Gemcitabine, epirubicin and paclitaxel: pharmacokinetic and pharmacodynamic interactions in advanced breast cancer.

BACKGROUND: The objectives of this study were to investigate the disposition of gemcitabine, epirubicin, paclitaxel, 2',2'-difluorodeoxyuridine and epirubicinol, and characterize the pharmacokinetic and pharmacodynamic profile of treatment in patients with breast cancer. PATIENTS AND METHODS: The drug dispostion in 15 patients who received gemcitabine 1000 mg/m2, epirubicin 90 mg/m2 and paclitaxel 175 mg/m2 (GEP) on day 1 of a 21-day cycle, was compared with that of patients treated with epirubicin 90 mg/m2 and paclitaxel 175 mg/m2 (EP, n = 6) and epirubicin 90 mg/m2 alone (n = 6). Drug and metabolite levels in plasma and urine were assessed by high-performance liquid chromatography and parameters of drug exposure were related to hematological toxicity by a sigmoid-maximum effect (Emax) model. RESULTS: Paclitaxel administration significantly increased the epirubicinol area under the concentration-time curve, from 357+/-146 (epirubicin) to 603+/-107 (EP) and 640+/-81 h x ng/ml (GEP), and reduced the renal clearance of epirubicin and epirubicinol by 38 and 52.2% and 34.5 and 53% in GEP- and EP-treated patients, respectively, compared with epirubicin alone. Gemcitabine had no apparent effect on paclitaxel and epirubicin pharmacokinetics, and renal clearance of epirubicin and epirubicinol. The only pharmacokinetic/pharmacodynamic relationship observed was between neutropenia and the time spent above the threshold plasma level of 0.1 micromol/l (tC0.1) of paclitaxel, with the time required to obtain a 50% decrease in neutrophil count (Et50) of GEP being 7.8 h, similar to that of EP. CONCLUSIONS: Paclitaxel and/or its vehicle, Cremophor EL, interferes with the disposition and renal excretion of epirubicin and epirubicinol; gemcitabine has no affect on epirubicin and paclitaxel plasma pharmacokinetics and renal excretion of epirubicin, while neutropenia is not enhanced by gemcitabine.     

Phase I clinical and pharmacokinetic trial of the cyclin-dependent kinase inhibitor flavopiridol

PURPOSE: Flavopiridol (NSC 649890) is a synthetic flavone possessing significant antitumor activity in preclinical models. Flavopiridol is capable of inducing cell cycle arrest and apoptosis, presumably through its potent, specific inhibition of cyclin-dependent kinases. We conducted a phase I trial and pharmacokinetic study of flavopiridol given as a 72-h continuous intravenous infusion repeated every 2 weeks. METHODS: A total of 38 patients were treated at dose levels of 8, 16, 26.6, 40, 50 and 56 mg/m(2)/24 h. During the first infusion, plasma was sampled at 24, 48 and 72 h to determine steady-state concentrations, and peripheral blood lymphocytes were assessed by flow cytometry for evidence of apoptosis. Additional postinfusion pharmacokinetic sampling was done at the 40 and 50 mg/m(2)/24 h dose levels. RESULTS: Gastrointestinal toxicity was dose limiting, with diarrhea being the predominant symptom. Symptomatic orthostatic hypotension was also frequently noted. Several patients experienced tumor-specific pain during their infusions. The maximum tolerated dose (MTD) was determined to be 40 mg/m(2)/24 h. A patient with metastatic gastric cancer at this dose level had a complete response and remained disease-free for more than 48 months after completing therapy. Plasma concentrations at 24 h into the infusion were 94% of those achieved at steady state. Steady-state plasma flavopiridol concentrations at the MTD were 416.6+/-98.9 micro M. These concentrations are at or above those needed to see cell cycle arrest and apoptosis in vitro. The mean clearance of flavopiridol over the dose range was 11.3+/-3.9 l/h per m(2), similar to values obtained preclinically. Elimination was biphasic. The terminal half-life at the MTD was 26.0 h. No significant differences in pharmacokinetic parameters were noted between males and females. Patients taking cholestyramine to ameliorate flavopiridol-induced diarrhea had lower steady-state plasma concentrations. There was no significant change in the cell cycle parameters of peripheral blood lymphocytes analyzed by flow cytometry. CONCLUSIONS: The MTD and recommended phase II dose of flavopiridol given by this schedule is 40 mg/m(2)/24 h. The manageable gastrointestinal toxicity, early signs of clinical activity and lack of hematologic toxicity make further exploration in combination trials warranted.     

