Dose-finding study and pharmacokinetics of epirubicin and paclitaxel over 3 hours: a regimen with high activity and low cardiotoxicity in advanced breast cancer

Dose-dense epirubicin and paclitaxel with G-CSF: a study of decreasing intervals in metastatic breast cancer

Anthracyclines and taxanes are very effective drugs in the treatment of advanced breast cancer. With G-CSF support, the dose-intensity of this combination can be increased by reducing the interval between chemotherapy cycles, the so-called 'shortening of cycle time'. We treated 36 patients with advanced breast cancer in a multicentre phase I/II study. The treatment regimen consisted of epirubicin 75 mg m(-2) followed by paclitaxel 135 mg m(-2) (3 h) in combination with G-CSF. At least six patients were treated in each cohort and were evaluated over the first three cycles. Starting at an interval of 14 days, in subsequent cohorts of patients the interval could be shortened to 10 days. An 8-day interval was not feasible due mainly to incomplete neutrophil recovery at the day of the next scheduled cycle. In the 10-day interval cohort it was feasible to increase the paclitaxel dose to 175 mg m(-2). The haematological and non-haematological toxicity was relatively mild. No cumulative myelosuppression was observed over at least three consecutive cycles. In combination with G-CSF, epirubicin 75 mg m(-2) and paclitaxel 175 mg m(-2) could be safely administered every 10 days over at least three cycles, enabling a dose intensity of 52 and 122 mg m(-2) per week, respectively.

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.

Preclinical evaluation of the cardiotoxicity of taxane-anthracycline combinations using the model of isolated perfused rat heart

Paclitaxel strongly potentiates the cardiotoxicity of doxorubicin in the clinical setting. In this study, we aimed (1) to determine whether this potentiation could be reproduced in an ex vivo model and, if so, (2) to select drugs and protocols that did not cause this potentiation. The effect of paclitaxel and docetaxel on the cardiotoxicity induced by doxorubicin and epirubicin was studied using the model of isolated perfused rat heart. Cardiac performances were evaluated after several combination protocols administered every 2 days over a period of 12 days, and anthracycline concentrations in the heart and liver were determined on Day 12. When administered simultaneously, paclitaxel strongly potentiated the cardiotoxicity of doxorubicin ex vivo, and this effect was not due to Cremophor EL, the solvent used in the formulation of paclitaxel. The potentiation of anthracycline cardiotoxicity could be avoided by the replacement of doxorubicin by epirubicin, and/or of paclitaxel by docetaxel. Cardiotoxic potentiation was also avoided by the introduction of a 24-h lag time between the repetitive injections of doxorubicin and docetaxel. The concentration of doxorubicin and its cardiotoxic metabolite, doxorubicinol, in the heart and liver was not significantly altered by the taxanes, but that of epirubicin was increased twofold both in the heart and the liver. These results show that the potentiation of doxorubicin-induced cardiotoxicity by paclitaxel can be reproduced with an ex vivo model, and that it is not related to an increase in tissue concentration of the drug or active metabolite. Our model, therefore, may be useful for the selection of anthracycline-containing protocols with no increased risk of cardiotoxicity for the patients.

Single agent epirubicin as first line chemotherapy for metastatic breast cancer patients

In order to better explore the toxicity and the activity of high dose epirubicin (120 mg/m2, 3 weeks) we analyzed a population of 127 metastatic breast cancer patients, treated in a randomized clinical trial conducted to evaluate the cardioprotective effect of dexrazoxane against epirubicin induced cardiotoxicity. All the patients had a diagnosis of metastatic breast cancer, an ECOG performance status < or = 2 and normal hematologic, renal, hepatic and cardiac function. No prior adjuvant chemotherapy including anthracycline was allowed. Epirubicin was given at the dose of 120 mg/m2 i.v. bolus every 3 weeks. One hundred twenty five patients were evaluable for toxicity and response. Seventeen patients (11%) had a complete response and 47 patients (37%) a partial response, for an overall response rate of 48%. The median progression free and overall survivals were 8.3 months and 18.3 months, respectively. Grade 3 and 4 leukopenia were observed in 8% and 7% of the patients, respectively. The most frequent nonhematological grade 3 toxicities were alopecia (87%), nausea and vomiting (16%), and mucositis (8%). Cardiotoxicity, defined as occurrence of congestive heart failure, decrease in resting left ventricular ejection fraction (L-VEF) to < or = 45%, or 20 EF units decrease from baseline L-VEF, was observed in 19% of the patients, after a median cumulative dose of epirubicin of 720 mg/m2 (range 120-1440). This study confirms in a large series of patients the activity of high dose epirubicin; however, the high incidence of cardiotoxicity requires a careful evaluation of cardiac risk factors before treatment.

