Kinase Inhibition with BAY 43–9006 in Renal Cell Carcinoma

Development and strategies of VEGFR-2/KDR inhibitors

VEGF is an important signaling protein involved in both vasculogenesis and angiogenesis. As an essential receptor protein tyrosine kinase propagating cellular signal transduction processes, VEGFR-2 is a central target for drug discovery against tumor-associated angiogenesis. Since the autophosphorylation of VEGFR-2 represents a key step in this signal pathway that contributes to angiogenesis, the discovery of small molecule inhibitors that block this reaction has attracted great interest for novel drugs research and development. Advances in the understanding of catalytic cleft and the conformational changes of DFG motif have resulted in the development of small molecule inhibitors known as type I and type II. High-resolution crystal structures of various inhibitors in complex with the receptor offer an insight into the relationship among binding modes, inhibition mechanisms, activity, selectivity and resistance. To control selectivity, improve activity and introduce intellectual property novelty, the strategies for the further development are discussed through structural and conformational analysis in this review.

Giant cavernous hepatic hemangioma shrunk by use of sorafenib

Here we report a case of a 76-year-old man with a giant cavernous hepatic hemangioma of more than 20 cm in diameter. Since the hepatic hemangioma was actually growing and might possibly rupture and he complained of abdominal symptoms, we decided to perform interventional therapy. First we performed transcatheter arterial embolization (TAE) of the hepatic arteries. However, since this was not sufficiently effective, we added sorafenib (600 mg/day). As a result, the tumor shrank with symptomatic improvement. Subsequently, an adverse event occurred, and we suspended the sorafenib therapy. Then, the tumor began to grow, and we resumed administering sorafenib at 400 mg/day. The tumor shrank again, and we continued the sorafenib therapy thereafter. The tumor shrinkage, although possibly induced by the effect of TAE, is considered primarily due to the effect of treatment with sorafenib, because (1) TAE did not sufficiently reduce the blood supply to the inside of the tumor; (2) other tumors shrank in the area not targeted by TAE; and (3) the tumor grew during suspension of sorafenib therapy and shrank again after resuming the treatment.

BRAF (V600E) mutation analysis in papillary thyroid carcinomas by peptide nucleic acid clamp real-time PCR

BACKGROUND

Activating somatic mutation of the BRAF (V600E) has been identified as the most common genetic event in papillary thyroid carcinoma (PTC) with a variable frequency (32-87%) in different series by different methods. The BRAF (V600E) mutation is associated with various clinicopathological parameters. The mutation is an important factor for the management of the PTC patients. The objective of this study was to detect the BRAF (V600E) mutation in PTCs by peptide nucleic acid (PNA) clamp real-time PCR and to analyze the results with clinicopathological parameters.

METHODS

We performed genetic analysis of BRAF (V600E) by PNA clamp real-time PCR in 211 PTCs in Korea, stratified by clinicopathological parameters.

RESULTS

The BRAF (V600E) mutation was detected in 90% of PTC cases, and it occurred significantly more often in female patients than in male patients (p = 0.001). The clinicopathological parameters of age, tumor size, and disease stage were not associated with the BRAF (V600E) mutation, while extrathyroid invasion (p = 0.031), lymph nodal metastasis (p = 0.002), and tumor multiplicity (p = 0.020) were.

CONCLUSIONS

The prevalence (90%) of the BRAF (V600E) mutation in this study is the highest ever reported, confirming the key role of this mutation in PTC tumorigenesis. The BRAF (V600E) mutation was associated with aggressive clinical behaviors including extrathyroid invasion, lymph nodal metastasis and tumor multifocality. The PNA clamp real-time PCR method for the BRAF (V600E) mutation detection is sensitive and is applicable in a clinical setting.

De novo design of N-(pyridin-4-ylmethyl)aniline derivatives as KDR inhibitors: 3D-QSAR, molecular fragment replacement, protein-ligand interaction fingerprint, and ADMET prediction

Vascular endothelial growth factor (VEGF) and its receptor tyrosine kinase VEGFR-2 or kinase insert domain receptor (KDR) have been identified as promising targets for novel anticancer agents. To achieve new potent inhibitors of KDR, we conducted molecular fragment replacement (MFR) studies for the understanding of 3D-QSAR modeling and the docking investigation of arylphthalazines and 2-((1H-Azol-1-yl)methyl)-N-arylbenzamides-based KDR inhibitors. Two favorable 3D-QSAR models (CoMFA with q(2), 0.671; r(2), 0.969; CoMSIA with q(2), 0.608; r(2), 0.936) have been developed to predict the biological activity of new compounds. The new molecular database generated by MFR was virtually screened using Glide (docking) and further evaluated with CoMFA prediction, protein-ligand interaction fingerprint (PLIF) and ADMET analysis. 44 N-(pyridin-4-ylmethyl)aniline derivatives as novel potential KDR inhibitors were finally obtained. In this paper, the work flow developed could be applied to de novo drug design and virtual screening potential KDR inhibitors, and use hit compounds to further optimize and design new potential KDR inhibitors.