A phase II study of weekly paclitaxel in elderly patients with advanced non-small cell lung cancer.

PURPOSE: Our aim was to evaluate the efficacy, toxicity, and pharmacokinetic behavior of single-agent paclitaxel given weekly to elderly patients with lung cancer. EXPERIMENTAL DESIGN: Previously untreated patients with stage IIIB/IV non-small cell lung cancer were eligible for the study if they were at least 70 years of age and had preserved organ function. Paclitaxel was administered over 1 h at a dose of 90 mg/m(2) for 6 consecutive weeks on an 8-week cycle. The pharmacokinetics of paclitaxel were assessed during the first and sixth week of therapy in a subgroup of eight patients. RESULTS: A total of 35 patients (median age, 76 years; range, 70-85) were enrolled. The overall response rate was 23%. Median time to failure was 5.2 months, whereas the median survival time was 10.3 months. Survival rates after 1 and 2 years were 45 and 22%, respectively. Grade 3/4 toxicities included neutropenia (5.8%), hyperglycemia (17.6%), neuropathy (5.8%), and infection (8.8%). Two patients died from treatment-related toxicity. There was no significant difference (P = 0.18) between the total body clearance of paclitaxel on the first (17.4 +/- 2.9 liters/h/m(2), mean +/- SD) and sixth (15.8 +/- 4.1 liters/h/m(2)) week of therapy. CONCLUSION: Paclitaxel administered as a weekly 1-h infusion at a dose of 90 mg/m(2) is a safe and effective therapy for elderly patients with advanced non-small cell lung cancer. Its pharmacokinetics in elderly patients do not appear to differ from historical data for younger patients, and there was no suggestion of a change in drug clearance after repeated weekly dosing.     

Influence of alternate sequences of epirubicin and docetaxel on the pharmacokinetic behaviour of both drugs in advanced breast cancer.

BACKGROUND: Previously we observed a pharmacokinetic interference of epirubicin elimination when paclitaxel is given in combination in a sequence-dependent manner (i.e. when paclitaxel is administered as first drug). The aim of this study was to determine whether these sequence-dependent pharmacological effects were also evident when epirubicin was combined with docetaxel. PATIENTS AND METHODS: Patients who received epirubicin 75 mg/m2 or 90 mg/m2 as an intravenous bolus followed immediately by docetaxel 70 mg/m2 or 80 mg/m2 over a 1-h infusion, or the opposite sequence, every 3 weeks were eligible for this study. The pharmacokinetics of docetaxel, epirubicin and its metabolites were studied at the first and second cycle of treatment. Pharmacokinetic data were normalised to the lower dose of each drug. Toxicity was recorded at nadir and graded according to National Cancer Institute Common Toxicity Criteria. RESULTS: Twelve consecutive patients, each acting as their own control, entered the study. The sequence of drug administration of docetaxel and epirubicin did not affect the pharmacokinetics of the parent anthracycline. Statistically significant lower glucuronidation metabolism of epirubicin was observed in patients who received docetaxel before epirubicin. The pharmacokinetics of docetaxel were not influenced by the sequence of drug administration. No difference in haematological and non-haematological toxicity was observed in the two sequences of treatment. CONCLUSIONS: The pharmacokinetics of the parent anthracycline and of docetaxel were similar between the two schemes of treatment. The metabolic variations observed, i.e. differences in the plasma levels of epirubicin glucuronides, seem not to have clinical relevance.     

Low dose–high dose: what is the right dose? Pharmacokinetic modeling of etoposide

PURPOSE: Some clinical studies on etoposide (Eto) have shown marked schedule dependency of the effect (starting at about 1 mg/l) and toxicity (over about 10 mg/l) whereas other studies have not confirmed these results. What are the conclusions we can draw from these inconsistent results when developing new low-dose (LD) and high-dose (HD) Eto schedules? METHODS: A pharmacokinetic model for Eto based on individual pharmacokinetic data was used to simulate different LD (450 mg/m(2)) and HD (1800 mg/m(2)) schedules. The duration of exposure and the AUC of relevant concentration ranges (>1 mg/l, 1-10 mg/l, >10 mg/l) as well as peak levels were calculated in relation to the standard low dose (150 mg/m(2) over 2 h daily for 3 days). RESULTS: The fourfold dose increase from the LD to the HD schedule was associated with a complementary increase in total AUC. However, variations in infusion time for the HD schedule were associated with large differences in AUC distribution and drug exposure with constant total AUC. Short infusions (0.5 h and 4 h) resulted in extreme peak levels (factors of 17.6+/-1.5 and 8.7+/-0.4 compared to the standard LD schedule) and an AUC >10 mg/l (factors of 17.5+/-4.9 and 17.2+/-4.8, and 83+/-2.4% and 82+/-2.4% of the corresponding total AUC), and the 96-h infusion yielded a long duration of exposure to concentrations >10 mg/l (factor 7.9+/-2.6), whereas continuous i.v. infusion over 55+/-11 days was associated with a multiple increase in the duration of exposure to "standard" drug concentrations (1 mg/l ). CONCLUSIONS: According to evidence against schedule dependency, only target dose and pharmacokinetic variability would be appropriate rationales for Eto dosing. However, arguing for schedule dependency, simulated pharmacokinetic profiles for new Eto schedules over a wide range support that Eto-containing regimens should be designed on the basis of clear pharmacokinetic hypotheses of target levels, exposure times and AUC distributions, to allow subsequent development of pharmacokinetic/pharmacodynamic modeling.     

