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Purpose: To determine maximum tolerated dose (MTD) and evidence of antitumor activity of topotecan in combination with gemcitabine in refractory cancer patients.Methods: This was a Phase I, prospective, dose-escalation trial that employed a novel-dosing schema to investigate clinical safety. Patients were treated in six cohorts with topotecan (T)+gemcitabine (G). The doses of T and G were administered by 30-minute IV infusion, T on days one through five (0.3 mg/m2 to 1 mg/m2) and G on days one and 15 of a 28-day cycle (1000 mg/m2 to 1500 mg/m2). Toxicity was monitored.Results: Twenty-three cancer patients were enrolled (colorectal, n=5; lung, n=4; gastric, n=4; esophageal, n=2; other, n=8). Two of three patients developed grade 3 nonhematologic toxicity attributed to study regimen, thereby fulfilling dose limiting toxicity requirements at cohort 6 (T, 1 mg/m2, G, 1500 mg/m2). Maximum tolerated dose (MTD) was established at cohort 5 (T, 1 mg/m2, G, 1250 mg/m2). Ten patients were treated at cohort 5. Nonhematologic adverse effects (AEs) >grade 3 attributed to the study regimen were not observed. Hematologic toxicity was frequent. Twenty-five percent of patients in cohort 2 and 50% of patients in cohorts 4, 5, and 6 had a reduction of ANC to <500 mm3. All neutropenic episodes were less than one week in duration. Five of the patients in the last three cohorts required delay and/or dose-reduction of G. Nineteen of 23 enrolled patients were evaluable for response. Two patients achieved a minimal response.Conclusions: The MTD was observed at a T dose of 1 mg/m2 administered on days 1 through 15, and a G dose of 1250 mg/m2 administered on days 1 and 15 via 30 minute intravenous (IV) infusion. [ABSTRACT FROM AUTHOR]

In a prospective, randomized trial, 205 febrile episodes in granulocytopenic cancer patients were treated with ceftazidime with or without tobramycin (C +/- T), both agents being administered only if the initial granulocyte count was below 200/microliters, or ceftazidime plus piperacillin (C + P). The overall response rate was 71% (39 of 60 for C +/- T and 45 of 58 for C + P). Logistic regression analyses documented no evidence of a significant difference between the two regimens in overall treatment effect after accounting for the linear effects of potentially important variables, such as infection type and granulocyte count. Although the response rates for the subgroup of patients with bacteremias was better with the C + P regimen (P = 0.06), there was no difference in response for patients with bacteremia and profound (< 100/microliters) sustained granulocytopenia. The double beta-lactam combination demonstrated in vitro synergism in 73%; antagonism was not seen. Both regimens produced excellent serum bactericidal levels (C +/- T geometric mean peak 1:170; C + P peak 1:137) against gram-negative but not gram-positive pathogens (1:4; 1:7 respectively) that had caused bacteremia. Emergence of resistance and significant coagulopathy and/or bleeding did not occur during therapy. Antibiotic-related nephrotoxicity was noted in 7 of 95 trials in the C + P and in 6 of 89 trials in the C +/- T group (P = 0.19). The incidence of secondary infections in patients with profound (< 100/microliters) sustained granulocytopenia was lower in the C +/- T group (P = 0.04). Alimentary canal anaerobic flora preservation with C +/- T, and suppression with C + P, was demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]