Sunitinib in advanced pancreatic neuroendocrine tumors: latest evidence and clinical potential

Based on preclinical data available in the RIP1-Tag2 transgenic mouse model, sunitinib is an inhibitor of angiogenesis in pancreatic neuroendocrine tumors blocking vascular endothelial growth factor receptors and platelet-derived growth factor receptors in endothelial cells and pericytes, respectively. Evidence of objective response in phase I trials justified the initiation of a large phase II/III program using sunitinib in patients with advanced/metastatic well-differentiated pancreatic neuroendocrine tumors. In the phase II study, sunitinib showed potent antitumor activity and a safe toxicity profile. In a recent double-blind placebo-controlled randomized phase III trial, sunitinib doubled the progression-free survival of patients, induced objective responses, and reduced the risk of death of patients with advanced/metastatic well-differentiated tumors. These data allowed the approval of sunitinib in several countries including Europe and the United States of America. These recent data provide hope for patients with well-differentiated pancreatic neuroendocrine tumors and will change standards of care in this disease.

Chemical genetic discovery of targets and anti-targets for cancer polypharmacology

The complexity of cancer has led to recent interest in polypharmacological approaches for developing kinase-inhibitor drugs; however, optimal kinase-inhibition profiles remain difficult to predict. Using a Ret-kinase-driven Drosophila model of multiple endocrine neoplasia type 2 and kinome-wide drug profiling, here we identify that AD57 rescues oncogenic Ret-induced lethality, whereas related Ret inhibitors imparted reduced efficacy and enhanced toxicity. Drosophila genetics and compound profiling defined three pathways accounting for the mechanistic basis of efficacy and dose-limiting toxicity. Inhibition of Ret plus Raf, Src and S6K was required for optimal animal survival, whereas inhibition of the 'anti-target' Tor led to toxicity owing to release of negative feedback. Rational synthetic tailoring to eliminate Tor binding afforded AD80 and AD81, compounds featuring balanced pathway inhibition, improved efficacy and low toxicity in Drosophila and mammalian multiple endocrine neoplasia type 2 models. Combining kinase-focused chemistry, kinome-wide profiling and Drosophila genetics provides a powerful systems pharmacology approach towards developing compounds with a maximal therapeutic index.

Novel small molecule Raf kinase inhibitors for targeted cancer therapeutics

Aberrant activation of Raf signaling pathway is frequently found in various human tumors, it has been considered as distinct and promising molecular target for cancer therapeutics. B-Raf is most attractive drug target out of three Raf isoforms (A-Raf, B-Raf and C-Raf) because it exhibits high kinase activity due to frequent mutations in human tumors. However, most recently, it has been reported that Raf isoforms show the cross-activation in the presence of specific B-Raf inhibitors, which brings about the paradoxical p-ERK activation as well as tumor promoting effect. According to these findings, it remains controversy whether pan-Raf kinase inhibitor is more valuable and promising rather than specific B-Raf inhibitor under certain conditions in terms of cancer therapeutics. In this short review, novel Raf kinase inhibitors undergoing clinical investigation are introduced. Moreover, the paradoxical p-ERK activation is discussed with specific B-Raf inhibitors, PLX4032/4720 compounds.

Detection of BRAF(V600E) Mutations in Papillary Thyroid Carcinomas by Peptide Nucleic Acid Clamp Real-Time PCR: A Comparison with Direct Sequencing

BACKGROUND

Papillary thyroid carcinoma (PTC) of the thyroid is the most common endocrine malignancy. High prevalence of an activating point mutation of BRAF gene, BRAF(V600E), has been reported in PTC. We assessed the efficiency of peptide nucleic acid clamp real-time polymerase chain reaction (PNAcqPCR) for the detection of BRAF(V600E) mutation in PTC in comparison with direct sequencing (DS).

METHODS

A total of 265 thyroid lesions including 200 PTCs, 5 follicular carcinomas, 60 benign lesions and 10 normal thyroid tissues were tested for BRAF(V600E) mutation by PNAcqPCR and DS.

