Epirubicin--docetaxel combination in first-line chemotherapy for patients with metastatic breast cancer: final results of a dose-finding and efficacy study

Pharmacogenetic impact of docetaxel on neoadjuvant treatment of breast cancer patients

AIM

This study aimed to investigate the effect of CYP3A4 and CYP3A5 genotypes on clinical outcomes of docetaxel treatment.

PATIENTS & METHODS

In the PROMIX trial, 150 breast cancer patients received docetaxel preoperatively. CYP3A4 and CYP3A5 genotype combinations were transformed into total CYP 3A phenotypes.

RESULTS

Seven patients were characterized as poor metabolizer (PM), 22 patients as extensive metabolizer and 121 patients as intermediate metabolizer. The frequency of grade 3/grade 4 adverse events was higher in the PM group (p = 0.002). One PM subject who basically lacked enzyme activity died from typhlitis. Total 45 recurrences were reported after a median of 5-year follow-up; none of these was PM.

CONCLUSION

The allelic variants CYP3A4*22 and CYP3A5*3 contribute to the interpatient variations of docetaxel.

Weekly Docetaxel and Gemcitabine following Docetaxel plus Epirubicin or Vinorelbine as First-Line Treatment of Metastatic Breast Cancer: Results of a Multicenter Phase II Study

AIMS AND BACKGROUND

Sequential docetaxel and gemcitabine following initial docetaxel plus epirubicin or vinorelbine association could be worthwhile as first-line treatment of metastatic breast cancer.

METHODS

Fifty-eight patients entered a phase II study that included two sequential phases. In the first phase, 36 and 22 patients previously unexposed or exposed to adjuvant anthracyclines received the association of docetaxel (75 mg/m2, day 1) with epirubicin (75 mg/m2, day 1) or vinorelbine (20 mg/m2, days 1 and 5), respectively, every 21 days for 4 courses. In the second phase, patients who had a response (R) or stable disease (SD) received docetaxel (35 mg/m2) and gemcitabine (800 mg/m2) on days 1, 8 and 15 every 28 days for 4 courses.

RESULTS

In the first phase, grade > or = III neutropenia occurred in 51% and 37% of patients during docetaxel-epirubicin and docetaxel-vinorelbine, respectively. In the second phase, it occurred in the 27% and 15% of patients initially treated with docetaxel-epirubicin and docetaxel-vinorelbine, respectively. On an intention to treat basis, the complete (CR) + partial response (PR) rate to the first phase was 71%, and 22% of patients had SD, without a significant difference between the docetaxel-epirubicin and docetaxel-vinorelbine arms. After the second phase, the CR + PR rate was 65%, and 14% of patients had SD. Median time to progression and survival were 12.1 and 22.0 months, respectively, without a significant difference between patients initially treated with docetaxel-epirubicin and docetaxel-vinorelbine.

CONCLUSIONS

Following an initial docetaxel-based treatment, weekly docetaxel and gemcitabine maintains high percentages of R and SD, with improved toxicity. Survival was similar in patients previously untreated and treated with adjuvant anthracyclines.

Revisiting Dosing Regimen Using Pharmacokinetic/Pharmacodynamic Mathematical Modeling: Densification and Intensification of Combination Cancer Therapy

Controlling effects of drugs administered in combination is particularly challenging with a densified regimen because of life-threatening hematological toxicities. We have developed a mathematical model to optimize drug dosing regimens and to redesign the dose intensification-dose escalation process, using densified cycles of combined anticancer drugs. A generic mathematical model was developed to describe the main components of the real process, including pharmacokinetics, safety and efficacy pharmacodynamics, and non-hematological toxicity risk. This model allowed for computing the distribution of the total drug amount of each drug in combination, for each escalation dose level, in order to minimize the average tumor mass for each cycle. This was achieved while complying with absolute neutrophil count clinical constraints and without exceeding a fixed risk of non-hematological dose-limiting toxicity. The innovative part of this work was the development of densifying and intensifying designs in a unified procedure. This model enabled us to determine the appropriate regimen in a pilot phase I/II study in metastatic breast patients for a 2-week-cycle treatment of docetaxel plus epirubicin doublet, and to propose a new dose-ranging process. In addition to the present application, this method can be further used to achieve optimization of any combination therapy, thus improving the efficacy versus toxicity balance of such a regimen.

