977 Phase I/II trial evaluating blockade of tumour blood supply and tumour cell proliferation with combined bevacizumab and erlotinib HCl as targeted cancer therapy in patients with recurrent non-small cell lung cancer

Targeted therapy: an evolving world of lung cancer

Lung cancer remains one of the most fatal illnesses. Recent development in cancer genomics and molecular targeted therapy leads to a paradigm shift in management of advanced-stage non-small cell lung cancer. Patients with activated mutation of epidermal growth factor receptor (EGFR) responded dramatically to EGFR tyrosine kinase inhibitor such as gefitinib or erlotinib. Multiple randomized studies have showed EGFR tyrosine kinase inhibitor to be superior to standard first-line chemotherapy in this biomarker-selected population. As the vasculature is considered to be the 'Achillus heel' of the tumour, anti-angiogenic treatment is considered to be a suitable target. Inhibition of vascular endothelial growth factor may improve the efficacy of chemotherapy, although a practical biomarker has not been identified. We have entered an era of personalized therapy for lung cancer and this evolvement holds great promises for better treatment in future.

Translational therapies for malignant pleural mesothelioma

Malignant pleural mesothelioma is a highly invasive tumor arising from the mesothelial cells of serosal surfaces. Several chemotherapeutic agents have been tested for the treatment of this disease and doublet cisplatin with antifolates has been demonstrated to have significant efficacy in Phase III studies. However, the benefit of these treatments remains poor and the median survival time of patients is low, ranging between 9 and 17 months. Targeted therapies are being developed in oncology and emerging evidence suggests that they offer disease control in several tumors. This article reviews the knowledge on the malignant pleural mesothelioma molecular pathway and focuses on results of clinical trials conducted on this devastating disease.

Combination of sunitinib, cetuximab and irradiation in an orthotopic head and neck cancer model

BACKGROUND

Recent preclinical and clinical studies indicate beneficial effects from combining radiotherapy with either anti-angiogenic drugs or anti-epidermal growth factor receptor (EGFR)-targeting agent. To investigate the effect of combining these approaches, we evaluated in vivo the antitumor efficacy of the anti-angiogenic compound sunitinib, an oral, multi-targeted tyrosine kinase inhibitor that inhibits among others vascular endothelial growth factor (VEGF) receptors-1, -2 and -3, cetuximab, a mAb targeting the EGFR, and irradiation (RT) given alone and in combination.

MATERIALS AND METHODS

Investigations were carried out using a VEGF-secreting human head and neck tumor cell line, CAL33, with a high EGFR content, growing as orthotopic xenografts in nude mice. Three days after tumor cell injection, sunitinib (20 mg/kg, p.o.), cetuximab (1 mg/kg, i.p.), both 5 days/week seven doses, and RT (6 Gy, 3 days/week, four doses) were administered alone and in combination during 9 days.

RESULTS

Concomitant administration of drugs produced a marked and significant supra-additive decrease, and the addition of RT completely abolished tumor growth. The drug association markedly reduced tumor cell proliferation (Ki67) and the number of the vessels, but enhanced cell differentiation.

CONCLUSION

The efficacy of this combination of sunitinib, cetuximab and RT may be of clinical importance in the management of head and neck cancer patients.

Combined effects of bevacizumab with erlotinib and irradiation: a preclinical study on a head and neck cancer orthotopic model

Clinical benefit has been demonstrated in patients with head and neck tumours receiving an anti-epidermal growth factor receptor (EGFR) agent in combination with radiotherapy (RT). Recent preclinical and clinical studies suggest beneficial effects from combining anti-angiogenic drugs with RT. To investigate the effect of combining these approaches, we evaluated in vivo the anti-tumour efficacy of the anti-angiogenic compound bevacizumab, a highly specific monoclonal antibody directed against the vascular endothelial growth factor (VEGF), erlotinib, an EGFR tyrosine kinase inhibitor, and irradiation given alone and in combination. Investigations were performed using a VEGF-secreting human head and neck tumour cell line, CAL33, with a high EGFR content, injected as orthotopic xenografts into the mouth floor of nude mice. Three days after tumour cell injection, bevacizumab (5 mg kg(-1), 5 days a week, i.p.), erlotinib (100 mg kg(-1), 5 days a week, orally) and irradiation (6 Gy, 3 days a week) were administered alone and in combination for 10 days. As compared with the control, concomitant administration of drugs produced a marked and significant supra-additive decrease in tumour mass; the addition of irradiation almost completely abolished tumour growth. The drug association markedly reduced the number of metastatic nodes and the triple combination significantly reduced the total number of pathologically positive lymph nodes as compared with controls. The RT-induced proliferation, reflected by Ki67 labelling, was reduced to control level with the triple combination. Radiotherapy induced a strong and very significant increase in tumour angiogenesis, which was no longer observed when combined with erlotinib and bevacizumab. The efficacy of the combination of bevacizumab+erlotinib and RT may be of clinical importance in the management of head and neck cancer patients.