Toxicity profile and pharmacokinetic study of a phase I low-dose schedule-dependent radiosensitizing paclitaxel chemoradiation regimen for inoperable non-small-cell lung cancer

PURPOSE: We report the toxicity profile and pharmacokinetic data of a schedule-dependent chemoradiation regimen using pulsed low-dose paclitaxel for radiosensitization in a Phase I study for inoperable non-small-cell lung cancer. METHODS AND MATERIALS: Paclitaxel at escalating doses of 15 mg/m(2), 20 mg/m(2), and 25 mg/m(2) were infused on Monday, Wednesday, and Friday with daily chest radiation in cohorts of 6 patients. Daily radiation was delayed for maximal G2/M arrest and apoptotic effect, an observation from preclinical investigations. Plasma paclitaxel concentration was determined by high-performance liquid chromatography. RESULTS: Dose-limiting toxicities included 3 of 18 patients with Grade 3 pneumonitis and 3 of 18 patients with Grade 3 esophagitis. There was no Grade 4 or 5 pneumonitis or esophagitis. There was also no Grade 3 or 4 neutropenia, thrombocytopenia, anemia or neuropathy. For Dose Levels I (15 mg/m(2)), II (20 mg/m(2)), and III (25 mg/m(2)), the mean peak plasma level was 0.23 +/- 0.06 micromol/l, 0.32 +/- 0.05 micromol/l, and 0.52 +/- 0.14 micromol/l, respectively; AUC was 0.44 +/- 0.09 micromol/l, 0.61 +/- 0.1 micromol/l, and 0.96 +/- 0.23 micromol/l, respectively; and duration of drug concentration >0.05 micromol/l (t > 0.05 micromol/l) was 1.6 +/- 0.3 h, 1.9 +/- 0.2 h, and 3.0 +/- 0.9 h, respectively. CONCLUSION: Pulsed low-dose paclitaxel chemoradiation is associated with low toxicity. Pharmacokinetic data showed that plasma paclitaxel concentration >0.05 micromol/l for a minimum of 1.6 h was sufficient for effective radiosensitization.     

Multicenter phase II study of trastuzumab in combination with epirubicin and docetaxel as first-line treatment for HER2-overexpressing metastatic breast cancer

Summary The primary objective of study is to evaluate cardiac safety of trastuzumab in combination with epirubicin and docetaxel. HER2-overexpressing metastatic breast cancer patients were enrolled in a two-stage, multicenter phase II trial with weekly trastuzumab (4 and then 2 mg/kg) with epirubicin and docetaxel (either 75 mg/m²) on day 1 every 3 weeks. After eight courses of chemotherapy, trastuzumab was continued as a single agent. To assess cardiotoxicity, patients were evaluated for left ventricular ejection fraction (LVEF) at baseline, every two cycles during chemotherapy and trastuzumab, and every 3 months during trastuzumab alone. Cardiotoxicity was defined as signs and/or symptoms of congestive heart failure (CHF) and/or an absolute decrease in LVEF of ≥20 units or a decline to ≤45%. In the first stage of the study, three episodes of cardiotoxicity were observed (two asymptomatic declines of LVEF and one CHF) in 29 patients, and recruitment continued. During follow-up of patients who continued trastuzumab after chemotherapy, seven further cardiologic events occurred (three asymptomatic decline of LVEF and four CHF). Therefore, recruitment was interrupted after the 45th patient. The majority of cardiac events occurred late during trastuzumab alone, half were asymptomatic and all cases of CHF were resolved using cardiac therapy. Complete and partial responses were 20 and 47%, respectively, and the median time to progression was 15.7 months (95% CI, 11.6–19.0 months). In light of the cardiotoxicity experienced during this study, we currently recommend that this combination be used only in controlled clinical trials under vigilant cardiac monitoring.     