Revisiting dosing regimen using PK/PD modeling: the MODEL1 phase I/II trial of docetaxel plus epirubicin in metastatic breast cancer patients

The MODEL1 trial is the first model-driven phase I/II dose-escalation study of densified docetaxel plus epirubicin administration in metastatic breast cancer patients, a regimen previously known to induce unacceptable life-threatening toxicities. The primary objective was to determine the maximum tolerated dose of this densified regimen. Study of the efficacy was a secondary objective. Her2-negative, hormone-resistant metastatic breast cancer patients were treated with escalating doses of docetaxel plus epirubicin every 2 weeks for six cycles with granulocyte colony stimulating factor support. A total of 16 patients were treated with total doses ranging from 85 to 110 mg of docetaxel plus epirubicin per cycle. Dose escalation was controlled by a non-hematological toxicity model. Dose densification was guided by a model of neutrophil kinetics, able to optimize docetaxel plus epirubicin dosing with respect to pre-defined acceptable levels of hematological toxicity while ensuring maximal efficacy. The densified treatment was safe since hematological toxicity was much lower compared to previous findings, and other adverse events were consistent with those observed with this regimen. The maximal tolerated dose was 100 mg given every 2 weeks. The response rate was 45 %; median progression-free survival was 10.4 months, whereas 54.6 months of median overall survival was achieved. The optimized docetaxel plus epirubicin dosing regimen led to fewer toxicities associated with higher efficacy as compared with standard or empirical densified dosing. This study suggests that model-driven dosage adjustment can lead to improved efficacy-toxicity balance in patients with cancer when several anticancer drugs are combined.

Sequential docetaxel as adjuvant chemotherapy for node-positive or/and T3 or T4 breast cancer: clinical outcome (Mansoura University)

This trial compared 6 cycles of fluorouracil, epirubicin, and cyclophosphamide (FEC) with a sequential regimen of 3 cycles of FEC followed by 3 cycles of docetaxel (FEC-D) as adjuvant treatment for women with node-positive or/and T3 or T4 breast cancer. Between January 2006 and January 2010, 657 patients with operable breast cancer were randomly assigned to either FEC every 21 days for 6 cycles, or 3 cycles of FEC followed by 3 cycles of docetaxel, both given every 21 days. Radiotherapy was mandatory for all patients who had undergone breast conserving surgery. Radiation to the chest wall, supraclavicular area, was recommended following mastectomy. Hormone-receptor-positive patients received tamoxifen for 5 years after chemotherapy. The primary end point was 5-year disease-free survival (DFS). Median follow-up was 61 months. Five-year DFS rates were 74 % with FEC and 78 % with FEC-D (P = 0.013). Multivariate analysis adjusted for prognostic factors showed a 17 % reduction in the relative risk of relapse with FEC-D. Five-year overall survival rates were 85 % with FEC and 89.4 % with FEC-D, demonstrating a 27 % reduction in the relative risk of death (P = 0.014). The incidence of grade 3-4 neutropenia, the need for hematopoietic growth factor, and incidence of nausea/vomiting were higher with FEC. Docetaxel was associated with more febrile neutropenia, stomatitis, edema, and nail disorders. Though rare overall, there were fewer cardiac events after FEC-D, attributable mainly to the lower anthracycline cumulative dose. Sequential adjuvant chemotherapy with FEC followed by docetaxel significantly improves disease-free and overall survival in node-positive or/and T3 or T4 breast cancer patients. Although the magnitude of the benefit observed with FEC-D, differences in the toxicity profiles of FEC and FEC-D may influence the choice of treatment for patients.

Beyond cytotoxic chemotherapy for the first-line treatment of HER2-negative, hormone-insensitive metastatic breast cancer: current status and future opportunities

As reflected in its varied clinical behavior, appearances under the light microscope, and differential patterns of gene expression, metastatic breast cancer (MBC) is a heterogeneous disease. Systemic treatment decisions are guided by specific tumor characteristics and individual patient factors. For patients with hormone receptor (HR)-negative MBC and for those whose HR-positive disease has become refractory to hormonal therapies, cytotoxic chemotherapy has been the mainstay of systemic treatment. For hormone-insensitive, HER2-positive MBCs, the addition of trastuzumab to chemotherapy has resulted in improved outcomes. Hormone-insensitive MBC lacking HER2 overexpression includes the subset of patients with estrogen receptor/ progesterone receptor/HER2-negative (so-called triple-negative) disease, which represents a significant minority of all breast cancers. Therapeutic options for such patients are limited by the lack of specific targeted approaches, and this heterogeneous group will be considered collectively as well as separately in this overview of existing and emerging treatment strategies. Conventional cytotoxic chemotherapy, alone or in combination, has been the standard first-line treatment for patients with MBC not amenable to antiestrogen or trastuzumab therapy. The recent evaluation of new targeted therapies in combination with cytotoxic agents has created a new type of combination regimen. Agents targeting angiogenesis, the epidermal growth factor receptor, and various signal transduction pathways have been combined with chemotherapy and possess biologic activity in MBC. As these combinations are being investigated, parallel correlative studies aimed at enriching the population who will benefit most are under way.