Bevacizumab in non small cell lung cancer

Angiogenesis, the growth of new vessels from preexisting vessels, is a fundamental step in tumor growth and progression. Vascular endothelial growth factor (VEGF) is a key angiogenic factor implicated in tumor blood vessel formation and permeability. Overexpression of VEGF has been observed in a variety of cancers and has been associated with a worse relapse-free and overall survival. The antiangiogenic agent bevacizumab, a monoclonal antibody directed against VEGF, has shown clinical benefit in multiple cancers, including non-small cell lung cancer (NSCLC). Based on the favorable results of a prior randomized, phase II trial, the Eastern Cooperative Oncology Group conducted a trial (E4599) to evaluate the efficacy of bevacizumab in combination with paclitaxel and carboplatin in patients with recurrent or advanced stage IIIB or IV nonsquamous cell NSCLC. Exclusion criteria included squamous cell histology, brain metastases, significant hemoptysis, or inadequate organ function or performance status >1. The primary study end point was overall survival. The median duration of survival in the chemotherapy plus bevacizumab group was 12.3 months compared with 10.3 months in the chemotherapy alone group (P = 0.003). Significant bleeding was more frequent in the chemotherapy plus bevacizumab group, 4.4% compared with 0.9% (P = 0.001). There were 15 treatment-related deaths in the chemotherapy plus bevacizumab group, including 5 due to pulmonary hemorrhage. Future and current directions include evaluation of bevacizumab in earlier stages of NSCLC, in SCLC, and in combination with other targeted agents, such as erlotinib.

Dual inhibition of EGFR and VEGFR pathways in combination with irradiation: antitumour supra-additive effects on human head and neck cancer xenografts

The aim of this study was to investigate the effects of combining antiangiogenic treatment, epidermal growth factor receptor (EGFR) targeting and irradiation (RT). We evaluated AZD2171, a highly potent, orally active, vascular endothelial growth factor (VEGF) signalling inhibitor, gefitinib, an EGFR tyrosine kinase inhibitor and RT. The antitumour efficacy of these treatments, administered alone and in combination for 2 weeks, was assessed in a VEGF-secreting human head and neck tumour cell line, CAL33 that highly expresses EGFR, established as xenografts (250 mm(3)) in nude mice. The median time to reach a tumour volume of 1000 mm(3) was significantly increased for AZD2171 or gefitinib alone compared with the control. Greater inhibition of tumour growth was seen with the combination of AZD2171+gefitinib compared with either drug alone, and the triple combination compared with either AZD2171+gefitinib or RT alone. The intensity of endothelial cell staining was slightly reduced by each agent given alone, and markedly diminished by the double or triple combination. The triple combination almost completely abolished cell proliferation. The marked RT-induced enhancement in the DNA-repair enzyme ERCC1 expression was totally abolished by the triple combination. This observation could help to explain the supra-additive antitumour effect produced by this combination and could provide a basis for future innovative clinical trials.

Combining targeted agents: blocking the epidermal growth factor and vascular endothelial growth factor pathways

Bevacizumab is a recombinant, humanized monoclonal antibody against vascular endothelial growth factor. Erlotinib HCl is a reversible, highly selective epidermal growth factor receptor tyrosine kinase inhibitor. Additionally, both agents have shown benefit in patients with previously treated non-small cell lung cancer (NSCLC). Preclinical data in xenograft models produced greater growth inhibition with the combination than with either agent alone. A phase I/II study in two centers examined combined erlotinib and bevacizumab treatment in patients with nonsquamous stage IIIB/IV NSCLC with one or more prior chemotherapy. In phase I, 150 mg/d erlotinib orally plus 15 mg/kg bevacizumab i.v. every 21 days was established as the phase II dose. A total of 40 patients were enrolled and treated in this study (34 patients at phase II dose): 21 were female, 30 had adenocarcinoma histology, 9 were never smokers, and 22 had two or more prior regimens. The most common adverse events were mild to moderate rash, diarrhea, and proteinuria. Preliminary data showed no pharmacokinetic interaction between erlotinib and bevacizumab. Eight patients (20.0%) had partial responses and 26 (65.0%) had stable disease as their best response. The median overall survival for the 34 patients treated at the phase II dose was 12.6 months, with progression-free survival of 6.2 months. Encouraging antitumor activity and safety of erlotinib plus bevacizumab support further development of this combination for patients with advanced NSCLC. A randomized phase II trial has been completed, and a phase III trial is ongoing.

A review of erlotinib and its clinical use

Erlotinib is an orally available, reversible tyrosine kinase inhibitor of the epidermal growth factor receptor. Encouraging activity as a single agent and in combination with other targeted agents has been demonstrated in Phase II trials in many tumour types. Erlotinib has an established role in the treatment of advanced, refractory non-small cell lung cancer-based on a pivotal trial demonstrating a survival advantage over best supportive care. In a Phase III trial, the addition of erlotinib to gemcitabine improved survival in advanced pancreatic cancer. The toxicity profile of erlotinib includes diarrhoea and rash, with no haematological side effects. Predictive factors for response include the presence of a rash, epidermal growth factor receptor expression and mutation status. This article reviews the current clinical status of erlotinib.

