inhibition of lymph node metastasis. AEE788 alone or in combination with CPT-11 inhibited pEGFR, pVEGFR, and phosphorylated Akt expression on tumor-associated endothelial cells as well as on tumor cells. The combination therapy also significantly decreased microvessel density and tumor cell proliferation and increased the level of apoptosis in both tumor cells and tumor-associated endothelial cells. Collectively, these data suggest that the dual inhibition of EGFR and VEGFR signaling pathways in tumor cells and tumor-associated endothelial cells in combination with chemotherapy can provide a new approach to the treatment of colon cancer.

Novel therapies in lung cancer

This article reviews novel therapies that are under development for non-small cell lung cancer and small cell lung cancer.

Therapeutic targeting of receptor tyrosine kinases in lung cancer

Lung cancer is a difficult illness with a poor overall survival. Even though combination strategies with chemotherapy, radiation therapy and surgery have all been utilised, the overall outcome for this disease continues to be relatively disappointing. In order to make a difference in the treatment of lung cancer, novel therapeutics will have to be developed. Through basic biological studies, a number of receptor tyrosine kinases have been implicated in the pathogenesis and progression of lung cancer. In this review, the authors summarise the mechanisms of several major receptor tyrosine kinases in lung cancer, especially epidermal growth factor receptor, Her2/neu, MET, vascular endothelial growth factor and KIT. The biology associated with these receptors is described, and the various novel therapeutic inhibitory strategies that are ongoing in preclinical and clinical studies for lung cancer are detailed. Through understanding of receptor tyrosine kinases and the utilisation of specific inhibitors, it is hopeful that a dramatic impact will be made on the biology and therapy for lung cancer.

Second-line therapy for advanced colorectal carcinoma

The past decade has witnessed considerable advances in the treatment of colorectal cancer (CRC). The emergence and integration into clinical practice of new cytotoxic agents, such as irinotecan and oxaliplatin, has had a significant impact on outcomes from advanced CRC with median survivals of 18 to 21 months now achievable. Improvements in survival as a consequence of using these drugs as salvage therapies ultimately led to demonstration of efficacy for both in the first-line treatment of CRC. As the importance of second-line therapy is increasingly recognized, key issues, such as optimal schedules, chemotherapy combinations, and sequential therapy, need to be addressed. The integration of newer biologic agents, such as cetuximab and bevacizumab, for which recent data have emerged, has further added to the complexities of delivering therapy to patients with advanced CRC, heralding a new treatment era for this disease.

Chemotherapy of metastatic colorectal cancer

Over the past decade, metastatic colorectal cancer has evolved from a relatively resistant disease to one that is sensitive to a variety of chemotherapeutic drugs and combinations of drugs. During the same period, the median survival of patients with metastatic colorectal cancer increased from approximately 14 months to almost 20 months. First-line chemotherapy prolongs survival and delays the appearance of symptoms and should be considered in patients who are still asymptomatic. Patients with metastatic colorectal cancer and adequate performance status should be treated with a combination of fluorouracil (5-FU) and either oxaliplatin or irinotecan. Bevacizumab, the monoclonal antibody against the vascular endothelial growth factor, has been shown to prolong survival with acceptable toxicity and may be added when available. When the disease recurs, second-line chemotherapy may also prolong survival in appropriately selected patients. Typically, treatment includes 5-FU and one of the drugs not used in the first-line therapy (oxaliplatin or irinotecan). Several oral prodrugs of 5-FU are currently available. Capecitabine, approved in the United States, may be safely substituted for 5-FU in the majority of settings and combinations. Cetuximab is a monoclonal antibody against the epidermal growth factor receptor and is approved both as a single agent and in combination with irinotecan for patients with recurrent disease. This treatment may represent a second-line or third-line option in selected patients. Treatment of patients with isolated liver metastases may also include surgical or other ablative procedures. In carefully selected patients, these modalities add to the efficacy of chemotherapy and may be used with potentially curative intent. However, for the vast majority of patients with metastatic colorectal cancer treatment is palliative.

