Does biomodulation of 5-fluorouracil improve results?
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Antimetabolites, Antineoplastic↗
Biomedical subjects
D Rischin
Publications and source records attributed to D Rischin.
A phase I and pharmacokinetic study of paclitaxel and epirubicin in advanced cancer.
The objectives of this phase I trial were to determine the maximally tolerated doses of the combination of epirubicin and paclitaxel with and without G-CSF (granulocyte colony stimulating factor) support and to investigate whether epirubicin pharmacokinetics are altered by paclitaxel. Patients with advanced cancer, performance status 0-2, and a normal left ventricular ejection fraction who had received up to 1 prior chemotherapy regimen were treated with epirubicin followed by a 3-hour infusion of paclitaxel repeated every 3 weeks. Dose levels studied were (paclitaxel/epirubicin) 155/75, 175/75, 175/90, 200/90 mg/m2 without G-CSF and 175/90 mg/m2 with G-CSF. Thirty-five patients were entered and all were assessable for toxicity. The dose-limiting dose level was 175 mg/m2 paclitaxel and 90 mg/m2 epirubicin with limiting toxicities of febrile neutropenia, diarrhea and esophagitis. The addition of G-CSF did not allow escalation of epirubicin. No significant cardiac toxicity was observed. Epirubicin pharmacokinetics were studied during the first 2 cycles in 6 patients, who were randomized to receive 1 cycle with no interval between the completion of the epirubicin and the commencement of the paclitaxel infusion and the other cycle with a 72-hour interval between the drugs. There was no substantial effect of paclitaxel on epirubicin or epirubicinol pharmacokinetics, although there was a marginal increase in glucoronidation. In conclusion, paclitaxel 175 mg/m2 and epirubicin 75 mg/m2 is recommended for phase II and III studies.
Adult↗
Repetitive high-dose therapy with ifosfamide, thiotepa and paclitaxel with peripheral blood progenitor cell and filgrastim support for metastatic and locally advanced breast cancer: results of a phase I study.
BACKGROUND: This phase I study was designed to determine the optimal dosages of a novel repetitive high-dose therapy regimen for patients with metastatic breast cancer (MBC). PATIENTS AND METHODS: The planned treatment was three cycles of high-dose ifosfamide, thiotepa and conventional-dose paclitaxel delivered every 28 days with progressive dose-escalation in successive cohorts. Each cycle was supported by peripheral blood progenitor cells (PBPC) and filgrastim. RESULTS: Twenty-three patients were entered into this trial. Of the planned 69 treatment cycles, 59 were delivered and fifteen patients completed all three cycles. The dose-limiting toxicities were renal tubular acidosis, encephalopathy, mucositis and enterocolitis. There was one treatment-related hemorrhagic death. CONCLUSIONS: The recommended doses for phase II or III studies are ifosfamide (10 g/m2), thiotepa (350 mg/m2) and paclitaxel (175 mg/m2).
Adult↗
Induction of MDR1 gene expression by anthracycline analogues in a human drug resistant leukaemia cell line.
The effects of 4-demethoxydaunorubicin (idarubicin, IDA) and MX2, a new morpholino-anthracycline, on up-regulation of the MDR1 gene in the low-level multidrug resistant (MDR) cell line CEM/A7R were compared at similar concentrations (IC10, IC50 and IC90) over a short time exposure (4 and 24 h). The chemosensitivity of each drug was determined by a 3-day cell growth inhibition assay. Compared with epirubicin (EPI), IDA and MX2 were 17- and eightfold more effective in the CEM/A7R line respectively. No cross-resistance to 5-FU was seen in the CEM/A7R line. Verapamil (5 microM) and PSC 833 (1 microM), which dramatically reversed resistance to EPI in the CEM/A7R line, had no sensitizing effect on the resistance of this line to MX2, but slightly decreased resistance to IDA. The sensitivity to 5-FU was unchanged by these modulators. The induction of MDR1 mRNA expression by IDA, MX2 and 5-FU was analysed by Northern blotting and semiquantitatively assessed by scanning Northern blots on a phosphorimager. The relative level of MDR1 expression was expressed as a ratio of MDR1 mRNA to the internal RNA control glyceraldehyde-3-phosphate dehydrogenase (GAPDH). IDA, MX2 and 5-FU differentially up-regulated MDR1 mRNA in the CEM/A7R line in a dose-dependent manner. Both IDA and MX2 induced MDR1 expression within 4 h. 5-FU up-regulated MDR1 expression only when drug exposure was prolonged to 24 h. Based on MRK 16 binding, flow cytometric analysis of P-glycoprotein (Pgp) expression paralleled the increase in MDR1 mRNA levels. For the three anthracyclines, the increase in MDR1 expression was stable in cells grown in the absence of drug for more than 3 weeks after drug treatment. The induction of MDR1 expression by 5-FU was transient, associated with a rapid decrease in the increased Pgp levels which returned to baseline 72 h after the removal of 5-FU. This study demonstrates that MDR1 expression can be induced by analogues of anthracyclines not pumped by Pgp, and that this induction appears to be stable despite a 3-week drug-free period.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Ifosfamide in combination with paclitaxel or doxorubicin: regimens which effectively mobilize peripheral blood progenitor cells while demonstrating anti-tumor activity in patients with metastatic breast cancer.
