The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer participants' quality of life (QOL), and it is composed of five multi-item functional subscales (physical, role, emotional, cognitive, and social functioning), three multi-item symptom scales (fatigue, nausea/vomiting, and pain), a global health status scale (GHS)/QOL subscale, and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and the financial impact of cancer). The GHS/QOL was scored on a 7-point Likert scale where 1=very much to 7=not at all. Responses to GHS/QOL subscales were converted to a 0 to 100 scale. For GHS/QOL subscale, higher scores indicated a better QOL. Baseline values were those measured between enrollment and the day before treatment start.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer participants' QOL, and it is composed of five multi-item functional subscales (physical, role, emotional, cognitive, and social functioning), three multi-item symptom scales (fatigue, nausea/vomiting, and pain), a GHS/QOL subscale, and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and the financial impact of cancer). The GHS/QOL was scored on a 7-point Likert scale where 1=very much to 7=not at all. Responses to GHS/QOL subscales were converted to a 0 to 100 scale. For GHS/QOL subscale, higher scores indicated a better QOL. Baseline values were those measured between enrollment and the day before treatment start.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer participants' QOL, and it is composed of five multi-item functional subscales (physical, role, emotional, cognitive, and social functioning), three multi-item symptom scales (fatigue, nausea/vomiting, and pain), a GHS/QOL subscale, and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and the financial impact of cancer). The GHS/QOL was scored on a 7-point Likert scale where 1=very much to 7=not at all. Responses to GHS/QOL subscales were converted to a 0 to 100 scale. For GHS/QOL subscale, higher scores indicated a better QOL. Baseline values were those measured between enrollment and the day before treatment start.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer participants' QOL, and it is composed of five multi-item functional subscales (physical, role, emotional, cognitive, and social functioning), three multi-item symptom scales (fatigue, nausea/vomiting, and pain), a GHS/QOL subscale, and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and the financial impact of cancer). The GHS/QOL was scored on a 7-point Likert scale where 1=very much to 7=not at all. Responses to GHS/QOL subscales were converted to a 0 to 100 scale. For GHS/QOL subscale, higher scores indicated a better QOL. Baseline values were those measured between enrollment and the day before treatment start.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer participants' QOL, and it is composed of five multi-item functional subscales (physical, role, emotional, cognitive, and social functioning), three multi-item symptom scales (fatigue, nausea/vomiting, and pain), a GHS/QOL subscale, and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and the financial impact of cancer). The GHS/QOL was scored on a 7-point Likert scale where 1=very much to 7=not at all. Responses to GHS/QOL subscales were converted to a 0 to 100 scale. For GHS/QOL subscale, higher scores indicated a better QOL. Baseline values were those measured between enrollment and the day before treatment start.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer participants' QOL, and it is composed of five multi-item functional subscales (physical, role, emotional, cognitive, and social functioning), three multi-item symptom scales (fatigue, nausea/vomiting, and pain), a GHS/QOL subscale, and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and the financial impact of cancer). The GHS/QOL was scored on a 7-point Likert scale where 1=very much to 7=not at all. Responses to GHS/QOL subscales were converted to a 0 to 100 scale. For GHS/QOL subscale, higher scores indicated a better QOL. Baseline values were those measured between enrollment and the day before treatment start.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device for 10 hours or longer during a day except for bedtime.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer patients' QOL, and it's composed of five multi-item functional subscales (physical [P], role [R], emotional [E], cognitive [C], and social [S] functioning [F]). Response to functional scales is based on a 4-point Likert scale and ranges from 'not at all' to 'very much'. Responses to all functional sub-scales were converted to a 0 to 100 scale. For functional sub-scale, higher scores indicated a better level of functioning.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. All participants reported under 'Overall Number of Participants Analyzed' contributed data to table but may not have evaluable data for every row. Here, 'Number Analyzed' signifies number of participants analyzed for the specific timepoints.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer patients' QOL, and it's composed of three multi-item symptom scales (fatigue, nausea/vomiting, and pain), a global QOL) subscale, and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, and the financial impact of cancer). Response to symptom sub-scales is based on a 4-point Likert scale and a higher score indicated more severe symptoms. Responses to all symptom sub-scales were converted to a 0 to 100 scale. A higher score indicated more severe symptoms. A 10-point or higher change in scores from baseline was considered clinically significant.

