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  • 1
    ISSN: 1569-8041
    Keywords: cisplatin ; esophageal cancer ; gemcitabine ; schedule dependency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: To evaluate the tolerability of four alternating cisplatin–gemcitabine schedules. A secondary aim was to evaluate the clinical efficacy of this combination. Patients and methods: Forty-one patients with advanced solid tumors received alternating sequences with a 4- and 24-hour interval of cisplatin and gemcitabine. Gemcitabine 800 mg/m2 was administered as a 30-min infusion on day 1, 8 and 15, and cisplatin 50 mg/m2 over 1 hour on day 1 and 8; in case of the 24-hour time interval the second drug was administered one day later. Four cisplatin–gemcitabine schedules were studied: gemcitabine four hour before cisplatin (10 patients), or vice versa (14 patients) and gemcitabine twenty-four hours before cisplatin (9 patients) or vice versa (8 patients). The sequence of drug administration was reversed in the second cycle of therapy in each individual patient, enabling the evaluation of sequence-dependent side effects. Twenty-six patients had received prior chemotherapy, of which twenty-one platinum-based. Results: The main toxicity was myelosuppression. Overall, grade 3 and 4 thrombocytopenia was observed in 27 out of 41 patients (66%) and was not schedule dependent. No serious bleeding occurred. Leukopenia was significantly different between the 4 alternating schedules (P = 0.01); gemcitabine 24 hours before cisplatin was significantly less toxic compared to both cisplatin 4 hours and 24 hours before gemcitabine (P = 0.01 and P = 0.003, respectively). Furthermore, paired analysis of the 4-hour and 24-hour data sets showed that leukopenia was significantly more serious when cisplatin preceded gemcitabine (P = 0.005). Although most patients received prior treatment, both prior chemotherapy and radiotherapy were not related to toxicity. Overall, grade 3 and 4 leukopenia occurred in 19 out of 41 patients (46%). Anemia (Hb ≤6.0 mmol/l) was not sequence dependent and was observed in 63% of patients. Myelotoxicity was cumulative between cycles and caused frequent omission of gemcitabine on day 15. Overall, in 51% of administered cycles there was no omission of gemcitabine. A mean of 3.5 therapy cycles was administered. Non-hematological toxicity was moderate, consisting mainly of grade 1 and 2 nausea/vomiting and fatigue, and was not schedule dependent. Recently, we described that the schedule in which cisplatin was administered 24 hours before gemcitabine produced the best pharmacological profile. Based on this and because toxicity was manageable, the schedule cisplatin 24 hours prior to gemcitabine was chosen for phase II evaluation. Nine out of thirty-six evaluable patients had an objective response. These responses were observed in head and neck squamous-cell carcinoma (HNSCC), non-small-cell lung cancer (NSCLC), melanoma, adenocarcinoma of unknown origin, ovarian and esophageal carcinoma. Conclusions: Myelosuppression was the most important toxicity. Leukopenia was schedule dependent: gemcitabine before cisplatin was less toxic than the reversed sequence, in this respect. Some encouraging responses were seen in patients with esophageal cancer. Currently, a phase II study with cisplatin 24 hours before gemcitabine is ongoing in patients with advanced upper gastro-intestinal tumors.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1569-8041
    Keywords: cisplatin ; dFdCTP accumulation ; gemcitabine ; pharmacodynamics ; pharmacokinetics ; phase I study ; Pt-DNA adducts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: To determine possible schedule dependent pharmacokinetic and pharmacodynamic interactions between gemcitabine (2′,2′-difluorodeoxycytidine, dFdC) and cisplatin (cis-diamminedichloroplatinum, CDDP) in patients with advanced stage solid tumors in a phase I trial. Patients and methods: A total of 33 patients with advanced stage solid tumors were treated with gemcitabine (30-min infusion, 800 mg/m2) and cisplatin (one-hour infusion, 50 mg/m2). Sixteen patients had a four-hour interval between gemcitabine (days 1, 8, 15) and cisplatin (days 1 and 8), followed by the reverse schedule and seventeen patients had a 24-hour interval between gemcitabine (days 1, 8, 15) and cisplatin (days 2 and 9), followed by the reverse schedule. Gemcitabine and cisplatin pharmacokinetics were measured in plasma and white blood cells (WBC), isolated from blood samples taken at several time points after the start of treatment. Results: A four-hour time interval between both agents did not reveal major differences in plasma pharmacokinetics of gemcitabine, dFdU (deaminated gemcitabine) and platinum (Pt), and of gemcitabine–triphosphate (dFdCTP) accumulation and Pt-DNA adduct formation in WBC between the two different sequences of gemcitabine and cisplatin. In the patients treated with the 24-hour interval, cisplatin before gemcitabine did not significantly change peak gemcitabine levels and the AUC of plasma dFdU, but tended to increase dFdCTP AUC in WBC 1.5-fold (P 〈 0.06). Gemcitabine before cisplatin decreased the plasma AUC of Pt 2.1-fold (P = 0.03). No significant differences in Pt-DNA adduct levels in WBC were found, although gemcitabine before cisplatin tended to increase the 24-hour retention of Pt-DNA adducts. Creatinine clearance on day 28 was related to the peak plasma levels of total Pt (linear regression coefficient (r) = 0.47, P = 0.02, n = 26). Furthermore, the increase in the Pt-GG to Pt-AG ratio 24 hours after cisplatin treatment was related to the overall response of patients (r = 0.89, P 〈 0.01, n = 8). Conclusions: Of all schedules the treatment of patients with cisplatin 24 hours before gemcitabine led to the highest dFdCTP accumulation in WBC and total Pt levels in plasma. These characteristics formed the basis for further investigation of this schedule in a phase II clinical study.
    Type of Medium: Electronic Resource
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