RESULTS

The sensitivity and accuracy of the PNAcqPCR method were both higher than those of DS for the detection of the BRAF(V600E) mutation. In clinical samples, 89% of PTCs harbored the BRAF(V600E) mutation, whereas 5 follicular carcinomas, 50 benign lesions and 10 normal thyroid tissues lacked the mutation. The mutation was associated with aggressive clinical behaviors as extrathyroid invasion (p=0.015), lymph node metastasis (p=0.002) and multiple tumor numbers (p=0.016) with statistical significance.

CONCLUSIONS

The PNAcqPCR method is efficiently applicable for the detection of the BRAF(V600E) mutation in PTCs in a clinical setting.

Randomized study of autologous cytokine-induced killer cell immunotherapy in metastatic renal carcinoma

PURPOSE

The therapeutic benefit of the cytokine-induced killer (CIK) cells was unknown in the renal cell carcinoma (RCC). This prospectively randomized study was conducted to evaluate the effects of autologous CIK cell immunotherapy in patients with metastatic clear cell RCCs.

EXPERIMENTAL DESIGN

From June 2005 to June 2008, 148 patients with metastatic clear cell RCC were randomized to autologous CIK cell immunotherapy (arm 1, n = 74), or interleukin-2 treatment combination with IFN-α-2a (arm 2, n = 74). The primary endpoint was overall survival (OS) and secondary endpoint was progression-free survival (PFS) evaluated by Kaplan-Meier analyses and treatment HRs with the Cox proportional hazards model.

RESULTS

The 3-year PFS and OS in arm 1 were 18% and 61%, as compared with 12% and 23% in arm 2 (P = 0.031 and <0.001, respectively). The median PFS and OS in arm 1 were significantly longer than those in arm 2 (PFS, 12 vs. 8 months, P = 0.024; OS, 46 vs. 19 months, P < 0.001). Multivariate analyses indicated that the cycle count of CIK cell immunotherapy as a continuous variable was significantly associated with prolonged PFS [HR = 0.88; 95% confidence interval (CI), 0.84-0.93; P < 0.001] and OS (HR = 0.58; 95% CI, 0.48-0.69; P < 0.001) in arm 1.

CONCLUSION

The data suggested that CIK cell immunotherapy could improve the prognosis of metastatic clear cell RCC, and increased cycle count of CIK cell treatment could further enhance the beneficial effects.

Enhancing the clinical activity of sorafenib through dose escalation: rationale and current experience

Sorafenib is an oral multitargeted tyrosine and serine/threonine kinase inhibitor approved for the treatment of advanced renal cell and hepatocellular carcinoma. An understanding of its dose-toxicity relationship has paved the way for trials seeking to enhance its clinical activity through the exploration of alternative dosing strategies. In this article, we review the dose-toxicity relationship of sorafenib observed during its phase I and early phase II testing, explore its toxicity profile at the recommended dose and schedule, discuss the evidence for dose escalation to higher levels, and examine the preliminary evidence for clinical activity of this strategy. Owing to a temporal relationship between toxicity and dose, it may be possible in select patients to escalate sorafenib to doses beyond those currently employed. However, because of the potential for increased toxicity, sorafenib dose escalation should currently be performed only in the context of a clinical trial.

Sunitinib therapy for metastatic renal cell carcinoma: recommendations for management of side effects

Sunitinib, a new vascular endothelial growth factor receptor inhibitor, has demonstrated high activity in renal cell carcinoma (RCC) and is now widely used for patients with metastatic disease. Although generally well tolerated and associated with a low incidence of common toxicity criteria grade 3 or 4 toxicities, sunitinib exhibits a distinct pattern of novel side effects that require monitoring and management. This article summarizes the most important side effects and proposes recommendations for their monitoring, prevention and treatment, based on the existing literature and on suggestions made by an expert group of Canadian oncologists. Fatigue, diarrhea, anorexia, oral changes, skin toxicity and hypertension seem to be the most clinically relevant toxicities of sunitinib. Fatigue may be partly related to the development of hypothyroidism during sunitinib therapy for which patients should be observed and, if necessary, treated. Hypertension can be treated with standard antihypertensive therapy and rarely requires treatment discontinuation. Neutropenia and thrombocytopenia usually do not require intervention, in particular no episodes of neutropenic fever have been reported to date. A decrease in left ventricular ejection fraction is a rare, but potentially life-threatening side effect. Because of its metabolism by cytochrome P450 3A4 a number of drugs can potentially interact with sunitinib. Clinical response and toxicity should be carefully observed when sunitinib is combined with either a cytochrome P450 3A4 inducer or inhibitor and doses adjusted as necessary. Knowledge about side effects, as well as the proactive assessment and consistent management of sunitinib-related side effects, is critical to ensure optimal benefit from sunitinib treatment.

