Docetaxel and ifosfamide in patients with advanced solid tumors: results of a phase I study.

Docetaxel is a new antimicrotubule agent that has been shown to be active against a variety of solid tumors. Ifosfamide is an alkylating drug that has demonstrated activity against non-small cell lung cancer, testicular cancer, breast cancer, and soft tissue sarcoma. This phase I study of the combination of these drugs was performed to assess the feasibility of using the two agents together, to determine the maximum tolerated dose and the side effects, and to propose a safe schedule for further phase II studies. Thirty-four patients with histologically confirmed solid tumors who had not been treated previously with taxanes or ifosfamide and who had received no more than one line of chemotherapy for advanced disease were entered into the study. Treatment consisted of docetaxel given as a 1-hour infusion followed by ifosfamide as a 24-hour infusion (schedule A), or ifosfamide followed by docetaxel (schedule B) every 3 weeks. Docetaxel doses ranged from 60 to 85 mg/m2 and ifosfamide doses from 2.5 to 5.0 g/m2. Grades 3 and 4 granulocytopenia were observed in 89% of courses and appeared to be of short duration and related to the ifosfamide dose. Febrile neutropenia and sepsis occurred in 17% and 2% of courses, respectively. Severe anemia and thrombocytopenia were uncommon. Nonhematologic toxicities were mild to moderate, and included alopecia, nausea, vomiting, mucositis, diarrhea, sensory neuropathy, skin and nail toxicity, hypersensitivity reactions, and edema. Schedule B appeared to induce more gastrointestinal toxicity than schedule A. One complete response in soft tissue sarcoma and two partial responses, one in cancer of unknown primary and the other in non-small cell lung cancer, were documented. The dose-limiting toxicity for schedule A was neutropenic fever at a dose of 85 mg/m2 docetaxel and 5 g/m2 ifosfamide. The dose-limiting toxicity for schedule B was neutropenic fever at a dose of 75 mg/m2 docetaxel and 4 g/m2 ifosfamide. A dose of 75 mg/m2 docetaxel combined with 5 g/m2 ifosfamide according to schedule A can be recommended for further studies.

Pharmacokinetics of ifosfamide are changed by combination with docetaxel: results of a phase I pharmacologic study.

The pharmacokinetics of the combination of docetaxel and ifosfamide were studied in a phase I study. Docetaxel was given to cancer patients as a 1-hour infusion followed by a 24-hour infusion of ifosfamide (schedule A). After the dose-limiting toxicity of the combination was reached, ifosfamide was administered as a 24-hour infusion followed after 24 hours by a 1-hour infusion of docetaxel (schedule B). Cycle duration was 21 days. Docetaxel was determined by high-performance liquid chromatography, and ifosfamide and its metabolites, by gas chromatography-mass spectrometry. Twenty-seven patients were treated according to schedule A, and 6 according to schedule B. Combining the two drugs did not change their respective plasma half-lives. The sequence of drug administration did not affect the clearance and the area under the curve (AUC) of docetaxel. There was a decrease in the AUC of ifosfamide in schedule A compared with schedule B, resulting from an increase in the clearance of ifosfamide. The pharmacokinetics of docetaxel are not influenced by combination with ifosfamide, regardless of the drug sequence, but ifosfamide pharmacokinetics are changed by docetaxel, depending on the sequence of administration. The increase of clearance in schedule A may be due to the pretreatment with corticosteroids.

Phase I study on docetaxel and ifosfamide in patients with advanced solid tumours.

Docetaxel and ifosfamide have shown significant activity against a variety of solid tumours. This prompted a phase I trial on the combination of these drugs. This phase I study was performed to assess the feasibility of the combination, to determine the maximum tolerated dose (MTD) and the side effects, and to propose a safe schedule for further phase II studies. A total of 34 patients with a histologically confirmed solid tumour, who were not pretreated with taxanes or ifosfamide and who had received no more than one line of chemotherapy for advanced disease were entered into the study. Treatment consisted of docetaxel given as a 1-h infusion followed by ifosfamide as a 24-h infusion (schedule A), or ifosfamide followed by docetaxel (schedule B) every 3 weeks. Docetaxel doses ranged from 60 to 85 mg m(-2) and ifosfamide doses from 2.5 to 5.0 g m(-2). Granulocytopenia grade 3 and 4 were common (89%), short lasting and ifosfamide dose dependent. Febrile neutropenia and sepsis occurred in 17% and 2% of courses respectively. Non-haematological toxicities were mild to moderate and included alopecia, nausea, vomiting, mucositis, diarrhoea, sensory neuropathy, skin and nail toxicity and oedema. There did not appear to be any pharmacokinetic interaction between docetaxel and ifosfamide. One complete response (CR) (soft tissue sarcoma) and two partial responses (PRs) were documented. A dose of 75 mg m(-2) of docetaxel combined with 5.0 g m(-2) ifosfamide appeared to be manageable. Schedule A was advocated for further treatment.