Phase II trial of doxorubicin and paclitaxel plus granulocyte colony-stimulating factor in metastatic breast cancer: an Eastern Cooperative Oncology Group Study

PURPOSE

Several groups have reported that the combination of doxorubicin plus paclitaxel given as a 3-hour intravenous (IV) infusion for up to eight cycles produces a high response rate (> 80%) and complete response rate (> 20%) in metastatic breast cancer, but is also complicated by a 20% incidence of congestive heart failure (CHF). The purpose of this phase II trial was to evaluate the antineoplastic activity of the regimen in a multi-institutional setting and to reduce the incidence of cardiotoxicity by limiting treatment to a maximum of six cycles.

PATIENTS AND METHODS

Fifty-two patients with advanced breast cancer received doxorubicin (60 mg/m(2) by IV injection) followed 15 minutes later by paclitaxel (200 mg/m(2) by IV infusion over 3 hours) every 3 weeks for four to six cycles.

RESULTS

Objective responses occurred in 25 of 48 assessable patients (52%; 95% confidence interval [CI], 38% to 66%), including four complete responses (8%; 95% CI, 0% to 16%). The median cumulative doxorubicin dose given was 240 mg/m(2) (range, 132 to 360 mg/m(2)). Eleven patients (21%) were documented as having a decrease in the LVEF below normal, including three patients (6%; 95% CI, 0% to 12%) who developed CHF.

CONCLUSION

The doxorubicin/paclitaxel regimen that we used is unlikely to produce an objective response rate of more than 70% and a complete response rate of more than 20% in patients with metastatic breast cancer, and proved to be excessively cardiotoxic for use in the adjuvant setting.

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.

Epirubicin: a review of its efficacy as adjuvant therapy and in the treatment of metastatic disease in breast cancer

Epirubicin is a semisynthetic derivative of doxorubicin which has been extensively evaluated in patients with breast cancer. It is effective in the management of metastatic disease and as adjuvant therapy in patients with early breast cancer. In the adjuvant setting, epirubicin-based therapy appears to have efficacy at least equivalent to that of the standard therapy cyclophosphamide, methotrexate and fluorouracil (CMF), with the most recent trials, predominantly in premenopausal patients, reporting significant gains in relapse-free survival and overall survival for epirubicin-based vs CMF therapy. In a single trial, the 5-year relapse-free survival of postmenopausal patients receiving long term hormonal therapy (tamoxifen) was significantly increased when epirubicin was added as single-agent chemotherapy and compared with tamoxifen alone. In patients with metastatic disease, epirubicin- and doxorubicin-containing regimens (with cyclophosphamide and fluorouracil; FEC and FAC) are therapeutically equivalent. Increasing the dose of epirubicin appears to improve response rates in patients with either metastatic or early disease but, with the exception of 1 adjuvant study, improved overall survival has not been demonstrated. Quality of life (QOL) has yet to be adequately evaluated with epirubicin. The major adverse effects of epirubicin are acute dose-limiting haematotoxicity and cumulative dose-related cardiotoxicity. Other important adverse effects include mucositis, nausea and vomiting, reversible alopecia and local cutaneous reactions. However, the tolerability of epirubicin is better than that of doxorubicin at equimolar doses.

CONCLUSION

Epirubicin has been extensively investigated in patients with breast cancer and has been found to be a highly effective agent, both for the treatment of patients with metastatic disease and as an adjuvant therapy. Recent trials have confirmed that, in selected patients requiring adjuvant therapy, FEC therapy is at least as effective as CMF, a standard treatment. FEC is also therapeutically equivalent to FAC in patients with metastatic breast cancer, and because the therapeutic index appears to be better the opportunity exists to increase dose intensity in an effort to improve efficacy. Such trials, and those of combinations of epirubicin with newer or alternative agents, should result in the introduction of more effective and better tolerated epirubicin-based protocols for adjuvant therapy and the management of patients with advanced breast cancer. In the meantime there is sufficient evidence to justify consideration of epirubicin for inclusion in first-line therapies for patients with early or metastatic breast cancer.

