Randomized, double-blind trial of carboplatin and paclitaxel with either daily oral cediranib or placebo in advanced non-small-cell lung cancer: NCIC clinical trials group BR24 study

PURPOSE This phase II/III double-blind study assessed efficacy and safety of cediranib with standard chemotherapy as initial therapy for advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Paclitaxel (200 mg/m(2)) and carboplatin (area under the serum concentration-time curve 6) were given every 3 weeks, with daily oral cediranib or placebo at 30 mg (first 45 patients received 45 mg). Progression-free survival (PFS) was the primary outcome of the phase II interim analysis; phase III would proceed if the hazard ratio (HR) for PFS < or = 0.77 and toxicity were acceptable. Results A total of 296 patients were enrolled, 251 to the 30-mg cohort. The phase II interim analysis demonstrated a significantly higher response rate (RR) for cediranib than for placebo, HR of 0.77 for PFS, no excess hemoptysis, and a similar number of deaths in each arm. The study was halted to review imbalances in assigned causes of death. In the primary phase II analysis (30-mg cohort), the adjusted HR for PFS was 0.77 (95% CI, 0.56 to 1.08) with a higher RR for cediranib than for placebo (38% v 16%; P < .0001). Cediranib patients had more hypertension, hypothyroidism, hand-foot syndrome, and GI toxicity. Hypoalbuminemia, age > or = 65 years, and female sex predicted increased toxicity. Survival update (N = 296) 10 months after study unblinding favored cediranib over placebo (median of 10.5 months v 10.1 months; HR, 0.78; 95% CI, 0.57 to 1.06; P = .11). Causes of death in the cediranib 30-mg cohort were NSCLC (81%), protocol toxicity +/- NSCLC (13%), and other (6%); for the placebo group, they were 98%, 0%, and 2%, respectively. CONCLUSION The addition of cediranib to carboplatin/paclitaxel results in improved response and PFS, but does not appear tolerable at a 30-mg dose. Consequently, the National Cancer Institute of Canada Clinical Trials Group and the Australasian Lung Cancer Trials Group initiated a randomized, double-blind, placebo-controlled trial of cediranib 20 mg with carboplatin and paclitaxel in advanced NSCLC.

Phase I and Pharmacokinetic Study of Daily Oral AZD2171, an Inhibitor of Vascular Endothelial Growth Factor Tyrosine Kinases, in Combination With Carboplatin and Paclitaxel in Patients With Advanced Non–Small-Cell Lung Cancer: The National Cancer Institute of Canada Clinical Trials Group

Purpose

AZD2171 is a potent inhibitor of vascular endothelial growth factor receptors that showed broad antitumor activity in preclinical models. Doses of up to 45 mg/d of AZD2171 are tolerable when administered alone. This study evaluated escalating doses of AZD2171 in combination with standard chemotherapy in patients with advanced non–small-cell lung cancer.

Patients and Methods

Eligible patients received carboplatin targeted to an area under the concentration time curve of 6 mg · min/mL and paclitaxel 200 mg/m2, both on day 1 of a 3-week cycle; daily oral AZD2171 at either 30 mg or 45 mg commenced day 2 of cycle 1. Pharmacokinetics of all drugs were performed, and tumor response was assessed by Response Evaluation Criteria in Solid Tumors (RECIST).

Results

Twenty patients were enrolled. No dose-limiting toxicities were observed during cycle 1 at either dose. Fatigue, diarrhea, anorexia, and granulocytopenia were common; hypertension was manageable with a treatment algorithm designed for this protocol. No clinically significant drug-related bleeding was observed. At 45 mg/d, fatigue and diarrhea were increased, and headache and hoarseness were observed. Paclitaxel clearance decreased during cycle 2, but no other significant pharmacokinetic interactions were observed. After radiology review, confirmed responses were observed in nine patients (response rate, 45%; 95% CI, 23% to 68%); all but one enrolled patient showed evidence of tumor shrinkage, some with cavitation.

Conclusion

AZD2171 can be combined with standard doses of carboplatin/paclitaxel with encouraging antitumor activity. Toxicity is increased, but predictable and manageable.

Tyrosine kinase inhibitors and anti-angiogenic therapies in kidney cancer

Renal cell carcinoma (RCC) is a heterogeneous disease as reflected in its presentation and clinical course, pathological subtypes, nuclear grades and molecular biology. Emerging data indicate that renal tumors express a variety of molecular tumor markers and unique patterns of gene expression. Clinically the disease behaves quite heterogeneously, with courses ranging from indolent to highly aggressive. Surgical monotherapy or as part of a multimodal approach remains the standard of care for most cases of RCC. Radical or partial nephrectomy is associated with a 5-year cancer specific survival (CSS) of 85-97% for pT1 tumors. Unfortunately, 20% of patients have either locally advanced or node positive (N+) RCC while another 22% have metastatic RCC (mRCC) at presentation. Unlike the outcomes in early localized disease, survival rates for N+ patients are poor and patients with mRCC are rarely cured despite aggressive multimodal therapy. Classic cytotoxic chemotherapy has repeatedly been shown to have little effect and only 5-20% of patients with mRCC respond to immunologic agents such as interferon and/or interleukin. Cytoreductive nephrectomy with systemic immunotherapy is associated with few cures with median survivals of 12-24 months. Recent advances in our understanding of the molecular origins and pathways of RCC have led to the development of more effective targeted therapies. Here we review the molecular pathways that define the pertinent therapeutic targets in RCC and the clinical data for these new and promising agents.

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 potential of antiangiogenic therapy in non-small cell lung cancer

The long-term prognosis for patients with advanced non-small cell lung cancer (NSCLC) remains poor despite the availability of several cytotoxic chemotherapy regimens. The use of targeted therapies, particularly those against the key mediator of angiogenesis vascular endothelial growth factor (VEGF), has the potential to improve outcomes for NSCLC patients. Bevacizumab, a recombinant humanized monoclonal anti-VEGF antibody, is the most clinically advanced antiangiogenic agent in NSCLC. In a phase III study, bevacizumab showed significantly improved overall and progression-free survival when used in combination with standard first-line chemotherapy in patients with advanced NSCLC. Bevacizumab was generally well tolerated in patients with NSCLC; however, tumor-related bleeding adverse events have been noted in some patients, predominantly those with squamous cell histology or centrally located tumors. Several small-molecule VEGF receptor tyrosine kinase inhibitors have also shown promise in phase I and II trials in NSCLC. This review summarizes the most important findings of angiogenesis inhibitors in NSCLC and discusses the potential for the use of these novel agents in different settings of NSCLC.

VEGF/VEGFR signalling as a target for inhibiting angiogenesis

VEGFs and a respective family of tyrosine kinases receptors (VEGFRs) are key proteins modulating angiogenesis, the formation of new vasculature from an existing vascular network. There has been considerable evidence in vivo, including clinical observations, that abnormal angiogenesis is implicated in a number of disease conditions, which include rheumatoid arthritis, inflammation, cancer, psoriasis, degenerative eye conditions and others. Antiangiogenic therapies based on inhibition of VEGF/VEGFR signalling were reported to be powerful clinical strategies in oncology and ophthalmology. Current efforts have yielded promising clinical data for several antiangiogenic therapeutics. In this review, the authors elucidate key aspects of VEGFR signalling, as well as clinically relevant strategies for the inhibition of VEGF-induced angiogenesis, with an emphasis on small-molecule VEGFR inhibitors.