D C Talbot

University of Oxford, Oxford, ENG, United Kingdom

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Publications (46)269.82 Total impact

  • Article: Reply: Metronomic chemotherapy with cyclophosphamide and dexamethasone in patients with metastatic carcinoma of the prostate.
    British Journal of Cancer 03/2012; · 5.04 Impact Factor
  • Article: Continuous low-dose cyclophosphamide and methotrexate combined with celecoxib for patients with advanced cancer.
    British Journal of Cancer 10/2011; 105(8):1252. · 5.04 Impact Factor
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    Article: Continuous low-dose cyclophosphamide and methotrexate combined with celecoxib for patients with advanced cancer.
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    ABSTRACT: Combined therapy of metronomic cyclophosphamide, methotrexate and high-dose celecoxib targeting angiogenesis was used in a phase II trial. Patients with advanced cancer received oral cyclophosphamide 50 mg o.d., celecoxib 400 mg b.d. and methotrexate 2.5 mg b.d. for two consecutive days each week. Response was determined every 8 weeks; toxicity was evaluated according to CTC version 2.0. Plasma markers of inflammation, coagulation and angiogenesis were measured. Sixty-seven of 69 patients were evaluable for response. Twenty-three patients had stable disease (SD) after 8 weeks, but there were no objective responses to therapy. Median time to progression was 57 days. There was a low incidence of toxicities. Among plasma markers, levels of tissue factor were higher in the SD group of patients at baseline, and levels of both angiopoietin-1 and matrix metalloproteinase-9 increased in the progressive disease group only. There were no changes in other plasma markers. This metronomic approach has negligible activity in advanced cancer albeit with minimal toxicity. Analysis of plasma markers indicates minimal effects on endothelium in this trial. These data for this particular regimen do not support basic tenets of metronomic chemotherapy, such as the ability to overcome resistant tumours by targeting the endothelium.
    British Journal of Cancer 06/2011; 104(12):1822-7. · 5.04 Impact Factor
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    Article: Phase II study of single agent capecitabine in the treatment of metastatic non-pancreatic neuroendocrine tumours.
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    ABSTRACT: This study sought to determine the safety of single agent capecitabine, a pro-drug of 5FU, in patients with metastatic non-pancreatic neuroendocrine tumours (NETs). Multicentre phase II, first-line study design. Oral capecitabine was administered on days 1-14 of 3-week cycles. Treatment was safe and well tolerated. Common toxicities were diarrhoea and fatigue. The study provides evidence to support the use of capecitabine as a substitute for infusional 5FU in the management of NETs.
    British Journal of Cancer 03/2011; 104(7):1067-70. · 5.04 Impact Factor
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    Article: Phase II trial of the antiangiogenic agent IM862 in metastatic renal cell carcinoma.
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    ABSTRACT: IM862 is a naturally occurring dipeptide (L-glu-L-trp) with immunomodulatory and antiangiogenic properties. A significant anticancer activity has been reported recently in AIDS-related Kaposi's sarcoma, a tumour of endothelial cell origin. The high vascularity and responsiveness to immunotherapy of renal cell carcinoma (RCC) makes such a tumour a potential target for IM862. In all, 25 patients were accrued in a prospective phase II trial using a standard two-step design. The main inclusion criteria were WHO performance status </=2, age over 18 years, expected survival >3 months, normal marrow, kidney and liver functions. IM862 was given intranasally at a dose of 20 mg three times daily. Each cycle consisted of 8 consecutive weeks of treatment. All 25 patients were fully evaluable for response and 24 for toxicities. Median age was 62 years (range 42-76), median WHO PS was 1 (0-2). No grade 2 or 3 toxicities related to the study drug have been recorded. Eight patients had stable disease (SD) and 17 progressed while on treatment. Median survival was 7.9 months (range 2.7-20). Median time to progression was 1.9 months (range 1.2-12.6). Median duration of SD was 6 months (range 5.2-12.6+). Analysis of blood angiogenic markers showed a significant decrease of plasma vascular endothelial growth factor (VEGF) levels after 4 and 8 weeks of therapy. Treatment with IM862 has no toxicity, but does not lead to any significant objective responses in metastatic RCC. IM862 should not be further evaluated as a single agent at these doses and schedule for this population of patients. The decrease in VEGF levels warrants further investigation of IM862 as an antiangiogenic therapy.
