Phase I clinical and pharmacokinetic study of 3-weekly, 3-h infusion of ixabepilone (BMS-247550), an epothilone B analog, in Japanese patients with refractory solid tumors.
BACKGROUND
Ixabepilone (BMS-247550) is the first in a new class of anti-neoplastic agents, the epothilone analogs, and is a highly active non-taxane anti-microtubule agent. This phase I study aimed to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), safety profile, pharmacokinetics, and antitumor activity of ixabepilone in Japanese patients.


METHODS
Patients with solid tumors previously treated with up to four chemotherapy regimens received a 3-h intravenous infusion of ixabepilone every 3 weeks.


RESULTS
Fourteen patients received 43 cycles (median 3, range 1-8). The most common adverse events were neutropenia, mild-to-moderate fatigue, anemia, and peripheral neuropathy. DLTs occurred in one patient receiving 40 mg/m2 (grade 4 neutropenia for 9 days) and in two patients receiving 50 mg/m2 (grade 3 mucositis, ileus and febrile neutropenia; grade 4 neutropenia for 10 days). One paclitaxel- and docetaxel-pretreated patient with non-small cell lung cancer achieved a partial response lasting for 3 months; six additional patients (43%) achieved disease stabilization with tumor shrinkage of 3-35%. The plasma concentration-time profiles of ixabepilone during cycle 1 were similar across all doses evaluated.


CONCLUSIONS
The MTD of ixabepilone is 50 mg/m2 given over 3 h every 3 weeks. The recommended phase II dose is 40 mg/m2, which is well tolerated and active. Data from Japanese patients are consistent with published phase I data from non-Japanese patients.
Shimizu
Toshio
T
Division of Internal Medicine, National Cancer Center Hospital, Chuo-ku, Tokyo 104-0045, Japan. tshimizu@nara.med.kindai.ac.jp
Yamamoto
Noboru
N
Yamada
Yasuhide
Y
Fujisaka
Yasuhito
Y
Yamada
Kazuhiko
K
Fujiwara
Yutaka
Y
Takayama
Kyoko
K
Tokudome
Takuto
T
Klimovsky
Judith
J
Tamura
Tomohide
T
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D044466:Asian People; D004305:Dose-Response Relationship, Drug; D034261:Epothilones / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007564:Japan; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D034261:Epothilones; C430592:ixabepilone