{"analyses":[{"ciLowerLimit":"0.463","ciNumSides":"TWO_SIDED","ciPctValue":"95","ciUpperLimit":"0.718","groupIds":["OG000","OG001"],"nonInferiorityType":"SUPERIORITY_OR_OTHER_LEGACY","pValue":"<0.000001","pValueComment":"1-sided p-value from the stratified log-rank test.","paramType":"Hazard Ratio (HR)","paramValue":"0.576","statisticalMethod":"Stratified Log Rank"}],"classes":[{"categories":[{"measurements":[{"comment":"The value was not available because there was not enough disease progression events in the treatment group at the time of analysis, due to drug benefit.","groupId":"OG000","lowerLimit":"22.1","upperLimit":"NA","value":"24.8"},{"groupId":"OG001","lowerLimit":"12.9","upperLimit":"17.1","value":"14.5"}]}]}],"denoms":[{"counts":[{"groupId":"OG000","value":"444"},{"groupId":"OG001","value":"222"}],"units":"Participants"}],"description":"PFS is defined as the time from the date of randomization to the date of the first documentation of objective tumor progression as per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1) or death due to any cause in the absence of documented PD, whichever occurs first. If tumor progression data include more than 1 date, the first date will be used. PFS (in months) will be calculated as (first event date - randomization date +1)/30.4. Progression is defined using RECIST v1.1, as a 20% increase in the sum of diameters of target measurable lesions above the smallest sum observed (over baseline if no decrease in the sum is observed during therapy), with a minimum absolute increase of 5 mm, or unequivocal progression of pre-existing non-target lesions, or the appearance of new lesions.","dispersionType":"95% Confidence Interval","groups":[{"description":"Participants received letrozole 2.5 milligram (mg) orally QD (once daily) combined with palbociclib 125 mg QD for 21 days of every-28-day cycle, followed by 7 days off treatment.","id":"OG000","title":"Palbociclib Plus Letrozole"},{"description":"Participants received letrozole 2.5 mg orally QD combined with placebo QD for 21 days of every-28-day cycle, followed by 7 days off treatment.","id":"OG001","title":"Placebo Plus Letrozole"}],"paramType":"MEDIAN","populationDescription":"ITT population or full analysis set included all participants who were randomized, with study drug assignment designated according to initial randomization, regardless of whether participants received study medication or received a different drug from that to which they were randomized.","reportingStatus":"POSTED","timeFrame":"From randomization date to date of first documentation of progression or death (up to approximately 2.5 years)","title":"Progression-Free Survival (PFS) as Assessed by the Investigator","type":"PRIMARY","unitOfMeasure":"Months"}