    British Journal of Cancer 11/2004; 91(9):1645-50. · 5.04 Impact Factor
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    Article: Combination antiangiogenesis therapy with marimastat, captopril and fragmin in patients with advanced cancer.
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    ABSTRACT: Marimastat, low molecular weight heparins and captopril have antiangiogenic activity in vitro and in animal models. We studied the safety and efficacy of the combination of these drugs in patients with advanced cancer. In all, 50 patients were enrolled. Captopril was given orally at a dose of 50 mg bd daily. Fragmin was administered as a daily subcutaneous injection of 200 units kg(-1) for the first 28 days and 5000 units thereafter. Marimastat was given at 10 mg bd orally. Serum, plasma and urinary angiogenic factors were measured at baseline and after 1 month of treatment. Inhibition of release of tumour necrosis factor alpha (TNF-alpha) from peripheral lymphocytes was used as a surrogate pharmacodynamic end point. There was one case of haemorrhagic stroke and one upper gastrointestinal haemorrhage. The commonest toxicity was myalgia. One of 10 patients with renal cancer had a partial response, and three patients had a prolonged period of stable disease. The treatment significantly inhibited phytohaemagglutinin (PHA)-stimulated TNF-alpha release from patient's lymphocytes. The combination of marimastat, fragmin and captopril is well tolerated and has in vivo activity. Inhibition of PHA-stimulated TNF-alpha release from lymphocytes is a surrogate pharmacodynamic marker of metalloprotease inhibition.
    British Journal of Cancer 08/2004; 91(1):30-6. · 5.04 Impact Factor
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    Article: Comparison of prognostic factors in patients in phase I trials of cytotoxic drugs vs new noncytotoxic agents.
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    ABSTRACT: The aims of this study were to identify prognostic variables for toxicity and survival in patients with cancer participating in phase I clinical trials and compare characteristics of those treated with cytotoxic chemotherapy (CT) and non-cytotoxic drugs (non-CT). Data were collected from 420 (114 CT, 306 non-CT) patients enrolled in 16 phase I trials (five CT and 11 non-CT trials) in one cancer centre. Analyses of all patients were used to compare treatment groups, identify predictive variables for toxicity and to estimate prognostic factors in overall survival (OS). These were used to develop a prognostic index (PI). Multivariate analysis found those patients with better performance status, fewer sites of metastases, baseline Hb>12 g dl(-1) and WBC or LDH in the normal range had significantly better OS. Male gender, platelet count <450 x 10(9) l(-1), high WBC or treatment with a non-CT phase I agent significantly reduced the chance of grade 3/4 toxicity. Overall survival was not significantly different between the CT and non-CT groups (260 vs 192 days, P=0.47) except for those with liver metastases (228 vs 137 days, P=0.02). Overall tumour response was 4.9% (95% CI: 2.7-7.0%). The PI identified three distinct patient groups with median survival of 321, 257 and 117 days. In conclusion, entry into a phase I trial of a non-CT drug is a safe option for heavily pretreated patients with cancer. The PI generated from these data can estimate the survival probability for patients entering phase I studies.
    British Journal of Cancer 11/2003; 89(7):1166-71. · 5.04 Impact Factor
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    Article: A phase 1 study of tazarotene in adults with advanced cancer.
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    ABSTRACT: Tazarotene is an acetylenic retinoid which is metabolised to tazarotenic acid and which binds selectively to the retinoid receptors RARbeta and RARgamma. The safety, toxicity and pharmacokinetics of oral tazarotene were determined over 12 weeks of treatment in 34 patients with advanced cancer. Commonly seen toxicities were mucocutaneous symptoms, musculoskeletal pain and headache. Dose-limiting toxicities were hypercalcaemia, hypertriglyceridaemia and musculoskeletal pain. The maximum tolerated dose of tazarotene in this schedule is 25.2 mg day(-1). Plasma concentrations of tazarotenic acid were found to peak rapidly within 1-3 h of dosing and thereafter declined quickly. The C(max) and AUC values on day 0, and weeks 2 and 4 were similar indicating no drug accumulation. The dose-normalised C(max) and AUC values at different dose levels and different study days appeared to be similar indicating linear pharmacokinetics. No objective responses were seen, although stable disease was seen in six out of eight evaluable patients receiving the three highest dose levels of tazarotene (16.8, 25.2 or 33.4 mg day(-1)). We conclude that oral tazarotene is well tolerated when administered daily for 12 weeks, has a favourable toxicity profile compared with other retinoids and merits further investigation as an anticancer therapy.
