Realist Approach to Social Policies (RASP) study to reduce socioeconomic health inequalities through systems change: protocol for a research project combining mixed-methods realist research with institutional action research.

INTRODUCTION: Health inequalities are rooted in inequality in vital resources for health, including financial resources, a supportive informal network, a stable living situation, work or daytime activities or education and literacy. About 25% of Dutch citizens experience deprivation of such resources. Social policy consists of crucial instruments for improving resources in those groups but can also have adverse effects and lead to additional burdens. This project aims to contribute to the reduction of health inequalities through (1) a better understanding of how social policy interventions can contribute to reducing health inequality through the redistribution of burdens and resources and (2) developing anticipatory governance strategies to implement those insights, contributing to a change in social policy systems. METHODS AND ANALYSIS: Two systems approaches are combined for establishing a systems change in the Netherlands. First, a realist approach enables insights into what in social policy interventions may impact health outcomes, for whom and under what circumstances. Second, an institutional approach enables scaling up these insights, by acknowledging the crucial role of institutional actors for accomplishing a systems change. Together with stakeholders, we perform a realist review of the literature and identify existing promising social policy interventions. Next, we execute mixed-methods realist evaluations of selected social policy interventions in seven municipalities, ranging from small, mid-size to large, and in both urban and rural settings. Simultaneously, through action research with (national) institutional actors, we facilitate development of anticipatory governance strategies. ETHICS AND DISSEMINATION: This study is not liable to the Medical Research Involving Subjects Act (WMO). Informed consent to participate in the study is obtained from participants for the use of all forms of personally identifiable data. Dissemination will be codeveloped with target populations and includes communication materials for citizens, education materials for students, workshops, infographics and decision tools for policy-makers and publications for professionals.

The Nitrogen Mustards.

The nitrogen mustards are powerful cytotoxic and lymphoablative agents and have been used for more than 60 years. They are employed in the treatment of cancers, sarcomas, and hematologic malignancies. Cyclophosphamide, the most versatile of the nitrogen mustards, also has a place in stem cell transplantation and the therapy of autoimmune diseases. Adverse effects caused by the nitrogen mustards on the central nervous system, kidney, heart, bladder, and gonads remain important issues. Advances in analytical techniques have facilitated the investigation of the pharmacokinetics of the nitrogen mustards, especially the oxazaphosphorines, which are prodrugs requiring metabolic activation. Enzymes involved in the metabolism of cyclophosphamide and ifosfamide are very polymorphic, but a greater understanding of the pharmacogenomic influences on their activity has not yet translated into a personalized medicine approach. In addition to damaging DNA, the nitrogen mustards can act through other mechanisms, such as antiangiogenesis and immunomodulation. The immunomodulatory properties of cyclophosphamide are an area of current exploration. In particular, cyclophosphamide decreases the number and activity of regulatory T cells, and the interaction between cyclophosphamide and the intestinal microbiome is now recognized as an important factor. New derivatives of the nitrogen mustards continue to be assessed. Oxazaphosphorine analogs have been synthesized in attempts to both improve efficacy and reduce toxicity, with varying degrees of success. Combinations of the nitrogen mustards with monoclonal antibodies and small-molecule targeted agents are being evaluated. SIGNIFICANCE STATEMENT: The nitrogen mustards are important, well-established therapeutic agents that are used to treat a variety of diseases. Their role is continuing to evolve.

A behaviorally informed financial education program for the financially vulnerable: Design and effectiveness.

Financially vulnerable consumers are often associated with suboptimal financial behaviors. Evaluated financial education programs so far show difficulties to effectively reach this target population. In our attempt to solve this problem, we built a behaviorally informed financial education program incorporating insights from both motivational and behavioral change theories. In a quasi-experimental field study among Dutch financially vulnerable people, we compared this program with both a control group and a traditional program group. In comparison with the control group, we found robust positive effects of the behaviorally informed program on financial skills and knowledge and self-reported financial behavior, but not on other outcomes. Additionally, we did not find evidence that the behaviorally informed program performed better than the traditional program. Finally, we discuss the findings and limitations of this study in light of the financial education literature and provide implications for policymaking and directions for future research.

