A phase I trial of docetaxel and 5-day continuous infusion of 5-fluorouracil in patients with advanced or recurrent breast cancer

Modification of N-hydroxycytidine yields a novel lead compound exhibiting activity against the Venezuelan equine encephalitis virus

Nucleoside and nucleobase analogs capable of interfering with nucleic acid synthesis have played essential roles in fighting infectious diseases. However, many of these agents are associated with important and potentially lethal off-target intracellular effects that limit their use. Based on the previous discovery of base-modified 2'-deoxyuridines, which showed high anticancer activity while exhibiting lower toxicity toward rapidly dividing normal human cells compared to antimetabolite chemotherapeutics, we hypothesized that a similar modification of the N4-hydroxycytidine (NHC) molecule would provide novel antiviral compounds with diminished side effects. This presumption is due to the substantial structural difference with natural cytidine leading to less recognizability by host cell enzymes. Among the 42 antimetabolite species that have been synthesized and screened against VEEV, one hit compound was identified. The structural features of the modifying moiety were similar to those of the anticancer lead 2'-deoxyuridine derivative reported previously, providing an opportunity to pursue further structure-activity relationship (SAR) studies directed to lead improvement, and obtain insight into the mechanism of action, which can lead to identifying drug candidates against a broad spectrum of RNA viral infections.

A pharmacokinetic interaction study of docetaxel and cisplatin plus or minus 5-fluorouracil in the treatment of patients with recurrent or metastatic solid tumors

BACKGROUND

The purpose of this study was to look at the pharmacokinetics of docetaxel, cisplatin-derived platinum and 5-fluorouracil (5-FU), when used in combination, to exclude potential clinically relevant pharmacokinetic interactions.

METHODS

Fifteen patients with recurrent or metastatic solid tumors were randomized to receive docetaxel 75 mg/m2 and cisplatin 75 mg/m2 in the first treatment course on day 1 and the same combination plus 5-FU 750 mg/m2/day on days 1-5 in the second course, or the two treatment courses in reversed order. Cycles were repeated every 3 weeks. A pharmacokinetic analysis was performed during the first two cycles.

RESULTS

Full pharmacokinetic data was available for 12 of the 15 patients. Treatment was tolerated well, with frequency of toxicity consistent with the safety profile known for docetaxel, cisplatin and 5-FU. Mean clearance values for docetaxel and cisplatin showed no statistically significant difference across the "triple" and the "double" combination treatments, and the mean pharmacokinetic parameters of all agents were within the ranges for previously reported single agent treatment.

CONCLUSION

No clinically relevant pharmacokinetic interactions between docetaxel, cisplatin and 5-FU used in combination were noticed in this study.

Taxanes in head and neck cancer

Paclitaxel and docetaxel are cytotoxic agents that act on the microtubule system and cause cell death. They are active in patients with squamous cell carcinoma of the head and neck region. They can be combined with other cytotoxic agents and radiotherapy with acceptable toxicity. This article reviews of both docetaxel and paclitaxel data in this patient population. Taxanes do not yet have a a license for use in the standard treatment of patients with head and neck cancer in Europe.

Phase I dose-escalating study of docetaxel in combination with 5-day continuous infusion of 5-fluorouracil in patients with advanced gastric cancer

Background

Published data suggests that docetaxel combined with 5-fluorouracil (5-FU) may have synergistic activity in treating advanced gastric cancer. We performed a phase I study of docetaxel and 5-FU to determine the maximum tolerated dose (MTD), the recommended dose for phase II studies, and the safety of this combination.

Methods

Eligible patients had recurrent and/or metastatic advanced gastric cancer with normal cardiac, renal and hepatic function. Traditional phase I methodology was employed in assessing dose-limiting toxicity (DLT) and MTD. On day 1 every 3 weeks, docetaxel 75 mg/m² (fixed dose) was infused over 1-h, followed immediately by 5-FU as a 5-day continuous infusion.

Results

Dose escalation schema was as follows: dose level (DL) 1 (5-FU 250 mg/m²/day), 2 (500), 3 (750), and 4 (1000). Three patients were enrolled on DL1, without DLT. On DL2, 1 DLT (grade 3 stomatitis) was developed in first 3 patients, and this cohort was expanded to 6 patients. Three patients had been enrolled on DL3. Because two out of 3 patients had DLTs, the MTD was reached at DL3.