    British Journal of Cancer 10/2003; 89(5):808-15. · 5.04 Impact Factor
  • Article: Phase II study of exatecan mesylate (DX-8951f) as first line therapy for advanced non-small cell lung cancer.
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    ABSTRACT: Exatecan mesylate (DX-8951f) is a water soluble analogue of camptothecin that inhibits topoisomerase I. This multi-centre phase II study evaluated the activity of single agent exatecan in previously untreated patients with advanced non-small cell lung cancer (NSCLC). Patients with histologically or cytologically proven stage IIIb or IV NSCLC were treated with exatecan 0.5 mg/m(2) per day by 30 min intra-venous (i.v.) infusion for 5 days every 3 weeks to a maximum of six cycles. Measurable disease was documented prior to study entry and patients were re-staged every two cycles. Pharmacokinetic (PK) sampling was performed during cycle one. 39 patients (32 patients ECOG performance status 0 or 1; 29 male and ten female; mean age 63 years) were entered into the study. Thirty-three completed at least two cycles of exatecan and 11 completed six cycles. Two patients (5.1%, 95% C.I. 0.3-21.3%) had a partial response, 7 (18.0%) minor response and 8 (20.5%) stable disease. Median time to tumour progression (TTP) was 88 days and median overall survival 262 days. The main toxicity was reversible neutropenia. PK analysis of exatecan demonstrated a mean clearance of 2.28 l/h per m(2), volume of distribution 18.2 l/m(2) and mean elimination half-life of 7.9 h. Exatecan mesylate has limited activity in advanced NSCLC and is not recommended for further evaluation as a single agent in this tumour type. PK data from this trial supports results established in phase I studies.
    Lung Cancer 09/2003; 41(2):215-9. · 3.43 Impact Factor
  • Article: Phase I and pharmacokinetic study of the topoisomerase I inhibitor, exatecan mesylate (DX-8951f), using a weekly 30-minute intravenous infusion, in patients with advanced solid malignancies.
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    ABSTRACT: The topoisomerase I inhibitor exatecan mesylate (DX-8951f ) is a water-soluble hexacyclic analogue of camptothecin that does not require enzymatic activation. This study determined the toxicity, maximum tolerated dose (MTD), pharmacokinetics and pharmacodynamics of a weekly intravenous (i.v.) schedule of DX-8951f. Thirty-five patients with advanced solid malignancies, stratified as minimally (MP) or heavily (HP) pre-treated, received escalating doses of DX-8951f as 30-min i.v. infusions for three out of every 4 weeks. Pharmacokinetics were described after the first infusion of DX-8951f. Infusions (244) of DX-8951f were administered with a median of two cycles (range 1-10). The main toxicity observed was haematological. There was no significant gastrointestinal toxicity. Two patients (6%) had confirmed partial responses. Twelve patients (39%) had stable disease. DX-8951f had a terminal elimination half-life of approximately 8 h and a clearance of 2 l/h/m(2). The area under the plasma concentration versus time curve (AUC( infinity )) and the maximum plasma concentration (C(max)) increased linearly with the dose. A linear relationship was present for the percentage decrease in neutrophil counts or platelet counts and AUC( infinity ) as well as C(max). The dose-limiting toxicity of DX-8951f is neutropenia for MP patients and neutropenia and thrombocytopenia for HP patients. Evidence for clinical activity was seen, suggesting phase II study of the drug is indicated. Using this schedule the recommended dose is 2.75 mg/m(2)/week for MP patients and 2.10 mg/m(2)/week for HP patients.
