Study to Assess the Efficacy and Safety of the Epigenetic Modifying Effects of CC-486 (Oral Azacitidine) in Combination With Fulvestrant

Progression-free survival was defined as the duration from the date of randomization to the date of disease progression (DP) based on investigator's assessment using Response Evaluation Criteria in Solid Tumors (RECIST) Version 1.1 or death (from any cause), whichever occurred first. Per RECIST 1.1, progressive disease (PD) was defined as at least a 20% increase in the sum of diameters of target lesions from nadir or appearance of a new lesion.

Time frame: From the date of randomization of study drug to the date of the cut off date of 13 December 2016; follow-up for PFS was 21 months

Population: The Intent-to-treat population included all randomized participants regardless of whether the participant received any investigational product or had any efficacy assessments collected.

Duration of response was defined as the time from the first tumor assessment when the confirmed CR/PR criterion was first met to the date of disease progression, based on investigator's assessment following RECIST Version 1.1 criteria.

Time frame: From the date of randomization of study drug to the data cut-off of 13 December 2016; follow up for duration of response was 21 months

Population: Only participants who had a confirmed CR or PR response are included.

Overall survival was defined as the time from the date of randomization to the date of death (from any cause). All participants who were lost to follow up prior to the end of the study or who were withdrawn from the study were censored at the time of last contact.

Time frame: From the date of randomization of study drug to the data cut off date of 13 December 2016; participants were followed for overall survival for 21 months

Population: The ITT population included all randomized participants regardless of whether the participant received any IP or had any efficacy assessments collected.

Treatment-emergent adverse events (TEAEs) were defined as any AEs that begin or worsen with an onset date on or after the date of the first dose of IP through 28 days after the last dose. A serious AE (SAE) = any AE which results in death; is life-threatening; requires inpatient hospitalization or prolongation of existing hospitalization; results in persistent or significant disability/incapacity; is a congenital anomaly/birth defect; constitutes an important medical event. The severity of AEs were graded based on the participant's symptoms according to the Common Terminology Criteria for Adverse Events (CTCAE, Version 4.0); AEs were evaluated for severity as follows: Grade 1 = Mild - transient or mild discomfort; no medical intervention required; Grade 2 = Moderate - mild to moderate limitation in activity; Grade 3 = Severe; Grade 4 = Life threatening; Grade 5 = Death.

Time frame: Randomization to 28 days after the last dose of IP; those AEs known at any time thereafter being related to IP; up to the last subject last visit of 21 November 2017; TEAE follow-up occurred up to 155 weeks and 2 days

Population: The safety population included all randomized participants who received at least 1 dose of IP.

Overall response rate was defined as the percentage of participants who achieved a confirmed complete response or partial response based on RECIST Version 1.1 criteria. RECIST criteria v 1.1 defined a CR as the disappearance of all target lesions and a PR with at least a 30% decrease in the sum of diameters of target lesions from baseline. The two-sided 95% exact binomial CI for each arm was estimated by the Clopper-Pearson method.

Time frame: Disease response was assessed every 8 weeks, for the first 24 weeks, then every 12 weeks until DP; from date of randomization of study drug to data cut-off date of 13 December 2016; follow-up for overall response was 21 months

Population: The ITT population included all randomized participants regardless of whether the participant received any IP or had any efficacy assessments collected.

Percentage of participants with CR or PR or SD was defined per RECIST criteria v 1.1 as a CR that includes a disappearance of all target lesions, a PR was defined as having at least a 30% decrease in the sum of diameters of target lesions from baseline and SD as neither sufficient shrinkage to qualify for PR nor sufficient increase of lesions to qualify for progressive disease. The two-sided 95% exact binomial CI each arm was estimated by the Clopper-Pearson method.

Time frame: Disease response was assessed every 8 weeks, for the first 24 weeks, then every 12 weeks until DP; from date of randomization of study drug to the data cut-off date of 13 December 2016; follow-up for clinical benefit response was 21 months

Population: The ITT population included all randomized participants regardless of whether the participant received any IP or had any efficacy assessments collected.