Phase I clinical trial of STA-4783 in combination with paclitaxel in patients with refractory solid tumors.
OBJECTIVE
STA-4783 is a new compound that markedly enhances the therapeutic index of paclitaxel against human tumor xenograft models. A phase I clinical trial was undertaken to determine the maximum tolerated dose, toxicity profile, and pharmacokinetics of STA-4783 in combination with paclitaxel.


METHODS
Adults with refractory solid tumors concurrently received STA-4783 and paclitaxel as a 3-h i.v. infusion at starting doses of 44 and 135 mg/m(2), respectively. After increasing paclitaxel to 175 mg/m(2), the STA-4783 dose was escalated as permitted by dose-limiting toxicity during the first 21-day cycle.


RESULTS
Thirty-five patients were treated with eight dose levels of STA-4783/paclitaxel. In patients receiving 175 mg/m(2) paclitaxel, the incidence of severe toxicity increased with escalation of the STA-4783 dose above 263 mg/m(2), and 438 mg/m(2) was the maximum tolerated dose. All toxicities were typical of paclitaxel, with neutropenia, mucositis, and myalgia/arthralgia being dose limiting. Partial responses were achieved in one patient with Kaposi's sarcoma and another with ovarian cancer that progressed during prior treatment with paclitaxel. STA-4783 exhibited linear pharmacokinetics characterized by rapid elimination from plasma (biological half-life, 1.06 +/- 0.24 h) and a low steady-state apparent volume of distribution (25.1 +/- 8.1 L/m(2)). The total body clearance of paclitaxel decreased significantly with escalation of the STA-4783 dose.


CONCLUSIONS
The STA-4783/paclitaxel combination was well tolerated with a toxicity profile similar to single-agent paclitaxel. Enhanced systemic exposure to paclitaxel resulting from a dose-dependent interaction with STA-4783 was associated with increased toxicity. Objective responses in two heavily pretreated patients, both with taxane exposure, have encouraged further clinical evaluation of this regimen.
Berkenblit
Anna
A
Beth Israel Deaconess Medical Center, and Harvard Cancer Center, Boston, MA, USA.
Eder
Joseph P
JP
Ryan
David P
DP
Seiden
Michael V
MV
Tatsuta
Noriaki
N
Sherman
Matthew L
ML
Dahl
Thomas A
TA
Dezube
Bruce J
BJ
Supko
Jeffrey G
JG
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D006801:Humans; D006834:Hydrazines / Q000008:administration & dosage*; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D008956:Models, Chemical; D009369:Neoplasms / Q000188:drug therapy*; D017239:Paclitaxel / Q000008:administration & dosage*; D013997:Time Factors; D016896:Treatment Outcome
D006834:Hydrazines; C512195:elesclomol; D017239:Paclitaxel