For patients with metastatic breast cancer (MBC) who undergo high-dose therapy with autologous peripheral blood progenitor cell (PBPC) transplantation, an important prerequisite is a mobilization regimen that efficiently mobilizes PBPCs while producing an effective anti-tumor effect. We prospectively evaluated ifosfamide-based chemotherapy for mobilization efficiency, toxicity and disease response in 37 patients. Patients received two cycles of the ifosfamide-based regimen; ifosfamide (5 g/m2 with conventional-dose cycle and 6 g/m2 with mobilization cycle) with either 50 mg/m2 doxorubicin (if limited prior anthracycline and/or progression more than 12 months after an anthracycline-based regimen) or 175 mg/m2 paclitaxel. For the mobilization cycle, all patients received additional G-CSF (10 microg/kg SC, daily) commencing 24 h after completion of chemotherapy. The target yield was >6x10(6) CD34+ cells/kg, sufficient to support the subsequent three cycles of high-dose therapy. The mobilization therapy was well tolerated and the peak days for peripheral blood (PB) CD34+ cells were days 10-13 with no significant differences in the PB CD34+ cells mobilization kinetics between the ifosfamide-doxorubicin vs. ifosfamide-paclitaxel regimens. The median PBPC CD34+ cell content ranged from 2.9 to 4.0x10(6)/kg per day during days 9-14. After a median of 3 (range 1-5) collection days, the median total CD34+ cell, CFU-GM and MNC for all 44 individual sets of collections was 9.2x10(6)/kg (range 0.16-54.9), 37x10(4)/kg (range 5.7-247) and 7.3x10(8)/kg (range 2.1-26.1), respectively. The PBPC target yield was achieved in 35 of the 37 patients. The overall response rate for the 31 evaluable patients was 68% with 10% having progressive disease. Thirty-three patients have subsequently received high-dose therapy consisting of three planned cycles of high-dose ifosfamide, thiotepa and paclitaxel with each cycle supported with PBPCs. Rapid neutrophil and platelet recovery has been observed. Ifosfamide with G-CSF in combination with doxorubicin or paclitaxel achieves effective mobilization of PBPC and anti-tumor activity with minimal toxicity.
Adult↗
A phase II trial of carboplatin and etoposide for relapsed or metastatic carcinoma of the cervix.
This study reports the results of a phase II trial of carboplatin 100 mg/m2 combined with etoposide 120 mg/m2 each given for 3 consecutive days every 28 days in women with recurrent or metastatic carcinoma of the cervix. Seventeen eligible patients were treated between August, 1990 and May, 1993. In the 16 evaluable patients, there were 2 complete responses, and no partial responses with an overall objective response rate of 12.5% (95% confidence interval 1.6%-38%). The main toxicities of this regimen related to myelosuppression and emesis. The combination of carboplatin and etoposide did not achieve either a better response rate or a substantially improved toxicity profile than is seen with single agent cisplatin.
Antineoplastic Combined Chemotherapy Protocols↗
Low-dose versus standard-dose lenograstim prophylaxis after chemotherapy: a randomized, crossover comparison.
PURPOSE: Granulocyte colony-stimulating factor (G-CSF) administered prophylactically after chemotherapy reduces the duration and severity of neutropenia. This randomized crossover study was designed to assess whether a lower dose of G-CSF is as effective as a standard dose of 5 microg/kg daily. PATIENTS AND METHODS: Patients who received standard-dose chemotherapy regimens expected to cause neutropenia received G-CSF (lenograstim) that started the day after chemotherapy for 14 days or until the absolute neutrophil count (ANC) recovered to greater than 10 x 10(9)/L. The lenograstim dose was randomly allocated to be 2 or 5 microg/kg daily in the first cycle of chemotherapy and crossed over to the alternate dose for the second cycle. The study was designed to accrue 40 assessable patients to provide a power of 80% to detect a difference in duration of neutropenia of 1 day. Fifty-two patients were randomized to treatment and 43 patients completed two cycles of identical chemotherapy. RESULTS: There was little neutropenia irrespective of the dose used. Twenty-three patients (53%) had no grade III or IV neutropenia and 30 patients (70%) had no grade IV neutropenia. Crossover trial methodology was used to assess the difference in outcome caused by the lower dose compared with the standard dose (estimated treatment effect). There was no significant difference in the measures of neutropenia, hospitalization, or other clinical outcomes. The 95% confidence interval (one-sided) for the additional duration of neutropenia caused by the lower dose of lenograstim was 0.43 days or less for grade III or IV neutropenia and 0.34 days or less for grade IV neutropenia. CONCLUSION: Lenograstim 2 microg/kg provides similar protection to 5 microg/kg against neutropenia that complicates standard-dose chemotherapy. The use of a lower dose has important implications for the cost-effectiveness of prophylactic G-CSF therapy.
Adjuvants, Immunologic↗
Phase II study of docetaxel and cisplatin in advanced non-small-cell lung cancer.
PURPOSE: Docetaxel (Taxotere, Rhone-Poulenc Rorer, Antony, France) and cisplatin are two of the most active single agents used in the treatment of non-small-cell lung cancer (NSCLC). A recently reported phase I study of the combination of docetaxel and cisplatin recommended a dose of 75 mg/m2 of both drugs every 3 weeks for subsequent phase II study. PATIENTS AND METHODS: Eligible patients were aged 18 to 75 years with a World Health Organization (WHO) performance status < or = 2 and life expectancy > or = 12 weeks, with metastatic and/or locally advanced NSCLC proven histologically or cytologically. Patients were not permitted to have received prior chemotherapy, extensive radiotherapy, or any radiotherapy to the target lesion and must have had measurable disease. Concurrent treatment with colony-stimulating factors (CSFs) or prophylactic antibiotics was not permitted. Docetaxel (75 mg/m2) in 250 mL 5% dextrose was given intravenously (i.v.) over 1 hour immediately before cisplatin (75 mg/m2) in 500 mL normal saline given i.v. over 1 hour in 3-week cycles. Premedication included ondansetron, dexamethasone, promethazine, and standard hyperhydration with magnesium supplementation. RESULTS: A total of 47 patients, two thirds of whom had metastatic disease, were entered onto this phase II study. The majority of patients were male (72%) and of good (WHO 0 to 1) performance status (85%). All 47 patients were assessable for toxicity and 36 were for response. Three patients were ineligible and eight (17%) discontinued treatment because of significant toxicity. In assessable patients, the overall objective response rate was 38.9% (95% confidence limits [CL], 23.1% to 56.5%), 36.1% had stable disease, and 25% progressive disease. On an intention-to-treat analysis, the objective response rate was 29.8%. Median survival was 9.6 months and estimated 1-year survival was 33%. Significant (grade 3/4) toxicities included nausea (26%), hypotension (15%), diarrhea (13%), and dyspnea mainly related to chest infection (13%). One patient experienced National Cancer Institute (NCI) grade 3 neurosensory toxicity after eight cycles. Grade 3/4 neutropenia was common and occurred in 87% of patients, but thrombocytopenia > or = grade 3 was rare (one patient). Significant (grade 3/4) abnormalities of magnesium levels were common (24%). Febrile neutropenia occurred in 13% of patients and neutropenic infection in 11%, contributing to two treatment-related deaths. No neutropenic enterocolitis or severe fluid retention was reported. CONCLUSION: Compared with other active regimens used in this setting, the combination of docetaxel and cisplatin in advanced NSCLC is an active regimen with a similar toxicity profile to other combination regimens.
Adult↗
Phase I trial of cremophor EL with bolus doxorubicin.
Cremophor EL (cremophor), a component of the paclitaxel formulation, can potentially reverse P-glycoprotein-associated multidrug resistance. A Phase I trial of cremophor as a 6-h infusion every 3 weeks was performed with bolus doxorubicin (50 mg/m2). The cremophor dose was escalated from 1 to 60 ml/m2. A standard paclitaxel premedication was given before cremophor. Using a bioassay, potentially active cremophor levels (> or = 1 microl/ml) were measured in plasma from patients receiving cremophor doses of 30, 45, and 60 ml/m2. A cross-over design was used to assess the influence of cremophor 30 ml/m2 on the pharmacokinetics of doxorubicin and doxorubicinol. The plasma area under the concentration versus time curve (AUC) of doxorubicin increased from 1448 +/- 350 to 1786 +/- 264 ng/ml x h (P = 0.02) in the presence of cremophor, whereas the AUC of doxorubicinol increased from 252 +/- 104 to 486 +/- 107 ng/ml x h (P = 0.02). This pharmacokinetic interaction was associated with significantly increased neutropenia. With reduction of the doxorubicin dose to 35 mg/m2, the cremophor dose was increased to 60 ml/m2. Dose-limiting toxicities occurred in two of six patients after 45 ml/m2 and two of four patients after 60 ml/m2, which included febrile neutropenia and grade III cremophor-related toxicities of rash, pruritus, headache, and hypotension. All patients who received 45 ml/m2 cremophor reached plasma levels > or = 1.5 microl/ml, but at 60 ml/m2, only two of four reached this level, and the calculated plasma clearance of cremophor was significantly faster at this dose. One patient with hepatoma resistant to epirubicin achieved a near-complete response. Cremophor 45 ml/m2 over 6 h with 35 mg/m2 doxorubicin is recommended for further studies. The pharmacokinetic interaction between cremophor and doxorubicin is quantitatively similar to that described in trials of paclitaxel with doxorubicin and suggests that the cremophor in the paclitaxel formulation is responsible.
Adult↗
Plasma concentrations of polysorbate 80 measured in patients following administration of docetaxel or etoposide.
Docetaxel (Taxotere, Rhone-Poulenc Rorer) and etoposide are water-insoluble drugs formulated with polysorbate 80 for intravenous administration. We have previously reported that surfactants, including polysorbate 80 and Cremophor EL, can reverse the multidrug resistance (MDR) phenotype in an experimental system and that plasma Cremophor EL concentrations measured following a 3-h infusion of paclitaxel were > or = 1 microliter/ml, sufficient to modulate MDR in vitro. The purpose of this study was to measure polysorbate 80 plasma concentrations in patients following intravenous administration of etoposide or docetaxel using a bioassay in which MDR-expressing cells are incubated with daunorubicin (DNR) plus 50/50 growth medium/plasma and equilibrium intracellular DNR fluorescence is measured by flow cytometry. In vitro experiments show maximal reversal of MDR at concentrations of 1.0-2.0 microliters/ml and 50% reversal at 0.2-0.3 microliter/ml. Patients received docetaxel at 75 mg/m2 (five patients) or 100 mg/m2 (four patients) (total dose 125-178 mg, containing 3.12-4.45 ml polysorbate 80) over 60 min. The median end-infusion polysorbate 80 concentration was 0.1 microliter/ml (range 0.07-0.41 microliter/ml). Only one patient had a level of > 0.2 microliter/ml. Five patients received intravenous etoposide at 120 mg/m2 over 45-120 min (total dose 180-250 mg, containing 0.67-0.93 ml polysorbate 80). In the end-infusion plasma sample, polysorbate 80 was not detectable (< 0.06 microliter/ml) in any patient. Plasma polysorbate 80 levels following an intravenous infusion of 120 mg/m2 etoposide or of docetaxel at doses used in Phase II trials, are insufficient to show modulation of MDR in vitro.
Aged↗
Activity and toxicity of docetaxel (Taxotere) in women with previously treated metastatic breast cancer.
