Metabolism and excretion of paclitaxel after oral administration in combination with cyclosporin A and after i.v. administration

The objective of this study was to compare the quantitative excretion of paclitaxel and metabolites after i.v. and oral drug administration. Four patients received 300 mg/m2 paclitaxel orally 30 min after 15 mg/kg oral cyclosporin A, co-administered to enhance the uptake of paclitaxel. Three weeks later these and three other patients received 175 mg/m2 paclitaxel by i.v. infusion. Blood samples, urine and feces were collected up to 48-96 h after administration, and analyzed for paclitaxel and metabolites. The area under the plasma concentration-time curve of paclitaxel after i.v. administration (175 mg/m2) was 16.2 +/- 1.7 microM x h and after oral administration (300 mg/m2) 3.8 +/- 1.5 microM x h. Following i.v. infusion of paclitaxel, total fecal excretion was 56 +/- 25%, with the metabolite 6alpha-hydroxypaclitaxel being the main excretory product (37 +/- 18%). After oral administration of paclitaxel, total fecal excretion was 76 +/- 21%, of which paclitaxel accounted for 61 +/- 14%. In conclusion, after i.v. administration of paclitaxel, excretion occurs mainly in the feces with the metabolites as the major excretory products. Orally administered paclitaxel is also mainly excreted in feces but with the parent drug in highest amounts. We assume that this high amount of parent drug is due to incomplete absorption of orally administered paclitaxel from the gastrointestinal tract.     

Long-term survival in a phase III, randomised study of topotecan versus paclitaxel in advanced epithelial ovarian carcinoma.

BACKGROUND: We have continued to monitor the survival of patients randomised in a previously reported multicentre phase III study of topotecan versus paclitaxel in patients with advanced epithelial ovarian cancer who had failed one prior platinum-based regimen. PATIENTS AND METHODS: Patients with bidimensionally measurable disease were randomised to topotecan (1.5 mg/m(2)/day for 5 days) or paclitaxel (175 mg/m(2)/day as a 3-h infusion) every 21 days. Patients were eligible for treatment with the alternate therapy at third line. The European Organisation for Research and Treatment of Cancer Quality of Life (EORTC QOL)-C30 questionnaire was also used to measure eight symptoms at baseline and during each course (pain, anorexia, diarrhoea, fatigue, nausea and vomiting, dyspnea, constipation and insomnia). RESULTS: A total of 226 patients were evaluable for response. Demographic characteristics were similar in both treatment groups, as were results of the EORTC QOL-30 questionnaire. For the topotecan group, median time to progression was 18.9 weeks (range <1 to 92.6+ weeks; 25% censored), and, for paclitaxel, 14.7 weeks (range <1 to 137.3+ weeks; 12.3% censored); P = 0.076. At 4 years post-randomisation, median survival in the topotecan group was 63.0 weeks (range <1 to 238.4+ weeks; 20.5% censored) and, for paclitaxel, 53.0 weeks (range <1 to 226.3+ weeks; 12.3% censored); P = 0.44. CONCLUSION: Topotecan continues to demonstrate comparable efficacy and survival to paclitaxel with manageable and non-cumulative haematological toxicity. Non-haematological toxicity was generally mild for both groups. The long-term survival rate indicates substantial therapeutic benefit for this group of patients receiving topotecan at relapse of ovarian cancer.     

Phase I and pharmacokinetic study of the combination of topotecan and ifosfamide administered intravenously every 3 weeks