Plasma etoposide catechol increases in pediatric patients undergoing multiple-day chemotherapy with etoposide.

PURPOSE: The purpose of this research was to determine inter- and intrapatient differences in the pharmacokinetic profiles of etoposide and its genotoxic catechol metabolite during conventional multiple-day dosing of etoposide in pediatric patients. EXPERIMENTAL DESIGN: Seven pediatric patients with various malignancies received etoposide at a dose of 100 mg/m(2) i.v. over 1 h daily for 5 days. Blood samples were taken at selected time points on days 1 and 5. Plasma and protein-free plasma concentrations of etoposide and etoposide catechol were determined using a validated liquid chromatography/tandem mass spectrometry assay. Pharmacokinetic parameters of both etoposide and etoposide catechol were calculated using the WinSAAM modeling program developed at NIH. RESULTS: The mean maximum concentration (C(max)) for total (0.262 +/- 0.107 micro g/ml) and free catechol (0.0186 +/- 0.0082 micro g/ml) on day 5 were higher than the mean C(max) for total (0.114 +/- 0.028 micro g/ml) and free catechol (0.0120 +/- 0.0091 micro g/ml) on day 1. The mean area under the plasma concentration-time curve (AUC)(24h) for total (105.4 +/- 49.1 micro g.min/ml) and free catechol (4.89 +/- 2.23 micro g x min/ml) on day 5 were much greater (P < 0.05) than those for total (55.9 +/- 16.1 micro g x min/ml) and free catechol (3.04 +/- 1.04 micro g x min/ml) on day 1. In contrast, the AUC(24h) for etoposide was slightly lower on day 5 than on day 1. CONCLUSIONS: The C(max) and AUC(24h) for etoposide catechol were significantly higher on day 5 than on day 1. This suggests that metabolism of etoposide to its catechol metabolite increases in pediatric patients receiving multiple-day bolus etoposide infusions. These findings may be relevant to future reduction of the risk of leukemia as a treatment complication, because etoposide and etoposide catechol are both genotoxins.     

Cardiac safety of trastuzumab in combination with epirubicin and cyclophosphamide in women with metastatic breast cancer: results of a phase I trial

This prospective, parallel-group, dose-escalation study evaluated the cardiac safety of trastuzumab (Herceptin) plus epirubicin/cyclophosphamide (EC) in women with human epidermal growth factor receptor-2 (HER2)-positive metastatic breast cancer (MBC) and determined an epirubicin dose for further evaluation. HER2-positive patients received standard-dose trastuzumab plus epirubicin (60 or 90 mg/m(2))/cyclophosphamide (600 mg/m(2)) 3-weekly (EC60+H, n=26; EC90+H, n=25), for four to six cycles; 23 HER2-negative patients received EC alone (90/600 mg/m(2)) 3-weekly for six cycles (EC90). All patients underwent thorough cardiac evaluation. Two EC90+H-treated patients experienced symptomatic congestive heart failure 4.5 and 6 months after the end of chemotherapy. One EC60+H-treated patient experienced an asymptomatic decrease in left ventricular ejection fraction (LVEF) to <50% 6 months after the end of chemotherapy. No such events occurred in control patients. Asymptomatic LVEF decreases of >10% points were detected in 12 (48%), 14 (56%) and 5 (24%) patients treated with EC60+H, EC90+H, and EC90. Objective response rates with EC60+H and EC90+H were >60%, and 26% for EC90 alone. These results indicate that trastuzumab may be combined with EC with manageable cardiotoxicity and promising efficacy.     

Phase II study of epirubicin in advanced soft tissue sarcoma

Thirty-seven patients (pts) with previously untreated and measurable advanced soft tissue sarcoma entered this phase II study: 22 men and 15 women were included. Median age was 58 (range: 20-71). The starting dose of epirubicin was 100 mg/m2 IV bolus every 3 wks. In the case of minimal myelosuppression, the dose was increased by 10 mg/m2 to 130 mg/m2 (Mean dose per cycle: 105 mg/m2). Median cumulative dose of epirubicin administered was 445 mg/m2 (range: 200-1320 mg/m2). From 32 evaluable pts, one had a complete response (CR), 5 a partial response (PR), (CR + PR = 18.7% +/- 13.8%), 12 showed no change (37.5%) and 14 had progressive disease. The number of complete or partial responses observed was not modified by increasing the doses of epirubicin. Median time to progression was 4 months. From 32 pts evaluable for toxicity, hematologic toxicity at d 21 was mild. Non hematological toxicities consisted of nausea and vomiting in 74% of pts (WHO grade 3 = 5%), stomatitis in 12.2% (WHO grade 3 = 3%) and alopecia in 91% (WHO grade 2-3 = 72%). No cardiac dysfunction was recorded during the treatment, even though 7 patients received more than 800 mg/m2 of epirubicin (median: 850 mg/m2, range: 810-1320 mg/m2). The results of this study show that epirubicin is an active drug in advanced soft tissue sarcoma.     