Docetaxel in combination with epirubicin in metastatic breast cancer: pharmacokinetic interactions

Epirubicin (75 mg/m2) and docetaxel (75 mg/m2) were administered to 16 patients affected by metastatic breast cancer following two different schedules: (1) docetaxel as infusion administered 1 h after epirubicin administration (schedule A); and (2) docetaxel as infusion immediately (10 min) after the end of epirubicin i.v. bolus administration (schedule B). Experimental non-compartmental analyses such as AUC and Css, were affected very little by the drug combination, irrespective of whether the administration of docetaxel was immediately after the epirubicin bolus (10 min) or delayed (1 h). However, serum levels showed evidence of transient drug interaction: in schedule A, docetaxel infusion was associated with a transient increase of plasma epirubicin in correspondence with Cssmax of docetaxel. Bi-compartmental analysis showed a significant difference in epirubicin clearance between protocols A and B. It is suggested that polysorbate 80, used in minimal amounts to formulate docetaxel, may interfere with epirubicin plasma level.

Cardiotoxicity of epirubicin/paclitaxel-containing regimens: role of cardiac risk factors

PURPOSE

To evaluate the incidence of clinically relevant cardiac toxicity after treatment with epirubicin/paclitaxel-containing regimens in patients with metastatic breast cancer and to identify high-risk patients in whom the benefit of chemotherapy may be negated by the occurrence of congestive heart failure (CHF).

PATIENTS AND METHODS

A total of 105 patients who were referred for epirubicin/paclitaxel treatment were included in this study. Treatment regimens were as follows: (1) epirubicin 90 mg/m(2) plus paclitaxel 135 to 225 mg/m(2) over 3 hours (n = 76); and (2) gemcitabine 1,000 mg/m(2) on days 1 and 4 plus epirubicin/paclitaxel (n = 29). The occurrence of CHF was detected by physical examination, and left ventricular function was evaluated by bidimensional echocardiography to support the diagnosis. Cardiac risk factors examined in this study included age, prior radiotherapy to the chest, hypertension, and diabetes.

RESULTS

No patient experienced CHF while on treatment. Nine patients (9%) developed CHF after cumulative epirubicin doses of 1,080 mg/m(2) (n = 4), 720 mg/m(2) (n = 2), 630 mg/m(2) (n = 1), and 540 mg/m(2) (n = 2). One of the two patients who developed CHF after a cumulative epirubicin dose of 540 mg/m(2) had received consolidation with high-dose chemotherapy. Median time to appearance of cardiologic symptoms was 3 months after the end of treatment (range, 3 to 6 months). Overall, the incidence of CHF was 13% and 4% in patients with or without cardiac risk factors, respectively. The cumulative risk of developing CHF was estimated as 7.7% at a cumulative doses of 720 mg/m(2) and 48.7% at a cumulative dose of 1,080 mg/m(2).

CONCLUSION

This study shows that the incidence of CHF after an epirubicin/paclitaxel regimen is low up to cumulative epirubicin doses of 990 mg/m(2), thus allowing the safe administration of this regimen even in patients who received epirubicin in the adjuvant setting. However, the risk of developing CHF increases when a cumulative dose exceeding 990 mg/m(2) is reached, concomitantly with the presence of an additional cardiac risk factor.

Cisplatin-epirubicin-paclitaxel weekly administration in advanced breast cancer: a phase I study of the Southern Italy Cooperative Oncology Group

PURPOSE

Both cisplatin and epirubicin have been shown to enhance the antitumor activity of paclitaxel in vitro. Weekly administration could result in a substantial improvement in the therapeutic index of cisplatin and paclitaxel. This study was aimed at determining the MTDs of epirubicin and paclitaxel given weekly with a fixed dose of cisplatin.

PATIENTS AND METHODS

Sixty-three breast cancer patients with advanced disease (24 locally advanced and 39 metastatic), who had not received prior chemotherapy (except adjuvant), received weekly cisplatin (CDDP) doses of 30 mg/m2 together with escalating doses of paclitaxel (PTX) and epirubicin (EPI) for a minimum of six cycles. The dose escalation was stopped if DLT occurred during the first six treatment cycles in > 33% of patients of a given cohort.