ZD6474--clinical experience to date

ZD6474 selectively targets two key pathways in tumour growth by inhibiting vascular endothelial growth factor (VEGF)-dependent tumour angiogenesis and epidermal growth factor (EGF)-dependent tumour cell proliferation and survival. Phase I clinical evaluation has shown ZD6474 to be generally well tolerated, with a pharmacokinetic profile appropriate for once-daily oral dosing. Phase II evaluation of ZD6474 at doses of 100-300 mg is ongoing in a range of patient types in single and combination regimens. These include three randomised studies of patients with non-small-cell lung cancer. In one of these trials, the efficacy of ZD6474 monotherapy is being compared with that of the EGF receptor tyrosine kinase inhibitor gefitinib (Iressa) in previously treated patients. In the other two trials, the efficacy of ZD6474 in combination with certain standard chemotherapy regimens is being compared with that of standard chemotherapy alone: one with carboplatin and paclitaxel in previously untreated patients, and the second with docetaxel in patients who progressed after platinum-containing therapy. The advent of novel molecular-targeted agents such as ZD6474 has necessitated a re-evaluation of conventional cancer study design in order to optimise appraisal of this new generation of anticancer agents. The specific considerations of the ZD6474 clinical programme are discussed.

Systemtherapie des kolorektalen Karzinoms

Drug treatment of colorectal cancer has made impressive progress during the past 10 years. In addition to the traditional 5-fluorouracil, newer anticancer drugs are available including irinotecan and oxaliplatin. Monoclonal antibodies like bevacizumab and cetuximab have been integrated into modern treatment regimens. Based on randomized clinical trials we can formulate rational treatment strategies as outlined in this article.

Usefulness and limitation of multiple endoscopic biopsy sampling for epidermal growth factor receptor and c-erbB-2 testing in patients with gastric adenocarcinoma

BACKGROUND

Our objective was to examine the utility of endoscopic biopsy specimens in judging the status of epidermal growth factor receptor (EGFR) and c-erbB-2 genes and proteins in the entire tumor.

METHODS

Endoscopic biopsy specimens and specimens of whole representative cut surfaces of corresponding surgically resected tumors were obtained from 14 patients with gastric carcinoma, and immunohistochemistry and fluorescence in situ hybridization were then performed to determine the protein expression and gene amplification profiles, respectively, of EGFR and c-erbB-2 in these biopsy and surgical specimens.

RESULTS

Among the eight endoscopic biopsy specimens obtained from three gastric carcinomas in which EGFR protein overexpression and gene amplification were judged to be positive in the corresponding surgically resected tissue specimens, EGFR overexpression was detected in three specimens (38%), but EGFR amplification was not detected (0%). Among the 19 endoscopic biopsy specimens obtained from five gastric carcinomas in which c-erbB-2 protein overexpression and gene amplification were judged to be positive in the corresponding surgically resected tissue specimens, c-erbB-2 overexpression and amplification (c-erbB-2/CEP17 ratio) were detected in 14 (74%) and 16 (84%) specimens, respectively. All three cases with EGFR overexpression and all five cases with c-erbB-2 overexpression showed intratumor heterogeneity with regard to their EGFR and c-erbB-2 status, respectively.

CONCLUSIONS

The c-erbB-2 status could be adequately assessed not only by examining surgically resected materials, but also by examining multiple endoscopic biopsy specimens. On the other hand, to assess the EGFR status accurately, the use of surgically resected samples appeared to be more reliable than the use of multiple endoscopic biopsy samples.

Proapoptotic activity of cell-permeable anti-Akt single-chain antibodies

We developed anti-Akt1 single-chain antibodies (scFv) by panning a mouse phage-displayed scFv recombinant antibody library. Recombinant scFv that bound glutathione S-transferase (GST)-Akt1 were screened for their ability to inhibit Akt activity in vitro in a kinase reaction containing human recombinant Akt1 and an Akt/serum glucocorticoid-inducible kinase (SGK) substrate. Michaelis-Menten analysis of kinase inhibition by a selected scFv was consistent with scFv-mediated competition with enzyme's substrate for the catalytic site of Akt. To generate a membrane-permeable version of the anti-Akt1 scFv, the scFv gene was subcloned into a GST expression vector carrying a membrane-translocating sequence (MTS) from Kaposi fibroblast growth factor. A purified GST-anti-Akt1-MTS fusion protein accumulated intracellularly in 293T, BT-474, and PyVmT cells in a dose- and time-dependent fashion. Intracellular accumulation correlated temporally with inhibition of p-Ser(473) Akt and GSK-3alpha/beta phosphorylation, suggesting that Ser(473) is an Akt autophosphorylation site. Phosphorylated (activated) phosphoinositide-dependent kinase 1, mitogen-activated protein kinase, p38, and HER2 (erbB2) were not affected, supporting Akt kinase specificity for the inhibitory scFv. Exogenously expressed constitutively active Akt2 and Akt3 were also inhibited in vitro by the anti-Akt1 fusion protein. Furthermore, GST-anti-Akt1-MTS induced apoptosis in three cancer cell lines that express constitutively active Akt. Finally, systemic treatment with the anti-Akt scFv reduced tumor volume and neovascularization and increased apoptosis in PyVmT-expressing transgenic tumors implanted in mouse dorsal window chambers. Thus, GST-anti-Akt1-MTS is a novel cell-permeable inhibitor of Akt, which selectively inhibits Akt-mediated survival in intact cells both in vitro and in vivo.