Update on new drugs in small cell lung cancer

INTRODUCTION

Small cell lung cancer (SCLC) will account for 25,000 to 32,000 new lung cancer cases in the USA in 2010. Current treatmenta pproaches include platinum-based chemotherapy and etoposide with or without radiation therapy depending on stage and performance status. Five-year survival is approximately 25% for patients with limited stage disease and 1 -- 2% for patients with extensive stage disease and has noti mproved in almost two decades.

AREAS COVERED

This article reviews the results of recent clinical trials that have evaluated targeted agents and novel cytotoxic agents alone or in combination with standard chemotherapy in the treatment of patients with SCLC.

EXPERT OPINION

The lack of a targeted approach to the treatment of patients with SCLC has led investigators to evaluate a multitude of agents with overwhelmingly negative results. A more systematic approach to clinical trials in patients is needed to improve outcomes for patients with this disease.

Harnessing synthetic lethal interactions in anticancer drug discovery

Unique features of tumours that can be exploited by targeted therapies are a key focus of current cancer research. One such approach is known as synthetic lethality screening, which involves searching for genetic interactions of two mutations whereby the presence of either mutation alone has no effect on cell viability but the combination of the two mutations results in cell death. The presence of one of these mutations in cancer cells but not in normal cells can therefore create opportunities to selectively kill cancer cells by mimicking the effect of the second genetic mutation with targeted therapy. Here, we summarize strategies that can be used to identify synthetic lethal interactions for anticancer drug discovery, describe examples of such interactions that are currently being investigated in preclinical and clinical studies of targeted anticancer therapies, and discuss the challenges of realizing the full potential of such therapies.

Evaluation of response to multikinase inhibitor in metastatic renal cell carcinoma by FDG PET/contrast-enhanced CT

PURPOSE

Multikinase inhibitor (MKI) is a promising drug for treatment of metastatic renal cell carcinoma (mRCC). We explained the usefulness of [¹⁸F]-2-fluoro-2-deoxyglucose positron emission tomography/contrast-enhanced computed tomography (FDG PET/CECT) for mRCC in evaluating the early response to MKI and in predicting progression-free survival (PFS).

METHODS

Patients who planned MKI treatment for mRCC were included in this prospective study. FDG PET/CECT was performed before MKI treatment and after one cycle of MKI treatment. Evaluation of the response to MKI was assessed by PET according to the European Organization for Research and Treatment of Cancer, by CT according to the Response Evaluation Criteria in Solid Tumors and appearance of central hypoattenuation (CHA).

RESULTS

Twelve patients were enrolled in the study. Equality of response evaluation between PET and CT was in 8 patients (partial response [PR]: 1, stable disease [SD]: 6, progressive disease [PD]: 1). Among the other 4 patients, PET showed 2 patients with PR and 2 patients with PD, in contrast to the CT finding of SD in all 4 patients. PFS according to PET response showed a statistically significant difference between PR and SD (P < 0.05) and between PR and PD (P < 0.05), but not between PR and SD (P = 0.083). Positive CHA in metastatic lesions after MKI treatment was confirmed in 8 patients. PFS with positive CHA was 233.8 days, while that without CHA was 75.0 days (P < 0.05).

CONCLUSION

FDG PET/CECT shows potential for evaluating early treatment response to MKI in mRCC and for predicting PFS.

The design, synthesis, and evaluation of 8 hybrid DFG-out allosteric kinase inhibitors: a structural analysis of the binding interactions of Gleevec, Nexavar, and BIRB-796

The majority of kinase inhibitors developed to date are competitive inhibitors that target the ATP binding site; however, recent crystal structures of Gleevec (imatinib mesylate, STI571, PDB: 1IEP), Nexavar (Sorafenib tosylate, BAY 43-9006, PDB: 1UWJ), and BIRB-796 (PDB: 1KV2) have revealed a secondary binding site adjacent to the ATP binding site known as the DFG-out allosteric binding site. The recent successes of Gleevec and Nexavar for the treatment of chronic myeloid leukemia and renal cell carcinoma has generated great interest in the development of other kinase inhibitors that target this secondary binding site. Here, we present a structural comparison of the important and similar interactions necessary for Gleevec(R), Nexavar, and BIRB-796 to bind to their respective DFG-out allosteric binding pockets and the selectivity of each with respect to c-Abl, B-Raf, and p38alpha. A structural analysis of their selectivity profiles has been generated from the synthesis and evaluation of 8 additional DFG-out allosteric inhibitors that were developed directly from fragments of these successful scaffolds.