RESULTS

Nine different dose levels were tested, for a total of 506 weekly cycles delivered. G-CSF support on days 3-5 of each week was also given in the last four cohorts (24 patients). An overall 11 patients showed DLT in the first six cycles. EPI and PTX doses up to 40 and 85 mg/m2/week, respectively, were safely delivered without G-CSF support. However, the actually delivered mean dose intensity was only 64% in this cohort. Therefore, the dose escalation continued with the addition of filgrastim from day 3 to day 5 each week. Doses of EPI and PTX up to 50 and 120 mg/m2/week were administered without observing DLT in the first six cycles in more than one third of the patients enrolled. No toxic deaths were observed. Only two patients had to be hospitalized because of sepsis. Grade 3-4 neutropenia, thrombocytopenia, and anemia occurred in 25, 9, and 16 patients, respectively. Alopecia was almost universal. Other nonhematologic toxicities were generally mild, being of grade 3-4 in only eight patients (fatigue and loss of appetite in two cases, diarrhoea in four cases, peripheral neuropathy and mucositis in one case). Fifteen complete and 37 partial responses have been registered for an 82% (95% CI = 71-91) overall clinical response rate (ORR). Eight complete and 14 partial responses occurred in the 24 patients with locally advanced disease, for a 92% (95% CI = 73-99) ORR, as compared to seven complete and 23 partial responses in the 39 women with metastatic disease, 77% (95% CI = 61-89). A clear dose-response relationship was not observed, since an overall response rate of at least 70% was achieved at all dose levels. However, the ORR increased to 92% in the last four cohorts which included patients who received higher doses of EPI and PTX with G-CSF support. All of the 24 patients with locally advanced disease underwent modified radical mastectomy with axillary dissection. Three of them showed no invasive cancer on pathologic examination, and in another five patients a tumor smaller than 1 cm was found in the surgical specimen of the breast. At a nine-month median follow-up (range 2-14), 11 patients have progressed and three have died. Twenty-three out of 24 patients who underwent surgery are still free from progression. The one-year projected progression-free survival is 77% for the whole population.

CONCLUSIONS

The CDDP/EPI/PTX weekly administration is a well tolerated and very effective approach in advanced breast cancer patients. Full doses of all the three drugs can be delivered even in absence of G-CSF support. A very impressive increment of the dose-intensity can be obtained, however, by adding filgrastim. A phase II study is under way to better define the therapeutic efficacy of this regimen in patients with advanced breast cancer.

Phase II of doxorubicin/taxol in metastatic breast cancer. Argentine Multicenter Taxol Group

PURPOSE

To assess the response rate, survival, and toxicity of Taxol (paclitaxel) as 1-h infusion plus doxorubicin as first-line treatment for patients with metastatic breast cancer (MBC).

PATIENTS AND METHODS

Seventy-six patients with untreated MBC were recruited. All of them had measurable disease and were evaluable for toxicity. Fifty-five percent of the patients had visceral involvement. The dose of doxorubicin was fixed at 50 mg/m2 as a short intravenous infusion, followed by 200 mg/m2 of Taxol as a 1-h intravenous infusion. Doxorubicin was administered during the first seven cycles, continuing with Taxol only up to a maximum of ten cycles.

RESULTS

Neutropenia was the most important toxicity: 30% grade 3 and 18% grade 4. Only 2 patients showed a decrease in the left ventricular ejection fraction (LVEF) which caused discontinuing the treatment. No clinical congestive heart failure (CHF) was observed. Seventy-four patients were eligible for response evaluation: 10 (14%) achieved complete response (CR) and 46 (62%) achieved partial response (PR). The mean duration of response was 13.47+/-1.35 months (95% confidence interval (CI): 10.82; 16.12) and the mean survival was 21.50+/-1.42 months (95% CI: 18.72; 24.29).

CONCLUSION

The overall response (OR) rate was 76%. No CHF was assessed and 2 patients stopped treatment due to LVEF decrease. Although doxorubicin 50 mg/m2 followed by Taxol 200 mg/m2 in 1-h intravenous infusion presents a toxicity profile which demands a close follow-up, it represents a convenient outpatient schedule with similar activity rate compared to longer Taxol infusions.

Dose-finding study of epidoxorubicin and docetaxel as first-line chemotherapy in patients with advanced breast cancer

BACKGROUND

Anthracyclines and taxanes are the most active drugs against breast cancer and the search after their optimal combination is under intensive investigation in both the advanced and early disease settings. A dose-finding study of epidoxorubicin (E) and docetaxel (D) was conducted in advanced breast cancer (ABC) to define the maximum tolerated dose (MTD) of the combination with and without granulocyte colony-stimulating factor (G-CSF) support and to characterise its toxicity and activity profile.