    Annals of Oncology 07/2003; 14(6):913-21. · 6.43 Impact Factor
  • Article: Use of positron emission tomography in pharmacokinetic studies to investigate therapeutic advantage in a phase I study of 120-hour intravenous infusion XR5000.
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    ABSTRACT: XR5000 (N-[2-(dimethylamino)ethyl]acridine-4-carboxamide) is a topoisomerase I and II inhibitor. Because the cytotoxicity of XR5000 increases markedly with prolonged exposure, we performed a phase I study of weekly XR5000 by 120-hour continuous infusion over 3 weeks. Twenty-four patients with advanced solid cancer were treated at seven dose levels (700 to 4,060 mg/m2/120 hrs) for a total of 67 cycles. Three patients underwent positron emission tomography (PET) studies at the maximum-tolerated dose (MTD) to evaluate normal tissue and tumor carbon-11 radiolabeled XR5000 ([11C]XR5000) pharmacokinetics. The dose-limiting toxicity was National Cancer Institute Common Toxicity Criteria (version 1) grade 4 chest and abdominal pain affecting the single patient receiving 4,060 mg/m2/120 hours, and the MTD was 3,010 mg/m2/120 hours. Other grade 3-4 toxicities, affecting single patients at the MTD, were myelosuppression (grade 4), raised bilirubin, vomiting, and somnolence (all grade 3). There was one partial response (adenocarcinoma of unknown primary); the remainder had progressive disease. [11C]XR5000 distributed well into the three tumors studied by PET. Tumor uptake (maximum concentration or area under the concentration versus time curve [AUC]) was less than in normal tissue in which the tumors were located. Tumor exposure (AUC; mean +/- SD in m2/mL/sec) increased when [(11)C]XR5000 was administered during an infusion of XR5000 (0.242 +/- 0.4), compared with [11C]XR5000 given alone (0.209 +/- 0.04; P <.05), indicating that tumor drug exposure was not saturated [corrected]. The recommended dose for XR5000 in phase II studies is 3,010 mg/m2/120 hours. PET studies with 11C-labeled drug were feasible and demonstrated in vivo distribution into tumors. Saturation of tumor exposure was not reached at the MTD.
    Journal of Clinical Oncology 01/2003; 21(2):203-10. · 18.37 Impact Factor
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    Article: Randomised, phase II trial comparing oral capecitabine (Xeloda) with paclitaxel in patients with metastatic/advanced breast cancer pretreated with anthracyclines.
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    ABSTRACT: Capecitabine, an oral fluoropyrimidine carbamate, was designed to generate 5-fluorouracil preferentially at the tumour site. This randomised, phase II trial evaluated the efficacy and safety of capecitabine or paclitaxel in patients with anthracycline-pretreated metastatic breast cancer. Outpatients with locally advanced and/or metastatic breast cancer whose disease was unresponsive or resistant to anthracycline therapy were randomised to 3-week cycles of intermittent oral capecitabine (1255 mg m(-2) twice daily, days 1-14, (22 patients)) or a reference arm of i.v. paclitaxel (175 mg m(-2), (20 patients)). Two additional patients were initially randomised to continuous capecitabine 666 mg m(-2) twice daily, but this arm was closed following selection of the intermittent schedule for further development. Overall response rate was 36% (95% CI 17-59%) with capecitabine (including three complete responses) and 26% (95% CI 9-51%) with paclitaxel (no complete responses). Median time to disease progression was similar in the two treatment groups (3.0 months with capecitabine, 3.1 months with paclitaxel), as was overall survival (7.6 and 9.4 months, respectively). Paclitaxel was associated with more alopecia, peripheral neuropathy, myalgia and neutropenia, whereas typical capecitabine-related adverse events were diarrhoea, vomiting and hand-foot syndrome. Twenty-three per cent of capecitabine-treated patients and 16% of paclitaxel-treated patients achieved a > or =10% improvement in Karnofsky Performance Status. Oral capecitabine is active in anthracycline-pretreated advanced/metastatic breast cancer and has a favourable safety profile. Furthermore, capecitabine provides a convenient, patient-orientated therapy.
