Phase II Trial of Weekly or Every 3-week Ixabepilone for Patients With Metastatic Breast Cancer

PFS at 6 months was defined as proportion of participants who neither progressed nor died before 6 months. Computed using Kaplan-Meier estimates.

PFS is defined as time interval from the date of randomization to the date of (first) progression or date of death. Participants who progressed or died were counted as events. Participants lost to follow-up were censored as of the last date of contact. Participants who started a new treatment before they progressed were censored as of the date of start of the new treatment. Participants who had not progressed or died were censored at the date of last follow-up. PFS (months) = (End date - date of randomization + 1)/30.4375.

ORR is defined as the proportion of responders (complete response [CR] + partial response [PR] in participants with measurable disease) in that arm among all randomized participants.

CR: Disappearance of all evidence of target lesions. PR: At least 30% reduction from baseline in the sum of the longest diameter (LD) of all target lesions.

Measurable disease: Lesions that can be accurately measured in at least one dimension (LD to be recorded) as ≥20 mm with conventional techniques (computed tomography [CT], magnetic resonance imaging [MRI], X-ray) or as ≥10 mm with spiral CT scan.

Determined based on the sequence of disease status with corresponding best response. PD=At least a 20% increase in the sum of LD of target lesions in reference to the smallest sum LD recorded or the appearance of 1 or more new lesions; SD=Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD in reference to the smallest sum LD. NE=Participants who discontinued treatment secondary to toxicity or died (either before completion of 1 treatment cycle). Please refer outcome measure 3 for explanation of CR and PR. CR+PR+SD=overall disease control.

Survival was measured as the date of randomization to the date of death. Participants who were alive at the time of the database lock or lost to follow-up were censored at the last known alive date. The distribution of overall survival was analyzed via the Kaplan Meier method in each arm.

Survival time (months) = (End date - date of randomization + 1)/30.4375

Time to response is defined as the time from the start of treatment until the first (confirmed) CR or PR was recorded. Time to response was computed only for participants whose best response was PR or CR.

CR: Disappearance of all target lesions. PR: At least 30% reduction from baseline in the sum of the longest diameter (LD) of all target lesions with reference to the baseline sum LD.

Duration of overall response was defined as the period from the time first PR or CR was recorded until the first date of documented PD or death. Duration of response was computed for participants whose best response was either PR or CR. Participants who neither relapsed nor died were censored on the date of their last tumor assessment. Kaplan-Meier method was used to estimate the duration of response. Refer to outcome measures 3 and 4 for CR, PR, and PD.

All events of peripheral neuropathy were assessed and graded per National Cancer Institute (NCI) Common Terminology Criteria Adverse Events (CTCAE)Version 3. CTC Grade (GR) 1=Mild; GR2=Moderate; GR3=Severe or medically significant, not immediately life-threatening; and GR4=Life-threatening. All treatment-related and not related Neuropathy and Peripheral Neuropathy were included; serious adverse events (SAEs) were not included.

An AE is any new untoward medical occurrence or worsening of a preexisting medical condition that does not necessarily have a causal relationship with this treatment. An SAE is any untoward medical event that at any dose: results in death, persistent or significant disability/incapacity, drug dependency or abuse; is life-threatening, an important medical event, a congenital anomaly/birth defect; requires inpatient hospitalization; or prolongs existing hospitalization. Treatment related=possibly, probably, or certainly related to and of unknown relationship to study treatment. GR=Grade.