Evaluable population included all eligible participants who were enrolled in the study and who responded at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. All participants reported under 'Overall Number of Participants Analyzed' contributed data to table but may not have evaluable data for every row. Here, 'Number Analyzed' signifies number of participants evaluable for the specific timepoints.

Total estimated steps taken per week were reported in this outcome measure.

Evaluable population included all eligible participants who were enrolled in the study and who responded at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. All participants reported under 'Overall Number of Participants Analyzed' contributed data to table but may not have evaluable data for every row. Here, 'Number Analyzed' signifies number of participants evaluable for the specific timepoints.

Total estimated number of minutes of moderate or higher (moderate to vigorous) physical activity per date as calculated using the Staudenmayer '15 technique were reported in this outcome measure.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. All participants reported under 'Overall Number of Participants Analyzed' contributed data to table but may not have evaluable data for every row. Here, 'Number Analyzed' signifies number of participants evaluable for the specific timepoints.

AE= any untoward medical occurrence,could therefore be any unfavorable,unintended sign (including an abnormal laboratory finding),symptom,or disease,whether or not related to the participant's participation in the study. An SAE was any untoward medical occurrence at any dose that:resulted in death;was life-threatening(LT);required inpatient hospitalization or prolongation of existing hospitalization;resulted in persistent or significant disability/incapacity(substantial disruption of the ability to conduct normal life functions);resulted in congenital anomaly/birth defect;or an important medical event. AEs were graded(G) according to Common Terminology Criteria for AE(CTCAE) version 4.03. G3 (Severe AE),G4 (LT consequences;urgent intervention indicated),G5 (Death related to AE). TEAEs were those events with onset dates occurring during the on-treatment period (the time from start of study treatment up to 28 days after last dose). Relatedness was based on the investigator's judgement.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy.

The PRO-CTCAE is a PRO measurement system that includes a library of questions that measures symptomatic adverse events from the participant perspective. Participants were required to provide their responses to the questions on fatigue severity on a five-point Likert scale. For Fatigue Severity (FS) scoring was as follows: 0= None, 10= Mild, 20= Moderate, 30= Severe, 40= Very Severe.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure. Here, 'Number Analyzed' signifies number of participants evaluable for the specific rows.

The PRO-CTCAE is a PRO measurement system that includes a library of questions that measures symptomatic adverse events from the participant perspective. Participants were required to provide their responses to the questions on fatigue interference on a five-point Likert scale. For Fatigue Interference (FI) scoring was as follows: 0= Not at all/None/Never, 1= A Little bit, 2: Somewhat, 3= Quite a bit, 4= Very much.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure. Here, 'Number Analyzed' signifies number of participants evaluable for the specific rows.

The PRO-CTCAE is a PRO measurement system that includes a library of questions that measures symptomatic adverse events from the participant perspective. Participants were required to provide their responses to the questions on pain severity on a five-point Likert scale. For Pain Severity (PS) scoring was as follows: 0= None, 10= Mild, 20= Moderate, 30= Severe, 40= Very Severe.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure. Here, 'Number Analyzed' signifies number of participants evaluable for the specific rows.

The PRO-CTCAE is a PRO measurement system that includes a library of questions that measures symptomatic adverse events from the participant perspective. Participants were required to provide their responses to the questions on pain interference on a five-point Likert scale. For Pain Interference (PI) scoring was as follows: 0= Not at all/None/Never, 1= A Little bit, 2: Somewhat, 3= Quite a bit, 4= Very much.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure. Here, 'Number Analyzed' signifies number of participants evaluable for the specific rows.

