Synthesis and biological assessment of new pyrimidopyrimidines as inhibitors of breast cancer resistance protein (ABCG2).

Multidrug resistance constitutes a serious obstacle of the treatment success of cancer by chemotherapy. Mostly it is driven by expression of ABC transport proteins that actively efflux the anticancer agents out of the cell. This work describes the design and synthesis of 12 new pyrimidopyrimidines, as well as their inhibition of ABCG2 a transporter referred also to as breast cancer resistance protein, the selectivity versus ABCB1 (P-glycoprotein/P-gp) and ABCC1 as well as the investigation of their accumulation in single cells. From these results, N-(3,5-dimethoxyphenyl)-2-methyl-7-phenyl-5-(p-tolyl)pyrimido[4,5-d]pyrimidin-4-amine 7 h was identified as promising hit that deserves further investigation showing a selective and effective inhibition of ABCG2 with IC50 equal to 0.493 µM only 2-fold less active than Ko143.

Identification of structural fingerprints for ABCG2 inhibition by using Monte Carlo optimization, Bayesian classification, and structural and physicochemical interpretation (SPCI) analysis.

The human breast cancer resistance protein (BCRP), one of the members of the large ATP binding cassette (ABC) transporter superfamily, is crucial for resistance against chemotherapeutic agents. Currently, it has been emerged as one of the best biological targets for the designing of small molecule drugs capable of eliminating multidrug resistance in breast cancer. In order to gain insights into the relationship between the molecular structure of compounds and the ABCG2 inhibition, a multi-QSAR approach using different methods was performed on a dataset of 294 ABCG2 inhibitors with diverse scaffolds. The best models obtained by different chemometric methods have the following statistical characteristics: Monte Carlo Optimization-based QSAR (sensitivity = 0.905, specificity = 0.6255, accuracy = 0.756, and MCC = 0.545), Bayesian classification model (sensitivity = 0.735, specificity = 0.775, and concordance = 0.757); structural and physicochemical interpretation analysis-random forest method (balance accuracy = 0.750, sensitivity = 0.810, and specificity = 0.700). Additionally, structural fingerprints modulating the ABCG2 inhibitory properties were identified from the best models of each method and also validated with each other. The current modelling study is an attempt to get a deep insight into the different important structural fingerprints modulating ABCG2 inhibition.

Regulatory perspectives on next-generation sequencing and complementary diagnostics in Japan.

INTRODUCTION: The 'one biomarker/one drug' scenario is unsustainable because cancer is a complex disorder that involves a number of molecular defects. In the past decade, major technological advances have lowered the overall cost and increased the efficiency of next-generation sequencing (NGS). AREAS COVERED: We review recent regulations on NGS and complementary diagnostics in Japan, mainly focusing on high-quality studies that utilized these new diagnostic modalities and were published within the last 5 years. We highlight significant changes in regulation, and explain the direction of efforts to translate the results of NGS and complementary diagnostics into clinical practice. EXPERT OPINION: NGS holds a number of advantages over conventional companion and complementary diagnostics that enable simultaneous analyzes of multiple cancer genes to detect actionable mutations. Parallel technological developments and regulatory changes have led to the rapid adoption of NGS into clinical practice. NGS-based genomic data have been leveraged to better understand the characteristics of a disease that affects its patient's response to a given therapy. As NGS-based tests become more widespread, however, Japanese authorities will face significant challenges particularly with respect to the complexity of genomic data, which will have to be managed if NGS is to benefit patients.

A profile on cobas® EGFR Mutation Test v2 as companion diagnostic for first-line treatment of patients with non-small cell lung cancer.