To determine the maximum-tolerated dose (MTD), dose-limiting toxicities, and pharmacokinetics of topotecan administered as a 30-min intravenous (i.v.) infusion over 5 days in combination with a 1-h i.v. infusion of ifosfamide (IF) for 3 consecutive days every 3 weeks. Patients with advanced malignancies refractory to standard therapy were entered into the study. The starting dose of topotecan was 0.4 mg x m(-2) day(-1) x 5 days. Ifosfamide was administered at a fixed dose of 1.2 g x m(-2) day(-1) x 3 days. In all, 36 patients received 144 treatment courses. Owing to toxicities, the schedule of topotecan administration was reduced from 5 to 3 days. The MTD was reached at topotecan 1.2 mg x m(-2) day(-1) x 3 days with IF 1.2 g x m(-2) day(-1) x 3 days. Haematological toxicities were dose limiting. Neutropenia was the major toxicity. Thrombocytopenia and anaemia were rare. Nonhaematological toxicities were relatively mild. Partial responses were documented in three patients with ovarian cancer dosed below the MTD. Topotecan and IF did not appear to interact pharmacokinetically. The relationships between the exposure to topotecan lactone and total topotecan, and the decrease in absolute neutrophil count and the decrease in thrombocytes, were described with sigmoidal-E(max) models. The combination of 1.0 mg m(-2) day(-1) topotecan administered as a 30-min i.v. infusion daily times three with 1.2 g x m(-2) day(-1) IF administered as a 1-h i.v. infusion daily times three every 3 weeks was feasible. However, the combination schedule of topotecan and IF did result in considerable haematological toxicity and in conjunction with previously reported pronounced nonhaematological toxicities and treatment related deaths, it may be concluded that this is not a favourable combination.     

A randomised phase II multicentre trial of irinotecan (CPT-11) using four different schedules in patients with metastatic colorectal cancer

The purpose of this phase II trial was to compare the efficacy, safety and pharmacokinetics of four irinotecan schedules for the treatment of metastatic colorectal cancer. In total, 174 5-fluorouracil pretreated patients were randomised to: arm A (n=41), 350 mg m(-2) irinotecan as a 90-min i.v. infusion q3 weeks; arm B (n=38), 125 mg m(-2) irinotecan as a 90-min i.v. infusion weekly x 4 weeks q6 weeks; arm C (n=46), 250 mg m(-2) irinotecan as a 90-min i.v. infusion q2 weeks; or arm D (n=49), 10 mg m(-2) day(-1) irinotecan as a 14-day continuous infusion q3 weeks. No significant differences in efficacy across the four arms were observed, although a shorter time to treatment failure was noted for arm D (1.7 months; P=0.02). Overall response rates were in the range 5-11%. Secondary end points included median survival (6.4-9.4 months), and time to progression (2.7-3.8 months) and treatment failure (1.7-3.2 months). Similarly, there were no significant differences in the incidence of grade 3-4 toxicities, although the toxicity profile between arms A, B, and C and D did differ. Generally, significantly less haematologic toxicity, alopecia and cholinergic syndrome were observed in arm D; however, there was a trend for increased gastrointestinal toxicity. Irinotecan is an effective and safe second-line treatment for colorectal cancer. The schedules examined yielded equivalent results, indicating that there is no advantage of the prolonged vs short infusion schedules.     

Phase I and pharmacokinetic study of irinotecan administered as a low-dose, continuous intravenous infusion over 14 days in patients with malignant solid tumors.

PURPOSE: To evaluate the feasibility of administering irinotecan as a continuous intravenous infusion for 14 to 21 days. PATIENTS AND METHODS: Patients with solid tumors refractory to standard therapy received continuous infusions of irinotecan by means of an ambulatory infusion pump. The starting dosage was 12.5 mg/m(2)/d for 14 days every 3 weeks. After identification of the maximum-tolerated dose for the 14-day infusion schedule, the protocol was amended to prolong the infusion duration to 17 and 21 days. Pharmacokinetics of irinotecan and SN-38 and its glucuronide were determined using high-performance liquid chromatography and noncompartmental modeling. RESULTS: Thirty-three patients received 85+ courses. At the first dose level (12.5 mg/m(2)/d), cumulative grade 3 or 4 diarrhea and grade 3 or 4 neutropenia occurred in three of five patients. At a dosage of 10 mg/m(2)/d, 14-day administration resulted in grade 4 diarrhea in two of six patients and one episode of grade 4 vomiting occurred, whereas with 17-day administration, one episode of grade 3 nausea and two episodes of grade 3 or 4 diarrhea were observed in six patients. Increasing the number of days of infusion to 21 days was not feasible because of cumulative diarrhea. Hematologic toxicity was rare. The mean metabolic SN-38 area under the curve/irinotecan area under the curve ratio was 16% +/- 6% compared with 3% to 5% after short infusion schedules involving therapeutic dosages. Partial responses were observed in two patients with extraovarian and colorectal cancer. CONCLUSION: The recommended dosage is 10 mg/m(2)/d for 14 days, repeated every 3 weeks. Enhanced metabolism of irinotecan to SN-38 may explain in part the low recommended dose for this schedule.     