The PRO-CTCAE is a PRO measurement system that includes a library of questions that measures symptomatic adverse events from the participant perspective. Participants were required to provide their responses to the questions on pain frequency on a five-point Likert scale. For Pain Frequency (PF) scoring was as follows: 0= None, 1= Rarely, 2: Occasionally, 3= Frequently, 4=Almost Constantly.

Evaluable population included all eligible participants who were enrolled in the study and who responded to at least 1 item or measured at least 1 metrics of study application or device. Participants were analyzed according to the enrolled group. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure. Here, 'Number Analyzed' signifies number of participants evaluable for the specific rows.

Sedentary time was used to assess physical activity metrics. Sedentary time was derived by Actigraph's algorithm based on raw data collected by Actigraph Insight Watch. Physical activity metrics were averaged at weekly basis which included 5 or more days of wearing the device 10 hours or longer during a day except for bedtime. Disease progression was defined as greater than (>) 25% increase in sum of longest diameter of target lesions compared to baseline.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. As per statistical analysis plan, when associations for group 1 and 2 were similar, the data for group 1 and 2 were pooled. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Total estimated steps taken per week were reported in this outcome measure. Disease progression was defined as >25% increase in sum of longest diameter of target lesions compared to baseline.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. As per statistical analysis plan, when associations for group 1 and 2 were similar, the data for group 1 and 2 were pooled. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

Total estimated number of minutes of Moderate or higher (moderate to vigorous) physical activity per date as calculated using the Staudenmayer '15 technique were reported in this outcome measure. Disease progression was defined as >25% increase in sum of longest diameter of target lesions compared to baseline.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. As per statistical analysis plan, when associations for group 1 and 2 were similar, the data for group 1 and 2 were pooled. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure.

The EORTC-QLQ-C30 is a 30-item questionnaire to evaluate cancer participants' QOL,it's composed of five multi-item functional subscales (physical [P],role [R],emotional [E],cognitive [C], and social [S] functioning [F], three multi-item symptom scales (fatigue,nausea/vomiting,pain) a GHS/QOL subscale,and six single item symptom scales assessing other cancer-related symptoms (dyspnea, sleep disturbance, appetite loss, constipation,diarrhea,and the financial impact of cancer). The GHS/QOL was scored on a 7-point Likert scale where 1=very much to 7=not at all. Response to functional scales is based on a 4-point Likert scale and ranges from 'not at all' to 'very much'. Responses to GHS/QOL and all functional sub-scales were converted to a 0 to 100 scale. For GHS/QOL and functional subscale, higher scores indicated a better QOL and better level of functioning, respectively. Disease progression was defined as >25% increase in sum of longest diameter of target lesions compared to baseline.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. As per statistical analysis plan, when associations for group 1 and 2 were similar, the data for group 1 and 2 were pooled. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure. Here, 'Number Analyzed' signifies number of participants evaluable for the specific rows.

Treatment satisfaction was evaluated with single item question (eg,"How satisfied are you with your current breast cancer treatment?") using the smart phone application. Responses were provided on a four-point Likert scale (dissatisfied, neutral, satisfied, very satisfied).

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. Here, 'Overall Number of Participants Analyzed' signifies participants evaluable for this outcome measure. Here, 'Number Analyzed' signifies number of participants evaluable for the specific timepoints.

Number of participants according to starting dose of palbociclib treatment (125 milligrams [mg], 100 mg and 75 mg) is reported in this outcome measure. Baseline values are those measured between enrollment and the day before treatment start.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. No participant received palbociclib treatment in Group 2. Hence, no data was reported for Group 2.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. No participant received palbociclib treatment in Group 2. Hence, no data was reported for Group 2.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. No participant received palbociclib treatment in Group 2. Hence, no data was reported for Group 2.

Safety Analysis set included all participants who received at least 1 dose of palbociclib or endocrine therapy. No participant received palbociclib treatment in Group 2. Hence, no data was reported for Group 2.