INTRODUCTION: Among non-small cell lung cancer (NSCLC) patients, there is one molecularly defined subgroup harboring activating mutations in the epidermal growth factor receptor gene (EGFR), which results in constitutive activation of its intrinsic kinase activity. Consistent data have demonstrated that these patients have a better outcome when treated with specific tyrosine-kinase inhibitors (EGFR-TKIs). Therefore, analysis of EGFR mutational status for treatment guidance is mandatory in this context. AREAS COVERED: Herein we review the clinical development and technical features of cobas® EGFR Mutation Test v2 as a companion diagnostic test (CDx) for therapy with EGFR-TKIs, such as gefitinib, in advanced NSCLC. We also discuss the pros and cons of the current version of the CDx and its performance in both tissue and plasma samples. EXPERT OPINION: The RT-PCR based cobas® EGFR Mutation Test v2 is a reliable and rapid solution for EGFR mutational status assessment at the time of diagnosis in advanced NSCLC that allows eligibility of patients for EGFR-TKI treatment. This test determines EGFR mutations with acceptable sensitivity in tissue or plasma samples. Pre-analytical considerations like tumor cell content, tumor burden or location of metastasis should be considered to better interpret results in the clinical contexture.

Assessment of Transporter Polymorphisms as a Factor in a BCRP Drug Interaction Study With Lanabecestat.

Lanabecestat is a human ß-site amyloid precursor protein-cleaving enzyme 1 inhibitor in development to slow disease progression in patients with early Alzheimer's disease. The study evaluated the breast cancer resistance protein (BCRP) inhibition potential of lanabecestat on the pharmacokinetics (PK) of rosuvastatin, a probe for BCRP activity, in healthy white subjects who were not carriers of SLCO1B1 (c.521T>C), not homozygotes for ABCG2 (c.421C>A or c.34G>A), and not heterozygotes of ABCG2 (c.421C>A and c.34G>A). The safety of lanabecestat + rosuvastatin, the effects of rosuvastatin on the PK of lanabecestat, and the effects of multiple genetic polymorphisms on rosuvastatin exposure were assessed. Geometric mean ratios of the maximum observed rosuvastatin concentration (Cmax ), area under the rosuvastatin concentration-versus-time curve (AUC) from time 0 to infinity, and time of maximum observed drug concentration (tmax ) when rosuvastatin was administered alone and with lanabecestat were contained within 0.8-1.25, as were lanabecestat AUC at steady state and tmax at steady state when lanabecestat was administered alone or with rosuvastatin. Lanabecestat Cmax at steady state increased 8% in the presence of rosuvastatin. Except for an approximately 80% increase of rosuvastatin AUC (P < .05) in the heterozygotes of ABCG2 c.421C>A relative to the CC genotype, there were no statistically significant associations between rosuvastatin exposure and polymorphisms assessed. Lanabecestat + rosuvastatin was associated with few treatment-emergent adverse events, all of which resolved and were mild. Lanabecestat does not meaningfully impact BCRP activity; therefore, restriction of concomitant administration with BCRP substrates, such as rosuvastatin, may be unnecessary.

Comparative efficacy and safety of tyrosine kinase inhibitors for chronic myeloid leukaemia: A systematic review and network meta-analysis.

BACKGROUND: The pharmacotherapy of chronic myeloid leukaemia (CML) is mainly based on tyrosine kinase inhibitors (TKIs). The aim of this study was to compare the efficacy and safety of all TKIs in CML patients. METHODS: We conducted a systematic review with network meta-analysis (NMA) of randomised controlled trials (RCTs), including imatinib, nilotinib, dasatinib, bosutinib, radotinib and ponatinib. Searches were performed in PubMed, Scopus, Web of Science and SciELo (March 2018). The NMAs were built for six outcomes at 12 months: complete cytogenetic response (CCyR), major cytogenetic response (MCyR), deep molecular response, major molecular response (MMR), complete haematologic response and incidence of serious adverse events. We conducted rank order and surface under the cumulative ranking curve (SUCRA) analyses. RESULTS: Thirteen RCTs were included (n = 5079 patients). Statistical differences were observed for some comparisons in all outcomes. Imatinib 400 mg was considered the safest drug (SUCRA values of 10.3%) but presented low efficacy. Overall, nilotinib 600 mg was superior to the other TKI in efficacy (SUCRA values of 61.1% for CCyR, 81.0% for MMR, 90.0% for MCyR); however, no data on its safety profile at 12 months were reported. INTERPRETATION: Our results suggest that nilotinib should be upgraded to first-line therapy for CML, although further cost-effectiveness analyses, including the new TKI (i.e., ponatinib, radotinib), are needed.

Mutagenic assessment of chemotherapy and Smac mimetic drugs in cells with defective DNA damage response pathways.