BACKGROUND: Metastatic breast cancer is a major cause of cancer death in Australian women. Docetaxel is a new cytotoxic drug that has shown promise in the treatment of metastatic breast cancer in patients who have previously received other chemotherapy, particularly an anthracycline, and has recently been approved for marketing in Australia. AIM: To report the first Australian experience with docetaxel in a group of women with metastatic breast cancer. METHODS: Patients with progressive metastatic breast cancer who had previously received other chemotherapy were treated with docetaxel 75 mg/m2 or 100 mg/m2 given as a one hour infusion every three weeks. All patients received oral dexamethasone for five days starting 24 hours prior to docetaxel as prophylaxis against fluid retention. The patients' response to docetaxel and toxicity were assessed by standard criteria. RESULTS: Twenty-six patients were treated. The major toxicity was neutropenia with 92% of patients experiencing at least one episode of grade 4 (absolute neutrophil count < 0.5 x 10(9)/L) neutropenia. Hospital admission for febrile neutropenia occurred in 44% of patients with one death from sepsis. Cumulative fluid retention was observed but in only one patient was it dose-limiting. Apart from alopecia, other toxicities were infrequent and rarely serious. In 23 patients assessable for response, there were 11 partial responses (48%). Three other patients whose disease could not be assessed for response had clinical improvement. The median survival of all patients treated was eight months. CONCLUSIONS: The response rate observed with docetaxel is comparable to that seen in trials in the United States and Europe and confirms the high activity of this new cytotoxic agent. Neutropenia is the major toxicity, and consideration should be given to the use of prophylactic oral antibiotics or colony stimulating factors to try and prevent febrile episodes. Clinicians will need to balance the benefits, toxicities, and cost of docetaxel in determining the appropriateness of its use in their patients.
Adult↗
Phase I trial of docetaxel and cisplatin in previously untreated patients with advanced non-small-cell lung cancer.
PURPOSE: To determine the maximum-tolerated doses (MTDs), principal toxicities, and pharmacokinetics of the combination of docetaxel and cisplatin administered every 3 weeks to patients with advanced non-small-cell lung cancer (NSCLC) who have not received prior chemotherapy and to recommend a dose for phase II studies. PATIENTS AND METHODS: Patients with advanced NSCLC and performance status 0 to 2 who had not received prior chemotherapy received docetaxel over 1 hour followed by cisplatin over 1 hour with hydration. Dose levels studied were (docetaxel/cisplatin) 50/75, 75/75, 75/100, and 100/75 mg/m2 repeated every 3 weeks. Colony-stimulating factor (CSF) support was not used. Pharmacokinetics of docetaxel and cisplatin were studied in the first cycle of therapy. Most patients (79%) had metastatic disease or intrathoracic recurrence after prior radiation and/or surgery. RESULTS: Of 24 patients entered, all were assessable for toxicity and 18 for response. The MTD schedules were docetaxel 75 mg/m2 with cisplatin 100 mg/m2 (dose-limiting toxicities [DLTs] in five of six patients), and docetaxel 100 mg/m2 with cisplatin 75 mg/m2 (DLTs in two of two patients, including one fatal toxicity). Limiting toxicities were febrile neutropenia and nonhematologic, principally diarrhea and renal. Two patients had neutropenic enterocolitis. Pharmacokinetics of both drugs were consistent with results from single-agent studies, which suggests no major pharmacokinetic interaction. Neutropenia was related to docetaxel area under the plasma concentration-versus-time curve (AUC). An alternative schedule was investigated, with cisplatin being administered over 3 hours commencing 3 hours after docetaxel, but toxicity did not appear to be less. Independently reviewed responses occurred in eight of 18 patients (44%; 95% confidence interval, 22% to 69%), most following 75 mg/m2 of both drugs. CONCLUSION: Docetaxel 75 mg/m2 over 1 hour followed by cisplatin 75 mg/m2 over 1 hour is recommended for phase II studies. The responses seen in this phase I study suggest a high degree of activity of this combination in previously untreated advanced NSCLC.
Adult↗
Cremophor pharmacokinetics in patients receiving 3-, 6-, and 24-hour infusions of paclitaxel.