PATIENTS AND METHODS

Forty-two patients who received neither palliative chemotherapy nor adjuvant anthracyclines (55% with dominant visceral disease and 66% with > or = 2 sites involved) with measurable/evaluable lesions, were treated at four dose levels starting from E 75 mg/m2 and D 75 mg/m2 to E 120 mg/m2 and D 85 mg/m2. A maximum of four cycles of the combination was given every three weeks and four additional cycles of single agent D were allowed in responding patients. Cardiac function was monitored at baseline and at every second course by echocardiography.

RESULTS

Febrile neutropenia (two patients) and prolonged, severe neutropenia (absolute neutrophil count (ANC) < 0.1 x 10(9)/l for more than three days; one patient) defined the MTD of the combination without G-CSF support at E 90 mg/m2 and D 75 mg/m2. G-CSF was then routinely administered from the subsequent dose level of E 120 mg/m2 and D 75 mg/m2. The MTD with G-CSF support was established at E 120 mg/m2 and D 85 mg/m2 (one patient with neutropenic fever together with failure of ANC recovery at day 21, three patients with ANC less than 0.1 x 10(9)/l for more than three days, one patient with both and one patient with grade 4 thrombocytopenia and toxic death from typhlitis while neutropenic). No severe neurotoxicity, mucositis, or fluid retention were observed and there were no clinical signs of cardiotoxicity. Antitumor activity was not a primary endpoint of the study: the overall response rate (ORR) in 40 evaluable patients was 60% (95% confidence interval: 43%-75%, 58% in liver disease, 84% in soft tissue) with no apparent dose-related effect. After a median follow-up of 19 months (range 2-30+), the overall time to progression (TTP) in nine patients without maintenance hormonal therapy was five months.

CONCLUSIONS

The combination of E and D proved to be an effective and safe regimen in poor- prognosis patients with ABC. G-CSF support allowed higher doses to be delivered safely but dose escalation did not translate into improved response rates (RR). The MTD without growth factors support was used, in a phase II trial, which also included patients with previous anthracycline-containing adjuvant regimens.

Comparative effects of paclitaxel and docetaxel on the metabolism and pharmacokinetics of epirubicin in breast cancer patients

PURPOSE

To investigate whether paclitaxel and docetaxel influence the pharmacokinetics and metabolism of epirubicin.

PATIENTS AND METHODS

We studied the pharmacokinetics and biotransformation patterns of epirubicin in 27 cycles and 20 breast cancer patients. Four patients received epirubicin alone 90 mg/m(2) by intravenous (IV) bolus; eight patients received the same dose of epirubicin followed immediately by paclitaxel 175 mg/m(2) in a 3-hour infusion; the other eight patients received epirubicin 90 mg/m(2) followed immediately by docetaxel 70 mg/m(2) in a 1-hour infusion. Epirubicin and its metabolites, epirubicinol (EOL) and 7-deoxydoxorubicinone (7d-Aone), were identified by high-pressure liquid chromatography.

RESULTS

No pharmacokinetic interaction between the parent compound epirubicin and taxanes was detected. Conversely, a significant effect on epirubicin metabolism by both paclitaxel and docetaxel was found. Epirubicin given with paclitaxel or docetaxel yielded areas under the plasma concentration-time curves (AUC) for 7d-Aone 1. 7-fold and 1.9-fold higher (P <.05), respectively, than epirubicin alone. The appearance of two polar metabolites sensitive to glucuronidase was also significantly greater in both taxane groups. Quantitatively different metabolic rates and patterns for EOL were observed in the paclitaxel and docetaxel combinations. The EOL AUC after paclitaxel treatment (1,521 +/- 150 ng/mL*h) was significantly higher (P <.01) than the corresponding values after epirubicin administered either as a single agent (692 +/- 46 ng/mL*h) or in combination with docetaxel (848 +/- 237 ng/mL*h).

CONCLUSION

There is no apparent pharmacokinetic interaction between the parent compound epirubicin and paclitaxel or docetaxel. A different pattern of interaction between these taxanes and epirubicin metabolism is clearly evident.

Paclitaxel by 24-hour infusion with doxorubicin by 48-hour infusion as initial therapy for metastatic breast cancer: phase I results

PURPOSE

We and others have demonstrated the antineoplastic efficacy of paclitaxel as a single agent in metastatic breast cancer. We performed this phase I trial to evaluate the combination of paclitaxel with doxorubicin.