DNA damaging therapies can spur the formation of therapy-related cancers, due to mis-repair of lesions they create in non-cancerous cells. This risk may be amplified in patients with impaired DNA damage responses. We disabled key DNA damage response pathways using genetic and pharmacological approaches, and assessed the impact of these deficiencies on the mutagenicity of chemotherapy drugs or the "Smac mimetic" GDC-0152, which kills tumor cells by targeting XIAP, cIAP1 and 2. Doxorubicin and cisplatin provoked mutations in more surviving cells deficient in ATM, p53 or the homologous recombination effector RAD51 than in wild type cells, but suppressing non-homologous end joining (NHEJ) by disabling DNA-PKcs prevented chemotherapy-induced mutagenesis. Vincristine-induced mutagenesis required p53 and DNA-PKcs but was not affected by ATM status, consistent with it provoking ATM-independent p53-mediated activation of caspases and CAD, which creates DNA lesions in surviving cells that could be mis-repaired by NHEJ. Encouragingly, GDC-0152 failed to stimulate mutations in cells with proficient or defective DNA damage response pathways. This study highlights the elevated oncogenic risk associated with treating DNA repair-deficient patients with genotoxic anti-cancer therapies, and suggests a potential advantage for Smac mimetic drugs over traditional therapies: a reduced risk of therapy-related cancers.

In vitro assessment of the interactions of dopamine ß-hydroxylase inhibitors with human P-glycoprotein and Breast Cancer Resistance Protein.

Inhibition of the biosynthesis of noradrenaline is a currently explored strategy for the treatment of hypertension, congestive heart failure and pulmonary arterial hypertension. While some dopamine ß-hydroxylase (DBH) inhibitors cross the blood-brain barrier (BBB) and cause central as well as peripheral effects (nepicastat), others have limited access to the brain (etamicastat, zamicastat). In this context, peripheral selectivity is clinically advantageous, in order to prevent alterations of noradrenaline levels in the CNS and the occurrence of adverse central effects. A limited brain exposure results from the combination of several factors, such as a reduced passive permeability or affinity for efflux transporters, but efflux liabilities may also lead to unwanted drug-drug interactions (DDIs) in the presence of co-administered substrates or inhibitors. Thus, the purpose of the study herein presented was to explore the interaction of P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP), the two major efflux transporters of the BBB that hamper the entry of several drugs to the brain, with the DBH inhibitors, etamicastat, nepicastat and zamicastat. Madin-Darby canine kidney cells (MDCK II) and transfected lines with human MDR1 (MDCK-MDR1) and ABCG2 (MDCK-BCRP) genes were used as a BBB surrogate model. P-gp and BCRP substrates and/or inhibitors were identified through intracellular accumulation and bidirectional permeability assays. The obtained data revealed that zamicastat is a concentration-dependent dual P-gp and BCRP inhibitor with IC50 values of 73.8 ±â€¯7.2 µM and 17.0 ±â€¯2.7 µM, while etamicastat and nepicastat inhibited BCRP to greater extent than P-gp, with IC50 values of 47.7 ±â€¯1.8 µM and 59.2 ±â€¯9.4 µM, respectively. Additionally, etamicastat was identified as P-gp and BCRP dual substrate, as demonstrated by net flux ratios of 5.84 and 3.87 and decreased >50% by verapamil and Ko143. Conversely, nepicastat revealed to be a P-gp-only substrate, with a net flux ratio of 2.01, reduced to 0.92 in the presence of verapamil. Furthermore, nepicastat displayed a consistently higher apparent permeability (>8.49 × 10-6 cm s-1) than etamicastat (<0.58 × 10-6 cm s-1). The identification of etamicastat as a dual efflux substrate suggests that P-gp and BCRP may be partially responsible for the limited central exposure of this compound, in association with its low passive permeability. Moreover, the weak efflux inhibitory potencies of etamicastat and nepicastat revealed a low DDI risk, while the dual P-gp/BCRP inhibition of zamicastat could be studied in the future with synergically effluxed compounds, for which BBB penetration is severely impaired.

Description of patients excluded for Mohs surgery after pre-surgical evaluation: data from the Regesmohs Spanish registry. / Descripción de pacientes no aptos para ser sometidos a cirugía de Mohs tras valoración prequirúrgica: datos del registro español Regesmohs.

