An overview of the optimal planning, design, and conduct of phase I studies of new therapeutics

Phase I clinical trials represent the first step in bringing promising new treatments from the laboratory to the clinic. Although the importance of phase I clinical trials is widely recognized, there is currently no consensus among the scientific, medical, and statistical communities on how best to do these studies in humans. With the advent of targeted therapies, it has become evident that we need to tailor the design of phase I studies for the particular drug class under investigation and any endpoints that are being defined. The National Cancer Institute (NCI) Investigational Drug Steering Committee (IDSC) provides broad external scientific and clinical input on the design and prioritization of early-phase clinical trials with agents for which the NCI Cancer Therapy Evaluation Program (CTEP) holds an Investigational New Drug (IND) application through the U.S. Food and Drug Administration (FDA). The IDSC has formed a number of task forces and working groups, including the Clinical Trial Design Task Force and the Biomarker Working Group, many with membership from within the IDSC as well as external experts, including participants from academia, the pharmaceutical industry, and regulatory authorities. The Clinical Trials Design Taskforce sponsored a Phase I Workshop with the primary goal being to develop consensus recommendations for the optimal design of phase I studies. The primary focus included (1) efficient trial designs, (2) phase I drug combinations, and (3) appropriate statistical and correlative endpoints. In this CCR Focus series, articles summarize key aspects and recommendations on phase I studies (including combination trials), such as design, use of biomarkers, the European Union and Japanese perspectives on design, requirements for first-in-human and other phase I studies, and ensuring regulatory and International Conference on Harmonization (ICH) compliance. A final article summarizes recommendations for the design and conduct of phase II studies.

Vascular endothelial growth factor receptor tyrosine kinase inhibitors vandetanib (ZD6474) and AZD2171 in lung cancer

Vascular endothelial growth factor (VEGF) is a rational target for advanced non-small cell lung cancer (NSCLC), a hypothesis validated by the recent Eastern Cooperative Oncology Group E4599 trial showing that the addition of the VEGF monoclonal antibody bevacizumab to chemotherapy prolongs overall survival. Several new tyrosine kinase inhibitors targeting the VEGF pathway are currently in advanced clinical development for NSCLC and offer several possible advantages compared with monoclonal antibodies, including oral administration, more flexible dosing, a broader spectrum of target inhibition, and different toxicity profiles. Among these agents, vandetanib (ZD6474), an inhibitor of the VEGF receptor (VEGFR)-2 and epidermal growth factor receptor tyrosine kinase, has been the most extensively studied. In a randomized phase II study of patients with platinum-refractory NSCLC, including squamous histology, vandetanib prolonged progression-free survival compared with gefitinib. In another phase II trial, an improvement in progression-free survival was observed for vandetanib in combination with docetaxel compared with docetaxel alone. AZD2171 is an inhibitor of VEGFR-1, VEGFR-2, and VEGFR-3 and other tyrosine kinases that has shown clinical activity in NSCLC in combination with carboplatin and paclitaxel. Several phase III trials are under way testing these agents either as monotherapy or in combination with chemotherapy in patients with lung cancer. Early results with these agents, and others being tested, raise the possibility that there will eventually be multiple VEGF-targeted therapies available in the clinic that can potentially benefit a broader range of patients with advanced-stage NSCLC.

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.

A review of the latest clinical compounds to inhibit VEGF in pathological angiogenesis

Angiogenesis plays an important role in the formation of new blood vessels and is crucial for tumour development and progression. Imbalance between pro- and antiangiogenesis factors regulates the biological process of angiogenesis. The best characterised of the proangiogenic factors and the most potent is vascular endothelial growth factor (VEGF). The binding of VEGF to one of its transmembrane tyrosine kinase receptors, which are predominantly found on endothelial cells, results in receptor dimerisation, activation and autophosphorylation of the tyrosine kinase domain. This triggers a cascade of complex downstream signalling pathways. Several strategies targeting the VEGF signalling pathway have been developed. These include neutralising antibodies to VEGF (bevacizumab) or VEGF receptors (VEGFRs) (DC101), soluble VEGFR/VEGFR hybrids (VEGF-Trap), and tyrosine kinase inhibitors of VEGFRs (BAY43-9006, SU11248, ZD6474, AZD2171, PTK/ZK and others). Several of these agents are now being investigated in clinical trials.

Angiogenesis inhibitors in the treatment of lung cancer

Despite improvements in cytotoxic chemotherapy and combined modality therapies for lung cancer, the prognosis for patients remains poor, and the majority of patients die from the disease. Angiogenesis, i.e. the formation of new blood vessels, is important for tumor growth, invasion and metastasis and represents a rational target in the development of more effective treatments. The vascular endothelial growth factor (VEGF) signaling pathway plays a crucial role in the angiogenic process and consequently, inhibitors of this system are currently under development. The most studied anti-angiogenic agents include anti-VEGF monoclonal antibodies and VEGF receptor tyrosine kinase inhibitors. Recent clinical trials have yielded promising results. This article will review angiogenesis inhibitors targeting the VEGF pathway which are currently being developed for the treatment of lung cancer.