Trial Outcomes & Findings for Study to Compare Overall Survival in Medicare Patients With Metastatic Breast Cancer Treated With a Medicine Called Palbociclib in Combination With Aromatase Inhibitor and Aromatase Inhibitor by Itself. (NCT NCT06086340)
NCT ID: NCT06086340
Last Updated: 2025-11-18
Results Overview
Overall survival was defined as time in months from the study index date to all cause death. Study index date in this outcome measure was the date of first line of treatment initiation with palbociclib + AI or AI alone after the de novo mBC diagnosis. De novo mBC referred to breast cancer that physician diagnosed for the first time after it had already spread outside of the breast to distant parts of the body. Unadjusted analysis: analysis not considering any covariates, specifically potential differences in baseline characteristics that could confound the association between treatment and survival. Overall survival was assessed using Kaplan-Meier analysis.
COMPLETED
779 participants
From index date to death (approximately 69.9 months); retrospective data evaluated in 4 months (approximately) of this study
2025-11-18
Participant Flow
Data of eligible participants diagnosed with hormone receptor (HR+)/ human epidermal growth factor receptor 2-negative (HER2) metastatic breast cancer (mBC) treated with palbociclib in combination with aromatase inhibitor (AI) was extracted from clinical and administrative claims data from the linked surveillance, epidemiology, and end results (SEER)-Medicare database from 1-August-2014 until 31-December-2020 were observed retrospectively.
Available data from eligible participants was evaluated in approximately 4 months of this retrospective observational study.
Participant milestones
| Measure |
AI Alone
Participants who received an AI (alone) as first line therapy under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
Palbociclib + AI
Participants who received Palbociclib in combination with an AI under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
|---|---|---|
|
Overall Study
STARTED
|
483
|
296
|
|
Overall Study
COMPLETED
|
483
|
296
|
|
Overall Study
NOT COMPLETED
|
0
|
0
|
Reasons for withdrawal
Withdrawal data not reported
Baseline Characteristics
Here "number analyzed" signifies participant evaluable for this baseline measure.
Baseline characteristics by cohort
| Measure |
AI Alone
n=483 Participants
Participants who received an AI (alone) as first line therapy under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
Palbociclib + AI
n=296 Participants
Participants who received Palbociclib in combination with an AI under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
Total
n=779 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Customized
65-69 years
|
86 Participants
n=483 Participants
|
86 Participants
n=296 Participants
|
172 Participants
n=779 Participants
|
|
Age, Customized
70-74 years
|
91 Participants
n=483 Participants
|
84 Participants
n=296 Participants
|
175 Participants
n=779 Participants
|
|
Age, Customized
75-79 years
|
101 Participants
n=483 Participants
|
67 Participants
n=296 Participants
|
168 Participants
n=779 Participants
|
|
Age, Customized
Greater than or equal to (>=) 80 years
|
205 Participants
n=483 Participants
|
59 Participants
n=296 Participants
|
264 Participants
n=779 Participants
|
|
Sex: Female, Male
Female
|
480 Participants
n=480 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
294 Participants
n=294 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
774 Participants
n=774 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
|
Sex: Female, Male
Male
|
0 Participants
n=480 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
0 Participants
n=294 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
0 Participants
n=774 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
23 Participants
n=483 Participants
|
14 Participants
n=296 Participants
|
37 Participants
n=779 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
460 Participants
n=483 Participants
|
282 Participants
n=296 Participants
|
742 Participants
n=779 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=483 Participants
|
0 Participants
n=296 Participants
|
0 Participants
n=779 Participants
|
|
Race/Ethnicity, Customized
Race · American Indian or Alaska Native
|
0 Participants
n=476 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
0 Participants
n=292 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
0 Participants
n=768 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
|
Race/Ethnicity, Customized
Race · Asian or Pacific Islander
|
14 Participants
n=476 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
13 Participants
n=292 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
27 Participants
n=768 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
|
Race/Ethnicity, Customized
Race · Black
|
45 Participants
n=476 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
23 Participants
n=292 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
68 Participants
n=768 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
|
Race/Ethnicity, Customized
Race · White
|
417 Participants
n=476 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
256 Participants
n=292 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
673 Participants
n=768 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
|
Race/Ethnicity, Customized
Race · Other or unknown
|
0 Participants
n=476 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
0 Participants
n=292 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
0 Participants
n=768 Participants • Here "number analyzed" signifies participant evaluable for this baseline measure.
|
PRIMARY outcome
Timeframe: From index date to death (approximately 69.9 months); retrospective data evaluated in 4 months (approximately) of this studyPopulation: Analysis population included all eligible participants whose data was extracted and evaluated for the retrospective analysis.
Overall survival was defined as time in months from the study index date to all cause death. Study index date in this outcome measure was the date of first line of treatment initiation with palbociclib + AI or AI alone after the de novo mBC diagnosis. De novo mBC referred to breast cancer that physician diagnosed for the first time after it had already spread outside of the breast to distant parts of the body. Unadjusted analysis: analysis not considering any covariates, specifically potential differences in baseline characteristics that could confound the association between treatment and survival. Overall survival was assessed using Kaplan-Meier analysis.
Outcome measures
| Measure |
AI Alone
n=483 Participants
Participants who received an AI (alone) as first line therapy under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
Palbociclib + AI
n=296 Participants
Participants who received Palbociclib in combination with an AI under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
|---|---|---|
|
Overall Survival According to Unadjusted Analysis
|
24.2 Months
Interval 20.5 to 26.7
|
44.0 Months
Interval 37.3 to 54.5
|
PRIMARY outcome
Timeframe: From index date to death (approximately 69.9 months); retrospective data evaluated in 4 months (approximately) of this studyPopulation: Analysis population included all eligible participants whose data was extracted and evaluated for the retrospective analysis.
Overall survival was defined as time in months from the study index date to all cause death. Study index date in this outcome measure was the date of first line of treatment initiation with palbociclib + AI or AI alone after the de novo mBC diagnosis. De novo mBC referred to breast cancer that physician diagnosed for the first time after it had already spread outside of the breast to distant parts of the body. sIPTW analysis: stabilized inverse probability treatment weighting. This is a statistical method that reweights participants to create groups with similar baseline characteristics. The analysis therefore adjusts for differences in baseline characteristics that could confound the association between treatment and survival. Overall survival was assessed using Kaplan-Meier analysis.
Outcome measures
| Measure |
AI Alone
n=483 Participants
Participants who received an AI (alone) as first line therapy under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
Palbociclib + AI
n=296 Participants
Participants who received Palbociclib in combination with an AI under standard real world routine clinical practice for HR+/HER2- mBC during the period 1-February-2015 to 30-June-2020 were included in this retrospective observational study.
|
|---|---|---|
|
Overall Survival According to Stabilized Inverse Probability of Treatment Weighted (sIPTW) Analysis
|
25.5 Months
Interval 22.0 to 28.9
|
37.6 Months
Interval 34.8 to 42.0
|
Adverse Events
AI Alone
Palbociclib + AI
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