    British Journal of Cancer 05/2002; 86(9):1367-72. · 5.04 Impact Factor
  • Article: Phase I and pharmacological study of the oral matrix metalloproteinase inhibitor, MMI270 (CGS27023A), in patients with advanced solid cancer.
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    ABSTRACT: This Phase I study of MMI270, an p.o. administered matrix metalloproteinase inhibitor, assessed toxicity, pharmacokinetics, and tumor response data and investigated markers of biological activity to recommend a dose for Phase II studies. MMI270 was administered continuously at seven dose levels (50 mg once daily to 600 mg three times/day). Patients were evaluated for toxicity and tumor response, and blood and urine samples were taken for pharmacokinetics, bone resorption markers, direct targets of the inhibitor [matrix metalloproteinase-2 (MMP-2), MMP-8, and MMP-9], indirect targets [tissue inhibitor of metalloproteinase-1 (TIMP-1), TIMP-2, basic fibroblast growth factor, vascular endothelial growth factor, vascular cell adhesion molecule-1, soluble urokinase plasminogen activator receptor, and cathepsins B and H] and for a tumor necrosis factor-alpha cytokine release assay. Ninety-two patients were entered. There was no myelotoxicity. Eighteen patients developed a widespread maculopapular rash, which increased in frequency and severity at doses > or = 300 mg bid. Thirty nine patients developed musculoskeletal side effects, which were related to duration of treatment, not to dose level. Pharmacokinetics were linear, and MMI270 was rapidly absorbed and eliminated with minimal accumulation on chronic dosing. Sustained plasma concentrations in excess of 4 x mean IC(50) for the target enzymes were observed at dose levels > or = 150 mg bid. There were no tumor regressions; however, 19 patients had stable disease for > or = 90 days. There was a dose-response increase of MMP-2 and TIMP-1 with MMI270. Transient effects on the bone resorption markers were detected. MMI270 was generally well tolerated, with adequate plasma levels for target enzyme inhibition. The two main toxicities were rash, resulting in a maximum tolerated dose of 300 mg bid and musculoskeletal side effects. Biological marker data indicate drug effects. The rise in TIMP-1 suggests that a reflex rise in inhibitors could modify the effects of MMI270. The recommended Phase II dose is 300 mg bid.
    Clinical Cancer Research 08/2001; 7(7):1912-22. · 7.74 Impact Factor
  • Article: Phase I and pharmacokinetic study of PKC412, an inhibitor of protein kinase C.
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    ABSTRACT: N-Benzoyl staurosporine (PKC412) is a protein kinase C inhibitor with antitumor activity in laboratory models. We determined the toxicity of oral PKC412 administered daily for repeat cycles of 28 days. Thirty-two patients with advanced solid cancers were treated at seven dose levels (12.5 to 300 mg daily) for a total of 68 cycles. The most frequent treatment-related toxicities were nausea, vomiting, fatigue, and diarrhea. At the two top dose levels (225 and 300 mg/d), 15 of 16 patients experienced nausea/vomiting (common toxicity criteria [CTC], version 1), grade 2 in nine of 16 and grade 3 in three of 16 patients; and six of 16 patients developed CTC grade 2 diarrhea. After 1 month of treatment, there were significant reductions in circulating lymphocyte (P <.02) and monocyte (P <.01) counts in patients receiving doses > or = 100 mg/d. Nevertheless, only two patients developed myelosuppression (both grade 2). Of two patients with progressive cholangiocarcinoma, one attained stable disease lasting 4.5 months and one a partial response lasting 4 months. There was a linear relationship between PKC412 dose and area under the curve (0-24 hours) and maximum plasma concentration with marked interpatient variability. The estimated median elimination half-life was 1.6 days (range, 0.9 to 4.0 days), and a metabolite with a median half-life of 36 days was detected. Steady-state PKC412 plasma levels at the top three dose cohorts (150 to 300 mg) were five to 10 times the cellular 50% inhibitory concentration for PKC412 of 0.2 to 0.7 micromol/L. PKC412 can be safely administered by chronic oral therapy, and 150 mg/d is suitable for phase II studies. The pharmacokinetics and lack of conventional toxicity indicate that pharmacodynamic measures may be additionally needed to optimize the drug dose and schedule.