Phase II trial of topically applied miltefosine solution in patients with skin-metastasized breast cancer

Skin deposits from breast cancer can present serious therapeutic problems, especially when resistant to conventional therapy. Topical application of a cytotoxic drug may represent an attractive new treatment modality devoid of major systemic toxicity. Miltefosine was selected because of its efficacy in breast cancer models. A mixture of alkylated glycerols of various chain lengths and water was used as the pharmaceutical vehicle to dissolve and to further facilitate tissue penetration of miltefosine. In our Institute a phase II study was performed to determine the efficacy and tolerability of topically applied miltefosine in patients with cutaneous metastases from breast cancer. Thirty-three patients in total entered the trial. A 6% miltefosine solution was applied once daily in the first week and twice daily in the following weeks. The planned minimum treatment duration was 8 weeks. We found an overall response rate of 43% for 30 evaluable patients, composed of 23% complete response and 20% partial response. The median response duration was 18 weeks, range 8-68. Toxicity consisted mainly of localized skin reactions, which could be controlled by a paraffin-based skin cream and, where appropriate, by dose modification. No systemic toxicities were observed. We conclude that topical miltefosine is an effective treatment modality in patients with skin metastases from breast cancer.     

Doxorubicin versus doxorubicin and cisplatin in endometrial carcinoma: definitive results of a randomised study (55872) by the EORTC Gynaecological Cancer Group.

BACKGROUND: Combination chemotherapy yields better response rates which do not always lead to a survival advantage. The aim of this study was to investigate whether the reported differences in the efficacy and toxicity of monotherapy with doxorubicin (DOX) versus combination therapy with cisplatin (CDDP) in endometrial adenocarcinoma lead to significant advantage in favour of the combination. PATIENTS AND METHODS: Eligible patients had histologically-proven advanced and/or recurrent endometrial adenocarcinoma and were chemo-na?ve. Treatment consisted of either DOX 60 mg/m(2) alone or CDDP 50 mg/m2 added to DOX 60 mg/m2, every 4 weeks. RESULTS: A total of 177 patients were entered and median follow-up is 7.1 years. The combination DOX-CDDP was more toxic than DOX alone. Haematological toxicity consisted mainly of white blood cell toxicity grade 3 and 4 (55% versus 30%). Non-haematological toxicity consisted mainly of grade 3 and 4 alopecia (72% versus 65%) and nausea/vomiting (36 % versus 12%). The combination DOX-CDDP provided a significantly higher response rate than single agent DOX (P <0.001). Thirty-nine patients (43%) responded on DOX-CDDP [13 complete responses (CRs) and 26 partial responses (PRs)], versus 15 patients (17%) on DOX alone (8 CR and 7 PR). The median overall survival (OS) was 9 months in the DOX-CDDP arm versus 7 months in the DOX alone arm (Wilcoxon P = 0.0654). Regression analysis showed that WHO performance status was statistically significant as a prognostic factor for survival, and stratifying for this factor, treatment effect reaches significance (hazard ratio = 1.46, 95% confidence interval 1.05-2.03, P = 0.024). CONCLUSIONS: In comparison to single agent DOX, the combination of DOX-CDDP results in higher but acceptable toxicity. The response rate produced is significantly higher, and a modest survival benefit is achieved with this combination regimen, especially in patients with a good performance status.