Pharmacologic modulation of niche accessibility via tyrosine kinase inhibition enhances marrow and thymic engraftment after hematopoietic stem cell transplantation

Essential survival signals within hematopoietic stem cell (HSC) and thymic niches are mediated by receptor tyrosine kinases, which can be reversibly inhibited using clinically available drugs. We studied whether sunitinib, a multityrosine kinase inhibitor that inhibits KIT, enhances engraftment after bone marrow transplantation (BMT) in mice. Sunitinib diminished hematopoietic progenitor cell numbers, and sunitinib enhanced marrow, peripheral myeloid, and lymphoid engraftment after BMT in Rag1(-/-) mice. Sunitinib augmented HSC engraftment because recipients displayed increased myeloid and lymphoid engraftment and because sunitinib-treated recipients of purified HSCs showed enhanced engraftment of secondary hosts. However, sunitinib preferentially augmented T-cell engraftment with lesser effects on myeloid and HSC engraftment. Consistent with this, sunitinib preferentially depleted the early thymic progenitor subset in the thymus. Sunitinib did not increase engraftment in mice with deficient KIT signaling, and the pattern of more potent effects on T cell compared with HSC engraftment observed in sunitinib-treated hosts was also observed after BMT into KIT(W/Wv) mice. These results implicate KIT as a critical modulator of thymic niches. We conclude that transient, pharmacologic inhibition of KIT enhances accessibility of marrow and thymic niches, and provides a novel, noncytotoxic approach to accomplish engraftment after stem cell transplantation.

Sorafenib improves the survival of patients with advanced hepatocellular carcinoma: a meta-analysis of randomized trials

There is no effective systemic therapy for patients with advanced hepatocellular carcinoma (HCC) except liver transplantation. Sorafenib, a multikinase inhibitor, has been shown to significantly increase overall survival (OS) in a randomized, placebo-controlled, phase III trial of patients with HCC (SHARP). The aim of this study was to evaluate the effectiveness of sorafenib for advanced HCC by carrying out a meta-analysis of randomized controlled trials that compared sorafenib-based therapy with other agent-based therapy. Randomized controlled trials comparing sorafenib or combined chemotherapy with placebo or combined chemotherapy in advanced HCC between 2000 and 2008 were identified and the data were extracted from reports. Outcomes analyzed were objective response rate, time to progression (TTP), OS, and toxicity. The summary hazard ratios (HRs), odds ratios, and their 95% confidence intervals (CIs) for mortality, objective response rate, and toxicity were estimated. All statistical tests were two-sided. Three trials including 924 patients were identified. Sorafenib-based chemotherapy was also associated with a 79% prolongation of TPP (HR = 0.58, 95% CI = 0.49-0.69, P<0.001), and a 37.3% increase in OS (HR = 0.66, 95% CI = 0.55-0.78, P<0.001). Despite significant increases in the frequencies of hand-foot syndrome and diarrhea in patients receiving sorafenib-containing chemotherapy, no significant difference in other toxic events was observed. This meta-analysis suggests that sorafenib-based chemotherapy is superior to placebo-based chemotherapy in terms of TPP and OS without increase in severe toxic effects.

A review of kinases implicated in pancreatic cancer

The current 5-year survival rate of pancreatic cancer is about 3% and the median survival less than 6 months because the chemotherapy and radiation therapy presently available provide only marginal benefit. Clearly, pancreatic cancer requires new therapeutic concepts. Recently, the kinase inhibitors imatinib and gefitinib, developed to treat chronic myelogenous leukaemia and breast cancer, respectively, gave very good results. Kinases are deregulated in many diseases, including cancer. Given that phosphorylation controls cell survival signalling, strategies targeting kinases should obviously improve cancer treatment. The purpose of this review is to summarize the present knowledge on kinases potentially usable as therapeutic targets in the treatment of pancreatic cancer. All clinical trials using available kinase inhibitors in monotherapy or in combination with chemotherapeutic drugs failed to improve survival of patients with pancreatic cancer. To detect kinases relevant to this disease, we undertook a systematic screening of the human kinome to define a 'survival kinase' catalogue for pancreatic cells. We selected 56 kinases that are potential therapeutic targets in pancreatic cancer. Preclinical studies using combined inhibition of PAK7, MAP3K7 and CK2 survival kinases in vitro and in vivo showed a cumulative effect on apoptosis induction. We also observed that these three kinases are rather specific of pancreatic cancer cells. In conclusion, if kinase inhibitors presently available are unfortunately not efficient for treating pancreatic cancer, recent data suggest that inhibitors of other kinases, involved more specifically in pancreatic cancer development, might, in the future, become interesting therapeutic targets.