BACKGROUND: Paclitaxel (Taxol) is a new drug with efficacy against a variety of malignant tumors. The clinical formulation of paclitaxel contains 50% Cremophor EL, a polyethoxylated castor oil vehicle (carrier) that can reverse multidrug resistance (MDR) mediated by P-glycoprotein. Three-hour intravenous infusions of paclitaxel can yield end-of-infusion plasma Cremophor concentrations of 1 microL/mL or more, which are sufficient to reverse MDR in vitro by at least 50%. Despite extensive clinical use, the pharmacokinetics of Cremophor have not been described. PURPOSE: We studied the pharmacokinetics of Cremophor in patients with ovarian cancer who were undergoing treatment with paclitaxel to determine whether plasma Cremophor concentrations achieved during and following 3-, 6-, and 24-hour drug infusions were similar to those shown to modulate MDR in vitro. METHODS: Eleven patients with previously treated (i.e., with platinum-containing chemotherapy regimens) ovarian cancer were randomly assigned to receive one 3-hour, one 6-hour, and one 24-hour infusion of paclitaxel in varied sequences during their first three cycles of treatment with this drug. Blood samples were collected both during and following the three infusion periods, and Cremophor concentrations in these samples were measured by use of a bioassay based on the ability of Cremophor in plasma samples to reverse cellular resistance to daunorubicin in vitro. RESULTS: Ten patients were treated with paclitaxel at a dose level of 175 mg/m2, and one patient was treated at a dose level of 135 mg/m2. At the 175-mg/m2 dose level, peak plasma Cremophor concentrations of 1 microL/mL or more were achieved in eight of 10 patients during both the 3-hour and the 6-hour infusions; with the 24-hour infusion, only one patient achieved a peak plasma Cremophor concentration of 1 microL/mL or more. The eight patients who achieved plasma Cremophor concentrations of 1 microL/mL during the 3-hour infusion were above this level 30 minutes into the infusion; the total time that the plasma concentration was greater than 1 microL/mL was 8.9 +/- 5.0 hours (mean +/- standard deviation; range, 4.1-15.6 hours). For the eight patients who achieved plasma Cremophor concentrations of 1 microL/mL during the 6-hour infusion, the total time that the concentration was greater than 1 microL/mL was 10.2 +/- 9.0 hours (range, 0.3-21.9 hours). The patient who received paclitaxel at a dose of 135 mg/m2 achieved a peak plasma Cremophor concentration of 1 microL/mL or more only during the 3-hour infusion. CONCLUSIONS: Paclitaxel infusions of 3 and 6 hours can result in sustained plasma Cremophor concentrations sufficient for substantial reversal of P-glycoprotein-mediated MDR in vitro. These plasma Cremophor concentrations are not achieved during 24-hour infusions of paclitaxel.
Aged↗
Activity of gemcitabine in patients with advanced ovarian cancer: responses seen following platinum and paclitaxel.
Thirty-eight women with epithelial ovarian cancer were treated with gemcitabine, a new antimetabolite. All had previously received platinum, and 27 had also received paclitaxel. Four patients had a partial response giving a response rate of 13% in assessable patients (n = 31) and 11% for all patients entered. Additionally, 6 patients had stable disease with >50% reduction in CA-125 for at least 3 months. Activity was seen in patients resistant to both platinum and paclitaxel. Gemcitabine was well tolerated, with uncomplicated neutropenia the main hematological toxicity. Nonhematological toxicities were generally mild and included fatigue, myalgias, and skin rash. Gemcitabine has some activity in heavily pretreated ovarian cancer patients and deserves further investigation in this malignancy.
Adult↗
Ormaplatin resistance is associated with decreased accumulation of its platinum (II) analogue, dichloro(D,L-trans)1,2-diaminocyclohexaneplatinum (II).
Ormaplatin (also known as tetraplatin) is a platinum-containing analogue which has recently undergone clinical trials. Ormaplatin may undergo conversion to dichloro(D,L-trans)-1,2-diaminocyclohexaneplatinum(II) [P1Cl2(trans-dach)]. The cisplatin-resistant murine lymphoma cell lines E8 and E5, were found to be cross-resistant to ormaplatin and PtCl2(trans-dach). We found an inverse rank correlation between drug resistance and drug accumulation for PtCl2(trans-dach) similar to our previous findings with cisplatin; however, accumulation of ormaplatin in the resistant cells was increased. Ormaplatin cytotoxicity appears to result primarily from extracellular conversion to PtCl2(trans-dach), since ormaplatin cytotoxicity was decreased under conditions where extracellular conversion to PtCl2(trans-dach) was minimised. Co-incubation with different inhibitors of energy metabolism resulted in a 65-70% increase in PtCl2(trans-dach) accumulation in the parental cell line R1.1 and a 113-307% increase in the resistant cell line E5 which suggests that the decrease in accumulation in E5 may be at least partly energy dependent. We conclude from these findings that cross-resistance to ormaplatin is associated with an energy-dependent decreased accumulation of PtCl2(trans-dach) in these cisplatin-resistant cell lines.