Conclusion

The recommended phase II dose of this combination is 75 mg/m² docetaxel on day 1 immediately followed by a 5-day continuous infusion of 5-FU 500 mg/m²/day.

Increased antitumor activity in combined treatment TS-1 and docetaxel. A preclinical study using gastric cancer xenografts

As TS-1 and docetaxel (TXT) have different mechanisms of antitumor activity, the combination therapy is expected to have a higher response. Human gastric cancer xenografts SC-2, St-40, and SC-4 inoculated into nude rats were treated with TS-1 alone (TS-1 12 mg/kg/day, day 1-14), TXT alone (TXT 2 mg/kg/day, day 1 or day 8), and combination of both drugs. TS-1 alone showed antitumor activity against three tumors (growth inhibition rate (IR): SC-2 (38.6 and 40.5%), St-40 (54.5%), SC-4 (55.1%)). TXT was effective with minimal toxicity, especially on day 1 of administration (IR at day 1 administration: SC-2 (51.7%), St-40 (42.1%), SC-4 (46.3%)). In the combined TS-1 and TXT group, antitumor activity increased at day 1 and at day 8 TXT administration (IR at day 1 administration: SC-2 (68.4%), St-40 (72.5%), SC-4 (76.0%)). Weight loss of TS-1 and day 1 TXT administration was the same as that of TS-1 alone. TS-1 and TXT showed no pharmacokinetic interaction. Compared with 5-fluorouracil and cisplatin treatment, combined therapy with TS-1 and TXT showed the same antitumor activity and toxicity. Combined therapy with TS-1 and TXT showed enhanced antitumor activity compared with monotherapy of each drug. The outpatient-based treatment of this combination is worth investigating.

Timed flat infusion of 5-fluorouracil increases the tolerability of 5-fluorouracil/docetaxel regimen in metastatic breast cancer: a dose-finding study

A dose-finding study was undertaken to determine the maximum-tolerated dose, and the recommended dose of docetaxel in combination with 12-h timed (22:00–10:00) flat infusion of 5-fluorouracil (5-FU) in metastatic breast cancer patients. This schedule seems to reduce the occurrence of stomatitis of the docetaxel and infusional 5-FU regimen.

Phase I study of docetaxel and cyclophosphamide in patients with advanced or recurrent breast cancer

BACKGROUND

A phase I clinical study of combination chemotherapy with docetaxel and cyclophosphamide (CPA) was performed to determine the maximum tolerated dose (MTD), the incidence and severity of toxicities and the pharmacokinetics in patients with advanced or recurrent breast cancer.

METHODS

Docetaxel was administered by intravenous drip infusion over 60 minutes, followed by intravenous bolus injection of CPA every 3-4 weeks. The dosage of docetaxel/CPA was 40/200, 40/400, 50/400, or 60/400 mg/m(2)/day.

RESULTS

Fifteen patients were enrolled and received a total of 33 cycles of the combined therapy. The dose limiting toxicities (DLTs) were leukopenia, neutropenia and thrombocytopenia. The MTD was estimated to be docetaxel 60 mg/m(2) in combination with CPA 400 mg/m(2) per day. Plasma clearance of both drugs was similar regardless of dose. The recommended doses of docetaxel/CPA for a phase Utrial are 50/400 mg/m(2)/day every 3-4 weeks.

CONCLUSION

The MTD of this combined therapy was docetaxel 60 mg/m(2) and CPA 400 mg/m(2). Neutropenia and leukopeina were common and severe. It is important to stress the need for modification of the dosing scheme.

Phase I study of eniluracil and oral 5-fluorouracil in combination with docetaxel in the treatment of patients with metastatic breast carcinoma

PURPOSE

The authors conducted a single-institution Phase I clinical trial to determine the maximum tolerated doses and to define the toxic effects of oral eniluracil and oral 5-fluorouracil (5-FU) combined with docetaxel in patients with metastatic breast carcinoma.