    Journal of Clinical Oncology 04/2001; 19(5):1485-92. · 18.37 Impact Factor
  • Article: A phase II study of razoxane, an antiangiogenic topoisomerase II inhibitor, in renal cell cancer with assessment of potential surrogate markers of angiogenesis.
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    ABSTRACT: Renal cell carcinoma (RCC) is an angiogenic tumor resistant to standard cytotoxic chemotherapeutic agents. Although often responsive to immunomodulatory agents including interleukin 2 and IFN-alpha, the overall results in randomized Phase III studies are disappointing with only modest improvements in overall survival. This Phase II study evaluated the efficacy and tolerability of razoxane, an antiangiogenic topoisomerase II inhibitor, in 40 patients (32 men, 8 women; age: range, 31-76 years; median, 58 years) with inoperable RCC. Twenty patients received razoxane 125 mg p.o., twice a day for 5 days each week for 8 weeks (one cycle). This was repeated in patients with stable disease (StD), but was discontinued after 16 weeks if there was no evidence of an objective response. Because minimal toxicity was seen, subsequent patients (n = 20) were treated until progressive disease (PD) was documented. Of 38 evaluable patients, 11 (29%) had StD for a minimum of 4 months, and the remainder had PD. Median overall survival was 7.3 months. Duration of survival was significantly better in patients with StD compared with those with PD (P = 0.003). The effect of treatment on six potential surrogate serum/plasma (vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), urokinase plasminogen activator soluble receptor (uPAsr), E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and von Willebrand's factor (vWF) and two urinary (VEGF and bFGF) markers of angiogenesis was evaluated before and after 1 cycle of treatment. Pretreatment serum VEGF and E-selectin levels above the median value were associated with a poor prognosis. Serum VCAM-1 levels and urinary VEGF levels rose significantly after one cycle in patients with PD but not in those with StD. Serum VEGF, bFGF, VCAM-1 and vWF, plasma uPAsr and urinary bFGF levels were significantly higher in PD patients compared with StD patients before and/or after 1 cycle of treatment. In conclusion, razoxane is an antiangiogenic agent that has minimal toxicity and that requires further evaluation in combination with other active agents in the treatment of RCC. Surrogate serum and urinary markers of angiogenesis may have a role to play in predicting disease response and overall survival in RCC.
    Clinical Cancer Research 01/2001; 6(12):4697-704. · 7.74 Impact Factor
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    Article: Induction of thymidine phosphorylase as a pharmacodynamic end-point in patients with advanced carcinoma treated with 5-fluorouracil, folinic acid and interferon alpha.
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    ABSTRACT: Thymidine phosphorylase (TP) is an essential enzyme for the biochemical activation of 5-fluorouracil (5-FU). Interferon upregulates TP in vivo, although the dose and schedule of interferon for optimal biomodulation of 5-FU is not known. In this study, TP activity was measured in peripheral blood lymphocytes (PBLs) from patients with advanced carcinoma receiving treatment with 5-FU and folinic acid. Cohorts of patients were treated with interferon alpha (IFNalpha), immediately prior to 5-FU/folinic acid, at doses of 3 MIU m(-2), 9 MIU m(-2) and 18 MIUm(-2). IFNalpha was administered on day 0 cycle two, day-1 and day 0 cycle three and day-2, day-1 and day 0 cycle four. A fourth cohort was treated with IFNalpha 9 MIU m(-2) three times per week from cycle 2 onwards. Twenty-one patients were entered into the study with 19 evaluable for response. Six patients (32%) had stable disease and 13 (68%) progressive disease. There were no grade-IV toxicities. TP activity was detected in PBLs from all patients with wide interpatient variability in constitutive TP activity prior to chemotherapy, and in response to IFNalpha. 5-FU/folinic acid alone did not induce TP activity but a single dose of IFNalpha led to upregulation of TP within 2 h of administration with a further increase by 24 h (signed rank test, P = 0.006). TP activity remained elevated for at least 13 days (signed rank test, P= 0.02). There were no significant differences in TP activity between schedules or with additional doses of IFNalpha. A single dose of IFNalpha as low as 3 MIU m(-2) can cause sustained elevation of PBL TP activity in vivo indicating that biochemical markers are important pharmacodynamic endpoints for developing optimal schedules of IFNalpha for biomodulation of 5-FU.