BACKGROUND: Regesmohs registry is a nationwide registry including patients evaluated for Mohs surgery in 17 Spanish centres since July 2013. Given that Mohs surgery is the therapy with best results for high risk basal cell carcinoma (BCC) and other skin tumours, we wanted to describe the reasons that lead to some patients being excluded from this therapy and the alternative treatments that they received. These data may be useful to avoid excluding patients for Mohs surgery use, to estimate the healthcare demand of these patients and the demand for Hedgehog inhibitors therapy in this group. OBJECTIVE: To describe patients excluded for Mohs surgery after pre-surgical assessment, and the treatments that they received. METHODS: Regesmohs includes all consecutive patients assessed for Mohs surgery in the participating centres, collecting data on patient characteristics, intervention, and short and long-term results. Patients excluded for Mohs surgery after pre-surgical evaluation were described. RESULTS: 3011 patients were included in Regesmohs from July 2013 to October 2016. In 85, Mohs surgery was not performed as they were considered inadequate candidates. 67 had BCC. Reasons for exclusion were: medical contraindication (27.1%, n=23) low-risk tumour in (18.8%, n=16) and giant tumour and bone invasion (15.3%, n=13). Only 1 patient (1.2%) showed lymph node involvement and no patients had visceral metastases. Of the 85 excluded patients, 29 (34.1%) were treated with conventional surgery, 24 (28.3%) with radiotherapy, 4 (4.7%) with inhibitors of the Hedgehog pathway (only indicated for BCC), and 2 (2.4%) received palliative care. We had no follow-up data on 14 patients (16.5%). CONCLUSION: Medical comorbidities were the most common reason for withholding Mohs surgery. Withholding therapy on the basis of distant extension is uncommon. Most excluded patients received simpler therapies: conventional surgery or radiotherapy, with hedgehog inhibitors being a new option.

The Role of Target Therapy in the Treatment of Gastrointestinal Noncolorectal Cancers: Clinical Impact and Cost Consideration.

Gastrointestinal (GI) tumors are among the leading cause of death in cancer patients worldwide. Particularly, gastric cancer (GC) is the third cause of cancer deaths, whereas esophageal neoplasm is the eighth leading most common cancer worldwide and its incidence, especially adenocarcinoma type, is continuously increasing. Also, Hepatocellular carcinoma, Cholangiocarcinoma and pancreatic cancer represent a very interesting model to multidisciplinary approach and recently new drugs are used in their treatment. Currently, new clinical trials are designed including classic chemotherapy in association with either small molecule inhibitors (i.e. Tyrosine Kinase inhibitors) and/or monoclonal antibody (i.e. anti-EGFR antibody). Moreover, a comprehensive list of new molecules for target therapy is included in this issue. The development of new treatment modalities (multidisciplinary approach) and targeted therapy approaches have contributed to improving the outcome in these cancer diseases. During the past few years, remarkable progress in molecular biology of malignancy, the discovery of specific targets, and the resulting development of systemic drugs that block critical kinases and several molecular pathways have all contributed to progress in cancer treatment, also in GI non-colorectal cancer treatment.

Development of Lu-177-trastuzumab for radioimmunotherapy of HER2 expressing breast cancer and its feasibility assessment in breast cancer patients.

HER2/neu is over expressed in 20-25% of breast cancers. HER2 breast cancers are aggressive and are associated with poor prognosis. The aim of this study was to develop the clinical grade Lu-177-trastuzumab and its preliminary evaluation for specific tumor targeting in HER2 positive breast cancer patients. Trastuzumab was conjugated to bifunctional chelator, DOTA, and characterized for integrity and the number of molecules conjugated. Radiolabeling of DOTA-conjugated trastuzumab was optimized using Lu-177. Quality control parameters including radiochemical purity, stability, sterility, pyrogenicity and immunoreactivity were assessed. A preliminary pilot study was conducted on breast cancer patients (n = 6 HER2 positive and n = 4 HER2 negative) to evaluate the ability of Lu-177-trastuzumab for HER2 specific tumor targeting. The conjugates were efficiently labeled with Lu-177 with high radiochemical purity (up to 91%) and specific activity (6-13 µCi/µg). Lu-177-trastuzumab was stable up to 12 hr post labeling. The radioimmunoassay demonstrated good antigen binding ability and specificity for HER2 receptor protein. The patient studies showed the localization of Lu-177-trastuzumab at primary as well as metastatic sites (HER2 positive) in the planar and SPECT/CT images. No tracer uptake was observed in HER2 negative patients that indicated the specificity of Lu-177-trastuzumab. The study demonstrated that in-house developed Lu-177-trastuzumab has specific targeting ability for HER2 expressing lesions and may in future become a palliative treatment option in the form of targeted radionuclide therapy for disseminated HER2 positive breast cancer.