Multicenter Phase II Clinical Trial of Isolated Lung Perfusion in Patients With Lung Metastases.

BACKGROUND: Up to 66% of patients show local pulmonary disease progression after pulmonary metastasectomy. Regional treatment with isolated lung perfusion (ILuP) may improve local control with minimal systemic adverse effects. The aims of this study were to evaluate local and distant control after ILuP, determine the effect on overall survival compared with historical controls, and confirm the safety and feasibility of ILuP. METHODS: A total of 107 patients with resectable pulmonary metastases of colorectal carcinoma, osteosarcoma, and soft-tissue sarcoma were included in a prospective phase II study of pulmonary metastasectomy combined with ILuP with 45 mg melphalan at 37°C. Local and distant control, overall survival, lung function, and 90-day mortality and morbidity were monitored. RESULTS: We report 0% mortality, low morbidity, and no long-term pulmonary toxicity. For colorectal carcinoma, median time to local pulmonary progression, median time to progression, and median survival time were 31, 14, and 78 months, respectively. Median time to local progression was not reached for sarcoma, whereas median time to progression and median survival time were 13 and 39 months, respectively. The 5-year disease-free rate and pulmonary progression-free rate were 26% and 44% for colorectal carcinoma and 29% and 63% for sarcoma, respectively. CONCLUSIONS: ILuP with melphalan combined with metastasectomy is feasible and safe. Compared with historical controls, favorable results were obtained in this phase II study for local control. Further evaluation of locoregional lung perfusion techniques with other chemotherapeutic drugs is warranted.

Analysis of novel melphalan hydrolysis products formed under isolated lung perfusion conditions using liquid chromatography/tandem mass spectrometry.

RATIONALE: Melphalan is a widely used cytotoxic agent in cancer treatments. This phenylalanine analog has been shown an effective drug in the treatment of breast cancer, multiple myeloma and melanoma of the extremities. A good knowledge of the drug's degradation and metabolism are crucial for understanding its activity during cancer treatments. METHODS: The formation of hydrolysis products of melphalan is studied using ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS). Aqueous melphalan solutions were incubated at elevated temperatures and analyzed by UPLC/MS/MS. Two previously described hydrolysis products, mono- and dihydroxymelphalan (MOH and DOH), were formed in vitro and could be characterized during MS/MS and high-resolution experiments. RESULTS: Novel compounds with m/z values >500 Da were discovered. Comparison of the fragmentation patterns of these new molecules with those of MOH and DOH show great similarities. The higher masses are explained by the presence of two or more melphalan units. In total, more than 15 new hydrolysis products were found. Experiments were set up to study the formation and the chemical structures of these molecules. CONCLUSIONS: The hydrolysis of melphalan is studied in the scope of a phase II clinical trial (isolated lung perfusion, ILuP). Patient samples were screened for the presence of all documented and novel melphalan hydrolysis products. This study reports the formation of a new class of oligomeric compounds in both in vivo and in vitro samples.

The αVß3/αVß5 integrin inhibitor cilengitide augments tumor response to melphalan isolated limb perfusion in a sarcoma model.

Isolated limb perfusion (ILP) with melphalan and tumor necrosis factor (TNF)-α is used to treat bulky, locally advanced melanoma and sarcoma. However, TNF toxicity suggests a need for better-tolerated drugs. Cilengitide (EMD 121974), a novel cyclic inhibitor of alpha-V integrins, has both anti-angiogenic and direct anti-tumor effects and is a possible alternative to TNF in ILP. In this study, rats bearing a hind limb soft tissue sarcoma underwent ILP using different combinations of melphalan, TNF and cilengitide in the perfusate. Further groups had intra-peritoneal (i.p.) injections of cilengitide or saline 2 hr before and 3 hr after ILP. A 77% response rate (RR) was seen in animals treated i.p. with cilengitide and perfused with melphalan plus cilengitide. The RR was 85% in animals treated i.p. with cilengitide and ILP using melphalan plus both TNF and cilengitide. Both RRs were significantly greater than those seen with melphalan or cilengitide alone. Histopathology showed that high RRs were accompanied by disruption of tumor vascular endothelium and tumor necrosis. Compared with ILP using melphalan alone, the addition of cilengitide resulted in a three to sevenfold increase in melphalan concentration in tumor but not in muscle in the perfused limb. Supportive in vitro studies indicate that cilengitide both inhibits tumor cell attachment and increases endothelial permeability. Since cilengitide has low toxicity, these data suggest the agent is a good alternative to TNF in the ILP setting.