Gene copy number for epidermal growth factor receptor (EGFR) and clinical response to antiEGFR treatment in colorectal cancer: a cohort study

BACKGROUND

The antiepidermal growth factor receptor (antiEGFR) monoclonal antibodies cetuximab and panitumumab have good clinical activity in about 10% of patients with metastatic colorectal cancer that is resistant to chemotherapy. The molecular mechanisms underlying clinical response or resistance to these agents are unknown.

METHODS

Tumours from 31 patients with metastatic colorectal cancer who had either an objective response (n=10) or stable disease or progressive disease (n=21) after treatment with cetuximab or panitumumab were screened for genetic changes in EGFR or its immediate intracellular effectors. Specifically, we assessed the EGFR copy number and the mutation profile of the EGFR catalytic domain and of selected exons in KRAS, BRAF, and PIK3CA.

RESULTS

Eight of nine of patients with objective responses who were assessable by fluorescence in-situ hybridisation (FISH) had an increased EGFR copy number. By contrast, one of 21 non-responders assessable by FISH had an increased EGFR copy number (p<0.0001 for responders vs non-responders, Fisher's exact test). The mutation status of the EGFR catalytic domain and its immediate downstream effectors PIK3CA, KRAS, and BRAF did not correlate with disease response. In colorectal-cancer cell lines, the concentration of cetuximab that completely inhibited proliferation of cells with amplified EGFR copy number did not affect proliferation of cells with unamplified EGFR.

INTERPRETATION

We propose that the response to antiEGFR treatment has a genetic basis and suggest that patients might be selected for treatment on the basis of EGFR copy number.

A phase II trial of gefitinib with 5-fluorouracil, leucovorin, and irinotecan in patients with colorectal cancer

Inhibition of epidermal growth factor receptor (EGFR) signalling contributes to the therapy of colorectal cancer. Gefitinib, an oral EGFR tyrosine kinase inhibitor, shows supra-additive growth inhibition with irinotecan and fluoropyrimidines in xenograft models. We designed a study to determine the tolerability and efficacy of gefitinib in combination with irinotecan, infusional 5-fluorouracil (5-FU) and leucovorin (LV), on a 2-week schedule. Among 13 patients with advanced colorectal cancer, 10 required dose reductions of irinotecan and 5-FU because of dehydration, diarrhoea, and neutropenia, seven of whom required hospitalisation, three with neutropenic fever. One patient achieved partial response and seven had disease stabilisation. The combination of this standard chemotherapy regimen with gefitinib is associated with excessive toxicity, suggesting an interaction at a pharmacokinetic or pharmacodynamic level.

Genetic alterations in prostate cancer

Prostate cancer is the most common nondermatologic malignancy in men. Prostate cancer is characterized by clinical and biologic heterogeneity that has complicated molecular and epidemiologic studies. Like other epithelial malignancies, prostate tumors exhibit complex karyotypic abnormalities and harbor many specific genetic alterations. Although recent work has begun to elucidate many of the specific mutations associated with prostate cancer, we still lack a clear understanding of the complement of genetic changes that suffice to program the malignant state. Here, we review our current understanding of the genetic changes found in prostate cancer and explore the connections between specific genetic alterations and malignant phenotypes including cell growth, survival, invasion, and metastasis.

Epidermal Growth Factor Receptor Inhibitors in the Treatment of Non–Small-Cell Lung Cancer

Remarkable developments in the systemic treatment of advanced non–small-cell lung cancer have taken place in the past few years. Targeted therapies have been largely employed in patients with far advanced disease, and some of them have demonstrated consistent activity in this setting. Epidermal growth factor receptor (EGFR) inhibitors cause dramatic response in approximately 10% of white patients who had received prior chemotherapy. Responses are higher in Asians. These findings are at least partly caused by the substantially higher incidence of EGFR mutations in Asians compared with whites. Studies of EGFR inhibitors in combination chemotherapy in front-line therapy of advanced non–small-cell lung cancer have, however, failed to improve survival, and better understanding of interactions between chemotherapeutic agents and EGFR inhibitors will be essential in the development of more effective strategies.