Animals↗
Association of acquired Pelger-Huet anomaly with taxoid therapy.
We describe the occurrence of acquired Pelger-Huet anomaly (APHA) in 23 patients treated with paclitaxel (13) or docetaxel (10). A consistent peak of Pelger-Huet cells (PHC) within a range of 3-9 d after treatment with taxoids was noted. The APHA generally disappeared by day 21 after treatment. Peak PHC values for the first course were significantly different in paclitaxel versus docetaxel versus control groups (P < 0.0001) with the maximum PHC counts being significantly higher for docetaxel compared with paclitaxel (P < 0.001) and for paclitaxel compared with controls (P = 0.007). We conclude that taxoid therapy produces transient APHA which peaks between days 3 and 9 and is more pronounced with docetaxel than with paclitaxel.
Adult↗
Carboplatin dosing based on measurement of renal function--experience at the Peter MacCallum Cancer Institute.
BACKGROUND: Carboplatin is used in treating many types of cancer. Because renal excretion is the major variable determining the pharmacokinetics of this drug, a dosing formula based on glomerular filtration rate (GFR) has been proposed and is being increasingly used in carboplatin dosing. This method of dosing is critically dependent on accurate measurement of GFR. AIMS: To report the experience at a single major oncology centre of carboplatin dosing based on GFR, and comparisons of different methods of measuring renal function for use in this dosing method. METHODS: An initial group of patients (n = 24) was studied where GFR was measured by Cr51EDTA clearance and compared to Tc99mDTPA clearance, measured 24 hour urine creatinine clearance and the Cockcroft and Gault formula. The carboplatin area under the plasma concentration versus time curve (AUC) was calculated using total platinum measured in a single blood sample assayed by flameless atomic absorption spectrophotometry. A subsequent patient group (n = 16) was then studied using Tc99mDTPA clearance to measure GFR. RESULTS: Carboplatin dosing using Cr51EDTA clearance to measure GFR was accurate (< 25% difference between planned and measured AUC) in 87% of samples. Estimation of renal function using the Cockcroft and Gault formula correlated with Cr51EDTA clearance only in patients with GFR < 100 mL/minute. The measured 24 hour urine creatinine clearance did not correlate with Cr51EDTA clearance. Using Tc99mDTPA clearance to measure GFR, carboplatin dosing was accurate in 81% of samples. Across a GFR range of 42-239 mL/minute, the Cr51EDTA and Tc99mDTPA clearance were closely correlated (r = 0.98, slope of regression line = 1.02). CONCLUSIONS: Carboplatin dosing using a pharmacological formula based on GFR produces accurate targeting of the carboplatin AUC. Tc99mDTPA clearance can be used to measure GFR instead of Cr51EDTA clearance, which is both more convenient and has potential cost savings. Estimates of renal function using the Cockcroft and Gault formula or measured 24 hour creatinine clearance are insufficiently accurate to use for carboplatin dosing.
Antineoplastic Agents↗
Phase II trial of a 3-hour infusion of paclitaxel in previously untreated patients with advanced non-small-cell lung cancer.
PURPOSE: To determine the antitumor activity and toxicity of paclitaxel administered as a 3-hour infusion in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Fifty-one patients with advanced measurable or assessable NSCLC and performance status 0 to 2 who had not received prior chemotherapy were treated with paclitaxel 175 mg/m2 over 3 hours with premedication. Cycles were repeated every 3 weeks for a maximum of nine cycles. Most patients had prior radiotherapy (57%), extrathoracic metastatic disease (65%), and measurable disease (75%). Twenty-two percent had previously untreated stage III disease. RESULTS: The objective response rate was five of 51 (10%; 95% confidence interval, 3% to 21%). No subgroup with a higher response rate could be identified. There were no complete responses (CRs) and all responses lasted less than 5 months. Treatment was well tolerated with brief World Health Organization (WHO) grade IV neutropenia in only 16% of patients. Grade III/IV myalgia/athralgia occurred in 22% of patients. No significant hypersensitivity reactions occurred. CONCLUSION: The antitumor activity of this dose and schedule appears inferior to that reported in previously published phase II trials in NSCLC that used higher doses of paclitaxel infused over 24 hours, although confidence intervals for response overlap. Determining the optimal dose and schedule for using paclitaxel in NSCLC requires further investigation, and these results should caution against using shorter infusions outside appropriate clinical trials.
Adult↗