Phase I/II trial evaluating the anti-vascular endothelial growth factor monoclonal antibody bevacizumab in combination with the HER-1/epidermal growth factor receptor tyrosine kinase inhibitor erlotinib for patients with recurrent non-small-cell lung cancer

PURPOSE

Bevacizumab (Avastin; Genentech, South San Francisco, CA) is a recombinant, humanized anti-vascular endothelial growth factor monoclonal antibody. Erlotinib HCl (Tarceva, OSI-774; OSI Pharmaceuticals, New York, NY) is a potent, reversible, highly selective and orally available HER-1/epidermal growth factor receptor tyrosine kinase inhibitor. Preclinical data in various xenograft models produced greater growth inhibition than with either agent alone. Additionally, both agents have demonstrated benefit in patients with previously treated non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

A phase I/II study in two centers examined erlotinib and bevacizumab (A+T) in patients with nonsquamous stage IIIB/IV NSCLC with > or = one prior chemotherapy. In phase I, erlotinib 150 mg/day orally plus bevacizumab 15 mg/kg intravenously every 21 days was established as the phase II dose, although no dose-limiting toxicities were observed. Phase II assessed the efficacy and tolerability of A+T at this dose. Pharmacokinetic parameters were evaluated. ResultsForty patients were enrolled and treated in this study (34 patients at phase II dose); the median age was 59 years (range, 36 to 72 years), 21 were female, 30 had adenocarcinoma histology, nine were never-smokers, and 22 had > or = two prior regimens (three patients had > or = four prior regimens). The most common adverse events were mild to moderate rash, diarrhea, and proteinuria. Preliminary data showed no pharmacokinetic interaction between A + T. Eight patients (20.0%; 95% CI, 7.6% to 32.4%) had partial responses and 26 (65.0%; 95% CI, 50.2% to 79.8%) had stable disease as their best response. The median overall survival for the 34 patients treated at the phase II dose was 12.6 months, with progression-free survival of 6.2 months.

CONCLUSION

Encouraging antitumor activity and safety of A + T support further development of this combination for patients with advanced NSCLC and other solid tumors.

HER1/EGFR-targeted agents: predicting the future for patients with unpredictable outcomes to therapy

Therapeutic agents that target the epidermal growth factor receptor (HER1/EGFR) signal pathway, such as small-molecule tyrosine kinase inhibitors and monoclonal antibodies are now advanced in clinical development and two are already licensed for use. Complete/ongoing phase II studies with these agents clearly demonstrate that a small, but significant proportion of patients respond to HER1/EGFR inhibition. However, with our current understanding of tumour biology and genetics, we cannot explain why some patients respond well and others less so or not at all. These differences may be a result of many factors, such as patients' genotype and phenotype, pharmacological and pharmacokinetic differences between agents or the inherent molecular heterogeneity of tumours. In this article, we explore current strategies to identify patients who respond differently and ways to maximise the clinical benefit of these therapies. This includes defining optimal dose and dosing schedules, identifying appropriate combination partners and finding predictive and surrogate markers of response. The association between HER1/EGFR gene mutations in non-small cell lung cancer (NSCLC) tumours and response to HER1/EGFR-targeted agents is also discussed. This may help us to preselect responsive patients, tailor the dose according to the individual's tolerability, or monitor these agents to optimise/interrupt therapy at an early stage.

Overview of the Current Status of Human Epidermal Growth Factor Receptor Inhibitors in Lung Cancer

Although chemotherapy remains the standard of care for lung cancer, new less toxic drugs are urgently needed. Targeted agents represent a new era in cancer therapy, and non-small-cell lung cancer (NSCLC) is at the forefront of many development programs. An exciting target is the human epidermal growth factor receptor (EGFR, ie, HER1), and agents targeting this receptor, including gefitinib, cetuximab, and erlotinib (OSI-774; Tarceva), are being investigated. These agents have antitumor activity and are less toxic than most therapies. Based on phase II data, gefitinib received US approval for third-line treatment of patients with locally advanced or metastatic NSCLC. Cetuximab is licensed in the United States for patients with metastatic colorectal carcinoma. However, erlotinib, recently approved in the United States for second- and third-line treatment of patients with locally advanced or metastatic NSCLC, is the only agent of this class to improve survival as monotherapy in patients with advanced, refractory NSCLC, as shown in a phase III placebo-controlled trial. Phase III trials of erlotinib and gefitinib combined with chemotherapy were disappointing, which could be the result of drug scheduling, chemotherapy combinations, or other factors. Patient characteristics may also affect outcome, and research is ongoing to identify predictive markers of response to enable patient selection and improve outcome. Recently identified mutations within the HER1/EGFR tyrosine kinase (TK) domain may provide insight into why some patients respond rapidly to HER1/EGFR tyrosine kinase inhibitors. Surrogate markers of efficacy are also being investigated, including rash, which could be used to monitor and optimize antitumor activity. Therefore, although more work is required, data indicate that HER1/EGFR inhibitors will play an important role in treating patients with NSCLC.