Brazilian health-care policy for targeted oncology therapies and companion diagnostic testing.

A growing understanding of the molecular pathology of tumours combined with a surge of new drugs and associated diagnostic technologies (ie, precision medicine) has translated into substantial improvements in survival for patients with cancer. However, to achieve the promise that precision medicine has to offer will require overcoming hurdles within a national health-care system in which it is to be implemented. Brazil is one such nation, an emerging middle-income country with a very complex health-care system. To address the challenges associated with implementing precision medicine into a country such as Brazil, a group of experts convened (Nov 16-18, 2015, Miami) to discuss challenges related to precision medicine within an oncology setting. Complex regulatory hurdles, a shortage of human and technical resources, and the complexities of a two-tiered health-care delivery system were all identified as the main shortcomings to effectively implementing this new field of medicine. A path forward was proposed that relies on active collaboration between clinicians, private organisations, and government. It seems entirely possible that, despite many intrinsic economic and political problems, Brazil can readily emerge as a model for other countries in Latin America for the potential benefits of precision medicine and companion diagnostics.

Pattern of chronic myeloid leukemia in the imatinib era in a Sub-Saharan African setting.

Chronic myeloid leukemia (CML) is an orphan disease in Africa because of the inaccessibility to specific treatment and the high cost of diagnosis and monitoring patients. The aim of this study was to report CML treatment response in a developing country in the tyrosine kinase inhibitor era. We conducted a longitudinal study of our cohort of CML patients. Socio-demographic, diagnosis, therapeutic, and treatment response parameters were studied. Sokal score, disease phase at diagnosis, delay from diagnosis to treatment, and treatment response were analyzed for their impact on survival. Fifty-five patients with a diagnosis of CML and who received treatment with imatinib for a minimum of 3 months were included in this study. Median follow-up was 170 patient-years. The sex ratio (M/F) was 1.62 and median age at diagnosis was 42 years. At diagnosis, 85.5 % of the patients were in chronic phase (CP), 12.7 % in accelerated phase (AP), and 1.8 % in blast crisis (BC). Sokal risk score distribution was as follows: low risk 29.8 %, intermediate risk 38.3 %, and high risk 31.9 %. Median time from first symptoms to first medical visit was 6.2 months and median time from first medical visit to cytogenetic and or molecular confirmation was 12.4 months. Mean delay time from first medical visit to imatinib initiation was 12.5 months (95 % CI 6.3-18.7). The complete hematologic response (CHR) at 3 months, the major cytogenetic response (MCR) at 12 months, and the major molecular response (MMR) at 24 months were respectively 82.4, 75, and 25 %. The 2-year overall survival rate was 81 %. Advanced phase at the diagnosis, discontinuation of imatinib therapy over 15 % of the time, lack of CHR at 3 months, lack of MCR at 12 months, and progression of the disease during imatinib therapy were associated with a risk of death (p ≤ 0.05). Our data confirm the improved prognosis of CML treated with imatinib in the setting of a developing country. However, response rates are lower than in developed countries, and additional efforts should be made to facilitate early diagnosis and improve access to TKI, treatment compliance, and regular molecular monitoring of patients.

[Issues and current limits for immunohistochemical assessment of PD-L1 status in bronchial biopsies]. / Enjeux et limites actuelles de l'évaluation du statut de PD-L1 par immunohistochimie sur des biopsies bronchiques.