Targeted therapy for metastatic renal cell carcinoma: current treatment and future directions

An understanding of vascular endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) pathways has greatly changed the way metastatic renal cell carcinoma (RCC) is treated. Based on available phase III randomized trials, anti-VEGF agents such as sunitinib, sorafenib, bevacizumab-based therapy, and mTOR-targeted agents such as temsirolimus and everolimus have been used in the treatment armamentarium for this disease. Now that agents directed against these pathways have largely replaced immunotherapy as the standard of care, new questions have emerged and are the subject of ongoing clinical trials. The development of new targeted therapies including axitinib, pazopanib, cediranib, volociximab, tivozanib (AV-951), BAY 73-4506, and c-met inhibitors such as GSK1363089 and ARQ197 may potentially expand the list of treatment options. Sequential and combination targeted therapies are currently under investigation in advanced disease as are adjuvant and neo-adjuvant approaches around nephrectomy.

BRAF mutation status in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors characterized by mutations of KIT or PDGFRA. The objectives of this study were to evaluate BRAF mutations in GISTs and then to correlate BRAF mutational status in the tumor with clinical parameters, with B-raf expression, and with activation of some cellular pathways. BRAF mutation was screened in 321 GISTs with 70 wild-type GISTs. BRAF V600E was detected in 9 (13%) of 70 wild-type GISTs. No mutations were detected in GISTs bearing KIT or PDGFRA mutations. BRAF V600E detection in the tumor does not induce a higher expression of the B-raf protein or the preferential activation of the p42/44 mitogen-activated protein kinase (MAPK) signaling pathway compared with GISTs without the BRAF mutation. In comparison with the GIST group with KIT or PDGFRA mutation or the wild-type GIST group without BRAF mutation, the wild-type GIST group with a BRAF mutation is not different in terms of B-raf expression or the p44/42 MAPK- or AKT-activated signaling pathway.

Cutaneous side effects of inhibition of VEGF signal transduction

The VEGF signaling pathway (including ligands, surface-bound receptors and intracellular downstream signaling cascades) is critically involved in angiogenesis under normal and pathological conditions, in particular in malignant tumors. As a consequence, several therapies that target specific components of this pathway have been approved for clinical use or are in various stages of clinical development. Currently, the monoclonal antibodies bevacizumab and ranibizumab, as well as the small-molecule kinase inhibitors sorafenib and sunitinib, have been approved for cancer therapy. The spectrum of cutaneous side effects elicited by bevacizumab is considerably less pronounced than that seen with EGF inhibitors and includes peripheral sensory neuropathy, stomatitis, skin dryness, skin discoloration and exfoliative dermatitis. In contrast, unwanted cutaneous side effects seen with the less specific small molecule compounds include pruritic exanthems, nail changes, cheilitis and the painful hand-foot-syndrome.

Efficacy and safety of sorafenib in patients with advanced renal cell carcinoma with and without prior cytokine therapy, a subanalysis of TARGET

Before the development of targeted therapies, administration of cytokines (e.g., interleukin-2, interferon-alpha) was the primary systemic treatment option for advanced renal cell carcinoma. Sorafenib, an oral targeted, multikinase inhibitor, significantly prolonged progression-free survival and overall survival in the Treatment Approaches in Renal Cancer Global Evaluation Trial (TARGET), a large (N = 903) phase III, double-blind, randomised, placebo-controlled study of patients with advanced renal cell carcinoma resistant to standard therapy. This analysis of a patient subgroup from TARGET evaluated the safety and efficacy of sorafenib in patients who had received prior cytokine therapy (sorafenib: n = 374; placebo: n = 368) and in patients who were cytokine-naïve (sorafenib: n = 77; placebo: n = 84). Progression-free survival was significantly prolonged with sorafenib therapy compared with placebo among patients with and without prior cytokine therapy (respectively 5.5 vs. 2.7 months; hazard ratio, 0.54; 95% confidence interval, 0.45-0.64 and 5.8 vs. 2.8 months; hazard ratio, 0.48; 95% confidence interval, 0.32-0.73). Clinical benefit rates for sorafenib-treated patients compared with placebo patients were also higher (cytokine-treated: 83 vs. 54.3%; cytokine-naïve: 85.7 vs. 56.0%). Sorafenib was well tolerated in both subgroups (grade 3/4: 20 and 22%, respectively). Sorafenib demonstrated a consistent, significant clinical benefit against advanced renal cell carcinoma, with a twofold improvement in progression-free survival and disease control rate, with similar toxicities in patients with or without prior cytokine treatment.

