A phase I and pharmacokinetic study of a new camptothecin derivative, 9-aminocamptothecin.
Clin Cancer Res
; 1(3): 269-76, 1995 Mar.
Article
en En
| MEDLINE
| ID: mdl-9815982
ABSTRACT
Camptothecins are the only available antitumor agents which target the nuclear enzyme topoisomerase I. 9-Aminocamptothecin (9-AC) is a water-insoluble derivative of camptothecin which has demonstrated impressive antitumor activity in preclinical models. While two other water-soluble derivatives, CPT-11 and topotecan, have successfully completed Phase I and Phase II testing, biochemical and tissue culture studies suggest that camptothecin analogues differ in characteristics which may be important in determining antitumor activity. We performed a Phase I trial of 9-AC to determine the pharmacokinetics, dose-limiting toxicity, and maximum tolerated dose of this agent when administered as a 72-h continuous i.v. infusion. Thirty-one patients with resistant solid cancers received 5-60 microgram/m2/h 9-AC for 72 h, repeated at 3-week intervals. The drug was administered in a vehicle containing dimethylacetamide, polyethylene glycol, and phosphoric acid. Blood samples were collected and the lactone (closed ring) form of 9-AC was quantitated. The maximum tolerated dose of 9-AC was determined to be 45 microgram/m2/h. Dose-limiting toxicity consisted of neutropenia. Thrombocytopenia was also prominent. There were no significant nonhematological toxicities. Minimal responses were seen in patients with gastric, colon, and non-small cell lung cancer. Although significant interpatient variation in plasma 9-AC lactone levels was observed, pooled data were fit to a two-compartment model, with a terminal half-life of 36 h. Analyses of topoisomerase protein levels in peripheral blood cells indicated decreases in topoisomerase I accompanied by increases in topoisomerase II in two of three patients. 9-AC is an active antitumor agent and may be administered safely as a 72-h infusion in patients with cancer. Although Phase II trials with a 72-h infusion of 9-AC are warranted, alternate schedules should be evaluated given the dramatic preclinical activity seen with more prolonged administrations.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Camptotecina
/
Neoplasias
/
Antineoplásicos
Tipo de estudio:
Prognostic_studies
Límite:
Adult
/
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Clin Cancer Res
Asunto de la revista:
NEOPLASIAS
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos