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Palbociclib Plus Letrozole For Postmenopausal Women With HR(+) HER2(-) Advanced Breast Cancer For Whom Letrozole Is Deemed Appropriate

STUDY OF PALBOCICLIB IN COMBINATION WITH LETROZOLE AS TREATMENT OF POSTMENOPAUSAL WOMEN WITH HORMONE RECEPTOR POSITIVE, HER2-NEGATIVE ADVANCED BREAST CANCER FOR WHOM LETROZOLE THERAPY IS DEEMED APPROPRIATE

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02600923
Enrollment
131
Registered
2015-11-09
Start date
2016-04-15
Completion date
2019-05-28
Last updated
2022-01-20

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Advanced Breast Cancer Female

Keywords

palbociclib, ibrance, breast cancer

Brief summary

The purpose of this study is to provide access to palbociclib in Mexico and in selected Latin American countries before it becomes commercially available to patients with HR positive/HER2-negative ABC who are appropriate candidates for letrozole therapy.

Interventions

DRUGPalbociclib

Palbociclib will be administered orally once a day at 125 mg/day for 21 days followed by 7 days off treatment for each 28-day cycle (Schedule 3/1).

DRUGLetrozole

Letrozole will be administered orally at 2.5 mg once daily as continuous daily dosing schedule according to product labeling and in compliance with its local prescribing information.

Sponsors

Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
NA
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Adult women with proven diagnosis of advanced adenocarcinoma of the breast (locoregional recurrent or metastatic disease). * Women who are not of childbearing potential. * ER-positive and/or Progesterone receptor (PgR)-positive tumor based on local laboratory results (test as per local practice). * HER2-negative breast cancer based on local laboratory results (test as per local practice or local guidelines). * Patients must be appropriate candidates for letrozole therapy. * Eastern Cooperative Oncology Group (ECOG) performance status 0-2. * Adequate bone marrow function. * Adequate liver function * Adequate renal function.

Exclusion criteria

* Known hypersensitivity to letrozole, or any of its excipients, or to any palbociclib excipients. * Current use of food or drugs known to be potent inhibitors or inducers of CYP3A4 isoenzymes within 7 days prior to study entry. * Prior treatment with any CDK inhibitor. * Previous participation in a palbociclib clinical study. * Participation in other studies involving investigational drug(s) within 2 weeks prior to study entry and/or during study participation. * QTc \>480 msec; history of QT syndrome, Brugada syndrome or known history of QTc prolongation, or Torsade de Pointes. * High cardiovascular risk, including, but not limited to recent myocardial infarction, severe/unstable angina and severe cardiac dysrhythmias in the past 6 months prior to enrollment. * Diagnosis of any second invasive malignancy within the last 3 years prior to enrollment. Note: patients with adequately treated basal cell or squamous cell skin cancer, a history of intraepithelial neoplasia or in situ disease (eg, carcinoma in situ of the cervix or melanoma in situ) may enter. * Active uncontrolled or symptomatic brain metastases. Previously treated and clinically stable, brain metastases are permitted. * Other severe acute or chronic medical or psychiatric conditions. * Patients who are investigational site staff members directly involved in the conduct of the study and their family members, site staff members otherwise supervised by the investigator, or patients who are Pfizer employees directly involved in the conduct of the study.

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)3 yearsAn adverse event (AE) was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. All AEs reported after initiation of study drug treatment were considered as TEAE. AE severity was graded according to Common Terminology Criteria for AEs (CTCAE) version 4.03. Grade 1 AEs are mild AEs; Grade 2 AEs are moderate AEs; Grade 3 AEs are severe AEs, Grade 4 AEs are life-threatening consequences and Grade 5 AEs are deaths related to AEs. Each AE was counted once for the participant in the most severe severity.
Number of Participants With Palbociclib-related TEAEs3 yearsAn AE was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. All AEs reported after initiation of study drug treatment were considered as TEAE. AE severity was graded according to CTCAE version 4.03. Grade 1 AEs are mild AEs; Grade 2 AEs are moderate AEs; Grade 3 AEs are severe AEs, Grade 4 AEs are life-threatening consequences and Grade 5 AEs are deaths related to AEs. Palbociclib-related TEAEs were determined by the investigator.
Number of Participants With Serious Adverse Events (SAEs)3 yearsAn SAE was any untoward medical occurrence at any dose that resulted in death; was life threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; resulted in congenital anomaly/birth defect. AEs included both SAEs and AEs. Palbociclib-related SAEs were determined by the investigator.

Secondary

MeasureTime frameDescription
Number of Participants With Death3 yearsDeath from any cause while on treatment and within 28 days of palbociclib discontinuation was only counted below.
The Objective Response Rate (ORR)3 yearsThe tumor response was based on the response reported by investigator per local practice. No response confirmation was applied. ORR was defined as the percentage of participants with complete response or partial response relative to all as-treated population.

Countries

Argentina, Brazil, Colombia, Mexico

Participant flow

Pre-assignment details

A total of 131 participants were enrolled and assigned to study treatment, and 130 participants were treated in the study.

