Regimen medications were defined as systemic therapies included in line regimen based on synapse line of therapy algorithm. Treatment regimen distribution included: first-line regimen; palbociclib along with aromatase inhibitor and second-line regimen; CDK4/6 inhibitor plus endocrine and chemotherapy. Systemic anticancer treatment here refers to one or more sequential monotherapy or combination therapy regimens occurring within discrete lines of treatment, each ending with a disease progression.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Line of therapy was defined as line number (1; 2; 3; etc.) in the A/MBC setting assigned based on synapse line of therapy algorithm. Systemic anticancer treatment here refers to one or more sequential monotherapy or combination therapy regimens occurring within discrete lines of treatment, each ending with a disease progression.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Percentage of participants with starting and end dose at 125 mg, 100 mg, 75 mg and unknown were reported.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

In this outcome measure type of dose adjustments were recorded and reported. It included dose increase, decrease, no adjustment and unknown categories.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Percentage of participants with discontinuation reason as progression, intolerance/toxicity, participant choice, treatment for other diseases, left health system, end of planned therapy, changes in insurance, death, hospice referral, physician choice, actionable mutation found, other/unknown were recorded and reported in this outcome measure.

Analysis population (AP) included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Time to dose adjustment (TTDA) was defined as the time from the start of palbociclib and AI treatment until the date of treatment dose adjustment.

AP: all participants who met following criteria: 1)Diagnosis of A/MBC;2)Aged >=18years at A/MBC diagnosis;3)Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on/after 03 February 2015-31 July 2019;4)Evidence of ER/PR positive disease and HER2 negative disease/absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis. Overall number of participants analyzed=participants evaluable for this outcome measure.

Probability of being event free (event defined as disease progression [PD] or death due to any cause) at 3 months. rwPFS was defined as the extent of time from the start of palbociclib and AI treatment until disease progression, date of death prior to initiation of the 2nd line treatment. Participants who were not indicated to be deceased at the time of analysis were censored for rwPFS analysis at the date of initiation of the 2nd line treatment, date of last contact or the end of study period whichever occurred first. Probability of participants with rwPFS at 3 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of being event free (event defined as PD or death due to any cause) at 6 months. rwPFS was defined as the extent of time from the start of palbociclib and AI treatment until disease progression, date of death prior to initiation of the 2nd line treatment. Participants who were not indicated to be deceased at the time of analysis were censored for rwPFS analysis at the date of initiation of the 2nd line treatment, date of last contact or the end of study period whichever occurred first. Probability of participants with rwPFS at 6 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of being event free (event defined as PD or death due to any cause) at 12 months. rwPFS was defined as the extent of time from the start of palbociclib and AI treatment until disease progression, date of death prior to initiation of the 2nd line treatment. Participants who were not indicated to be deceased at the time of analysis were censored for rwPFS analysis at the date of initiation of the 2nd line treatment, date of last contact or the end of study period whichever occurred first. Probability of participants with rwPFS at 12 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of being event free (event defined as PD or death due to any cause) at 18 months. rwPFS was defined as the extent of time from the start of palbociclib and AI treatment until disease progression, date of death prior to initiation of the 2nd line treatment. Participants who were not indicated to be deceased at the time of analysis were censored for rwPFS analysis at the date of initiation of the 2nd line treatment, date of last contact or the end of study period whichever occurred first. Probability of participants with rwPFS at 18 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of being event free (event defined as PD or death due to any cause) at 24 months. rwPFS was defined as the extent of time from the start of palbociclib and AI treatment until disease progression, date of death prior to initiation of the 2nd line treatment. Participants who were not indicated to be deceased at the time of analysis were censored for rwPFS analysis at the date of initiation of the 2nd line treatment, date of last contact or the end of study period whichever occurred first. Probability of participants with rwPFS at 24 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of being event free (event defined as PD or death due to any cause) at 30 months. rwPFS was defined as the extent of time from the start of palbociclib and AI treatment until disease progression, date of death prior to initiation of the 2nd line treatment. Participants who were not indicated to be deceased at the time of analysis were censored for rwPFS analysis at the date of initiation of the 2nd line treatment, date of last contact or the end of study period whichever occurred first. Probability of participants with rwPFS at 30 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of being event free (event defined as PD or death due to any cause) at 36 months. rwPFS was defined as the extent of time from the start of palbociclib and AI treatment until disease progression, date of death prior to initiation of the 2nd line treatment. Participants who were not indicated to be deceased at the time of analysis were censored for rwPFS analysis at the date of initiation of the 2nd line treatment, date of last contact or the end of study period whichever occurred first. Probability of participants with rwPFS at 36 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

rwOS was defined as the time from the start of palbociclib and AI treatment until the date of death, date of last contact or the end of study period. Participants who were not indicated to be deceased at the time of analysis were censored for rwOS analysis at the date of last contact or the end of study period whichever occurred first. Probability of participants with rwOS at 3 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