Substantial variation in transplacental transfer of chemotherapeutic agents in a mouse model.

OBJECTIVE: Data on the transplacental transfer of chemotherapeutic agents are lacking. We aimed to measure the maternofetal transfer of cytotoxic drugs in a mouse model. STUDY DESIGN: The transplacental transfer of doxorubicin (9 mg/kg), epirubicin (11 mg/kg), vinblastine (6 mg/kg), carboplatin (50 mg/kg), paclitaxel (10 mg/kg), and cytarabine (100 mg/kg) was tested in a C57/Bl6J mouse model. Ninety minutes after intravenous (IV) drug injection on gestational day 18.5, maternal and fetal blood were collected simultaneously. Plasma drug levels were determined using high performance liquid chromatography or atomic absorption spectrometry. RESULTS: Fetal plasma concentrations of doxorubicin, epirubicin, vinblastine, and cytarabine were 5.1% ± 0.6% (n = 8), 4.8% ± 3.8% (n = 8), 13.8% ± 5.8% (n = 6), and 56.7% ± 22.6% (n = 6) of the maternal concentrations, respectively. Total platinum passed the mouse placenta easily (117.0% ± 38.9%, n = 6). Paclitaxel could not be detected in fetal plasma samples (n = 6). CONCLUSIONS: Substantial variations in transplacental transfer were noted among the tested drugs. Current findings contribute to the understanding of reported pregnancy outcomes in humans.

Pharmacokinetics of chemotherapeutic agents in pregnancy: a preclinical and clinical study.

OBJECTIVE: To determine the impact of physiologic changes of pregnancy on pharmacokinetics of chemotherapeutic agents. DESIGN: A preclinical and a clinical case-control trial. SETTING: Institute of Primate Research Nairobi and collaborating hospitals in Belgium, the Netherlands and Czech Republic. POPULATION: Pregnant and nonpregnant women and baboons receiving chemotherapy. METHODS: Chemotherapy pharmacokinetics was compared between the pregnant and nonpregnant state. Standard-dosed chemotherapy regimens were administered in pregnant and nonpregnant baboons/women, followed by serial blood samplings. Drug plasma levels were determined using high performance liquid chromatography and atomic absorption spectrometry. MAIN OUTCOME MEASURES: Area under the curve (AUC), maximal plasma concentration, terminal elimination half-life, clearance and distribution volume of each drug in pregnant and nonpregnant state. RESULTS: Intraindividual comparative pharmacokinetic data were obtained for doxorubicin and paclitaxel/platinum in three and two baboons, respectively. In the clinical trial, two patients were exposed to doxorubicin and one patient was exposed to paclitaxel/platinum during and after pregnancy. Furthermore, a pooled analysis was performed based on 16 cycles of pregnant and 11 cycles of nonpregnant women. Numbers of pregnant/nonpregnant patients were 5/2, 7/5, 4/4 and 2/2 for paclitaxel, doxorubicin, epirubicin and platinum, respectively. For all drugs tested in the preclinical and clinical study, a decreased AUC and maximal plasma concentration and an increased distribution volume and clearance were observed in pregnancy. CONCLUSIONS: Although numbers were too small for statistical significance, pregnancy-associated physiologic alterations appear to lead to a decrease in plasma exposure of chemotherapeutic drugs. The importance of long-term follow-up of women treated with chemotherapy during pregnancy is underscored.