Participants by arm

ArmCount
Palbociclib+Letrozole
Participants received palbociclib orally once daily at 125 mg for 21 days followed by 7 days off treatment for each 28-day cycle, and letrozole orally at 2.5 mg QD as a continuous daily dosing schedule. Participants continued to receive treatments with palbociclib+letrozole until disease progression, symptomatic deterioration, unacceptable toxicity, death, withdrawal of consent, or time of commercial availability of palbociclib, whichever occurred first.
130
Total130

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyAdverse Event3
Overall StudyDeath10
Overall StudyGlobal deterioration of health status2
Overall StudyInsufficient clinical response6
Overall StudyLost to Follow-up1
Overall StudyNot treated1
Overall StudyObjective progression or relapse50
Overall StudyStudy terminated by Sponsor53
Overall StudyWithdrawal by Subject5

Baseline characteristics

CharacteristicPalbociclib+Letrozole
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
41 Participants
Age, Categorical
Between 18 and 65 years
89 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
130 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Sex: Female, Male
Female
130 Participants
Sex: Female, Male
Male
0 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
10 / 130
other
Total, other adverse events
129 / 130
serious
Total, serious adverse events
32 / 130

Outcome results

Primary

Number of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)

An adverse event (AE) was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. All AEs reported after initiation of study drug treatment were considered as TEAE. AE severity was graded according to Common Terminology Criteria for AEs (CTCAE) version 4.03. Grade 1 AEs are mild AEs; Grade 2 AEs are moderate AEs; Grade 3 AEs are severe AEs, Grade 4 AEs are life-threatening consequences and Grade 5 AEs are deaths related to AEs. Each AE was counted once for the participant in the most severe severity.

Time frame: 3 years

Population: The analysis population included all participants who received at least 1 dose of palbociclib treatment.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Palbociclib+LetrozoleNumber of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)Grade 10 Participants
Palbociclib+LetrozoleNumber of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)Grade 217 Participants
Palbociclib+LetrozoleNumber of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)Grade 382 Participants
Palbociclib+LetrozoleNumber of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)Grade 423 Participants
Palbociclib+LetrozoleNumber of Participants With All-causality Treatment-emergent Adverse Events (TEAEs)Grade 57 Participants
Primary

Number of Participants With Palbociclib-related TEAEs

An AE was any untoward medical occurrence in a clinical investigation participant administered a product; the event did not need to have a causal relationship with the treatment. All AEs reported after initiation of study drug treatment were considered as TEAE. AE severity was graded according to CTCAE version 4.03. Grade 1 AEs are mild AEs; Grade 2 AEs are moderate AEs; Grade 3 AEs are severe AEs, Grade 4 AEs are life-threatening consequences and Grade 5 AEs are deaths related to AEs. Palbociclib-related TEAEs were determined by the investigator.

Time frame: 3 years

Population: The analysis population included all participants who received at least 1 dose of palbociclib treatment.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Palbociclib+LetrozoleNumber of Participants With Palbociclib-related TEAEsGrade 12 Participants
Palbociclib+LetrozoleNumber of Participants With Palbociclib-related TEAEsGrade 225 Participants
Palbociclib+LetrozoleNumber of Participants With Palbociclib-related TEAEsGrade 381 Participants
Palbociclib+LetrozoleNumber of Participants With Palbociclib-related TEAEsGrade 420 Participants
Palbociclib+LetrozoleNumber of Participants With Palbociclib-related TEAEsGrade 50 Participants
Primary

Number of Participants With Serious Adverse Events (SAEs)

An SAE was any untoward medical occurrence at any dose that resulted in death; was life threatening; required inpatient hospitalization or prolongation of existing hospitalization; resulted in persistent or significant disability/incapacity; resulted in congenital anomaly/birth defect. AEs included both SAEs and AEs. Palbociclib-related SAEs were determined by the investigator.

Time frame: 3 years

Population: The analysis population included all participants who received at least 1 dose of palbociclib treatment.

ArmMeasureGroupValue (COUNT_OF_PARTICIPANTS)
Palbociclib+LetrozoleNumber of Participants With Serious Adverse Events (SAEs)All-causality32 Participants
Palbociclib+LetrozoleNumber of Participants With Serious Adverse Events (SAEs)Palbociclib-related6 Participants
Secondary

Number of Participants With Death

Death from any cause while on treatment and within 28 days of palbociclib discontinuation was only counted below.

Time frame: 3 years

Population: The analysis population included all participants who received at least 1 dose of palbociclib treatment.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Palbociclib+LetrozoleNumber of Participants With Death5 Participants
Secondary

The Objective Response Rate (ORR)

The tumor response was based on the response reported by investigator per local practice. No response confirmation was applied. ORR was defined as the percentage of participants with complete response or partial response relative to all as-treated population.

Time frame: 3 years

Population: The analysis population included participants with efficacy data contributing to the analysis.

ArmMeasureValue (NUMBER)
Palbociclib+LetrozoleThe Objective Response Rate (ORR)24.8 percentage of evaluable participants

Source: ClinicalTrials.gov · Data processed: Feb 8, 2026