562 research outputs found

    DNA alkylation and interstrand cross-linking by treosulfan

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    The anti-tumour drug treosulfan (L-threitol 1,4-bismethanesulphonate, Ovastat) is a prodrug for epoxy compounds by converting non-enzymatically to L-diepoxybutane via the corresponding monoepoxide under physiological conditions. The present study supports the hypothesis that this conversion of treosulfan is required for cytotoxicity in vitro. DNA alkylation and interstrand cross-linking of plasmid DNA is observed after treosulfan treatment, but this is again produced via the epoxide species. Alkylation occurs at guanine bases with a sequence selectivity similar to other alkylating agents such as the nitrogen mustards. In treosulfan-treated K562 cells, cross-links form slowly, reaching a peak at approximately 24 h. Incubation of K562 cells with preformed epoxides shows faster and more efficient DNA cross-linking. © 1999 Cancer Research Campaig

    Oxaliplatin-DNA adduct formation in white blood cells of cancer patients

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    In this study, we investigated the kinetics of oxaliplatin-DNA adduct formation in white blood cells of cancer patients in relation to efficacy as well as oxaliplatin-associated neurotoxicity. Thirty-seven patients with various solid tumours received 130 mg m−2 oxaliplatin as a 2-h infusion. Oxaliplatin-DNA adduct levels were measured in the first cycle using adsorptive stripping voltammetry. Platinum concentrations were measured in ultrafiltrate and plasma using a validated flameless atomic absorption spectrometry method. DNA adduct levels showed a characteristic time course, but were not correlated to platinum pharmacokinetics and varied considerably among individuals. In patients showing tumour response, adduct levels after 24 and 48 h were significantly higher than in nonresponders. Oxaliplatin-induced neurotoxicity was more pronounced but was not significantly different in patients with high adduct levels. The potential of oxaliplatin-DNA adduct measurements as pharmacodynamic end point should be further investigated in future trials

    Phase I dose escalation study of telatinib (BAY 57-9352) in patients with advanced solid tumours

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    Telatinib (BAY 57-9352) is an orally available, small-molecule inhibitor of vascular endothelial growth factor receptors 2 and 3 (VEGFR-2/-3) and platelet-derived growth factor receptor β tyrosine kinases. In this multicentre phase I dose escalation study, 71 patients with refractory solid tumours were enroled into 14 days on/7 days off (noncontinuous dosing) or continuous dosing groups to receive telatinib two times daily (BID). Hypertension (23%) and diarrhoea (7%) were the most frequent study drug-related adverse events of CTC grade 3. The maximum-tolerated dose was not reached up to a dose of 1500 mg BID continuous dosing. Telatinib was rapidly absorbed with median tmax of 3 hours or less. Geometric mean Cmax and AUC0−12 increased in a less than dose-proportional manner and plateaued in the 900–1500 mg BID dose range. Two renal cell carcinoma patients reached a partial response. Tumour blood flow measured by contrast-enhanced magnetic resonance imaging and sVEGFR-2 plasma levels decreased with increasing AUC0−12 of telatinib. Telatinib is safe and well tolerated up to a dose of 1500 mg BID continuous dosing. Based on pharmacokinetic and pharmacodynamic criteria, 900 mg telatinib BID continuously administered was selected as the recommended phase II dose

    A clinical phase II study with sorafenib in patients with progressive hormone-refractory prostate cancer: a study of the CESAR Central European Society for Anticancer Drug Research-EWIV

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    Sorafenib is a multi-kinase inhibitor with antiangiogenic and antiproliferative activity. The activity of sorafenib in progressive hormone-refractory prostate cancer (HRPC) patients was investigated in a phase II clinical study. Progressive HRPC patients received sorafenib 400 mg bid p.o. continuously. Only patients with no prior chemotherapy, and either one-unidimensional measurable lesion according to RECIST-criteria or increasing prostate-specific antigen (PSA) values reflecting a hormone-refractory situation, were eligible for study entry. The primary study objective was the rate of progression-free survival of ⩾12 weeks (PFS12). Secondary end points were overall response, overall survival, and toxicity. Fifty-seven patients with PC were enrolled. Two patients had to be withdrawn from the set of eligible patients. According to RECIST criteria, 4 patients out of 55 evaluable patients showed stable disease (SD). According to PSA–response, we saw 11 patients with SD PSA and 2 patients were responders at 12 weeks (PFS12=17/55=31%). Among the 257 adverse events, 15 were considered drug related of maximum CTC-grade 3. Twenty-four serious adverse events occurred in 14 patients (14/55=26%). Seven of them were determined to be drug related. No treatment-related death was observed. Sorafenib has antitumour activity in HRPCP when evaluated for RECIST- and PSA-based response. Further investigation as a component of combination regimens is necessary to evaluate its definite or overall clinical benefit for HRPCP

    Search for resonant WZ production in the fully leptonic final state in proton–proton collisions at √s=13 TeV with the ATLAS detector

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    Measurement of exclusive pion pair production in proton–proton collisions at √s=7 TeV with the ATLAS detector