Transplacental transfer of paclitaxel, docetaxel, carboplatin, and trastuzumab in a baboon model.

BACKGROUND: The paucity of data on fetal effects of prenatal exposure to chemotherapy prompted us to study the transplacental transport of commonly used anticancer agents in a pregnant baboon model. METHODS: Single or combination chemotherapy with paclitaxel, docetaxel, carboplatin, and trastuzumab was administered to 9 baboons at a mean (SD) gestational age of 117 (26) days (paclitaxel, 100 mg/m2 [n = 2]; docetaxel, 100 mg/m2 [n = 2]; paclitaxel, 175 mg/m2 with carboplatin, area under the curve of 6 at standard dosage [n = 2] and 50% dosage [n = 1]; docetaxel, 75 mg/m2 with carboplatin, area under the curve 6 [n = 1]; and docetaxel, 75 mg/m2 with trastuzumab, 8 mg/kg [n = 1]). Serial fetal and maternal blood samples, amniotic fluid, maternal urine, and fetal and maternal tissue samples were collected for the first 76 hours after drug infusion. Levels of carboplatin were determined by atomic absorption spectrometry, docetaxel and paclitaxel by high-performance liquid chromatography, and trastuzumab by enzyme-linked immunosorbent assay. RESULTS: Fetal plasma concentrations of carboplatin averaged 57.5% (14.2%) of maternal concentrations (n = 7). Fetal plasma concentrations were 1.5% (0.8%) of maternal concentrations (n = 7). Immediately after ending the infusion, paclitaxel was not detectable in fetal tissues, whereas, after 3 hours, fetal tissues contained 15% of maternal tissue concentrations.Docetaxel could not be detected in fetal blood samples (n = 9). In the first 3 hours after docetaxel infusion, fetal tissues contained 5.0% to 50.0% of maternal tissue concentrations, whereas equal fetal and maternal tissue concentrations were found after 26 and 76 hours.The transplacental passages of trastuzumab were 85.0% and 3.0%, 2 and 26 hours after trastuzumab infusion, respectively. After 26 hours, amniotic fluid contained 36.4% of the fetal plasma concentration. Fetal tissue concentrations varied between 5.0% and 14.0% of the maternal concentration. CONCLUSION: Variable plasma and/or tissue concentrations of taxanes, carboplatin, and trastuzumab were encountered in the fetal compartment. These data are important when cancer treatment is considered during pregnancy and underline the need for long-term follow-up of children after prenatal exposure to these cytotoxic agents.

Interaction of imatinib with human organic ion carriers.

PURPOSE: The activity of imatinib in leukemia has recently been linked with expression of the organic cation transporter 1 (OCT1) gene SLC22A1. Here, we characterized the contribution of solute carriers to imatinib transport in an effort to further understand mechanisms involved in the intracellular uptake and retention (IUR) of the drug. EXPERIMENTAL DESIGN: IUR of [3H]imatinib was studied in Xenopus laevis oocytes and HEK293 cells expressing OATP1A2, OATP1B1, OATP1B3, OCT1-3, OCTN1-2, or OAT1-3. Gene expression was determined in nine leukemia cell lines using the Affymetrix U133 array. RESULTS: Imatinib was not found to be a substrate for OCT1 in oocytes (P = 0.21), whereas in HEK293 cells IUR was increased by only 1.20-fold relative to control cells (P = 0.002). Furthermore, in 74 cancer patients, the oral clearance of imatinib was not significantly altered in individuals carrying reduced-function variants in SLC22A1 (P = 0.99). Microarray analysis indicated that SLC22A1 was interrelated with gene expression of various transporters, including ABCB1, ABCC4, ABCG2 (negative), and OATP1A2 (positive). Imatinib was confirmed to be a substrate for the three efflux transporters (P < 0.05) as well as for OATP1A2 (P = 0.0001). CONCLUSIONS: This study suggests that SLC22A1 expression is a composite surrogate for expression of various transporters relevant to imatinib IUR. This observation provides a mechanistic explanation for previous studies that have linked SLC22A1 with the antitumor activity of imatinib. Because of its high expression in the intestine, ciliary body, gliomas, and leukemia cells, OATP1A2 may play a key role in imatinib pharmacokinetics-pharmacodynamics.