Sequence effect of epirubicin and paclitaxel treatment on pharmacokinetics and toxicity.

PURPOSE: Sequence-dependent clinical and pharmacokinetic interactions between paclitaxel and doxorubicin have been reported. Some data have shown an influence of paclitaxel on epirubicin metabolism, but no data are available about the effect of diverse sequences of these drugs. We investigated whether reversing the sequence of epirubicin and paclitaxel affects the pattern or degree of toxicity and pharmacokinetics. PATIENTS AND METHODS: Patients receiving epirubicin 90 mg/m(2) by intravenous bolus followed by paclitaxel 175 mg/m(2) over 3-hour infusion or the opposite sequence every 3 weeks for four cycles were eligible. Toxicity was recorded at nadir. Pharmacokinetic data were evaluated at the first and the second cycle and were correlated with toxicity parameters. RESULTS: Thirty-nine consecutive stage II breast cancer patients were treated. Twenty-one patients received epirubicin followed by paclitaxel (ET group), and 18 received the opposite sequence (TE group). No significant difference in nonhematologic toxicity was seen. A lower neutrophil and platelet nadir and a statistically significant slower neutrophil recovery was observed in the TE group. Area under the concentration-time curve (AUC) of epirubicin was higher in the TE group (2,346 ng/mL. h v 1,717 ng/mL. h; P =.002). An inverse linear correlation between epirubicin AUC and neutrophil recovery was also observed (P =.012). No difference was detected in paclitaxel pharmacokinetics. CONCLUSION: Our results support a sequence-dependent effect of paclitaxel over epirubicin pharmacokinetics that is associated with increased myelotoxicity. Because schedule modifications of anthracyclines and paclitaxel can have clinical consequences, the classical way of administration (ie, anthracyclines followed by paclitaxel) should be maintained in clinical practice.     

Epirubicin plus low-dose trastuzumab in HER2 positive metastatic breast cancer

Purpose This phase II study, evaluated the activity and cardiotoxicity of first-line epirubicin plus low-dose trastuzumab (LD-T) in patients with HER2 positive MBC. Methods Patients received epirubicin 90 mg/sqm every 3 weeks plus weekly LD-T (2 mg/kg loading dose, then 1 mg/kg). After 6/8 cycles of epirubicin, single agent trastuzumab was continued. Cardiotoxicity was defined as signs or symptoms of congestive heart failure (CHF), or ≥15% decline in LVEF without symptoms, or <15% LVEF decline to less than 50%, without symptoms. Results Forty-five patients were enrolled. Twenty-three received prior adjuvant anthracyclines. Overall response rate was 61.4%. The median time to progression was 7.4 months and the median survival was 32.8 months. Two (4.5%) patients developed CHF. Conclusions Epirubicin plus LD-T is an active regimen, however, the relatively high rate of cardiotoxicity together with the availability of less cardiotoxic and active trastuzumab-containing combinations precludes further evaluation of this regimen. An invited commentary to this article can be found at doi:.     

The pharmacokinetics of high-dose epirubicin and of the cardioprotector ADR-529 given together with cyclophosphamide, 5-fluorouracil,and tamoxifen in metastatic breast-cancer patients