rwOS was defined as the time from the start of palbociclib and AI treatment until the date of death, date of last contact or the end of study period. Participants who were not indicated to be deceased at the time of analysis were censored for rwOS analysis at the date of last contact or the end of study period whichever occurred first. Probability of participants with rwOS at 6 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

rwOS was defined as the time from the start of palbociclib and AI treatment until the date of death, date of last contact or the end of study period. Participants who were not indicated to be deceased at the time of analysis were censored for rwOS analysis at the date of last contact or the end of study period whichever occurred first. Probability of participants with rwOS at 12 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

rwOS was defined as the time from the start of palbociclib and AI treatment until the date of death, date of last contact or the end of study period. Participants who were not indicated to be deceased at the time of analysis were censored for rwOS analysis at the date of last contact or the end of study period whichever occurred first. Probability of participants with rwOS at 18 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

rwOS was defined as the time from the start of palbociclib and AI treatment until the date of death, date of last contact or the end of study period. Participants who were not indicated to be deceased at the time of analysis were censored for rwOS analysis at the date of last contact or the end of study period whichever occurred first. Probability of participants with rwOS at 24 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

rwOS was defined as the time from the start of palbociclib and AI treatment until the date of death, date of last contact or the end of study period. Participants who were not indicated to be deceased at the time of analysis were censored for rwOS analysis at the date of last contact or the end of study period whichever occurred first. Probability of participants with rwOS at 30 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