Taxanes in breast cancer: An update

Over the past decade the taxanes have proved to be fundamental in the treatment of breast cancer. Initially found to have efficacy in metastatic breast cancer, the taxanes are now vital components in the treatment of early-stage disease, in which their addition to adjuvant treatment of early breast cancer has been shown to improve overall survival. In addition, the taxanes have demonstrated a role in first-line therapy for metastatic disease, with some of the highest efficacy of any class of chemotherapy. Targeted therapies in combination with the taxanes have further improved survival for both early and metastatic disease. New formulations of taxanes may both improve antitumor activity and reduce toxicity.

Sequential adjuvant epirubicin-based and docetaxel chemotherapy for node-positive breast cancer patients: the FNCLCC PACS 01 Trial

PURPOSE

The PACS 01 trial compared six cycles of fluorouracil, epirubicin, and cyclophosphamide (FEC) with a sequential regimen of three cycles of FEC followed by three cycles of docetaxel (FEC-D) as adjuvant treatment for women with node-positive early breast cancer.

PATIENTS AND METHODS

Between June 1997 and March 2000, 1,999 patients with operable node-positive breast cancer were randomly assigned to either FEC every 21 days for six cycles, or three cycles of FEC followed by three cycles of docetaxel, both given every 21 days. Hormone-receptor-positive patients received tamoxifen for 5 years after chemotherapy. The primary end point was 5-year disease-free survival (DFS).

RESULTS

Median follow-up was 60 months. Five-year DFS rates were 73.2% with FEC and 78.4% with FEC-D (unadjusted P = .011; adjusted P = .012). Multivariate analysis adjusted for prognostic factors showed an 18% reduction in the relative risk of relapse with FEC-D. Five-year overall survival rates were 86.7% with FEC and 90.7% with FEC-D, demonstrating a 27% reduction in the relative risk of death (unadjusted P = .014; adjusted P = .017). The incidence of grade 3 to 4 neutropenia, the need for hematopoietic growth factor, and incidence of nausea/vomiting were higher with FEC. Docetaxel was associated with more febrile neutropenia in the fourth cycle, stomatitis, edema, and nail disorders. Though rare overall, there were fewer cardiac events after FEC-D (P = .03), attributable mainly to the lower anthracycline cumulative dose.

CONCLUSION

Sequential adjuvant chemotherapy with FEC followed by docetaxel significantly improves disease-free and overall survival in node-positive breast cancer patients and has a favorable safety profile.

The role of taxanes in the treatment of breast cancer

Among the novel chemotherapeutic agents introduced in the last decade, the taxanes have emerged as the most powerful group of compounds, and results available so far confirm that they will be remembered in the future as the breast cancer chemotherapy of the 1990s. Two taxanes are available (paclitaxel and docetaxel) and they share some characteristics, although they do have some significant differences both in terms of their preclinical profile and, most importantly, their clinical characteristics. There are three main clinical differences: different efficacy-toxicity ratio in relation to dose and schedule; different integrability in anthracycline- and taxane-containing regimens, secondary to differences in pharmacokinetic interactions with anthracyclines; and different level of synergism between each taxane and trastuzumab. In clinical practice, the taxanes are now standard therapy in metastatic breast cancer. Their role as monochemotherapy or in combination with anthracyclines in advanced breast cancer has suggested their potential therapeutic impact in the treatment of patients with early breast cancer. Recent results in the adjuvant setting show that taxanes, used either in combination or in sequential therapy, possess the capability to induce significant improvements, in particular in terms of survival; thus confirming the positive impact of taxanes on the natural history of breast cancer. However, further results of all completed or ongoing Phase III trials in the early setting will help define the optimal use of taxanes and maximise the induced benefits for breast cancer patients.