Evaluation of sorafenib treatment in metastatic renal cell carcinoma with 2-fluoro-2-deoxyglucose positron emission tomography and computed tomography

OBJECTIVE

New potent tyrosine kinase inhibitors such as sorafenib are the most effective treatment for metastatic renal cell carcinoma (MRCC) today. In this study, we used [18F]-2-fluoro-2-deoxyglucose (FDG) with positron emission tomography (PET) combined with computed tomography (CT) to evaluate early effects of sorafenib in patients with MRCC.

METHODS

Ten patients, eight males and two females, with a mean age of 61 years (49-72 years), with MRCC were enrolled. A total of 52 lesions, two to nine lesions/patient, out of which 39 were soft lesions, were evaluated. The [18F]FDG-PET/CT was performed before treatment and after 1-2 months. A region of interest (ROI) was identified including the lesions where the glucose uptake was measured, calculating the average value within the ROI and using the cerebellum as the reference. The same ROI was measured in the subsequent FDG-PET. The sum of the diameters was measured in CT according to the Response Evaluation Criteria in Solid Tumors (RECIST). Sorafenib was given 400 mg twice daily orally.

RESULTS

After 1-2 months, the mean glucose uptake in all lesions decreased to 75% (32-105%) of initial values of ROI as measured by FDG-PET. The mean glucose uptake in soft lesions decreased to 71% (32-108%) and in skeletal lesions to 82% (53-101%). The sum of the diameters measured by CT decreased to 80% (57-94%) of the initial value in soft lesions according to the RECIST.

CONCLUSION

An early decrease in the mean glucose uptake was found in both soft and skeletal lesions after treatment with sorafenib. FDG-PET thus seems to be advantageous, compared with RECIST evaluation, which is limited to soft lesions.

Epidermal growth factor receptor inhibitors and antiangiogenic agents for the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is a major global health problem and represents the leading cause of cancer-related deaths worldwide. The majority of patients with NSCLC are diagnosed with advanced-stage disease, and the prognosis for such patients is poor. The currently approved cytotoxic chemotherapy is associated with substantial limitations in both efficacy and safety. The availability of agents targeted against the epidermal growth factor receptor (EGFR), as well as the antiangiogenic agent bevacizumab, have provided some clinical benefit. Nonetheless, the efficacy of these agents is also inadequate, and resistance has emerged as a clinical problem. Numerous novel targeted therapies are now in clinical development and may have potential for overcoming the limitations associated with currently available agents. In this article we review clinical data for molecular-targeted therapies in NSCLC, with emphasis on EGFR inhibitors and antiangiogenic agents.

Phase II, multicenter, uncontrolled trial of single-agent sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer

PURPOSE

Sorafenib is an oral multikinase inhibitor that targets the Ras/Raf/MEK/ERK mitogenic signaling pathway and the angiogenic receptor tyrosine kinases, vascular endothelial growth factor receptor 2 and platelet-derived growth factor receptor beta. We evaluated the antitumor response and tolerability of sorafenib in patients with relapsed or refractory, advanced non-small-cell lung cancer (NSCLC), most of whom had received prior platinum-based chemotherapy.

PATIENTS AND METHODS

This was a phase II, single-arm, multicenter study. Patients with relapsed or refractory advanced NSCLC received sorafenib 400 mg orally twice daily until tumor progression or an unacceptable drug-related toxicity occurred. The primary objective was to measure response rate.

RESULTS

Of 54 patients enrolled, 52 received sorafenib. The predominant histologies were adenocarcinoma (54%) and squamous cell carcinoma (31%). No complete or partial responses were observed. Stable disease (SD) was achieved in 30 (59%) of the 51 patients who were evaluable for efficacy. Four patients with SD developed tumor cavitation. Median progression-free survival (PFS) was 2.7 months, and median overall survival was 6.7 months. Patients with SD had a median PFS of 5.5 months. Major grades 3 to 4, treatment-related toxicities included hand-foot skin reaction (10%), hypertension (4%), fatigue (2%), and diarrhea (2%). Nine patients died within a 30-day period after discontinuing sorafenib, and one patient experienced pulmonary hemorrhage that was considered drug related. CONCLUSION Continuous treatment with sorafenib 400 mg twice daily was associated with disease stabilization in patients with advanced NSCLC. The broad activity of sorafenib and its acceptable toxicity profile suggest that additional investigation of sorafenib as therapy for patients with NSCLC is warranted.