PATIENTS AND METHODS

Eligible patients had measurable or evaluable metastatic breast cancer for which this was the initial cytotoxic treatment. They may have received adjuvant chemotherapy with other drugs. The study had four parts. In part 1, the patients received paclitaxel by 24-hour infusion followed by doxorubicin by 48-hour infusion. The paclitaxel dose was to be escalated from a starting dose of 125 mg/m2, and the doxorubicin dose was to remain constant at 60 mg/m2 with treatment repeated every three weeks. The results of part 1 prompted part 2 which was a study of the reverse sequence. Part 3 was a formal study of pharmacology and has been reported (J Clin Oncol 14: 2713-21, 1996). In part 4, patients received doxorubicin 50 mg/m2 by bolus followed by paclitaxel 150 mg/m2 by 24-hour infusion for courses 1 and 2. In all subsequent courses doxorubicin was administered by 48-hour infusion. All patients in all four parts of the study had baseline cardiac scans. All patients received standard premedication for paclitaxel.

RESULTS

Forty-eight patients were treated in all four parts of the study. In part 1 (10 patients), the maximum tolerated dose (MTD) was paclitaxel 125 mg/m2/24 hours followed by doxorubicin 48 mg/m2/48 hours as defined by dose-limiting mucositis and neutropenic fever which occurred at the starting dose. For part 2 (21 patients), the MTD was doxorubicin 60 mg/m2/48 hours followed by paclitaxel 160 mg/m2/24 hours. In part 4 (seven patients), the MTD was doxorubicin 50 mg/m2/bolus followed by paclitaxel 135 mg/m2/24 hours. In parts 2 and 4, the dose-limiting toxic effect was neutropenia. Of the entire cohort of 48 patients, seven (15%) had a complete response (one persists at five years without intervening therapy), 26 (54%) had a partial response for an objective response rate of 69% (95% confidence interval (95% CI): 54%-81%). The median follow-up of all living patients is 38+ months (range 20+ to 62+); the median response duration is seven months (range 2-33.7+); the median overall survival is 20.5 months (range 5-54+). The median time to progression is 9.6 months (range 1-33.7+ months). Two patients developed congestive heart failure, one at 24 months after her final dose of doxorubicin which amounted to a cumulative lifetime total doxorubicin dose of 870 mg/m2, one after a total of 660 mg/m2. In both, cardiac symptoms were controlled with medications.

CONCLUSIONS

The combination of paclitaxel/24 hours with doxorubicin/48 hours is an effective antineoplastic treatment for metastatic breast cancer. However, the incidence of complete response, the median overall survival, and time to progression were not greater than for standard doxorubicin-based combinations. Additionally, a sequence-dependent interaction between paclitaxel and doxorubicin, given in the schedule described here, was defined. Other strategies and schedules should be evaluated to maximize the antineoplastic efficacy of these two potent agents.

Putting the taxanes to work: unanswered questions

The promising activity of taxanes in advanced breast cancer patients has prompted the investigators to explore their role in the adjuvant setting. Methodological issues, still unsolved pharmacokinetic and pharmacodynamic problems, and potential severe toxicities could jeopardize these attractive regimens and should be taken into account in the design and interpretation of adjuvant trials. In order to minimize the methodological drawbacks, the potential role of taxanes in the adjuvant setting should be assessed in clinical trials powered to detect an absolute survival increase of near 7% at 10 years. The use of paclitaxel in combination with anthracyclines is complicated by pharmacokinetic interactions which may be responsible for unexpected side effects and/or subadditive cytotoxicity. Moreover, possible interactions between taxanes and tamoxifen are still unclear, and therefore more data are necessary before recommending the combined use of the two drugs in the adjuvant setting. Nowadays, the majority of breast cancer patients receive conservative surgery followed by radiotherapy; when adjuvant taxanes are used, radiotherapy should be delayed because of their radiosensitization effect, with potential detrimental effects. Finally, the majority of side effects of taxane-containing regimens are short-lasting and reversible, but other potential toxicities, such as the cardiotoxicity and long-term possible sequelae of the use of high-dose steroids, need long-term evaluation.