PATIENTS AND METHODS

Patients with metastatic breast carcinoma were eligible if they had disease progression after anthracycline-based therapy and had never been exposed to taxanes. The starting doses of oral eniluracil and oral 5-FU were 11.5 mg/m(2) and 1.15 mg/m(2), respectively, twice daily on Days 1-14. Docetaxel was given intravenously at a starting dose of 50 mg/m(2) on Day 1 only. The dose of docetaxel was escalated among cohorts until a maximum tolerated dose was reached. Courses were repeated every 21 days.

RESULTS

The authors treated 19 patients with Stage IV breast carcinoma, of whom 5 had received prior chemotherapy for their metastatic disease. Fifty-three percent had a performance status of 1, and 53% had bone or soft tissue involvement as the dominant site of disease. All patients had received prior therapy with doxorubicin. The dose-limiting toxicity was neutropenic fever. No episodes of sepsis were observed. Significant antitumor activity was observed with a total of two complete and nine partial responses. The recommended doses for Phase II studies are 72 mg/m(2) docetaxel on Day 1 and 10.0/1.0 mg/m(2) oral eniluracil/5-FU twice daily for a total of 14 days, with courses being repeated every 21 days.

CONCLUSIONS

The combination of oral eniluracil/5-FU and intravenous docetaxel is a safe and well tolerated regimen. Significant antitumor activity is associated with this combination.

Combination chemotherapy of the taxanes and antimetabolites: its use and limitations

In an effort to improve response rates of chemotherapy, taxanes have been combined with other cytotoxic agents such as antimetabolites. However, the use of some of these combinations in patients has been restricted by severe toxicity. The significance of the sequence of drug administration in combining methotrexate (MTX) and taxanes was recognised in in vitro studies, showing synergistic effects for the sequence of MTX followed by paclitaxel, and antagonism for exposure in the reverse order. A possible explanation might be an MTX-induced synchronisation of cells in the S phase of the cell cycle, after which cells are more susceptible for the cytotoxic action of taxanes. Clinical studies using this sequence were hampered by severe neutropenia and mucositis at relatively low doses of both drugs. As no pharmacokinetic interactions were observed, the excess of toxicity may have been due to sequence-dependent synergistic actions on bone marrow and mucosa. In contrast, and confusingly, in vitro studies on 5-fluorouracil (5-FU) and taxanes indicate that 5-FU preceeding or simultaneously given to paclitaxel impairs cytotoxicity as compared with paclitaxel monotherapy, while the reverse sequence results in additive or synergistic cytotoxicity. While almost all clinical studies have used the sequence of a taxane followed by 5-FU, various schedules appeared feasible and effective. The combination of a 5-FU analogue, capecitabine and taxanes was supported by in vitro data. A large phase III trial confirmed the feasibility and superior efficacy of this combination in breast cancer patients relapsing after an anthracycline. Conflicting results exist on the benefit of combining gemcitabine and taxanes in tumour cell lines. Although the accumulation of gemcitabine triphosphate (dFdCTP) in mononuclear cells was significantly higher with an increasing dose of paclitaxel, no pharmacokinetic interactions for both agents were noticed. A pharmacokinetic analysis of the gemcitabine-docetaxel combination therapy has not been published in detail. Despite numerous trials, so far no optimum schedule has been established. Regarding data on actually delivered dose intensities, a 2- or 3-weekly cycle seems favourable and feasible. However, possible severe pulmonary toxicity warrants cautious monitoring of patients treated with this combination. Different outcomes of preclinical and clinical studies reveal that combining two chemotherapeutic agents is not simply a matter of putting antitumour activities together. Drug interaction may result in synergism, not only of efficacy but also of toxic side-effects. Adding two drugs may also implicate antagonism in drug efficacy due to unwanted interference in cytotoxicity or pharmacokinetics. For agents acting at a specific phase of the cell cycle, the sequence of administration may determine the efficacy and toxicity of a combination therapy. Because of an observed discrepancy between in vitro data and clinical studies, we would like to emphasise the need for adequate dose-finding clinical trials together with pharmacokinetic data analysis before examining any new combination chemotherapy in more detail in phase II studies.

