Efficacy and safety of ixabepilone (BMS-247550) in a phase II study of patients with advanced breast cancer resistant to an anthracycline, a taxane, and capecitabine.
OBJECTIVE
To evaluate the efficacy and safety of ixabepilone in patients with metastatic breast cancer (MBC) resistant to anthracycline, taxane, and capecitabine, in this multicenter, phase II study.


METHODS
Patients with measurable disease who had tumor progression while receiving prior anthracycline, taxane, and capecitabine were enrolled. Ixabepilone 40 mg/m(2) monotherapy was administered as a 3-hour intravenous infusion on day 1 of a 21-day cycle. The primary end point was objective response rate (ORR), assessed by an independent radiology facility (IRF).


RESULTS
A total of 126 patients were treated and 113 were assessable for response. Patients were heavily pretreated: 88% had received at least two lines of prior chemotherapy in the metastatic setting. IRF-assessed ORR was 11.5% (95% CI, 6.3% to 18.9%) for response-assessable patients. Investigator-assessed ORR for all treated patients was 18.3% (95% CI, 11.9% to 26.1%). Fifty percent of patients achieved stable disease (SD); 14.3% achieved SD >or= 6 months. Median duration of response and progression-free survival were 5.7 and 3.1 months, respectively. Median overall survival was 8.6 months. Patients received a median of 4.0 treatment cycles (range, one to 16 cycles), and 25% of patients received >or= eight cycles. Grade 3/4 treatment-related events included peripheral sensory neuropathy (14%), fatigue/asthenia (13%), myalgia (8%), and stomatitis/mucositis (6%). Resolution of grade 3/4 peripheral sensory neuropathy occurred after a median period of 5.4 weeks.


CONCLUSIONS
Ixabepilone demonstrated clear activity and a manageable safety profile in patients with MBC resistant to anthracycline, taxane, and capecitabine. Responses were durable and notable in patients who had not previously responded to multiple prior therapies.
Perez
Edith A
EA
Department of Hematology and Oncology, Mayo Clinic, Jacksonville, FL 32224, USA. Perez.edith@mayo.edu
Lerzo
Guillermo
G
Pivot
Xavier
X
Thomas
Eva
E
Vahdat
Linda
L
Bosserman
Linda
L
Viens
Patrice
P
Cai
Can
C
Mullaney
Brian
B
Peck
Ronald
R
Hortobagyi
Gabriel N
GN
D000328:Adult; D000368:Aged; D018943:Anthracyclines / Q000494:pharmacology*; D000903:Antibiotics, Antineoplastic / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D000069287:Capecitabine; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D018572:Disease-Free Survival; D019008:Drug Resistance, Neoplasm; D034261:Epothilones / Q000627:therapeutic use*; D005260:Female; D005472:Fluorouracil / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D043823:Taxoids / Q000494:pharmacology*; D016896:Treatment Outcome
D018943:Anthracyclines; D000903:Antibiotics, Antineoplastic; D034261:Epothilones; D043823:Taxoids; D003841:Deoxycytidine; D000069287:Capecitabine; C430592:ixabepilone; D005472:Fluorouracil