PubMed Health⌕ Search

Biomedical subjects

G Jayson

Publications and source records attributed to G Jayson.

17 recordsLinked to original sources
PubMed2006

Method validation and preliminary qualification of pharmacodynamic biomarkers employed to evaluate the clinical efficacy of an antisense compound (AEG35156) targeted to the X-linked inhibitor of apoptosis protein XIAP.

Data are presented on pharmacodynamic (PD) method validation and preliminary clinical qualification of three PD biomarker assays. M65 Elisa, which quantitates different forms of circulating cytokeratin 18 (CK18) as putative surrogate markers of both apoptotic and nonapoptotic tumour cell death, was shown to be highly reproducible: calibration curve linearity r2 = 0.996, mean accuracy > 91% and mean precision < 3%, n = 27. Employing recombinant (r) CK18 and caspase cleaved CK18 (CK18 Asp396 neo-epitope) as external standards, kit to kit reproducibly was < 6% (n = 19). rCK18 was stable in plasma for 4 months at -20 degrees C and -80 degrees C, for 4 weeks at 4 degrees C and had a half-life of 2.3 days at 37 degrees C. Cytokeratin 18 Asp396 NE, the M30 Apoptosense Elisa assay antigen, was stable in plasma for 6 months at -20 degrees C and -80 degrees C, for 3 months at 4 degrees C, while its half-life at 37 degrees C was 3.8 days. Within-day variations in endogenous plasma concentrations of the M30 and M65 antigens were assessed in two predose blood samples collected from a cohort of 15 ovarian cancer patients receiving carboplatin chemotherapy and were shown to be no greater than the variability associated with methods themselves. Between-day fluctuations in circulating levels of the M30 and M65 antigens and in XIAP mRNA levels measured in peripheral blood mononuclear cells by quantitative (q) RT-PCR were evaluated in two predose blood samples collected with a 5- to 7-day gap from 23 patients with advanced cancer enrolled in a phase I trial. The mean variation between the two pretreatment values ranged from 13 to 14 to 25%, respectively, for M65, M30 and qRT-PCR. These data suggest that the M30 and M65 Elisa's and qRT-PCR as PD biomarker assays have favourable performance characteristics for further investigation in clinical trials of anticancer agents which induce tumour apoptosis/necrosis or knockdown of the anti-apoptotic protein XIAP.

Apoptosis↗
PubMed2005

Targeted antitumour therapy--future perspectives.

The advent of targeted therapy presents an unprecedented opportunity for advances in the treatment of cancer. A key challenge will be to translate the undoubted promise of targeted agents into tangible clinical benefits. Achieving this goal is likely to be dependent upon a number of factors. These include continued research to improve our understanding of the heterogeneity and complexity of the tumour microenvironment; refinement of clinical trial design to incorporate nontraditional end points such as the optimum biological dose and health-related quality of life; and the use of technological advancements in proteomics, genomics and biomarker development to better predict tumour types and patient subsets that may be particularly responsive to treatment, as well as enable a more accurate assessment of drug effect at the molecular level. In summary, the future success of targeted agents will require an integrated multidisciplinary approach involving all stakeholders.

Antibodies, Monoclonal↗
PubMed2003

Paclitaxel plus platinum-based chemotherapy versus conventional platinum-based chemotherapy in women with relapsed ovarian cancer: the ICON4/AGO-OVAR-2.2 trial.

BACKGROUND: Despite improvements in the treatment of ovarian cancer, most patients develop recurrent disease within 3 years of diagnosis. There is no agreed second-line treatment at relapse. We assessed paclitaxel plus platinum chemotherapy as such treatment. METHODS: In parallel international, multicentre, randomised trials, between January, 1996, and March, 2002, 802 patients with platinum-sensitive ovarian cancer relapsing after 6 months of being treatment-free were enrolled from 119 hospitals in five countries. Patients were randomly assigned paclitaxel plus platinum chemotherapy or conventional platinum-based chemotherapy. Analysis was by intention to treat, except for toxic effects. FINDINGS: With a median follow-up of 42 months, 530 patients have died. Survival curves showed a difference in favour of paclitaxel plus platinum (hazard ratio 0.82 [95% CI 0.69-0.97], p=0.02), corresponding to an absolute difference in 2-year survival of 7% between the paclitaxel and conventional treatment groups (57 vs 50% [95% CI for difference 1-12]), and median survival of 5 months (29 vs 24 months [1-11). 717 patients developed progressive disease or died. The progression-free survival curves show a difference in favour of paclitaxel plus platinum (hazard ratio 0.76 [0.66-0.89], p=0.0004), corresponding to an absolute difference in 1-year progression-free survival of 10% (50 vs 40% [4-15]) and in median progression-free survival of 3 months (13 vs 10 months [1-5]). INTERPRETATION: Paclitaxel plus platinum chemotherapy seems to improve survival and progression-free survival among patients with relapsed platinum-sensitive ovarian cancer compared with conventional platinum-based chemotherapy.

