Trial Outcomes & Findings for Study to Evaluate Overall Survival in Japanese Patients With HR+/HER2- Advanced Breast Cancer Treated With Palbociclib Plus Letrozole (NCT NCT04735367)
NCT ID: NCT04735367
Last Updated: 2025-12-09
Results Overview
OS was defined as the time from the date of the first dose of the investigational product in Japanese Phase 2 study (A5481010) to the date of any-cause death. In the absence of confirmation of death, survival time was censored to last date the participant was known to be alive. Kaplan-Meier method was used for analysis.
COMPLETED
42 participants
From the date of the first dose of the treatment in study A5481010 to the date of any-cause death or censoring date (maximum of 103.16 months of follow-up); data collected and observed retrospectively over 32 months in A5481154 study
2025-12-09
Participant Flow
Data was collected from participants who were treated with palbociclib plus letrozole in Japanese Phase 2 study A5481010 (NCT01684215). Data was collected retrospectively from individual participant medical records for participants under survival follow up at the time of completion of study A5481010 and for participants who died or refused follow-up in study A5481010, data collected in Phase 2 study was used for analysis.
Participant milestones
| Measure |
Palbociclib+ Letrozole
Participants with hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) advanced breast cancer who were treated with palbociclib plus letrozole in study A5481010 (NCT01684215).
|
|---|---|
|
Overall Study
STARTED
|
42
|
|
Overall Study
COMPLETED
|
42
|
|
Overall Study
NOT COMPLETED
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Race and Ethnicity were not collected from any participant.
Baseline characteristics by cohort
| Measure |
Palbociclib+ Letrozole
n=42 Participants
Participants with HR+/HER2- advanced breast cancer who were treated with palbociclib plus letrozole in study A5481010 (NCT01684215).
|
|---|---|
|
Age, Categorical
<=18 years
|
0 Participants
n=42 Participants
|
|
Age, Categorical
Between 18 and 65 years
|
26 Participants
n=42 Participants
|
|
Age, Categorical
>=65 years
|
16 Participants
n=42 Participants
|
|
Sex: Female, Male
Female
|
42 Participants
n=42 Participants
|
|
Sex: Female, Male
Male
|
0 Participants
n=42 Participants
|
PRIMARY outcome
Timeframe: From the date of the first dose of the treatment in study A5481010 to the date of any-cause death or censoring date (maximum of 103.16 months of follow-up); data collected and observed retrospectively over 32 months in A5481154 studyPopulation: Analysis set included participants who were enrolled in J-Ph2 and received the investigational product excluding surviving participants who did not give written or oral consent.
OS was defined as the time from the date of the first dose of the investigational product in Japanese Phase 2 study (A5481010) to the date of any-cause death. In the absence of confirmation of death, survival time was censored to last date the participant was known to be alive. Kaplan-Meier method was used for analysis.
Outcome measures
| Measure |
Palbociclib+ Letrozole
n=42 Participants
Participants with HR+/HER2- advanced breast cancer who were treated with palbociclib plus letrozole in study A5481010 (NCT01684215).
|
|---|---|
|
Overall Survival (OS)
|
85.42 Months
Interval 64.26 to
Upper limit of 95% confidence interval (CI) could not be estimated because of insufficient number of participants with events.
|
SECONDARY outcome
Timeframe: From start of subsequent treatment in study A5481010 until date of death, withdrawal of consent or end of study (maximum of 103.16 months of follow-up); data collected and observed retrospectively over 32 months in A5481154 studyPopulation: Analysis set included participants who were enrolled in J-Ph2 and received the investigational product excluding surviving participants who did not give written or oral consent.
Participants were classified based on types of subsequent treatment and by line of subsequent treatment. Subsequent treatments included: endocrine therapy-based, chemotherapy-based and others (Investigational drug + Endocrine therapy/Chemotherapy).
Outcome measures
| Measure |
Palbociclib+ Letrozole
n=42 Participants
Participants with HR+/HER2- advanced breast cancer who were treated with palbociclib plus letrozole in study A5481010 (NCT01684215).
|
|---|---|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
Second Subsequent Therapy: Chemotherapy
|
21.4 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
Second Subsequent Therapy: Other
|
4.8 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
Second Subsequent Therapy: Endocrine therapy + Chemotherapy
|
2.4 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
Received Second Subsequent Therapy
|
69.0 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
Second Subsequent Therapy: Endocrine-based therapy
|
40.5 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
Received First Subsequent Therapy
|
81.0 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
First Subsequent Therapy: Endocrine-based therapy
|
69.0 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
First Subsequent Therapy: Endocrine therapy + Chemotherapy
|
0.0 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
First Subsequent Therapy: Chemotherapy
|
7.1 Percentage of participants
|
|
Percentage of Participants According to Types and Line of Subsequent Treatment
First Subsequent Therapy: Other
|
4.8 Percentage of participants
|
SECONDARY outcome
Timeframe: From start of subsequent treatment in study A5481010 until date of death, withdrawal of consent or end of study (maximum of 103.16 months of follow-up); data collected and observed retrospectively over 32 months in A5481154 studyPopulation: Analysis set included participants who were enrolled in J-Ph2 and received the investigational product excluding surviving participants who did not give written or oral consent. All participants reported under "Number of Participants Analyzed" contributed data to the table; however, may not have evaluable data for every row. Here "Number Analyzed" refers to the number of participants evaluable for the specified rows.
Duration of subsequent therapy defined as time from the start date to the end date of each line of treatment among participants who received subsequent treatment. Kaplan-Meier method was used.
Outcome measures
| Measure |
Palbociclib+ Letrozole
n=42 Participants
Participants with HR+/HER2- advanced breast cancer who were treated with palbociclib plus letrozole in study A5481010 (NCT01684215).
|
|---|---|
|
Duration of Subsequent Therapy by Line of Therapy
First Subsequent Therapy
|
7.64 Months
Interval 3.91 to 9.0
|
|
Duration of Subsequent Therapy by Line of Therapy
Second Subsequent Therapy
|
6.01 Months
Interval 3.25 to 14.88
|
Adverse Events
Palbociclib+ Letrozole
Serious adverse events
Adverse event data not reported
Other adverse events
Adverse event data not reported
Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publication until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
- Publication restrictions are in place
Restriction type: OTHER