Putting taxanes to work in operable breast cancer: a search for selective indications from empirical studies

The taxanes paclitaxel and docetaxel are the prototype drugs of a new class of anticancer drugs that exploits a completely new mechanism of action. Their testing in metastatic breast cancer has been extensive. The results indicating very high response rate with either taxane have given rise to an unprecedented effort in the scientific community to define their optimal application in all stages of the disease. In metastatic breast cancer, initial data suggest that paclitaxel may increase the survival obtained with standard combinations such as CMFP, and similarly promising studies of docetaxel are almost complete. Significant therapeutic benefit has also been observed by the addition of sequential paclitaxel after adjuvant doxorubicin plus cyclophosphamide in operable breast cancer. Overall, more than 20 randomized studies with paclitaxel or docetaxel, either as single agents or in combination, are ongoing or planned in women with high-risk operable breast cancer. This massive effort is mainly based on empirical study designs. However, some preclinical characteristics of the taxanes, such as their increased antitumor effect in tumors overexpressing HER2/neu, the preclinical and clinical evidence of potential synergism with monoclonal antibodies directed against the HER2 receptor, and preclinical evidence of antiangiogenic properties should be pursued to test whether the use of taxanes in breast cancer could be tailored to individual tumor characteristics rather than following the usual pattern of indiscriminate application.

First-line chemotherapy with epirubicin, paclitaxel, and carboplatin for advanced ovarian cancer: a phase I/II study of the Arbeitsgemeinschaft Gynäkologische Onkologie Ovarian Cancer Study Group

PURPOSE

Despite the progress that has been achieved over the years, survival rates in patients with advanced ovarian cancer are still disappointing. New methods to improve the efficiency of first-line chemotherapy are warranted. One method to improve results is to add more non-cross-resistant drugs to platinum-paclitaxel combination regimens. Anthracyclines are among the candidates for incorporation as the "third drug" into first-line regimens for advanced ovarian cancer.

PATIENTS AND METHODS

We performed a phase I/II trial with escalating doses of epirubicin (60, 75, and 90 mg/m2) combined with fixed doses of paclitaxel and carboplatin in 27 previously untreated patients with advanced gynecologic malignancies.

RESULTS

Dose-limiting toxicity occurred at dose level 2 (75 mg/m2 epirubicin) and consisted of myelosuppression (neutropenia, thrombocytopenia). No dose-limiting, nonhematologic toxicities were observed. The maximum tolerable dose was epirubicin 60 mg/m2 (E) combined with a 3-hour infusion of paclitaxel 175 mg/m2 (T) and carboplatin AUC 5 (Carbo). Preliminary analysis indicated promising activity against ovarian cancer.

CONCLUSION

The three-drug combination ET-Carbo, given according to the outlined dose and schedule, should be considered for further phase III evaluation. A randomized German-French intergroup trial comparing ET-Carbo with carboplatin-paclitaxel has already been initiated.

Epirubicin/vinorelbine as first line therapy in metastatic breast cancer

This study was aimed at investigating the toxicity and activity of the combination epirubicin and vinorelbine in chemotherapy-naive patients with metastatic breast cancer. Fifty-one patients with measurable or evaluable metastatic breast cancer entered the study. The regimen consisted of epirubicin 90 mg/m2 as a slow i.v. infusion on day 1, followed by vinorelbine 25 mg/m2 by 30-minute intravenous infusion on days 1 and 8; the courses were repeated every 21 days for a maximum of 8 cycles. All the patients were assessable for toxicity and 47 were evaluable for response according to the World Health Organization (WHO) criteria. Objective responses were observed in 33 out of 47 evaluable patients (70.2%; 95% C.I. 55.1%-82.6%) with 4 complete (8.5%) and 29 partial responses (61.7%); 11 patients had stable disease (23.4%) and 3 patients progressed while on treatment. The median time to progression was 10 months (range 1-21) and the median overall survival was 23 months (range 2 - 32+). Neutropenia was the most frequent toxicity: a grade 4 neutropenia (WHO) was reported in 70% of 252 courses with a median duration of 3 days (range 1-6). Seventeen episodes of febrile neutropenia were observed but only 1 patient required hospital admission. Other hematologic toxicities were negligible. One patient experienced a paralytic ileus requiring hospitalization; no peripheral neuropathy such as muscle weakness or paresthesia was observed. No treatment-related cardiotoxicity was reported. The encouraging response rate achieved with epirubicin/vinorelbine, the easily manageable toxicities of the combination, and its feasibility in an outpatient setting make this combination worthy of further comparative trials with standard regimens.