Celecoxib inhibits growth of tumors in a syngeneic rat liver metastases model for colorectal cancer.

INTRODUCTION: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce the risk of colorectal cancer in cyclooxygenase-2 (COX-2) overexpressing colorectal cancers. The present study was designed to evaluate the inhibitory effects of the COX-2 inhibitor celecoxib on the growth of colorectal cancer liver metastases in a syngeneic rat model, CC531. MATERIALS AND METHODS: The effects of celecoxib on cell viability in vitro were evaluated by treatment of CC531 tumor cell cultures with celecoxib. In vivo, Wag/Rij rats were inoculated with CC531 tumor cells at two sites in the liver and treated with celecoxib starting one week before, or directly after tumor inoculation. Control rats were inoculated without treatment. Three weeks after tumor inoculation rats were sacrificed. Tumor size, immune cell infiltration, caspase-3 activity, PGE(2) and celecoxib levels were determined. RESULTS: CC531 tumors did not show COX-2 expression. Tumor growth was significantly inhibited by celecoxib treatment in a dose dependent manner. Immune cell infiltration was decreased after celecoxib treatment, indicating that the immune system was not involved in preventing tumor growth. Tumor caspase-3 levels were only significantly increased if treatment was started before tumor inoculation. Celecoxib serum concentration starting at 0.84 microg/ml significantly inhibited the outgrowth of CC531 liver tumors. In contrast, in vitro concentrations of celecoxib of at least 12 microg/ml were needed to affect tumor cell viability. CONCLUSION: These results suggest that the inhibitory effects of celecoxib on tumor growth are not by direct cytotoxicity, but by creating an unfavorable environment for tumor growth.

Isolated hypoxic hepatic perfusion with retrograde outflow in patients with irresectable liver metastases; a new simplified technique in isolated hepatic perfusion.

BACKGROUND: Isolated hepatic perfusion with high-dose chemotherapy is a treatment option for patients with irresectable metastases confined to the liver. Prolonged local control and impact on survival have been claimed. Major drawbacks are magnitude and costs of the procedure. We developed an isolated hypoxic hepatic perfusion (IHHP) with retrograde outflow without the need for a heart-lung machine. PATIENTS AND METHODS: Twenty-four consecutive patients with irresectable metastases of various origins were treated. IHHP inflow was via the hepatic artery, outflow via the portal vein with occlusion of the retrohepatic caval vein. Radiolabeled albumine was used for leakage monitoring. Melphalan was used at 1-2 mg/kg. A 25-minute perfusion period was followed by a complete washout. Local and systemic melphalan concentrations were determined. RESULTS: Compared with oxygenated classical IHP, the IHPP procedure reduced operation time from >8 h to 4 hours, blood loss from >4000 to 900 cc and saved material and personnel costs. Leakage was 0% with negligible systemic toxicity and 0% perioperative mortality. Tumor response: complete response (CR) in 4%, partial response (PR) in 58%, and stable disease (SD) in 13%. Median time to progression was 9 months (2-24 months); pharmacokinetics demonstrated intrahepatic melphalan concentrations more than 9 fold higher than postperfusion systemic concentrations. CONCLUSIONS: IHPP is a relatively simple procedure with reduced costs, reduced blood loss, no mortality, limited toxicity, and response rates comparable to classic IHP. The median duration of 9 months of tumor control should be improved. Hereto, vasoactive drugs, will be explored in further studies.

Population pharmacokinetics and pharmacodynamics of doxorubicin and cyclophosphamide in breast cancer patients: a study by the EORTC-PAMM-NDDG.