Docetaxel in combination with 5-fluorouracil in patients with metastatic breast cancer previously treated with anthracycline-based chemotherapy: a phase I, dose-finding study

This phase I study evaluated the maximum tolerated dose, dose-limiting toxicity and recommended dose of docetaxel in combination with 5-fluorouracil (5-FU) in patients with metastatic breast cancer previously treated with anthracycline-based chemotherapy. 32 patients received docetaxel at 60, 75, 85 or 100 mg/m(2) by 1-h intravenous (i.v.) infusion, followed, after a 1-h interval, by 5-FU at 250, 350, 500 or 750 mg/m(2)/day by continuous infusion over 5 days every 3 weeks. Dose-limiting stomatitis defined the maximum tolerated dose at a docetaxel dose of 100 mg/m(2) with 5-FU 750 mg/m(2)/day. None of 5 patients treated at the previous dose level (docetaxel 85 mg/m(2) with 5-FU 750 mg/m(2)/day) had a dose-limiting toxicity in the first cycle, and this was, therefore, considered the recommended dose. The combination was generally well tolerated. Grade 4 neutropenia was common (29 patients; 91%), but no patient experienced febrile neutropenia of duration >3 days requiring i.v. antibiotics. An objective response was achieved by 18 patients overall (56%), and in 4 out of 5 patients treated with the determined recommended dose. No pharmacokinetic interaction between docetaxel and 5-fluorouracil was apparent. The activity of docetaxel 85 mg/m(2) with 5-fluorouracil 750 mg/m(2)/day will be explored more extensively in phase II studies of patients with metastatic breast cancer previously treated with anthracycline-based chemotherapy.

Role of taxoids in head and neck cancer

Docetaxel and paclitaxel represent a new class of cytotoxic agents having both a specific chemical structure and mechanism of action. They act to promote tubulin polymerization and the formation of stable microtubules. The microtubules produced in the presence of taxoids are resistant to disassembly by physiologic stimuli, and cells exposed to these agents exhibit an accumulation of disorganized microtubule arrays. This affects the normal mitotic process and eventually results in cell death. Both drugs are active as single agents in patients with head and neck cancer with response rates ranging from 20% to 40%. They may be combined with other cytotoxic agents, radiotherapy, or both. A review is given of the presently available data.

A phase I study of docetaxel and 5-fluorouracil in patients with advanced solid malignancies

PURPOSE

This study was undertaken to evaluate the feasibility of administering docetaxel (Taxotere; Rhône-Poulenc-Rorer) as a one-hour intravenous (i.v.) infusion on day 1 combined with 5-fluorouracil (5-FU) as a bolus i.v. injection for five (days 1-5) or three (days 1-3) consecutive days every four weeks.

PATIENTS AND METHODS

Thirty-seven patients with advanced solid malignancies were treated with 115 total courses involving seven dose levels of the two regimens of docetaxel and 5-FU (docetaxel/5-FU [mg/m2]/mg/m2/d]). In an effort to reduce fluid retention and hypersensitivity phenomena related to docetaxel, patients received premedication with dexamethasone 8 mg orally twice daily for three consecutive days beginning 24 hours before treatment.

RESULTS

Severe (grade 4) neutropenia lasting longer than seven days with or without fever and/or severe mucositis, precluded further dose escalation above docetaxel 60 mg/m2 on day 1 and 5-FU 300 mg/m2/day administered on days 1-5 every four weeks. The rates of these toxic effects were also unacceptably high above docetaxel 60 mg/m2 on day 1 and 5-FU 300 mg/m2/day administered on days 1-3 every four weeks. Nine patients experienced various manifestations of fluid-retention that were potentially related to study drugs. However, neither treatment delay nor discontinuation of treatment was required. Nausea, vomiting, diarrhea, and fatigue, were mild to modest in severity and occurred infrequently (< 10% of courses). Two patients with metastatic breast cancer experienced complete responses and a partial response occurred in a patient with metastatic non-small-cell lung cancer.

CONCLUSION

Based on the results of this study, the regimen of docetaxel 60 mg/m2 on day 1 followed by 5-FU 300 mg/m2/d i.v. for three or five days every four weeks is well tolerated and these doses are recommended for further evaluations. The feasibility of administering docetaxel 60 mg/m2 followed by 5-FU 300 mg/m2 for three or five days every four weeks and the preliminary antitumor activity noted indicate that further disease-directed studies of docetaxel and 5-FU are warranted in patients with relevant solid malignancies.