Neoadjuvant treatment of unresectable colorectal liver metastases: correlation between tumour response and resection rates

BACKGROUND

Long-term survival is reported in patients with liver metastases of colorectal cancer. Recently, an increased number of reports on liver resection following neoadjuvant chemotherapy in patients with initially unresectable liver metastases has been published.

METHODS

We analysed all published or presented trials and retrospective studies that report the rate of objective response and the rate of resection of initially unresectable metastases to correlate objective response and the rate of resection of metastases.

RESULTS

In studies that enrolled patients with metastases confined to the liver, 24-54% of patients were resected following chemotherapy, compared to 1-26% of patients in trials that included non-selected patients with metastatic colorectal cancer. A strong correlation was found between response rates and the resection rate in studies with patients with isolated liver metastases (r = 0.96, P=0.002). Likewise, in studies with non-selected patients, the resection rate of metastases also was associated with the objective response rate (r = 0.74, P <0.001).

CONCLUSIONS

Patient selection and efficacy of pre-operative chemotherapy are both strong predictors for resectability of liver metastases. Resectability is a novel endpoint focusing on the curative potential of treatment compared with classical endpoints of response or progression-free survival that are important if palliation is the aim. Therefore, patients with potentially resectable liver metastases should be investigated in special trials and interdisciplinary teams.

Tailored Therapy of Colorectal Cancer

Colorectal cancer is a leading cause of cancer mortality and morbidity. Despite the recent results of systemic chemotherapy, more than 40% of patients with advanced cancer still do not achieve substantial benefits with cytotoxic agents. Therefore, new tailored strategies are warranted to improve the probability of disease control. The rationale for this approach is based on the identification of the in vivo interactions among patient's characteristics, disease physiopathology, and drug pharmacodynamics and pharmacokinetics. Genomic and proteomic technologies may clarify the mechanisms involved in cancer growth and progression in each single patient and in the molecular basis of interindividual differences of anticancer drugs in terms of efficacy and toxicity. Despite the recent encouraging data, the clinical use of targeted therapy is hampered by several questions, such as: optimal biologic dose and schedule, lack of predictive surrogate biomarkers, and modalities of combination with chemotherapy/radiotherapy. Further efforts are needed to improve the reliability of genomic and proteomic technologies, in particular regarding their standardization and widespread availability. These unsolved issues make tailored therapy an open challenge.

Erupción acneiforme secundaria a cetuximab

C225 (cetuximab) is a monoclonal antibody that targets the epidermal growth factor receptor (EGF-R). It is used for the treatment of solid malignant tumors in advanced stages. It works against tumors by inhibiting cell proliferation, angiogenesis and the formation of metastases, as well as by promoting cell apoptosis. We present the case of a 64-year-old male patient affected with a colon neoplasm with hepatic metastases, for which treatment with cetuximab was indicated. He came to our department because of a skin eruption with papules and pustules located on the face, neck, presternal area and upper back, but with no cysts or comedones. The biopsy was compatible with an acneiform eruption. The patient was treated with minocycline, 100 mg/day for 2 weeks, with the clinical symptoms responding favorably. When he was given further doses of cetuximab, he once again presented with new eruptions, but of lesser intensity. Because of the high frequency with which this adverse effect appears, it is recommended that cetuximab be included on the list of drugs causing acneiform eruptions.

Skin rash and good performance status predict improved survival with gefitinib in patients with advanced non-small cell lung cancer

BACKGROUND

Gefitinib (Iressa) is active as a single agent in the treatment of select patients with recurrent non-small cell lung cancer (NSCLC). The clinical characteristics of patients treated with gefitinib on an Expanded Access Program (EAP) at our institution identified predictive variables associated with better outcome.

PATIENTS AND METHODS

Patients (n=199) with advanced NSCLC were treated with gefitinib (250 mg) upon progression with chemotherapy. Baseline patient characteristics were: median age, 69 years; males, 57%; adenocarcinoma, 56%.

RESULTS

Partial responses were noted in two patients (1%) and disease stabilization in 66 (35%) patients. The median survival (MS) was 5.9 months [95% confidence interval (CI) 4.1-7.1] and median time to progression was 3 months (95% CI 2.0-3.0). The predictive factors analyzed were gender, skin rash, diarrhea, tumor histology and performance status (PS). Patients who developed skin rash (any grade) had MS of 10.8 months versus 4.0 months for those without rash (P <0.0001, log rank test). Patients with PS 0, 1 and 2 had MS of 8.4, 6.2 and 2.8 months, respectively (P <0.0002). The other factors did not impact survival.

CONCLUSIONS

Occurrence of skin rash and baseline PS of 0/1 were associated with improved survival with gefitinib for recurrent NSCLC patients at our institution.