AIMS: To investigate the population pharmacokinetics and pharmacodynamics of doxorubicin and cyclophosphamide in breast cancer patients. PATIENTS AND METHODS: Sixty-five female patients with early or advanced breast cancer received doxorubicin 60 mg/m(2) over 15 minutes followed by cyclophosphamide 600 mg/m(2) over 15 minutes. The plasma concentration-time data of both drugs were measured, and the relationship between drug pharmacokinetics and neutrophil counts was evaluated using nonlinear mixed-effect modelling. Relationships were explored between drug exposure (the area under the plasma concentration-time curve [AUC]), toxicity and tumour response. RESULTS: Fifty-nine patients had complete pharmacokinetic and toxicity data. In 50 patients with measurable disease, the objective response rate was 60%, with complete responses in 6% of patients. Both doxorubicin and cyclophosphamide pharmacokinetics were associated with neutrophil toxicity. Cyclophosphamide exposure (the AUC) was significantly higher in patients with at least stable disease (n = 44) than in patients with progressive disease (n = 6; 945 micromol . h/L [95% CI 889, 1001] vs 602 micromol . h/L [95% CI 379, 825], p = 0.0002). No such correlation was found for doxorubicin. Body surface area was positively correlated with doxorubicin clearance; AST and patient age were negatively correlated with doxorubicin clearance; creatinine clearance was positively correlated with doxorubicinol clearance; and occasional concurrent use of carbamazepine was positively correlated with cyclophosphamide clearance. CONCLUSIONS: The proposed inhibitory population pharmacokinetic-pharmacodynamic model adequately described individual neutrophil counts after administration of doxorubicin and cyclophosphamide. In this patient population, exposure to cyclophosphamide, as assessed by the AUC, might have been a predictor of the treatment response, whereas exposure to doxorubicin was not. A prospective study should validate cyclophosphamide exposure as a predictive marker for the treatment response and clinical outcome in this patient group.

Pharmacokinetics of isolated lung perfusion with melphalan for resectable pulmonary metastases, a phase I and extension trial.

BACKGROUND: Isolated lung perfusion (ILuP) with melphalan was performed under normo- and hyperthermic conditions combined with pulmonary metastasectomy for patients with resectable lung metastases. We present the results of pharmacokinetic analysis of a phase I and extension trial. METHODS: Twenty-one procedures of ILuP with melphalan were performed in the phase I trial according to a dose-escalation schedule under normothermic and hyperthermic conditions followed by surgical resection of pulmonary metastases. In an extension trial 8 additional procedures with 15 and 45 mg melphalan were performed under hyperthermic conditions. Samples of serum, perfusate, lung, and tumor tissue were obtained. RESULTS: High perfusate concentrations of melphalan were recorded in contrast to low systemic concentrations. Marked interindividual variability was observed in melphalan concentrations in perfusate, tumor, and lung tissue. Statistically significant correlation between melphalan dose, and perfusate area under the concentration-time curve (R(2) = 0.578, P = 0.001) and lung tissue concentrations (R(2) = 0.459, P = 0.028) were noted. No significant correlation between melphalan dose and tumor tissue concentrations could be established. CONCLUSION: Isolated lung perfusion effectively delivers high doses of melphalan to the lung and tumor tissues with minimal systemic levels. Significant correlation between perfused melphalan dose, perfusate area under the concentration-time curve and lung tissue melphalan concentrations were observed.

Simultaneous determination of AMN107 and Imatinib (Gleevec, Glivec, STI571) in cultured tumour cells using an isocratic high-performance liquid chromatography procedure with UV detection.

A reversed phase high-performance liquid chromatographic (HPLC) method with UV detection was developed for the simultaneous determination of imatinib (Gleevec, Glivec, STI571) and AMN107 in cultured tumour cells, using clozapine as an internal standard. The compounds of interest were extracted by liquid-liquid extraction using TOXI-TUBES((R)) A extraction tubes. Chromatographic separation was performed on a Phenomenex Gemini C18 reversed phase column (150 mm x 2.0 mm, 5 microm particle size), using a mixture of 65% CH(3)OH (methanol) and 35% NH(4)Ac (Ammonium acetate) buffer (20mM, pH 10). Separation was achieved under isocratic conditions at a flow rate of 0.5 ml/min. Imatinib, clozapine and AMN107 are detected by UV detection at 260 nm. Calibration curves were linear from 50 to 7500 ng/ml with correlation coefficients (r(2)) better than 0.998. The limit of quantitation (LOD) was 50 ng/ml. The method has been successfully applied to a cellular kinetics study.

