An Open-label, Multicenter, Phase 2 Study to Evaluate the Efficacy and Safety of Eribulin Mesylate in Previously Treated Subjects With Advanced or Metastatic Soft Tissue Sarcoma (Study E7389-J081-217)

The PFR at 12 weeks was the percentage of participants with progression-free survival (success) measured as a binary variable based on the tumor response assessed at Week 12 after the start of study treatment. Participants were considered a success if one radiological evaluation performed at least Week 12 after start of therapy indicated stable disease (SD), or complete response (CR) or partial response (PR), as defined according to Response Evaluation Criteria in Solid Tumor version 1.1 (RECIST v1.1); all other cases were considered as failures (including disease progression or death before the Week 12 evaluation, or had unknown disease status at Week 12). If new anticancer treatments were started before the Week 12 evaluation, participants were considered failures. A 2-sided 90% confidence interval (CI) was calculated using the exact method of binomial distribution.

Progression-free survival was defined as the time from the date of treatment start to the first documented date of event (disease progression or death from any cause, whichever occurred first). PFS was assessed every six weeks (until disease progression was confirmed, or sooner, if clinically indicated) and was based on Investigator and Independent Review Committee (IRC) assessments according to RECIST v1.1. Disease progression was measured using computed tomography (CT) or magnetic resonance imaging (MRI) on targeted tumors and defined as at least a 20% relative increase and 5 mm absolute increase in the sum of diameters of target lesions (taking as reference the smallest sum on study), recorded since the treatment started or the appearance of 1 or more new lesions. A 95% CI was calculated using Kaplan-Meier estimate and Greenwood Formula. A generalized Brookmeyer and Crowley method was used to construct a log-log-transformed 95% CI.

Overall survival was defined as the time from the date of treatment start to the date of death from any cause. Participants were followed for survival every twelve weeks after PD. In the absence of confirmation of death, participants were censored either at the date that the participant was last known alive or the date of study cutoff, whichever came earlier. Participants censored before database cutoff included those who were lost to follow up and who withdrew consent. A 95% CI was calculated using Kaplan-Meier estimate and Greenwood Formula. A generalized Brookmeyer and Crowley method is used to construct a log-log-transformed 95% CI.

Objective response rate was defined as the percentage of participants who had a best overall rate (BOR) of CR or PR. Tumor assessment was performed at Week 6 and Week 12 after the start of study treatment, and every six weeks thereafter. The BOR of CR and PR in this study required confirmation by a subsequent assessment of response at least four weeks (28 days) later. CR and PR were determined by the Investigator and IRC using RECIST v1.1 for target lesions assessed by MRI/CT scans. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had to have reduction in short axis to less than 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. A 95% CI was calculated using exact method of binomial distribution.

Disease control rate was defined as the percentage of participants who had BOR of CR + PR + SD. BOR of SD must have manifested at least five weeks (35 days) after the first dose of study treatment. Tumor assessment was performed at Week 6 and Week 12 after the start of treatment, and every six weeks thereafter. CR was defined as disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) had to have reduction in short axis to less than 10 mm. PR was defined as at least a 30% decrease in the sum of diameters of target lesions, taking as reference the baseline sum diameters. SD was defined as neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum of the longest diameter since the treatment started. A 95% CI was calculated using exact method of binomial distribution.

CBR was defined as the percentage of participants who had a BOR of CR + PR + dSD (duration of SD greater than or equal to 11 weeks [77 days] after the first dose of study treatment). Tumor assessment was performed at Week 6 and Week 12 after the start of study treatment, and every six weeks thereafter. For participants whose BOR was SD, the duration of SD was defined as the time from the date of the first dose of study treatment to the first documented PD or death, whichever occurred first (i.e., same definition of PFS). If the dSD was censored at a time less than 11 weeks, the participant was considered as not having a clinical benefit. A 95% CI was calculated using exact method of binomial distribution.

Durable stable disease rate was defined as the percentage of participants who manifested durable stable disease (the duration of stable disease for greater than or equal to eleven weeks) and was estimated based on the tumor response assessments performed according to RECIST v1.1. Tumor assessment was performed at Week 6 and Week 12 after the start of study treatment, and every six weeks thereafter. A 2-sided 95% CI was calculated using the exact method of binomial distribution.

The best overall response categories (CR, PR, SD [including non-CR/non-PD], PD, not evaluable [NE], and unknown [UNK]) were derived based on time point tumor responses during the study as assessed by the IRC as well as the investigator. Tumor assessment was performed at Week 6 and Week 12 after the start of study treatment, and every six weeks thereafter. BOR of SD must have occurred at least 35 days (at least 5 weeks) after the first dose of study drug. If a participant had a BOR of non-CR/non-PD, the participant's BOR was grouped with the SD category.