Treatment for pancreatic cancer: current therapy and continued progress

In the last decade, continued efforts in pancreas cancer research have led to the development of new, more effective therapies. Additionally, progress in understanding the molecular processes underlying the development and progression of this disease provides hope for the development of more effective treatment strategies. Recent clinical trials have provided reason for hope that novel chemotherapy combinations and molecularly targeted agents will lead to improved clinical outcomes for patients with this disease. This article will summarize the data that has led to the current standards of therapy for patients with resectable and advanced pancreatic cancer and review new treatment strategies for this disease.

A Fully Human Recombinant IgG-like Bispecific Antibody to Both the Epidermal Growth Factor Receptor and the Insulin-like Growth Factor Receptor for Enhanced Antitumor Activity

Both the epidermal growth factor receptor (EGFR) and the insulin-like growth factor receptor (IGFR) have been implicated in the tumorigenesis of a variety of cancers. Here we propose that simultaneous targeting of both receptors with a bispecific antibody would lead to enhanced antitumor activity. To this end, we produced a recombinant human IgG-like bispecific antibody, a Di-diabody, using the variable regions from two antagonistic antibodies: IMC-11F8 to EGFR and IMC-A12 to IGFR. The Di-diabody binds to both EGFR and IGFR and effectively blocked both EGF- and IGF-stimulated receptor activation and tumor cell proliferation. The Di-diabody also inherited the biological properties from both of its parent antibodies; it triggers rapid and significant IGFR internalization and degradation and mediates effective antibody-dependent cellular cytotoxicity in a variety of tumor cells. Finally, the Di-diabody strongly inhibited the growth of two different human tumor xenografts in vivo. Our results underscore the benefits of simultaneous targeting of two tumor targets with bispecific antibodies.

Impact of EGFR expression on colorectal cancer patient prognosis and survival

BACKGROUND

Epidermal growth factor receptor (EGFR) is overexpressed in many types of cancers, especially colorectal cancer (CRC), and seems to reflect more aggressive histological and clinical behaviors. The aim of this study was to evaluate EGFR immunohistochemical reactivity in CRC biopsies, and to analyze its relationship with various histological and clinical characteristics and survival.

PATIENTS AND METHODS

A composite EGFR score, obtained by multiplying the grade (% positive cells) by the intensity of labeling (0-9) was used to define patients with low or high EGFR expression whose clinicopathological features were then compared. Univariate tests and multivariate Cox proportional hazards model were applied for data analysis.

RESULTS

Tissue sections from 150 CRC patients with a median follow-up of 40 months were examined. Median patient age at diagnosis was 70 years (range 38-89 years). EGFR reactivity was positive for 143 patients (97%) and high for 118 (80%). According to multivariate analysis, EGFR overexpression was significantly associated with tumor stage, with a higher percentage of EGFR overexpression in T3 than T4 (P=0.003) and not with overall survival.

CONCLUSIONS

EGFR was overexpressed in this CRC patient population and was significantly associated with TNM (tumor-node-metastasis) stage T3. In the context of a new therapeutic strategy using EGFR-targeted therapies, although EGFR remains a controversial prognostic factor, this expression-stage association may play a crucial role in a decision to initiate an adjuvant treatment.

Epidermal growth factor receptor dynamics influences response to epidermal growth factor receptor targeted agents

Analysis of gene expression of cancer cell lines exposed to erlotinib, a small molecule inhibitor of the epidermal growth factor receptor (EGFR), showed a marked increase in EGFR mRNA in resistant cell lines but not in susceptible ones. Because cetuximab induces EGFR down-regulation, we explored the hypothesis that treatment with cetuximab would interfere with erlotinib-induced EGFR up-regulation and result in antitumor effects. Exposure of the resistant biliary tract cancer cell line HuCCT1 but not the susceptible A431 epidermoid cell line to erlotinib induced EGFR mRNA and protein expression. Combined treatment with cetuximab blunted the erlotinib-induced EGFR up-regulation and resulted in inhibition of cell proliferation and apoptosis in the HuCCT1 cells. Blockage of erlotinib-induced EGFR synthesis in HuCCT1 cells by small interfering RNA resulted in identical antitumor effects as cetuximab, providing mechanistic specificity. In mice xenografted with A431, HuCCT1, and the pancreatic cancer cell line Panc430, maximal growth arrest and decrease in Ki67 proliferation index were documented with combined therapy, and EGFR down-regulation was observed in cetuximab-treated tumors. These results may indicate that resistance to EGFR kinase inhibition may be, at least in part, mediated by a highly dynamic feedback loop consisting of up-regulation of the EGFR upon exposure to EGFR kinase inhibitors. Abrogation of this response by small interfering RNA-mediated EGFR mRNA down-regulation and/or by cetuximab-mediated protein clearance induced tumor arrest across several cancer models with different EGFR expression levels, suggesting that resistance and sensitivity are dynamic events where proportional decrease in the target rather than absolute content dictates outcome.