Clinical and immunologic effects of intranodal autologous tumor lysate-dendritic cell vaccine with Aldesleukin (Interleukin 2) and IFN-{alpha}2a therapy in metastatic renal cell carcinoma patients

PURPOSE

To evaluate the clinical and immunologic outcomes of DC (dendritic cell) vaccine with interleukin (IL)-2 and IFN-alpha 2a in metastatic renal cell carcinoma patients.

EXPERIMENTAL DESIGN

Eighteen consented and eligible patients were treated. Peripheral blood monocytes were cultured ex vivo into mature DCs and loaded with autologous tumor lysate. Treatment consisted of five cycles of intranodal vaccination of DCs (1 x 10(7) cells/1 mL Lactated Ringer's solution), 5-day continuous i.v. infusion of IL-2 (18MiU/m2), and three s.c. injections of IFN-alpha 2a (6MiU) every other day. Response Evaluation Criteria in Solid Tumors criteria were used for disease assessment. Correlative immunologic end points included peripheral blood lymphocyte cell phenotype and function as well as peripheral blood anti-renal cell carcinoma antibody and cytokine levels.

RESULTS

All patients received between two and five treatment cycles. Toxicities consisted of known and expected cytokine side effects. Overall objective clinical response rate was 50% with three complete responses. Median time to progression for all patients was 8 months, and median survival has not been reached (median follow up of 37+ months). Treatment-related changes in correlative immunologic end points were noted and the level of circulating CD4(+) T regulatory cells had a strong association with outcome. Pre-IP-10 serum levels approached significance for predicting outcome.

CONCLUSIONS

The clinical and immunologic responses observed in this trial suggest an interaction between DC vaccination and cytokine therapy. Our data support the hypothesis that modulation of inflammatory, regulatory, and angiogenic pathways are necessary to optimize therapeutic benefit in renal cell carcinoma patients. Further exploration of this approach is warranted.

Angiogenesis in the treatment of non-small cell lung cancer

Lung cancer is the leading cause of cancer-related mortality in the United States. Patients with advanced disease have a median survival of approximately 10 months when treated with standard platinum-based therapy. Improvements in our understanding of cancer biology have led to the development of novel agents that more precisely affect the target of interest, allowing for a more rational approach to clinical trial design. Angiogenesis, the growth of new vessels from pre-existing vessels, is a fundamental step in tumor growth and progression. Inhibition of tumor-related angiogenesis has become an attractive target for anticancer therapy. A large randomized trial demonstrated an improvement in overall survival when bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF), was combined with chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). Small molecule inhibitors targeting both the VEGF receptor (VEGFR) and the tyrosine kinase receptor have also shown promise when combined with standard chemotherapy, but their role in the treatment of patients with NSCLC remains to be determined. This paper reviews clinical trials that have incorporated antiangiogenic agents in the treatment of patients with NSCLC.

Pyridoimidazolones as novel potent inhibitors of v-Raf murine sarcoma viral oncogene homologue B1 (BRAF)

BRAF is a serine/threonine kinase that is mutated in a range of cancers, including 50-70% of melanomas, and has been validated as a therapeutic target. We have designed and synthesized mutant BRAF inhibitors containing pyridoimidazolone as a new hinge-binding scaffold. Compounds have been obtained which have low nanomolar potency for mutant BRAF (12 nM for compound 5i) and low micromolar cellular potency against a mutant BRAF melanoma cell line, WM266.4. The series benefits from very low metabolism, and pharmacokinetics (PK) that can be modulated by methylation of the NH groups of the imidazolone, resulting in compounds with fewer H-donors and a better PK profile. These compounds have great potential in the treatment of mutant BRAF melanomas.

State-of-the-art treatment of metastatic renal cell carcinoma

Targeted therapy has greatly changed the way in which metastatic renal cell carcinoma (RCC) is treated. Agents that inhibit the vascular endothelial growth factor and mammalian target of rapamycin pathways that otherwise lead to angiogenesis have now become the standard of care. Much research into the sequence and combination of these agents is ongoing, and new anti-angiogenic agents are being developed. This overview covers the standard treatment of metastatic rcc with targeted therapy, immunotherapy, and surgery. Future directions and ongoing clinical trials are also discussed.