A high-pressure liquid chromatographic method for determination of the bisdioxopiperazine derivative ADR-529 (ICRF-187), a compound proven effective in protection against anthracycline-induced cardiotoxicity, has been developed. The limit of quantitation was 5 ng/ml using a narrow-bore 5-m silica column and UV detection. The method was used for determination of pharmacokinetic profiles of ADR-529 after a 3-weekly i.v. administration of different doses of ADR-529 (600–1000 mg/m²) together with different doses of epirubicin (E, 60–100 mg/m²), fixed-dose cyclophosphamide (C, 600 mg/m²), fixed-dose 5-fluorouracil (F, 600 mg/m²), and daily administration of tamoxifen (T, 30 mg; CEF-T) in the treatment of patients with metastatic breast cancer. Pharmacokinetic parameters for epirubicin were also determined. The aim of the study was to determine (1) whether the pharmacokinetics of ADR-529 as part of a combination with CEF-T changes with increasing doses of ADR-529 and increasing doses of epirubicin and (2) whether the pharmacokinetics of epirubicin in the same combinations is altered with the administration of increasing doses of ADR-529. A total of 82 patients were included. A crossover study including 16 of the patients showed no significant difference in epirubicin pharmacokinetic parameters when epirubicin was given with or without concomitant administration of ADR-529. Apart from minor changes in the distributional half-lives, the pharmacokinetic parameters of epirubicin were not altered with increasing doses of ADR-529, nor were the pharmacokinetic parameters of ADR-529 itself. Escalating doses of epirubicin did not significantly alter the pharmacokinetic parameters of ADR-529 with the exception of a 30% increase in the terminal half-life and a decrease in total body clearance when the epirubicin dose was raised from 60 to 100 mg/m². We conclude that concomitant administration of ADR-529 does not alter the distribution and elimination of epirubicin in doses suitable for preventing the anthracycline-induced cardiotoxicity.     

Clinical and pharmacologic study of the epirubicin and paclitaxel combination in women with metastatic breast cancer.

PURPOSE: A pharmacokinetic interaction may cause increased cardiotoxicity of paclitaxel (PTX) and high cumulative dose of doxorubicin. We tested antitumor activity, tolerability, and pharmacokinetics of the lesser cardiotoxic epirubicin (EPI) and PTX (ET combination). PATIENTS AND METHODS: Twenty-seven women with untreated metastatic breast cancer, median age of 56 years, and prominent visceral involvement (74%) were studied. Three-weekly EPI (90 mg/m(2)) and PTX (200 mg/m(2) over 3 hours) were given for a maximum nine cycles. EPI was administered 24 hours before PTX (E --> T) in cycle 1, and 15 minutes before PTX (ET) thereafter. EPI, epirubicinol (EOL), EPI-glucuronide (EPI-glu), EOL-glucuronide (EOL-glu), PTX, and 6alpha-OH-PTX were measured in plasma and urine in 14 women. RESULTS: Patients received 205 cycles of ET and a median EPI dose of 720 mg/m(2). Grade 4 neutropenia (49% of cycles) was the most frequent toxicity. Cardiac contractility was decreased in five patients. Mild congestive heart failure occurred in two (7.4%). Response rate was 76% (28% complete). Median overall survival was 29 months. On the basis of intrapatient comparison in the first 24 hours of E --> T and ET cycles, PTX did not affect EPI disposition, but significantly increased plasma exposure to EOL (by 137%), EPI-glu (threefold) and EOL-glu (twofold). Urinary excretion of EPI dose went from 8.2% in E --> T to 11.8% in ET cycles. Clearance of PTX was 30% slower in ET than E --> T. ET cycles caused lower neutrophil nadir than E --> T (644 +/- 327 v 195 +/- 91, P <.05) CONCLUSION: ET is feasible, devoid of excessive cardiac toxicity, and active. A reciprocal pharmacokinetic interference between the two drugs has pharmacodynamic consequences, and suggests a direct effect of PTX on EPI metabolism requiring ad hoc investigation.     

A prospective randomized comparison of epirubicin and doxorubicin in patients with advanced breast cancer

Fifty-four patients with advanced breast cancer who had failed prior non-anthracycline combination chemotherapy were randomized to treatment with either epirubicin 85 mg/m2 or doxorubicin 60 mg/m2 intravenously every three weeks. Of 52 evaluable patients, 25% (six of 24) treated with epirubicin, and 25% (seven of 28) treated with doxorubicin experienced major therapeutic responses. The median duration of response to epirubicin was 11.9 months compared to 7.1 months with doxorubicin. Cardiotoxicity was monitored by serial multigated radionuclide cineangiocardiography performed at rest and after exercise. Laboratory evidence of cardiotoxicity was defined as a decrease in resting left ventricular ejection fraction of greater than 10% from the baseline value, or a decrease of 5% or greater with exercise compared with the resting study performed on the same day. Fifteen patients treated with epirubicin and 18 patients treated with doxorubicin had at least two determinations of left ventricular ejection fraction and were evaluable for laboratory cardiotoxicity. Using methods of survival analysis, the median doses to the development of laboratory cardiotoxicity were estimated to be 935 mg/m2 of epirubicin and 468 mg/m2 of doxorubicin. Four patients treated with epirubicin and five treated with doxorubicin developed symptomatic congestive heart failure. The median cumulative dose at which congestive heart failure occurred was 1,134 mg/m2 of epirubicin compared with 492 mg/m2 of doxorubicin. Fewer episodes of nausea and vomiting were observed in patients receiving epirubicin. Epirubicin is a new anthracycline with reduced cardiac toxicity, but preserved efficacy in the treatment of patients with advanced breast cancer.     