Immunotherapy targeting the PD-L1/PD-1 axis has shown recently some promising results in metastatic lung cancer patients. This treatment seems to be more effective when a high expression of PD-L1 is detected by immunohistochemistry in bronchial biopsies. In this regard, this targeted therapy will be proposed soon in metastatic lung cancer patients. This immunotherapy could be dependent to the immunohistochemical (IHC) assessment of PD-L1 expression, thus considered as a companion diagnostic test. This near perspective poses challenges with regard to the positivity threshold value for PD-L1 expression before therapy administration, the positive cellular compartment (tumour cells and/or immune cells), the percentage of positive cells and the clone which is used. A couple of patients have a good response to treatment targeting the PD-1/PD-L1 axis despite the absence or a weak PD-L1 expression. However the assessment of PD-L1 expression by immunohistochemistry will be the only mandatory approach before therapeutic strategies targeting the PD1/PD-L1 axis for lung cancer patients. In this review, the main challenges of using PD-L1 immunohistochemistry as a potential companion diagnostic tool for metastatic lung cancer patient immunotherapy will be discussed.

[Desperately seeking targets]. / Recherche cibles, désespérément - Chroniques génomiques.

In clinical oncology, obtaining sequence data from tumour samples has become practical in terms of logistics, turnover time and costs. The major issue now is the interpretation of this sequence to define actionable targets, i.e. genome changes that are involved in tumorogenesis and that predict the efficacy of existing and available targeted treatments. This is the focus of major efforts from public clinical centres and from companies that see it as a promising commercial activity.

Co-clinical assessment identifies patterns of BRAF inhibitor resistance in melanoma.

Multiple mechanisms have been described that confer BRAF inhibitor resistance to melanomas, yet the basis of this resistance remains undefined in a sizable portion of patient samples. Here, we characterized samples from a set of patients with melanoma that included individuals at baseline diagnosis, on BRAF inhibitor treatment, and with resistant tumors at both the protein and RNA levels. Using RNA and DNA sequencing, we identified known resistance-conferring mutations in 50% (6 of 12) of the resistant samples. In parallel, targeted proteomic analysis by protein array categorized the resistant samples into 3 stable groups, 2 of which were characterized by reactivation of MAPK signaling to different levels and 1 that was MAPK independent. The molecular relevance of these classifications identified in patients was supported by both mutation data and the similarity of resistance patterns that emerged during a co-clinical trial in a genetically engineered mouse (GEM) model of melanoma that recapitulates the development of BRAF inhibitor resistance. Additionally, we defined candidate biomarkers in pre- and early-treatment patient samples that have potential for predicting clinical responses. On the basis of these observations, we suggest that BRAF inhibitor-resistant melanomas can be actionably classified using protein expression patterns, even without identification of the underlying genetic alteration.

[Extension study and evaluation of the therapeutic response in a patient with metastatic lung adenocarcinoma using sequential study with ¹8F-FDG PET-CT and ¹8F-fluoride PET-CT]. / Estudio de extensión y valoración de la respuesta terapéutica en un paciente con adenocarcinoma pulmonar metastásico mediante estudio secuencial con (18)F-FDG PET-TC y (18)F-fluoruro PET-TC.

We report a case of a patient with lung adenocarcinoma and bone and extraosseus metastases studied with (18)F-FDG PET-CT, (99m)Tc-HMDP and (18)F-fluoride PET-CT. It assesses the usefulness of (18)F-FDG PET-CT for initial staging of the disease and monitoring response to therapy. For the study of the sclerotic bone metastases it shows the superiority of 99mTc-HMDP bone scintigraphy and (18)F-fluoride PET-CT over (18)F-FDG PET-CT, and (18)F-fluoride PET-CT over bone scintigraphy. It also shows the usefulness of (18)F-fluoride PET-CT for monitoring the bone metastases.

p38MAPK inhibition: a new combined approach to reduce neuroblastoma resistance under etoposide treatment.