Docetaxel and gemcitabine combination therapy in advanced transitional cell carcinoma of the urothelium: results of a phase II and pharmacologic study.

Our objective was to determine the response to gemcitabine plus docetaxel in advanced urothelial transitional cell carcinoma in a phase II trial, and gemcitabine distribution between plasma and erythrocytes, following docetaxel administration. Patients with locally advanced or metastatic transitional cell carcinoma, following a maximum of one prior chemotherapy regimen, were given gemcitabine 800 mg/m on days 1 and 8 plus docetaxel 85 mg/m on day 8, every 21 days. Gemcitabine was measured in the plasma and erythrocytes of nine patients before and after docetaxel administration. Thirty-four patients (median 63 years; range 49-79 years), of whom seven had prior chemotherapy and 27 were chemotherapy-naive, received a median of six cycles (range 1-6). Complete and partial remissions were observed in two and 16 (including three pretreated) patients, respectively, for an overall response rate of 53%. Median response duration was 5 months (range 1-39+). Haematoxicity was manageable, despite grade 3 infections in 24% of patients, but other toxicities were mostly mild. An apparent shift of gemcitabine from plasma to erythrocytes occurred after docetaxel in five of six patients evaluable for this analysis. We conclude gemcitabine plus docetaxel is tolerable and highly active in treated and untreated patients with advanced transitional cell carcinoma.

Decreased response rates by the combination of histamine and IL-2 in melphalan-based isolated limb perfusion.

Histamine (Hi) combined to melphalan in a rat experimental model of isolated limb perfusion (ILP) for lower limb soft tissue sarcoma, resulted in overall response rates (OR) of 66%. Likewise, ILP with interleukin-2 (IL-2) resulted in OR of 67%, when combined to melphalan, in the same experimental model. In systemic immunotherapy, the combination of IL-2 and Hi has been used for solid tumor treatment based on immunomodulatory effects. In this study, we used our well-established ILP experimental model to evaluate whether the synergistic effect between the two drugs seen in the systemic setting, could further improve response rates in a loco-regional setting. Histological evaluation was done directly and 24 h after ILP. Melphalan uptake by tumor and muscle were measured. Hi and IL-2 together, combined to melphalan in the ILP led to OR of only 28%. Histology of tumors demonstrated partial loss of Hi-induced hemorrhagic effect when IL-2 was present. Melphalan accumulation in the tumor when both Hi and IL-2 were added (3.1-fold) was very similar to accumulation with Hi only (2.8-fold), or IL-2 only (3.5-fold) combined to melphalan. In vitro there was no synergy between the drugs. In conclusion there was a negative synergistic effect between IL-2 and Hi in the regional setting.

Association of enzyme and transporter genotypes with the pharmacokinetics of imatinib.