Comparative pharmacokinetic analysis of 5-fluorouracil and its major metabolite 5-fluoro-5,6-dihydrouracil after conventional and reduced test dose in cancer patients.

The aim of this study was to investigate the clinical pharmacokinetics of 5-fluorouracil (5-FU) and its major metabolite 5-fluoro-5,6-dihydrouracil (5-FDHU) in 20 colorectal cancer patients given two dose levels of 5-FU, 250 and 370 mg/m2, administered by i.v. bolus. A reverse-phase high-performance liquid chromatographic method was used for the simultaneous assay of 5-FU and 5-FDHU in plasma samples obtained at baseline and at multiple time points from 5 min to 4 h after 5-FU bolus as well as to assess the activity of dihydropyrimidine dehydrogenase (DPD) in peripheral blood mononuclear cells (PBMCs) before 5-FU dosing. Plasma pharmacokinetic parameters of patients given 250 mg/m2 5-FU were significantly different from those receiving 370 mg/m2; main differences were observed in the trapezoidal areas under the plasma levels-versus-time curve from to to the last measurable concentration (area under the curve, 3.77+/-0.21 versus 13.61+/-2.3 h x microg/ml), peak plasma concentration (Cmax, 18.15+/-1.35 versus 48.41+/-7.69 microg/ml), and total body clearance (CL(TB), 54.64+/-3.54 versus 25.43+/-2.3 l/h/m2). Significant differences were also observed in the main pharmacokinetic parameters of 5-FDHU after 250 and 370 mg/m2 5-FU including the area under the curve from to to 4 h (5.39+/-0.32 versus 8.75+/-1.24 h x microg/ml), Cmax (3.60+/-0.16 versus 5.26+/-0.55 microg/ml) and time to Cmax (Tmax, 0.45+/-0.03 versus 0.69+/-0.06 h). The mean DPD activity in PBMCs in this group of patients was 205.7+/-36.4 pmol of 5-FDHU/min/mg of protein and was within the normal range; however, no significant correlations were found between 5-FU or 5-FDHU pharmacokinetic parameters at two dose levels and DPD activity of PBMCs. The results of the present study provide the first detailed comparison of the distribution of 5-FU and its major metabolite 5-FDHU at the therapeutic level as well as at reduced test dose levels to obtain pharmacokinetic data to be used as reference values for the identification of patients at risk of major 5-FU toxicity due to impaired metabolism to 5-FDHU.     

Therapy of peritoneal carcinosis with intraperitoneal administration of cis-diamminedichloroplatinum and systemic sodium thiosulfate protection. Clinical results of a pilot study and pharmacokinetics

Six patients with peritoneal carcinosis and ascites received 13 courses of ip cis-platinum (c-DDP). C-DDP (170-250 mg in 2L saline, dwell 4 h) was administered via Pig-Tail-Cordis catheter with concurrent infusion of sodium thiosulfate (bolus 7.5 g/m2 followed by 2.13 g/m2/h for 12 h). The patients received pre- and post-therapy hydration (250 ml/h) and mannitol-induced diuresis. Courses were given in 4 weekly intervals. With a dwell time of 4 h 27.0% +/- 14.6% (mean +/- SD) of platinum were recovered. Total serum platinum peaked at 3.1 +/- 1.0 microgram/ml. The peritoneal/serum ratio of platinum concentration was 49.5 +/- 12.6 after 1 h, 7.4 +/- 1.7 after 5 h and 4.2 +/- 1.7 after 12 h. Within 12 h 30.9% +/- 10.0% of the administered dose were excreted in urine. In 4 patients the ascites had disappeared lasting 14+, 15+, 5+, 3+ months. 2 patients died within 1 month caused by systemic tumor progression. Following toxicity was observed: 9/13 nausea and vomiting grade 1 (WHO), 2/13 hematological toxicity grade 2, 1/13 sterile peritonitis, no renal or neurological toxicity. This pilot study demonstrates a pharmacokinetic advantage of ip chemotherapy with c-DDP and an effectiveness against peritoneal carcinosis.     

Reversibility of trastuzumab-related cardiotoxicity: new insights based on clinical course and response to medical treatment.

PURPOSE: Trastuzumab is an important biologic agent with significant activity in breast cancers that overexpress the HER2/neu marker. However, trastuzumab is associated with cardiotoxicity that has not yet been fully explored. We present our experience with patients who developed trastuzumab-related cardiotoxicity. PATIENTS AND METHODS: Over a 4-year period, 38 patients with HER2/neu-positive breast cancer were referred for suspected trastuzumab-related cardiotoxicity. All patients had previously received anthracycline-based chemotherapy. Results After doxorubicin but before trastuzumab, the mean (+/- standard deviation) left ventricular ejection fraction (LVEF) was 0.61 +/- 0.13, and the LVEF decreased to 0.43 +/- 0.16 after trastuzumab (P < .0001). After withdrawal of trastuzumab, the LVEF increased to 0.56 +/- 0.11. Mean time to recovery of LVEF was 1.5 months and was temporally associated with medical treatment in 32 (84%) of the 38 patients but occurred without treatment in six patients (16%). Increases in LVEF were noted in 37 of the 38 patients. Twenty-five of these patients were re-treated with trastuzumab; three patients had recurrent left ventricular dysfunction, but 22 patients (88%) did not. All re-treatment patients continued on their therapeutic regimen for heart failure when rechallenged with trastuzumab. Nine patients underwent endomyocardial biopsy. Ultrastructural changes were not seen. CONCLUSION: Patients who develop cardiotoxicity while receiving trastuzumab therapy generally improve on removal of the agent. The mechanism of trastuzumab-related cardiac dysfunction is different from that of anthracycline cardiotoxicity, in part, demonstrated by the absence of anthracycline-like ultrastructural changes. Reintroducing trastuzumab may be appropriate for some individuals who previously have experienced trastuzumab-related cardiac dysfunction.     

A phase I and pharmacokinetic study of capecitabine in combination with epirubicin and cisplatin in patients with inoperable oesophago-gastric adenocarcinoma.

BACKGROUND: The purpose of this study was to evaluate the dose-limiting toxicity (DLT) and maximum tolerated dose of capecitabine when used in combination with epirubicin and cisplatin (ECC) in patients with oesophageal or gastric adenocarcinoma. Response rate, progression-free survival (PFS) and overall survival were also determined, and the effect of previous oesophago-gastric surgery or concurrent oesophago-gastric cancer on the absorption and metabolism of capecitabine was evaluated. PATIENTS AND METHODS: Patients with inoperable oesophago-gastric adenocarcinoma received up to six cycles of epirubicin (50 mg/m(2) i.v., 3-weekly), cisplatin (60 mg/m(2) i.v., 3-weekly) and capecitabine, the latter administered orally in an intermittent schedule (14 days treatment; 7-day rest period) at 3-weekly intervals. Patients were recruited into one of four escalating dose cohorts (500, 825, 1000 and 1250 mg/m(2) bd). Dose escalation occurred after six patients had completed at least one cycle of chemotherapy at the previous dose level, with DLT assessed on the toxicity of the first cycle only. Blood sampling for pharmacokinetic analyses was performed over the first 10 h of day 1 of cycle 1. RESULTS: Thirty-two patients, median age 63 years (range 32-76 years), ECOG performance status < or =2 with locally advanced (10) or metastatic (22) disease were recruited and were evaluable for toxicity. Two of five patients experienced DLT at 1250 mg/m(2) bd with grade II stomatitis (one patient) and grade III diarrhoea with febrile neutropenia (one patient). Cumulative toxicity for all cycles (n = 140) (worst grade per patient) includes grade IV oesophagitis (one patient), grade III diarrhoea (five), grade IV neutropenia with infection (seven), grade II stomatitis (four) and grade IV thrombocytopenia (one). Of 29 patients with evaluable disease, there was one complete response and six partial responses [24% response rate [95% confidence interval (CI) 10% to 44%]], a median PFS of 22 weeks (95% CI 17-27 weeks) and median overall survival of 34 weeks (95% CI 19-49 weeks). Capecitabine was rapidly absorbed after oral administration, with a t(max) of 1-2 h for capecitabine, DFCR (5'-deoxy-5-fluorocytidine) and DFUR (5'-deoxy-5-fluorouridine). The C(max) and AUC(0-)( infinity ) for capecitabine, DFCR and DFUR were similar to those observed in previous monotherapy studies of capecitabine taken after food. CONCLUSION: A dose of 1000 mg/m(2) bd of capecitabine is recommended for use on an intermittent schedule in combination with these doses and schedule of epirubicin and cisplatin. This regimen is tolerable and active in oesophago-gastric adenocarcinoma. A randomised phase III comparison with ECF is justified.