rwOS was defined as the time from the start of palbociclib and AI treatment until the date of death, date of last contact or the end of study period. Participants who were not indicated to be deceased at the time of analysis were censored for rwOS analysis at the date of last contact or the end of study period whichever occurred first. Probability of participants with rwOS at 36 months were reported in this outcome measure. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without first-line treatment discontinuation or death at month 3 were reported in this outcome measure. Real-world time to treatment discontinuation (rwTTD) was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date the participant discontinued first-line therapy or date of death. Participant alive and without first-line therapy discontinuation were censored at the earliest of last known use of first-line therapy or end of study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without first-line treatment discontinuation or death at month 6 were reported in this outcome measure. rwTTD was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date the participant discontinued first-line therapy or date of death. Participant alive and without first-line therapy discontinuation were censored at the earliest of last known use of first-line therapy or end of study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without first-line treatment discontinuation or death at month 12 were reported in this outcome measure. rwTTD was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date the participant discontinued first-line therapy or date of death. Participant alive and without first-line therapy discontinuation were censored at the earliest of last known use of first-line therapy or end of study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without first-line treatment discontinuation or death at month 18 were reported in this outcome measure. rwTTD was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date the participant discontinued first-line therapy or date of death. Participant alive and without first-line therapy discontinuation were censored at the earliest of last known use of first-line therapy or end of study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without first-line treatment discontinuation or death at month 24 were reported in this outcome measure. rwTTD was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date the participant discontinued first-line therapy or date of death. Participant alive and without first-line therapy discontinuation were censored at the earliest of last known use of first-line therapy or end of study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without first-line treatment discontinuation or death at month 30 were reported in this outcome measure. rwTTD was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date the participant discontinued first-line therapy or date of death. Participant alive and without first-line therapy discontinuation were censored at the earliest of last known use of first-line therapy or end of study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without first-line treatment discontinuation or death at month 36 were reported in this outcome measure. rwTTD was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date the participant discontinued first-line therapy or date of death. Participant alive and without first-line therapy discontinuation were censored at the earliest of last known use of first-line therapy or end of study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent line of therapy initiation or death at month 3 were reported in this outcome measure. Real-world time to next treatment (rwTTNT) was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent line of treatment, date of death, date of last contact or the end of study period. Participant alive and without subsequent line of therapy initiation were censored at the earliest of the following events: date of last contact or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent line of therapy initiation or death at month 6 were reported in this outcome measure. rwTTNT was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent line of treatment, date of death, date of last contact or the end of study period. Participant alive and without subsequent line of therapy initiation were censored at the earliest of the following events: date of last contact or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent line of therapy initiation or death at month 12 were reported in this outcome measure. rwTTNT was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent line of treatment, date of death, date of last contact or the end of study period. Participant alive and without subsequent line of therapy initiation were censored at the earliest of the following events: date of last contact or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent line of therapy initiation or death at month 18 were reported in this outcome measure. rwTTNT was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent line of treatment, date of death, date of last contact or the end of study period. Participant alive and without subsequent line of therapy initiation were censored at the earliest of the following events: date of last contact or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent line of therapy initiation or death at month 24 were reported in this outcome measure. rwTTNT was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent line of treatment, date of death, date of last contact or the end of study period. Participant alive and without subsequent line of therapy initiation were censored at the earliest of the following events: date of last contact or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent line of therapy initiation or death at month 30 were reported in this outcome measure. rwTTNT was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent line of treatment, date of death, date of last contact or the end of study period. Participant alive and without subsequent line of therapy initiation were censored at the earliest of the following events: date of last contact or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent line of therapy initiation or death at month 36 were reported in this outcome measure. rwTTNT was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent line of treatment, date of death, date of last contact or the end of study period. Participant alive and without subsequent line of therapy initiation were censored at the earliest of the following events: date of last contact or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent chemotherapy or death at month 3 were reported in this outcome measure. Real-world time to chemotherapy (rwTTC) was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent chemotherapy or date of death. Participant alive and without subsequent chemotherapy were censored at the earliest of the following events: date of last contact or end of the study period, whichever came later. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent chemotherapy or death at month 6 were reported in this outcome measure. rwTTC was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent chemotherapy or date of death. Participant alive and without subsequent chemotherapy were censored at the earliest of the following events: date of last contact or end of the study period, whichever came later. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent chemotherapy or death at month 12 were reported in this outcome measure. rwTTC was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent chemotherapy or date of death. Participant alive and without subsequent chemotherapy were censored at the earliest of the following events: date of last contact or end of the study period, whichever came later. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent chemotherapy or death at month 18 were reported in this outcome measure. rwTTC was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent chemotherapy or date of death. Participant alive and without subsequent chemotherapy were censored at the earliest of the following events: date of last contact or end of the study period, whichever came later. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent chemotherapy or death at month 24 were reported in this outcome measure. rwTTC was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent chemotherapy or date of death. Participant alive and without subsequent chemotherapy were censored at the earliest of the following events: date of last contact or end of the study period, whichever came later. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent chemotherapy or death at month 30 were reported in this outcome measure. rwTTC was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent chemotherapy or date of death. Participant alive and without subsequent chemotherapy were censored at the earliest of the following events: date of last contact or end of the study period, whichever came later. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without subsequent chemotherapy or death at month 36 were reported in this outcome measure. rwTTC was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: start of subsequent chemotherapy or date of death. Participant alive and without subsequent chemotherapy were censored at the earliest of the following events: date of last contact or end of the study period, whichever came later. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without a first-line therapy dose adjustment at month 3 were reported in this outcome measure. Real-world time to dose adjustment (rwTTDA) was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date of first-line treatment dose adjustment or discontinuation, date of death, date of last contact or the end of study period. Participant alive and without a first-line therapy dose adjustment were censored at the earliest of the following events: first-line discontinuation, death, date of last contact, or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without a first-line therapy dose adjustment at month 6 were reported in this outcome measure. rwTTDA was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date of first-line treatment dose adjustment or discontinuation, date of death, date of last contact or the end of study period. Participant alive and without a first-line therapy dose adjustment were censored at the earliest of the following events: first-line discontinuation, death, date of last contact, or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without a first-line therapy dose adjustment at month 12 were reported in this outcome measure. rwTTDA was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date of first-line treatment dose adjustment or discontinuation, date of death, date of last contact or the end of study period. Participant alive and without a first-line therapy dose adjustment were censored at the earliest of the following events: first-line discontinuation, death, date of last contact, or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without a first-line therapy dose adjustment at month 18 were reported in this outcome measure. rwTTDA was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date of first-line treatment dose adjustment or discontinuation, date of death, date of last contact or the end of study period. Participant alive and without a first-line therapy dose adjustment were censored at the earliest of the following events: first-line discontinuation, death, date of last contact, or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without a first-line therapy dose adjustment at month 24 were reported in this outcome measure. rwTTDA was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date of first-line treatment dose adjustment or discontinuation, date of death, date of last contact or the end of study period. Participant alive and without a first-line therapy dose adjustment were censored at the earliest of the following events: first-line discontinuation, death, date of last contact, or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without a first-line therapy dose adjustment at month 30 were reported in this outcome measure. rwTTDA was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date of first-line treatment dose adjustment or discontinuation, date of death, date of last contact or the end of study period. Participant alive and without a first-line therapy dose adjustment were censored at the earliest of the following events: first-line discontinuation, death, date of last contact, or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.

Probability of participants without a first-line therapy dose adjustment at month 36 were reported in this outcome measure. rwTTDA was defined as length of time from the start of first-line therapy with palbociclib plus an aromatase inhibitor to the earliest of one the following: date of first-line treatment dose adjustment or discontinuation, date of death, date of last contact or the end of study period. Participant alive and without a first-line therapy dose adjustment were censored at the earliest of the following events: first-line discontinuation, death, date of last contact, or end of the study period. Analysis was performed using Kaplan-Meier method.

Analysis population included all participants who met following criteria: 1) Diagnosis of A/MBC; 2) Aged >=18 years at A/MBC diagnosis; 3) Initiated palbociclib in combination with AI as first-line therapy after A/MBC diagnosis on or after 03 February 2015 through 31 July 2019; 4) Evidence of ER or PR positive disease and HER2 negative disease or absence of any indication of ER and PR negative disease and HER2 positive disease closest to A/MBC diagnosis.