Gastrointestinal cancer: recent developments in medical oncology

BACKGROUND

Progress in the medical oncological treatment of gastrointestinal cancer has resulted from advances in tumour biology as well as randomised clinical trials. This review updates oncologists on developments in perioperative therapy for gastrointestinal tumours, optimal use of chemotherapy for colorectal cancer, and novel targeted monoclonal antibodies (mAbs).

METHODS

The recent literature, including published abstracts, was reviewed with respect to current and developing treatments for gastrointestinal cancers. Emphasis was given to randomised clinical trials published within the last 5 years.

RESULTS

Randomised evidence exists to support the use of pre-operative chemotherapy in patients with resectable oesophageal cancer and pre-operative chemo-radiotherapy for rectal cancer. There is preliminary randomised evidence to support the use of perioperative chemotherapy for gastric cancer. Adjuvant therapy for pancreatic cancer has been shown to improve survival. Improved disease-free survival for colorectal cancer patients treated with either adjuvant capecitabine or oxaliplatin has been demonstrated. MAbs targeting epidermal growth factor receptor and vascular endothelial growth factor have been shown to improve outcomes in patients with advanced colorectal cancer.

CONCLUSIONS

Multidisciplinary strategies for patients with localised gastrointestinal cancers; and improved systemic therapies for patients with advanced disease are leading to superior patient outcomes. Further improvements are required, and targeted agents may contribute to future progress.

Multicenter, phase II study of cetuximab in combination with carboplatin in patients with recurrent or metastatic nasopharyngeal carcinoma

PURPOSE

To evaluate efficacy and toxicity of cetuximab plus carboplatin in recurrent or metastatic nasopharyngeal carcinoma (NPC) resistant to platinum treatment.

PATIENTS AND METHODS

A multicenter, open-label, single-arm, phase II study in patients with epidermal growth factor receptor-expressing NPC who progressed on or within 12 months after termination of platinum-based chemotherapy for recurrent or metastatic disease. Cetuximab was administered at an initial dose of 400 mg/m2 followed by weekly doses of 250 mg/m2. Carboplatin area under the curve 5 was administered every 3 weeks up to a maximum of eight cycles.

RESULTS

Sixty patients were enrolled (46 males, 14 females; median age, 44.5 years; range, 23 to 64 years), and all patients were included in the intent-to-treat and safety analyses. Of the 59 patients assessable for efficacy, there were seven partial responses (11.7%), 29 patients (48.3%) with stable disease, and 23 patients (38.3%) with progressive disease, giving an overall response rate of 11.7% (95% CI, 4.8% to 22.6%). The median time to progression was 81 days in all patients and was longest in the group of patients with a confirmed response (173 days). The median overall survival time was 233 days in all patients. Six patients (10%) experienced serious treatment-related adverse events. Grade 3 or 4 toxicities occurred in 31 patients (51.7%); of these patients, only 19 (31.7%) were considered to have toxicity related to cetuximab.

CONCLUSION

Cetuximab in combination with carboplatin demonstrates clinical activity and an acceptable safety profile in heavily pretreated patients with recurrent or metastatic NPC who had previously experienced treatment failure with platinum-based therapy.

Reversing resistance to targeted therapy

The development of molecular targeted anticancer drugs is rapidly changing cancer therapeutics. However, drug resistance to these novel agents remains a real clinical concern. Reports now indicate that resistance to many of these molecular targeted agents--including hormone therapies, trastuzumab, imatinib, and gefitinib--occurs via common resistance mechanisms. These include 1) inadequate target blockade due to sub-optimal drug delivery; 2) altered target expression at the DNA (gene amplification), mRNA or protein level; 3) an altered target such as a mutated kinase domain; 4) modified target regulating proteins (e.g. altered expression of co-activators and/or co-repressors for nuclear steroid hormone receptors); 5) signalling by alternative proteins (functional redundancy) or different signalling pathways. It is envisioned that the molecular evaluation of clinical anticancer drug resistance, which requires the detailed study of pharmacokinetics, pharmacogenetics and pharmacodynamics, will allow the development of rational reversal strategies and improved patient outcome.

