A phase II and pharmacokinetic study of ecteinascidin 743 in patients with gastrointestinal stromal tumors.
OBJECTIVE
To assess the efficacy, tolerability, and pharmacokinetics of ecteinascidin 743 (ET-743) in patients with advanced gastrointestinal stromal tumors (GISTs).


METHODS
The study was confined to adult patients with radiographically measurable GISTs. ET-743 was administered as a 24-hour continuous i.v. infusion at a dose of 1.5 mg/m(2) repeated every 3 weeks. Pharmacokinetic blood sampling was performed during the first cycle of therapy. Tumors were restaged after every second cycle of therapy.


RESULTS
A total of 20 patients was enrolled in the study, 19 of whom were treated with 47 cycles of ET-743 (median 2, range 1-10). Severe toxicities were limited to reversible grade 3 transaminitis in 10 patients and grade 3 fatigue in one patient. There were no objective responses, and disease stabilization occurred in two patients lasting for periods of 4 and 10 months. The 1-year survival rate was 71.1%. Mean +/- standard deviation values of the maximum plasma concentration and total plasma clearance were 1.1 +/- 0.4 ng/ml and 44 +/- 16 l/h/m(2), respectively, for 19 of the 20 patients.


CONCLUSIONS
This study is the first report of a prospective phase II trial to evaluate a cytotoxic agent in patients with GISTs. This study underscores the primary resistance of GISTS to chemotherapy and stands in stark contrast to the encouraging results recently achieved with STI571. The lack of response may be associated with a therapeutically ineffective exposure to the drug based upon the lower incidence of severe toxicities and greater clearance than described in phase I and II trials of ET-743.
Ryan
David P
DP
Division of Hematology-Oncology, Massachusetts General Hospital, Harvard Medical School, 100 Blossom Street, Boston, MA 02114, USA. dpryan@partners.org
Puchalski
Thomas
T
Supko
Jeffrey G
JG
Harmon
David
D
Maki
Robert
R
Garcia-Carbonero
Rocio
R
Kuhlman
Caroline
C
Winkelman
Jennifer
J
Merriam
Priscilla
P
Quigley
Travis
T
Jimeno
Jose
J
Manola
Judith
J
Demetri
George D
GD
D000328:Adult; D000368:Aged; D018906:Antineoplastic Agents, Alkylating / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D019540:Area Under Curve; D004149:Dioxoles / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy*; D006801:Humans; D007262:Infusions, Intravenous; D007546:Isoquinolines / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016019:Survival Analysis; D044005:Tetrahydroisoquinolines; D000077606:Trabectedin; D016896:Treatment Outcome
D018906:Antineoplastic Agents, Alkylating; D004149:Dioxoles; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; D000077606:Trabectedin