Aged↗
PubMed2002

Breath-hold perfusion and permeability mapping of hepatic malignancies using magnetic resonance imaging and a first-pass leakage profile model.

We have applied a novel pharmacokinetic model of the distribution of contrast media to dynamic contrast-enhanced MRI data from patients with hepatic neoplasms. The model uses data collected during the passage of a bolus of contrast medium and allows breath-hold image acquisition. The aims of the study were to investigate the feasibility of permeability mapping using the first pass technique and breath-hold acquisitions, and to examine the reproducibility of the technique and the effect of the liver's dual vascular supply on the assumptions of the model. Imaging was performed in 14 patients with hepatic neoplasms. Dynamic data clearly demonstrated differences in the timing and shape of the contrast medium concentration-time course curve in the systemic arterial and portal venous systems. Mapping of the arrival time (T(0)) of contrast medium allowed identification of tissue supplied by the hepatic arteries and portal vein. Hepatic tumours all showed typical hepatic arterial enhancement. Repeated measurements of endothelial permeability surface area product (k(fp)) and relative blood volume (rBV), performed in five patients, showed excellent reproducibility with variance ratios (V(r)) of 0.134 and 0.113, respectively. Measurement of enhancing tumour volume was also highly reproducible (V(r) = 0.096) and this was further improved by the use of T(0) maps to identify pixels supplied by the hepatic artery (V(r) = 0.026). Estimates of k(fp) and rBV in normal hepatic tissue supplied by the portal vein were highly inaccurate and these pixels were identified by use of the T(0) parameter and excluded from the analysis. In conclusion, dynamic MRI contrast enhancement combined with a pharmacokinetic model of the distribution of contrast media in the first pass allows us to produce highly reproducible parametric maps of k(fp) and rBV from hepatic tumours that are supplied by the hepatic arterial system using breath-hold acquisitions.

Adenocarcinoma↗
PubMed2002

The EORTC and drug development. European Organisation for Research and Treatment of Cancer.

Early drug development at EORTC has always been subject to structural changes to adapt to the rapid changes that occur in oncological drug development. The expertise of early drug developers has always been cross-fertilised with disease-/tumour-oriented groups and also backwards to the laboratory research groups. This results in the establishment of a solid and dedicated network of medical oncologists with focused expertise in cancer drug development. The EORTC Data Center is fully equipped with all expertise to support clinical research activities and includes regulatory, safety, and quality assurance desks. The EORTC New Drug development Programme (NDDP) provides methodological expertise to early clinical trials and coordinates phase I and phase II studies addressing various approaches. Through NDDP, the early clinical groups and the disease-/tumour-oriented groups have created specific networks to address early drug development in specific tumour types. This results in very efficient networks which have the resources and the patients to address and conduct challenging clinical trials in a standardised fashion ensuring the highest standards in cancer treatment.

Antineoplastic Agents↗
PubMed2001

What do patients, their relatives and medical staff know about genetic therapy?

OBJECTIVES: To investigate the knowledge of, and attitudes towards gene therapy of cancer patients, their relatives, and the staff treating the patients. DESIGN: Cross sectional questionnaire study. SUBJECTS: a) One hundred patients with ovarian cancer either 1) in current treatment with chemotherapy, or 2) in follow up after chemotherapy. b) The relatives accompanying these patients to clinic. c) Fifty doctors and fifty nurses at the hospital in question. MAIN OUTCOME MEASURES: Knowledge about genes and gene therapy, attitudes toward gene therapy and its introduction in the NHS, willingness to accept additional side-effects for a given-therapeutic gain. RESULTS: Patients and relatives have only limited knowledge about genes and gene therapy, but knowledge is also limited about how chemotherapy works. The attitude towards gene therapy is positive, and the worry about gene therapy being like 'playing God' is accepted by less than 10%. There is a strong belief that if gene therapy is effective it should be paid by the NHS (over 85% agree with this).

Attitude of Health Personnel↗
PubMed1998

High-performance liquid chromatographic assay for the novel antitumor drug, bryostatin-1, incorporating a serum extraction technique.

An HPLC assay incorporating a solid-phase extraction technique has been devised for bryostatin-1. Quantitation of bryostatin was found to be linear over the concentration range 0.012-25 microg/ml (0.2-25 ng on column) and was found to have a limit of detection of 0.2 ng on column, with a correlation coefficient of 0.9999. Following extraction of bryostatin over a range of concentrations from horse serum (0.012-25 microg/ml) and human serum (0.01-0.32 microg/ml) using a 100-mg C18 solid-phase extraction cartridge, extraction efficiencies consistently greater than 90% were obtained for extraction from horse serum and varied between 57 and 85% from human serum. However, on extending this work to blood samples from patients undergoing therapy with bryostatin-1, the drug was not detectable even at the maximum dose given, demonstrating the rapid loss of this agent from peripheral circulation.

Animals↗
PubMed1998

Bryostatin 1-tamoxifen combinations show synergistic effects on the inhibition of growth of P388 cells in vitro.

This study shows that combinations of bryostatin 1, a novel modulator of protein kinase C currently under clinical evaluation, with the anti-oestrogenic agent tamoxifen caused a large synergistic enhancement of growth inhibition in P388 cells in vitro. The growth-inhibitory effects of bryostatin 1 in the presence of non-inhibitory concentrations of tamoxifen were increased by approximately 200-fold, whereas growth inhibition by tamoxifen in the presence of non-inhibitory concentrations of bryostatin 1 were increased over 30-fold. These data have been confirmed by isobologram analysis. The precise mechanism underlying this effect is unknown, although preliminary data implicating protein kinase C is presented. The magnitude of this synergistic effect, together with evidence of clinical responses seen when these agents were given sequentially in ovarian cancer, merits further study.

Animals↗
PubMed1997

Gemcitabine: symptomatic benefit in advanced non-small cell lung cancer.

Recent studies have indicated that chemotherapy not only provides some survival benefit, but also reduces tumor-related symptoms and improves the performance status of patients receiving chemotherapy. Data from single-agent gemcitabine studies demonstrate improvements in a range of tumor symptoms, including cough, hemoptysis, pain, dyspnea, and anorexia, as well as increases in performance status. Indeed, more patients benefit from gemcitabine chemotherapy than suggested by the objective response rate. Surveys also have shown that patients are much more likely to accept chemotherapy for what is perceived by health care professionals as potentially small benefits. Gemcitabine has a role in the palliative treatment of patients with advanced non-small cell lung cancer.

Antimetabolites, Antineoplastic↗
PubMed1997

Single-agent paclitaxel in advanced non-small cell lung cancer: single-center phase II study using a 3-hour administration schedule.

The efficacy and safety of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) administered as a 3-hour infusion was investigated in a phase II study involving 21 patients with stage III/IV non-small cell lung cancer. The study included two quality of life assessments (the Hospital Anxiety and Depression Scale and the Rotterdam Symptom Checklist) to test their suitability for use in a future randomized phase III trial of paclitaxel and best supportive care versus best supportive care alone. Four (19%) of the 21 patients (95% confidence interval, 8% to 38%) achieved a partial response. The median time to disease progression for all patients entered was 19 weeks. Paclitaxel was well tolerated, with dose reduction required in only one patient because of arthralgia/myalgia. No dose reductions, delays, or discontinuations were required for hematologic toxicity. Completion and compliance with quality of life questionnaires was high, and these research tools proved to be acceptable for future use in phase III studies with paclitaxel.

Adult↗
PubMed1996

A randomised trial investigating the dose intensity of primary chemotherapy in patients with ovarian carcinoma: a comparison of chemotherapy given every four weeks with the same chemotherapy given at three week intervals.

