Intravenous administration of paclitaxel is hindered by poor water solubility of the drug. Currently, paclitaxel is dissolved in a mixture of ethanol and Cremophor EL; however, this formulation (Taxol) is associated with significant side effects, which are considered to be related to the pharmaceutical vehicle. A new polymer-conjugated derivative of paclitaxel, PNU166945, was investigated in a dose-finding phase I study to document toxicity and pharmacokinetics. A clinical phase I study was initiated in patients with refractory solid tumors. PNU16645 was administered as a 1-h infusion every 3 weeks at a starting dose of 80 mg/m(2), as paclitaxel equivalents. Pharmacokinetics of polymer-bound and released paclitaxel were determined during the first course. Twelve patients in total were enrolled in the study. The highest dose level was 196 mg/m(2), at which we did not observe any dose-limiting toxicities. Hematologic toxicity of PNU166945 was mild and dose independent. One patient developed a grade 3 neurotoxicity. A partial response was observed in one patient with advanced breast cancer. PNU166945 displayed a linear pharmacokinetic behavior for the bound fraction as well as for released paclitaxel. The study was discontinued prematurely due to severe neurotoxicity observed in additional rat studies. The presented phase I study with PNU166945, a water-soluble polymeric drug conjugate of paclitaxel, shows an alteration in pharmacokinetic behavior when paclitaxel is administered as a polymer-bound drug. Consequently, the safety profile may differ significantly from standard paclitaxel.
The report of some antitumour efficacy, the high selectivity of neutropenia, the lack of significant non-hematological toxic effects and the occurrence of detectable but still low plasma drug concentrations suggest that further clinical evaluation of higher doses of tallimustine in combination with colony-stimulating factors would be justified.
Between 1976 and 1986, 2,093 children with ALL were enrolled in three consecutive generations of trials conducted by the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP). A 50% event-free survival at 5 years was achieved overall in this population, approximately accounting for more than 50% of the entire childhood ALL population in Italy. Participation in the group protocols increased from the original seven founding centers to the current 37 institutions. Results in the standard population (non-T immunophenotype, non-FAB L3, and less than 50,000 white blood cells (WBC/ml) were considerably better with more recent, more aggressive protocols. The two major results in this population (N = 540) were a relatively low incidence (8% at 5 years) of central nervous system (CNS) relapse in the "good"-risk population (less than 10,000 WBC, ages 3-6 years, and FAB L1), without the use of cranial irradiation, and a projected 4-year disease-free interval for bone-marrow relapse of 80% in the "average"-risk group, where a three-drug reinduction program was adopted after consolidation. Overall, the event-free survival of the most recent generation (protocol 82, median follow-up time of 38 months) is 66% at 4 years (95% confidence limits [CL] 61-71). Based on these 10 years of experience, the general strategy of the group for the 90s is outlined and discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.