OBJECTIVE: Our objective was to explore the relationships between imatinib pharmacokinetics and 9 allelic variants in 7 genes coding for adenosine triphosphate-binding cassette transporters (ABCB1 and ABCG2) and enzymes (cytochrome P450 [CYP] 2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5) of putative relevance for imatinib. METHODS: Imatinib transport in vitro was studied by use of human embryonic kidney 293 cells transfected with wild-type ABCG2 and an ABCG2 Q141K clone. Steady-state pharmacokinetics of imatinib was obtained in 82 patients with gastrointestinal stromal tumors treated with oral imatinib at doses ranging from 100 to 1000 mg/d. Genotyping was carried out via direct sequencing or restriction fragment length polymorphism-based techniques. RESULTS: Human embryonic kidney 293 cells transfected with ABCG2 Q141K exhibited greater drug accumulation in vitro in comparison with cells expressing wild-type ABCG2 (P = .028). However, pharmacokinetic parameters of imatinib in vivo were not statistically significantly different in 16 patients who were heterozygous for ABCG2 421C>A compared with 66 patients carrying the wild-type sequence (P = .479). The apparent oral clearance of imatinib was potentially reduced in individuals with at least 1 CYP2D6*4 allele (median, 7.78 versus 10.6 L/h; P = .0695). Pharmacokinetic parameters were not related to any of the other multiple-variant genotypes (P >or= .230), possibly because of the low allele frequencies. CONCLUSIONS: This study indicates that common genetic variants in the evaluated genes have only a limited impact on the pharmacokinetics of imatinib. Further investigation is required to quantitatively assess the clinical significance of homozygous variant ABCG2 and CYP2D6 genotypes in patients treated with imatinib.

Early destruction of tumor vasculature in tumor necrosis factor-alpha-based isolated limb perfusion is responsible for tumor response.

Addition of high-dose tumor necrosis factor-alpha to melphalan-based isolated limb perfusion enhances anti-tumor effects impressively. Unfortunately, the mechanism of action of tumor necrosis factor-alpha is still not fully understood. Here, we investigated the effects of tumor necrosis factor-alpha on the tumor microenvironment and on secondary immunological events during and shortly after isolated limb perfusion in soft-tissue sarcoma-bearing rats. Already during isolated limb perfusion, softening of the tumor was observed. Co-administration of tumor necrosis factor-alpha in the isolated limb perfusion with melphalan induced a six-fold enhanced drug accumulation of melphalan in the tumor compared with isolated limb perfusion with melphalan alone. In addition, directly after perfusion with tumor necrosis factor-alpha plus melphalan, over a time-frame of 30 min, vascular destruction, erythrocyte extravasation and hemorrhage was detected. Interstitial fluid pressure and pH in the tumor, however, were not altered by tumor necrosis factor-alpha and no clear immune effects, cellular infiltration or cytokine expression were observed. Taken together, these results indicate that tumor necrosis factor-alpha induces rapid damage to the tumor vascular endothelial lining resulting in augmented drug accumulation. As other important parameters were not changed (e.g. interstitial fluid pressure and pH), we speculate that the tumor vascular changes, and concurrent hemorrhage and drug accumulation are the key explanations for the observed synergistic anti-tumor response.

Modified approach of administering cytostatics to the lung: more efficient isolated lung perfusion.

BACKGROUND: Isolated lung perfusion (ILuP) is an experimental technique for the treatment of pulmonary metastases. We hypothesized that part of the drug taken up by the lung during ILuP is washed out during the flush procedure. Therefore, we investigated gemcitabine uptake at different inflow concentrations, and the effect of delayed clamp release after ILuP on lung levels was studied. METHODS: Thirty rats had ILuP during 30 minutes using gemcitabine perfusate levels of 1.3, 2.7, 4.0, 5.3, and 6.7 mg/mL. Another 37 rats underwent ILuP with gemcitabine perfusate levels of 6.7 mg/mL during 6 minutes followed by a 5-minute flush and 30 or 60 minutes of reperfusion, while two other groups had ILuP and delayed clamp release for 30 or 60 minutes followed by a 5-minute flush. All effluent and lung samples were stored for later analysis. Results were evaluated using Friedmann two-way analysis and two-way analysis of variance. RESULTS: At 6 minutes, steady-state of gemcitabine uptake was achieved for all inflow concentrations and a linear relation (r = 0.933, p < 0.0001) between effluent and lung levels was observed. Delayed clamp release resulted in significantly higher lung levels compared with immediate restoration of blood circulation after ILuP (456% at 30 minutes and 828% at 60 minutes). CONCLUSIONS: Effective gemcitabine lung levels are already achieved after 6 minutes of ILuP with 6.7 mg/mL followed by delayed clamp release during 30 minutes instead of the clinically applied 30 minutes ILuP.