Docetaxel in the treatment of breast cancer: current experience and future prospects

It has become clear over the past 10 years that docetaxel, a semisynthetic taxoid antineoplastic agent, is among the most promising compounds to have been developed in the 1990s for the treatment of breast cancer. Data indicate that this drug became standard therapy in the treatment of patients with metastatic disease who have failed anthracycline treatment, and secondarily showed very encouraging results in the first-line metastatic setting either in monochemotherapy or when docetaxel was combined with an anthracycline. More recently, docetaxel also became one of the standard therapies in the adjuvant and neoadjuvant settings, and a promising partner for novel biologic therapies. Current research is further exploring the effect of docetaxel on outcome of early breast cancer in order to fully determine the extent that this chemotherapeutic agent will change the natural history of breast cancer.

Dose-finding study of weekly docetaxel, anthracyclines plus fluoropyrimidines as first-line treatment in advanced breast cancer

BACKGROUND

The efficacy and safety of prolonged fluoropyrimidines, either intravenously or orally, prompted their integration with taxanes and anthracyclines in the treatment of advanced breast cancer (ABC). We conducted three subsequent dose-finding studies on first-line chemotherapy in ABC with anthracyclines, either epirubicin (E) or doxorubicin (A), and docetaxel (T), both given on days 1 and 8 every 3 weeks, plus continuous infusion (CI) 5-fluorouracil (F) or capecitabine (X).

PATIENTS AND METHODS

Sixty-two patients (37% dominant visceral disease, 48% locally advanced disease, 45% two or more sites involved), received different doses of T (60--80 mg/m(2)), A (40--50 mg/m(2)) or E (60--90 mg/m(2)) and X (1,650 and 2,000 mg/m(2)), or CI F at a fixed daily dose of 200 mg/m(2). Cardiac function was monitored at baseline and then every four cycles by echocardiography.

RESULTS

The median number of cycles per patient with all regimens was four (range one to eight). Haematological and gastrointestinal toxicity defined the maximum tolerated doses, at T-80/E-90 mg/m(2) with TEF, T-70/A50/X-2,000 mg/m(2) with TAX and T-70/E-80/X-1,650 mg/m(2) with TEX. Two patients treated with TEF developed transient cardiac toxicity (dilatative cardiomyopathy and coronary subtotal stenosis requiring stenting) after cumulative E doses of 400 mg and 1,100 mg/m(2), respectively. Fifty-nine patients were evaluable for response; the overall response rates (ORR) were comparable between regimens (54% with TEF, 71% with TAX and 86% with TEX), with an 81% ORR in 31 patients with locally advanced disease.

CONCLUSIONS

The addition of fluoropyrimidines to weekly, intermittent ET is well tolerated and active in ABC.

Model Describing the Relationship Between Pharmacokinetics and Hematologic Toxicity of the Epirubicin-Docetaxel Regimen in Breast Cancer Patients

Purpose

The aims of the present study were (1) to characterize the pharmacokinetics of both component drugs and (2) to describe the relationship between the pharmacokinetics and the dose-limiting hematologic toxicity for the epirubicin (EPI)/docetaxel (DTX) regimen in breast cancer patients.

Patients and Methods

Forty-four patients with advanced disease received EPI and DTX every 3 weeks for up to nine cycles. The initial doses (EPI/DTX) were 75/70 mg/m2. Based on leukocyte (WBC) and platelet counts, the subsequent doses were, stepwise, either escalated (maximum, 120/100 mg/m2) or reduced (minimum, 40/50 mg/m2). Hematologic toxicity was monitored in all patients, whereas pharmacokinetics was studied in 16 patients. A semiphysiological model, including physiological parameters as well as drug-specific parameters, was used to describe the time course of WBC count following treatment.

Results

In the final pharmacokinetic model, interoccasion variability was estimated to be less than interindividual variability in the clearances for both drugs. The sum of the individual EPI and DTX areas under concentration-time curve correlated stronger to WBC survival fraction than did the corresponding sum of doses. A pharmacokinetic-pharmacodynamic (PK-PD) model with additive effects of EPI and DTX could adequately describe the data.

Conclusion

The final PK-PD model might provide a tool for calculation of WBC time course, and hence, for prediction of nadir day and duration of leukopenia in breast cancer patients treated with the EPI/DTX regimen.