Strategies for multiple signalling inhibition

Cancer cells hyperactivate signalling molecules, including EGFR, Akt and the angiogenic factor VEGF to escape apoptosis, thus contributing also to resistance to treatment. While single signalling inhibitors have produced limited advantages in clinical trials, their combination with conventional treatments is more effective; however, the rate of responses is generally around 20%. A major limitation is represented by the activation of escape pathways, due to an intensive cross-talk and redundancy of signals in the transduction network. A novel and more rational approach is the combination of multiple signalling inhibitors, according to the molecular context of disease, in combination with selected conventional treatments.

Clinical experience with monoclonal antibodies to epidermal growth factor receptor

Recent knowledge about the intermediate steps and final consequences of ligand-dependent epidermal growth factor receptor (EGFR) activation has clearly supported the notion that EGFR plays a fundamental role in regulating the proliferation and survival of malignant neoplasms. Among the rationally designed target-based therapeutics that are being assessed, those targeting EGFR appear to be some of the most clinically relevant. The strategy of using monoclonal antibodies (mAbs) to block ligand binding to the extracellular domain of the EGFR has led to the development of therapeutics that robustly arrest malignant cell proliferation and, in some cases, induce profound tumor regression. The chimeric mAb against EGFR, cetuximab, has already been approved by regulatory agencies worldwide to treat patients with advanced colorectal cancer. Other mAbs against EGFR, particularly panitumumab (ABX-EGF), h-R3, and EMD72000, are in advanced stages of clinical development.

Cetuximab in the treatment of colorectal cancer

The role of epidermal growth factor receptor (EGFR)-driven signaling in different stages of colorectal carcinogenesis, as well in the acquisition of therapy resistance, has been established. Multiple strategies have been developed for the therapeutic targeting of EGFR. Cetuximab is a chimeric monoclonal antibody selective for EGFR with efficacy alone or in combination with irinotecan in the treatment of metastatic colorectal cancer patients, who have progressed to using irinotecan-containing chemotherapy. Cetuximab is well tolerated and does not exacerbate the toxicity of concomitant chemotherapy. Based on this data, the combination of cetuximab with standard chemotherapy regimens such as irinotecan/5-FU/folinic acid (FA) or oxaliplatin/5-FU/FA are currently being investigated in Phase III trials for chemotherapy-naive patients with metastatic colorectal cancer.

An Overview of Approaches to Adjuvant Therapy for Colorectal Cancer in the United States

Adjuvant chemotherapy for colon cancer and combined chemotherapy and radiation therapy (RT) for rectal cancer increases the proportion of patients cured of their disease. Adjuvant chemotherapy is indicated for stage III colon cancer, and although controversial for stage II disease, there is evidence to suggest that these patients may benefit as well. Adjuvant chemotherapy and RT is recommended for patients with stage II/III rectal cancer. Studies incorporating oral fluoropyrimidines as well as combination chemotherapy have been completed, with results demonstrating the value of these approaches. A new generation of studies will evaluate the biologic agents bevacizumab and cetuximab in the adjuvant therapy of colorectal cancer. For rectal cancer, optimal outcomes are dependent not only on the systemic therapy, but also on the expertise of the surgeon and the timing of RT, with improved local control and toxicity seen with preoperative therapy.

Phase I trial of irinotecan, infusional 5-fluorouracil, and leucovorin (FOLFIRI) with erlotinib (OSI-774): early termination due to increased toxicities

PURPOSE

This phase I study was conducted to establish the dose-limiting toxicities and maximum-tolerated dose of erlotinib, an oral epidermal growth factor receptor tyrosine kinase inhibitor, in combination with FOLFIRI, a standard regimen of irinotecan, leucovorin, and infusional 5-fluorouracil (5-FU) in patients with advanced colorectal cancer.

EXPERIMENTAL DESIGN

The trial used a dose-escalation design beginning with 100 mg/day erlotinib continuously and dose-reduced FOLFIRI (150 mg/m2 i.v. day 1 irinotecan, 200 mg/m2 i.v. leucovorin, 320 mg/m2 i.v. bolus days 1 to 2 5-FU, and 480 mg/m2 i.v. 5-FU infusion over 22 hours, days 1 to 2) administered in 6-week cycles (three FOLFIRI treatments). Plasma sampling was performed for irinotecan, erlotinib, and 5-FU for pharmacokinetic analysis during cycle 1.