    British Journal of Cancer 08/2000; 83(2):219-24. · 5.04 Impact Factor
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    Article: Phase II study of the oxygen saturation curve left shifting agent BW12C in combination with the hypoxia activated drug mitomycin C in advanced colorectal cancer.
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    ABSTRACT: BW12C (5-[2-formyl-3-hydroxypenoxyl] pentanoic acid) stabilizes oxyhaemoglobin, causing a reversible left-shift of the oxygen saturation curve (OSC) and tissue hypoxia. The activity of mitomycin C (MMC) is enhanced by hypoxia. In this phase II study, 17 patients with metastatic colorectal cancer resistant to 5-fluorouracil (5-FU) received BW12C and MMC. BW12C was given as a bolus loading dose of 45 mg kg(-1) over 1 h, followed by a maintenance infusion of 4 mg kg(-1) h(-1) for 5 h. MMC 6 mg m(-2) was administered over 15 min immediately after the BW12C bolus. The 15 evaluable patients had progressive disease after a median of 2 (range 1-4) cycles of chemotherapy. Haemoglobin electrophoresis 3 and 5 h after the BW12C bolus dose showed a fast moving band consistent with the BW12C-oxyhaemoglobin complex, accounting for approximately 50% of total haemoglobin. The predominant toxicities--nausea/vomiting and vein pain--were mild and did not exceed CTC grade 2. Liver 31P magnetic resonance spectroscopy of patients with hepatic metastases showed no changes consistent with tissue hypoxia. The principle of combining a hypoxically activated drug with an agent that increases tissue hypoxia is clinically feasible, producing an effect equivalent to reducing tumour oxygen delivery by at least 50%. However, BW12C in combination with MMC for 5-FU-resistant colorectal cancer is not an effective regimen. This could be related to drug resistance rather than a failure to enhance cytotoxicity.
    British Journal of Cancer 07/2000; 82(11):1776-82. · 5.04 Impact Factor
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    Article: Phase II study of second-line therapy with DTIC, BCNU, cisplatin and tamoxifen (Dartmouth regimen) chemotherapy in patients with malignant melanoma previously treated with dacarbazine.
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    ABSTRACT: This study assessed response rates to combination dacarbazine (DTIC), BCNU (carmustine), cisplatin and tamoxifen (DBPT) chemotherapy in patients with progressive metastatic melanoma previously treated with DTIC, as an evaluation of DBPT as a second-line regimen, and as an indirect comparison of DBPT with DTIC. Thirty-five consecutive patients received DBPT. The patients were divided into two groups. Group 1 comprised 17 patients with progressive disease (PD) on DTIC + tamoxifen therapy who were switched directly to DBPT. Group 2 comprised 18 patients not immediately switched to DBPT and included patients who had either a partial response (PR; one patient) or developed stable disease (SD; four patients) with DTIC, or received adjuvant DTIC (nine patients). All except four patients had received tamoxifen at the time of initial DTIC treatment. Median times since stopping DTIC were 22 days (range 20-41) and 285 days (range 50-1,240) in Groups 1 and 2 respectively. In Group 1, one patient developed SD for 5 months and the remainder had PD. In Group 2, there were two PRs, four patients with SD (4, 5, 6, and 6 months), and 11 with PD. These results indicate that the DBPT regimen is not of value in melanoma primarily refractory to DTIC. There were responses in patients not directly switched from DTIC to DBPT, suggesting combination therapy may be of value in a small subgroup of melanoma patients.
    British Journal of Cancer 07/2000; 82(11):1759-63. · 5.04 Impact Factor
  • Article: Evaluation of the alkaline comet assay and urinary 3-methyladenine excretion for monitoring DNA damage in melanoma patients treated with dacarbazine and tamoxifen.