Phase II study of docetaxel in combination with epirubicin and protracted venous infusion 5-fluorouracil (ETF) in patients with recurrent or metastatic breast cancer. A Yorkshire breast cancer research group study

This study was originally designed as a phase I/II study, with a dose escalation of docetaxel in combination with epirubicin 50 mg m⁻² and 5-fluorouracil (5-FU) 200 mg m⁻² day⁻¹. However, as dose escalation was not possible, the study is reported as a phase II study of the combination to assess response and toxicity. A total of 51 patients with locally advanced or metastatic breast cancer were treated on this phase II study, with doses of docetaxel 50 mg m⁻², epirubicin 50 mg m⁻² and infusional 5-FU 200 mg m⁻² day⁻¹ for 21 days. The main toxicity of this combination was neutropenia with 89% of patients having grade 3 and 4 neutropenia, and 39% of patients experiencing febrile neutropenia. Nonhaematological toxicity was mild. The overall response rate in the assessable patients was 64%, with median progression-free survival of 38 weeks, and median survival of 70 weeks. The ETF regimen was found to be toxic, and it was not possible to escalate the dose of docetaxel above the first dose level. This regimen has therefore not been taken any further, but as a development of this a new study is ongoing, combining 3-weekly epirubicin, weekly docetaxel and capecitabine, days 1–14.

Perspectives on cancer therapy-induced mucosal injury: pathogenesis, measurement, epidemiology, and consequences for patients

BACKGROUND

A frequent complication of anticancer treatment, oral and gastrointestinal (GI) mucositis, threatens the effectiveness of therapy because it leads to dose reductions, increases healthcare costs, and impairs patients' quality of life. The Multinational Association of Supportive Care in Cancer and the International Society for Oral Oncology assembled an international multidisciplinary panel of experts to create clinical practice guidelines for the prevention, evaluation, and treatment of mucositis.

METHODS

The panelists examined medical literature published from January 1966 through May 2002, presented their findings at two separate conferences, and then created a writing committee that produced two articles: the current study and another that codifies the clinical implications of the panel's findings in practice guidelines.

RESULTS

New evidence supports the view that oral mucositis is a complex process involving all the tissues and cellular elements of the mucosa. Other findings suggest that some aspects of mucositis risk may be determined genetically. GI proapoptotic and antiapoptotic gene levels change along the GI tract, perhaps explaining differences in the frequency with which mucositis occurs at different sites. Studies of mucositis incidence in clinical trials by quality and using meta-analysis techniques produced estimates of incidence that are presented herein for what to our knowledge may be a broader range of cancers than ever presented before.

CONCLUSIONS

Understanding the pathobiology of mucositis, its incidence, and scoring are essential for progress in research and care directed at this common side-effect of anticancer therapies.

Docetaxel-anthracycline combinations in metastatic breast cancer

The taxanes and anthracyclines have emerged as the most active agents for treating women with advanced breast cancer. As such, investigation of the two drug classes in combination regimens has been eagerly pursued. The rationale for combining docetaxel with an anthracycline includes high clinical activity of each individual agent, lack of complete clinical cross resistance, and non-overlapping toxicity profiles. Phase II trials of the docetaxel combinations with either doxorubicin or epirubicin showed high activity, with acceptable tolerability in patients with metastatic breast cancer. Consequently, three randomized trials have compared docetaxel-anthracycline-based regimens with standard anthracycline-based polychemotherapies as first-line therapy for women with advanced breast cancer. Improved outcome was reported in favor of the docetaxel-anthracycline combinations, with manageable hematologic toxicity and favorable non-hematologic safety profiles. Therefore, docetaxel-anthracycline combinations represent a validated option in first-line treatment for women with advanced breast cancer, and are further evaluated as adjuvant treatment for early stage breast cancer, with already promising prospects and the potential to change the natural history of breast cancer.

Docetaxel plus epirubicin is a highly active, well-tolerated, first-line chemotherapy for metastatic breast cancer: results of a large, multicentre phase II study

PURPOSE

In this multicentre phase II study, the efficacy and safety profile of the combination of docetaxel and epirubicin as first-line chemotherapy for metastatic breast cancer (MBC) were evaluated.

METHODS

Epirubicin (75 mg/m(2)) and docetaxel (75 mg/m(2)) were given intravenously once every 3 weeks for six cycles to 133 patients with MBC.

RESULTS

The overall clinical response rate was 67% (complete and partial responses were 23% and 44%, respectively). The median time to progression was 10.8 months (95% CI 9.7-12.6) and the median overall survival was 19.5 months. Granulocyte colony-stimulating factor support was administered to 32% of patients and in 22% of cycles. Grade 3/4 neutropenia occurred in 35% of patients and febrile neutropenia in 19%. The most frequent grade 3/4 non-haematological toxicities (as percent of patients) were asthenia (6%), vomiting (5%) and nausea (5%). No patients developed congestive heart failure.