Neuroblastoma (NB) is the second most common solid pediatric tumor and is characterized by clinical and biological heterogeneity, and stage-IV of the disease represents 50% of all cases. Considering the limited success of present chemotherapy treatment, it has become necessary to find new and effective therapies. In this context, our approach consists of identifying and targeting key molecular pathways associated with NB chemoresistance. This study has been carried out on three stage-IV NB cell lines with different status of MYCN amplification. Cells were exposed to a standard chemotherapy agent, namely etoposide, either alone or in combination with particular drugs, which target intracellular signaling pathways. Etoposide alone induced a concentration-dependent reduction of cell viability and, at very high doses, totally counteracted cell tumorigenicity and neurosphere formation. In addition, etoposide activated p38 mitogen-activated protein kinase (MAPK), AKT and c-Jun N-terminal kinase. Pre-treatment with SB203580, a p38MAPK inhibitor, dramatically sensibilized NB cells to etoposide, strongly reducing the dosage needed to inhibit tumorigenicity and neurosphere formation. Importantly, SB203580-etoposide cotreatment also reduced cell migration and invasion by affecting cyclooxygenase-2, intercellular adhesion molecule-1, C-X-C chemokine receptor-4 and matrix metalloprotease-9. Collectively, our results suggest that p38MAPK inhibition, in combination with standard chemotherapy, could represent an effective strategy to counteract NB resistance in stage-IV patients.

Molecular targets in the discovery and development of novel antimetastatic agents: current progress and future prospects.

Tumour invasion and metastasis have been recognized as major causal factors in the morbidity and mortality among cancer patients. Many advances in the knowledge of cancer metastasis have yielded an impressive array of attractive drug targets, including enzymes, receptors and multiple signalling pathways. The present review summarizes the molecular pathogenesis of metastasis and the identification of novel molecular targets used in the discovery of antimetastatic agents. Several promising targets have been highlighted, including receptor tyrosine kinases, effector molecules involved in angiogenesis, matrix metalloproteinases (MMPs), urokinase plasminogen activator, adhesion molecules and their receptors, signalling pathways (e.g. phosphatidylinositol 3-kinase, phospholipase Cγ1, mitogen-activated protein kinases, c-Src kinase, c-Met kinases and heat shock protein. The discovery and development of potential novel therapeutics for each of the targets are also discussed in this review. Among these, the most promising agents that have shown remarkable clinical outcome are anti-angiogenic agents (e.g. bevacizumab). Newer agents, such as c-Met kinase inhibitors, are still undergoing preclinical studies and are yet to have their clinical efficacy proven. Some therapeutics, such as first-generation MMP inhibitors (MMPIs; e.g. marimastat) and more selective versions of them (e.g. prinomastat, tanomastat), have undergone clinical trials. Unfortunately, these drugs produced serious adverse effects that led to the premature termination of their development. In the future, third-generation MMPIs and inhibitors of signalling pathways and adhesion molecules could form valuable novel classes of drugs in the anticancer armamentarium to combat metastasis.

Treatment with unfunded drugs in oncology: the impact of access programmes and clinical trials.

BACKGROUND: Where proven cancer therapies remain unfunded, patients are faced with difficult decisions regarding personally covering some or all of the treatment cost. Clinical trials provide an alternative form of access to unfunded drugs. AIMS: To examine the patient population and utilisation of the colorectal cancer cetuximab Interim Access Programme (IAP) in Australia. METHODS: We retrospectively analysed de-identified data collected as part of the costsharing colorectal cancer cetuximab IAP in Australia, which extended from June 2005 until November 2009. The impact of the CO20 clinical trial that opened in early 2008 and provided free access to cetuximab was also examined. RESULTS: Eight hundred and fifty-eight patients received ≥1 treatment on the IAP. The median age of participants was lower than the general colorectal cancer population (61 vs 71 years). A greater uptake by males was limited to patients over 65 years old. Socioeconomic status correlated with programme enrolment, and there appeared to be lower uptake among regional patients. The majority (93%) of patients received combination treatment with irinotecan, with a trend towards increasing use of single-agent cetuximab over time. The median time-on-treatment was longer in patients treated with combination therapy than with monotherapy (12 vs 8 weeks). The CO20 trial had minimal impact on IAP enrolment and approximately doubled the number of Australian patients receiving cetuximab. CONCLUSIONS: Patients' age and gender in older patients impacted on participation in the IAP. Both the IAP and the CO20 trial contributed to a substantial proportion of Australian patients accessing an unfunded treatment, with an estimated 50% of the eligible patient population receiving cetuximab.