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    ABSTRACT: To develop, using dacarbazine as a model, reliable techniques for measuring DNA damage and repair as pharmacodynamic endpoints for patients receiving chemotherapy. A group of 39 patients with malignant melanoma were treated with dacarbazine 1 g/m(2) i.v. every 21 days. Tamoxifen 20 mg daily was commenced 24 h after the first infusion and continued until 3 weeks after the last cycle of chemotherapy. DNA strand breaks formed during dacarbazine-induced DNA damage and repair were measured in individual cells by the alkaline comet assay. DNA methyl adducts were quantified by measuring urinary 3-methyladenine (3-MeA) excretion using immunoaffinity ELISA. Venous blood was taken on cycles 1 and 2 for separation of peripheral blood lymphocytes (PBLs) for measurement of DNA strand breaks. Wide interpatient variation in PBL DNA strand breaks occurred following chemotherapy, with a peak at 4 h (median 26.6 h, interquartile range 14.75-40.5 h) and incomplete repair by 24 h. Similarly, there was a range of 3-MeA excretion with peak levels 4-10 h after chemotherapy (median 33 nmol/h, interquartile range 20.4-48.65 nmol/h). Peak 3-MeA excretion was positively correlated with DNA strand breaks at 4 h (Spearman's correlation coefficient, r=0.39, P=0.036) and 24 h (r=0.46, P=0.01). Drug-induced emesis correlated with PBL DNA strand breaks (Mann Whitney U-test, P=0.03) but not with peak 3-MeA excretion. DNA damage and repair following cytotoxic chemotherapy can be measured in vivo by the alkaline comet assay and by urinary 3-MeA excretion in patients receiving chemotherapy.
    Cancer Chemotherapy and Pharmacology 02/2000; 45(2):111-9. · 2.83 Impact Factor
  • Article: Evaluation of toremifene for reversal of multidrug resistance in renal cell cancer patients treated with vinblastine.
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    ABSTRACT: Expression of P-glycoprotein (Pgp), which confers the multidrug resistance (MDR) phenotype, is thought to contribute to the insensitivity of renal cell cancer (RCC) to chemotherapy. The development of Pgp inhibitors for clinical application has been hampered by unacceptable toxicity at doses required to achieve adequate cellular concentration. Toremifene is able to reverse MDR and sensitise RCC to vinblastine in vitro. However, in vivo toremifene is tightly bound to serum proteins, in particular the acute phase protein alpha1-acid glycoprotein (AAG), which may limit tissue availability. In this phase I-II study we assessed the tolerability of short courses of high dose toremifene in combination with vinblastine and evaluated the key determinants of MDR reversal in vivo. Twenty-seven patients with metastatic RCC received escalating doses of oral toremifene for 3 days every 2 weeks in combination with vinblastine 6 mg/m2 i.v. on day 3 of each cycle. The serum concentration of toremifene, its metabolites and AAG were measured and the effect of patients' serum on inhibition of Pgp in vitro was determined. Twenty-six patients were evaluable for response. Eight patients (31%) had stable disease and 18 patients (69%) progressive disease. The mean serum concentration of toremifene at 780 mg daily for 3 days was 7.82 microM [standard deviation (SD) 2.48, range 2.50 to 14.70], which exceeds that known to reverse MDR in vitro. The serum concentration of the major metabolite of toremifene, N-demethyltoremifene, which also reverses MDR, was 5.13 microM (SD 1.78, range 1.80 to 9.00). In 60% of patients the pre-treatment AAG concentration was above that known to block the effects of toremifene in vitro. However, addition of serum from patients on toremifene to MCF-7 adr cells in vitro inhibited Pgp-mediated efflux of rhodamine 123. We have shown that short course, high-dose toremifene in combination with vinblastine is generally well tolerated and that the concentration of toremifene required to reverse MDR in vitro is achievable in vivo.
    Cancer Chemotherapy and Pharmacology 02/2000; 46(1):27-34. · 2.83 Impact Factor

Institutions

  • 1999–2012
    • University of Oxford
      • Department of Oncology
      Oxford, ENG, United Kingdom
  • 2003
    • Cancer Research UK
      London, ENG, United Kingdom
  • 1998
    • The University of Manchester
      • School of Pharmacy and Pharmaceutical Sciences
      Manchester, ENG, United Kingdom
  • 1995–1998
    • John Radcliffe Hospital
      Oxford, ENG, United Kingdom