CONCLUSIONS

The combination of docetaxel and epirubicin was highly active as first-line treatment for MBC and showed a manageable toxicity profile.

Capecitabine in combination with docetaxel and epirubicin in patients with previously untreated, advanced breast carcinoma

BACKGROUND

The objective of this study was to evaluate the activity and safety of oral capecitabine in combination with docetaxel and epirubicin (TEX) as first-line treatment for patients with locally advanced/metastatic breast carcinoma.

METHODS

This open-label, Phase II study was conducted at six Italian centers. Treatment consisted of epirubicin, 75 mg/m(2) (intravenous bolus), and docetaxel, 75 mg/m(2) (1-hour infusion), both administered on Day 1, plus oral capecitabine, 1000 mg/m(2) twice daily, on Days 1-14 of each 3-week treatment cycle.

RESULTS

A total of 67 patients received 392 cycles of treatment, with a median of 6 cycles in patients with Stage III disease (n = 34 patients) and a median of 8 cycles in patients with Stage IV disease (n = 33 patients). The objective response rate was 82%, including complete responses in 21% of patients. A greater proportion of patients with Stage III disease achieved tumor responses compared with patients who had Stage IV disease (97% vs. 67%, respectively). Among 34 patients with Stage III disease, pathologic complete responses were confirmed in 10 patients (29%). TEX chemotherapy demonstrated an acceptable safety profile. There was a low incidence of Grade 3 adverse events, and Grade 4 adverse events were particularly rare (4%). The most common Grade 3-4 adverse event was febrile neutropenia, which occurred in 16% of patients.

CONCLUSIONS

TEX combination therapy has important antitumor activity and an acceptable safety profile in this setting. A large, randomized, Phase III trial is ongoing to compare TEX chemotherapy with an epirubicin plus docetaxel regimen in patients with untreated, advanced breast carcinoma.

Docetaxel with epirubicin--investigations on cardiac safety

The aim was to evaluate clinical and subclinical cardiac toxicity of epirubicin-docetaxel (ET) combination. Breast cancer patients were given epirubicin (75 mg/m2 for 15 min), followed 1 h later by a 1-h infusion of docetaxel (75 mg/m2) q3w as first-line treatment. Cardiac function was monitored using a 24-h ambulatory electrocardiogram (ECG), left ventricular ejection fraction (LVEF), physical examination and chest radiography. The median LVEF did not decrease during the course of the treatment: median LVEF was 64% prior to treatment and 68% after cycle 8. The 24-h ECG did not reveal any significant changes in heart rate variability. The number of extrasystoles or cardiac arrhythmia did not increase with the ET treatment. No patient experienced congestive heart failure during treatment or the mean follow-up of 34 months. We conclude that first-line ET caused no major cardiac changes during 6 months of treatment (8 cycles) or during follow-up. Twenty-four-hour ECG, combined with echocardiography to measure LVEF, was a feasible method for the close monitoring of the cardiac effects during chemotherapy.

Phase II study of docetaxel and epirubicin in Chinese patients with metastatic breast cancer

The efficacy and safety of docetaxel-epirubicin chemotherapy in the treatment of metastatic breast cancer was investigated in Chinese women. Three-weekly cycles comprised epirubicin 75 mg/m2 i.v. followed 1 h later by docetaxel 75 mg/m2 i.v. After 3 cycles, responding patients received a further 3 cycles, followed by 3 cycles of docetaxel alone. Forty-six patients entered the study, of whom 37% had received prior adjuvant chemotherapy. Three patients withdrew due to toxicity and were not evaluable for response. There were five complete responses and 31 partial responses, giving an overall response rate of 83.7% (95% CI 72.7-94.8%). The median time to progression was 10.96 months (95% CI 7.76-12.86) and median survival was 24.2 months (95% CI 16.6-). The most common grade 3/4 adverse events were neutropenia (96% of patients) and neutropenia with fever (39%). Hepatotoxicity occurred in six patients, two being attributable to hepatitis B virus reactivation. No patients suffered grade 3/4 cardiac toxicity and there were no treatment-related mortalities. Quality of life aspects deteriorated after 3 cycles, but there was a trend towards improved emotional aspects after 9 cycles. We conclude that docetaxel-epirubicin chemotherapy is highly effective for recurrent metastatic/locoregional breast cancer, with myelosuppression being the main toxicity.

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.