RESULTS

The study was halted after six patients at the lowest dose level due to unexpectedly severe toxicities, including disfiguring grade 2 rash (three patients), grade 3 diarrhea (three patients), and grade > or = 3 neutropenia (three patients). All patients required some dose interruption or reduction of either erlotinib or FOLFIRI, and only one patient completed two 6-week cycles of therapy. Five patients had stable disease after one cycle, and one patient had a partial response. No plasma pharmacokinetic interaction was observed that could explain the observed increased toxicity.

CONCLUSIONS

FOLFIRI combined with erlotinib causes excessive toxicity at reduced doses. These findings contrast with available data regarding the optimal safety profile of trials combining small molecule epidermal growth factor receptor inhibitors with other conventional chemotherapy and highlight the need to perform safety-oriented studies of such combinations.

Mitomycin-C and capecitabine as third-line chemotherapy in patients with advanced colorectal cancer: a phase II study

PURPOSE

The aim of this study was to investigate the therapeutic value and safety of third-line treatment with mitomycin-C (MMC) and capecitabine (Xeloda) in patients with advanced colorectal cancer pretreated with combination regimens including 5-fluorouracil (5-FU), folinic acid (FA) and irinotecan (CPT-11) or 5-FU, FA and oxaliplatin (L-OHP).

PATIENTS AND METHODS

A total of 21 patients (M/F 16/5, median age 60.0 years) with advanced colorectal cancer, all of whom had developed progressive disease while receiving or within 6 months of discontinuing two sequential chemotherapy lines with 5-FU, FA and CPT-11 or 5-FU, FA and L-OHP, were accrued to this study. At the time of their relapse or progression, cytotoxic chemotherapy, consisting of intravenous MMC 7 mg/m(2) on therapeutic day 1 plus oral capecitabine 1000 mg/m(2) twice daily on days 1-14, was initiated. After rest for 7 days, capecitabine 1000 mg/m(2) twice daily was administered on days 22-35 followed by 7 days rest. Treatment courses were repeated every 6 weeks unless there was evidence of progressive disease, unacceptable toxicity or patient refusal of treatment.

RESULTS

All the patients were assessable for toxicity and 19 for response. The median number cycles of chemotherapy was two (range one to four). Only 1 patient (4.8%) had a partial response, 4 patients (19.0%) had stable disease, and 14 patients (66.7%) progressed. The median follow-up period was 7.3 months and median time to progression was 2.6 months. The median overall survival was 6.8 months. No toxic deaths occurred. Toxicities of third-line treatment were mild and manageable. As NCI/NIH common toxicity criteria, grade 3/4 anemia, neutropenia and thrombocytopenia occurred in two, one and one patients, respectively.

CONCLUSION

Our findings suggest that the combination of MMC and capecitabine in patients with advanced colorectal cancer pretreated with combination regimens including 5-FU, FA and CPT-11 or 5-FU, FA and L-OHP is safe. However, this regimen had a poor response rate and no definitive contribution to increasing patients' overall survival time. Further evaluation of other salvage regimens seems to be warranted.

Adjuvant therapy of colon cancer

Although surgical resection is still the only curative maneuver in the treatment of colon cancer, efforts of the past decades have proved that systemic chemotherapy in the adjuvant setting definitely improves the curative rate for those patients with localized colon cancer. The combination of the 5-fluorouracil (5-FU) and leucovorin (LV) remains the reference treatment. However, the advantage of infusional 5-FU/LV with oxaliplatin (FOLFOX) as adjuvant treatment may change the paradigm soon. Capecitabine may be considered as an alternative to 5-FU/LV in the adjuvant therapy of stage III colon cancer. The clinical benefit of adjuvant chemotherapy for localized node negative (stage II) disease is definite but small, even though there is yet no universal consensus. Novel molecular and biologic-oriented agents are being studied. Further analysis and definition of prognostic and predictive markers may allow future adjuvant therapy to be individualized.

The epidermal growth factor receptor as a target for colorectal cancer therapy

The epidermal growth factor receptor (EGFR) is the prototypical member of the erbB receptor family. The EGFR axis is activated by a variety of ligands that are crucial in the formation and propagation of many tumors, including colorectal cancer, through their effects on cell signaling pathways, cellular proliferation, control of apoptosis, and angiogenesis. The importance of the EGFR axis in tumorigenesis and tumor progression makes it an attractive target for the development of anticancer therapies. A variety of targeting strategies to exploit the role of EGFR in tumors have been employed. The most highly developed of these anti-EGFR approaches are the monoclonal antibodies and the tyrosine kinase inhibitors (TKIs). Clinical evaluations of these compounds have yielded some promising results. The role of the EGFR axis in colorectal cancer formation and progression is reviewed and the clinical development of these anticancer EGFR-targeted drugs is reviewed and updated.