BACKGROUND: The dose intensity of chemotherapy for patients with ovarian carcinoma remains a controversial issue. Few randomised trials have been conducted examining dose intensity using the same total dose of chemotherapy. This study was designed to investigate two schedules of chemotherapy using standard and higher dose intensity with both groups receiving the same total dose. PATIENTS AND METHODS: Patients with FIGO stage IC, II, III and IV epithelial ovarian carcinoma were randomised to receive cycles of cyclophosphamide (600 mg/m2) and carboplatin (300 mg/m2) alternating with doxorubicin (50 mg/ m2) and ifosfamide (5 g/m2) at either four-weekly (n = 47) or three-weekly (n = 97) intervals (1:2 randomisation). At randomisation patients were stratified according to histological grade and amount of post operative residual tumour (greater or less than 2 cm). The two arms of the study were well balanced in terms of the major prognostic features. RESULTS: There was no difference in either progression free survival or overall survival between the two arms. The median overall survival was 730 days for the three-weekly treatment and 740 days in the four-weekly arm (progression-free survival was 500 days and 483 days, respectively). The combined overall response rate (complete and partial response) in the 114 assessable patients was 65.7% (66.7% for the three-weekly treatment and 64% for the four-weekly treatment). These differences were not statistically different. CONCLUSIONS: A modest increase in the dose intensity of chemotherapy (1:3 fold) failed to improve the response rate, progression-free survival and overall survival in patients with ovarian carcinoma.

Adult↗
PubMed1995

Continuous infusion of 5-fluorouracil with alpha 2b interferon for advanced colorectal carcinoma.

Thirty patients with symptomatic colorectal carcinoma were commenced on treatment with 5-fluorouracil (2.5 g week-1) administered by continuous intravenous infusion and alpha 2b interferon (3 x 10(6) U s.c. three times a week). Six out of 30 patients (20%) achieved a partial response. Three patients (10%) had stable disease and 21 patients (70%) progressed on treatment. Twenty patients (67%) completed ten or more weeks of treatment. In nine patients, treatment was withdrawn after 2-9 weeks because of disease progression or death. One patient's treatment was interrupted by emergency surgery. The median survival for all patients was 210 days (7 months). The principal side-effects were oral mucositis (12/30 patients), nausea (8/30 patients) and transient diarrhoea (4/30 patients), and initial constitutional symptoms due to alpha 2b interferon. The combination of low-dose continuous infusional 5-fluorouracil and low-dose alpha 2b interferon is well tolerated but has no obvious advantage over alternative infusional regimens using 5-fluorouracil as a single agent.

Adult↗
PubMed1994

Immunomodulation in patients receiving intravenous Bryostatin 1 in a phase I clinical study: comparison with effects of Bryostatin 1 on lymphocyte function in vitro.

Bryostatin 1 is a protein kinase C activator that inhibits growth of tumour cells and activates lymphocytes in vitro, properties that have encouraged its use in phase 1 clinical studies as an anticancer agent. We investigated interleukin-2(IL-2)-induced proliferation and lymphokine-activated killer (LAK) cell activity in peripheral blood mononuclear cells (PBMC) from cancer patients receiving Bryostatin intravenously. After Bryostatin administration both LAK generation and proliferation were enhanced when patients' PBMC were stimulated with IL-2 in vitro. However, when normal donors' PBMC were cultured in vitro in the presence Bryostatin and IL-2, LAK induction was inhibited while IL-2-driven proliferation was increased. These effects were also seen following only 2 h exposure to Bryostatin and could be elicited by conditioned medium from Bryostatin-pretreated cells. Neither IL-4 nor interferon gamma was detected in the conditioned medium. Bryostatin in vitro was found to increase expression of IL-2 receptors on CD4+, CD8+ and CD56+ cells and augment the proportion of CD8+ cells in conjunction with IL-2. We conclude that Bryostatin in combination with IL-2 in vitro enhances proliferation and IL-2 receptor expression on lymphocytes, favouring CD8+ cells while suppressing the generation of LAK activity. Intravenous administration of Bryostatin increases the potential of IL-2 to induce proliferation and LAK activity in lymphocytes which, taken together with its putative direct antitumour effect, makes Bryostatin an interesting candidate for clinical trials in combination with IL-2.

Adjuvants, Immunologic↗