Palbociclib in Combination With Adjuvant Endocrine Therapy for Hormone Receptor Positive, HER2 Negative Invasive Breast Cancer

A Phase 2 Pilot Feasibility Study of Palbociclib in Combination With Adjuvant Endocrine Therapy for Hormone Receptor Positive Invasive Breast Carcinoma

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02040857

Enrollment

162

Registered

2014-01-20

Start date

2014-01-31

Completion date

2024-12-27

Last updated

2025-04-29

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

Conditions

Breast Cancer

Keywords

Breast Cancer

Brief summary

This research study is evaluating a drug called Palbociclib in combination with endocrine therapy as a possible treatment for hormone receptor positive breast cancer. * Palbociclib is a drug that may stop cancer cells from growing. Palbociclib blocks activity of two closely related enzymes (proteins that help chemical reactions in the body occur), called Cyclin D Kinases 4 and 6 (CDK 4/6). These proteins are part of a pathway, or a sequence of steps which is known to regulate cell growth. Laboratory testing has suggested palbociclib may stop the growth of hormone receptor positive breast cancer. * Endocrine therapy prevents breast cancer cell growth by blocking estrogen stimulation. During this study endocrine therapy will either be tamoxifen or an aromatase inhibitor. It is standard of care for premenopausal women to take tamoxifen and for postmenopausal women to take either an aromatase inhibitor or tamoxifen after a diagnosis of hormone receptor positive breast cancer.

Detailed description

After the screening procedures confirms that the participant is able to participate in the study. The participant will be given a dosing diary for each treatment cycle. Each treatment cycle lasts 28 days, during which time the participant will take Palbociclib once a day on days 1-21 of each 28 day cycle and the aromatase inhibitor that the participant is already taking once a day every day. The diary will also include special instructions for taking the study drug(s). All participants participating in the research study will receive the same dose of Palbociclib. While participating in the research study the participant will have the following tests and procedures: * Clinical Exams: The participant will have a physical exam on the first day of the month for first three months of therapy. After that, the participant will have a physical exam every other month until the end of the first year of therapy. After the first year, the participant will have a physical exam every 3 months during the second year of therapy. During the physical exam, the participant will be asked questions about their general health, questions about any problems that they may be experiencing, and any medications they are taking. * Blood tests: The participant will have blood drawn on the first and fifteenth days of the first three months of therapy. After that, the participant will have blood drawn every month for the remainder of the first year of treatment and the every other month until the end of therapy. These tests will be used to determine if the participant is having any side effects related to the study drug. * Electrocardiograms (EKG): The participant will have an EKG performed on the first day of the first three months of therapy. After that, the participant will have an EKG every other month until the end of the first year of therapy. After the first year of therapy, the participant will have an EKG every 3 months during the second year of therapy.

Interventions

DRUGPalbociclib

CDK 4/6 inhibitor

DRUGAromatase Inhibitor

Endocrine Therapy

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Participants must have histologically confirmed hormone receptor positive (HR+) HER2 negative stage II (except T2N0) or stage III invasive breast cancer. Evaluation for metastatic disease is not required in the absence of symptoms. * Men and both pre- and postmenopausal women are eligible. * Prior Treatment: * Participants may have received (neo)adjuvant chemotherapy, but must be at least 30 days after last dose, with no more than grade 1 residual toxicity at time of screening. * Participants may have received adjuvant radiotherapy, but must be at least 30 days after last dose , with no more than grade 1 residual toxicity at the time of screening. * If most recent therapy was surgery, participants must be at least 30 days out from definitive surgery with no active wound healing complications. * Participants must have demonstrated ability to tolerate endocrine therapy by prior successful completion of at least 1 month of tamoxifen or aromatase inhibitor (AI) therapy without significant adverse events, and in the opinion of the treating physician any ongoing toxicity does not preclude ability to continue on tamoxifen or AI for at least a projected 2 year continuous duration. Ongoing use of any endocrine therapy, including tamoxifen, letrozole, anastrozole, or exemestane, is allowed. Patients may enroll within 2 years of beginning endocrine therapy, as long as there is a plan for at least 2 more years of adjuvant endocrine therapy. * ECOG performance status 0-1 * Age ≥18 years. * Normal organ and marrow function * Baseline QTc ≤ 480 ms * The effects of palbociclib on the developing human fetus are unknown. Women who might become pregnant must use adequate contraception * Ability to understand and the willingness to sign a written informed consent document

Exclusion criteria

* Concurrent therapy with other investigational agents. * Prior therapy with any CDK4/6 inhibitor. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to palbociclib. * Participants receiving any medications or substances that are strong inhibitors or inducers of CYP3A isoenzymes are ineligible. * Current use of drugs that are known to prolong the QT interval * Subjects with organ allograft requiring immunosuppression. * Uncontrolled intercurrent illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. * Pregnant women are excluded from this study. Breastfeeding should be discontinued prior to entry onto the study. * Individuals with a history of a different malignancy are ineligible except for the following circumstances. Individuals with a history of other malignancies are eligible if they have been disease-free for at least 5 years and are deemed by the investigator to be at low risk for recurrence of that malignancy. Individuals with the following cancers are eligible if diagnosed and treated within the past 5 years: ductal carcinoma in situ of the breast, cervical cancer in situ, and basal cell or squamous cell carcinoma of the skin. * No ongoing combination antiretroviral therapy

Design outcomes

Primary

Measure	Time frame	Description
2-Year Treatment Discontinuation Rate	Evaluate upon completion of palbociclib, up to 2 years of treatment completion.	The 2-year treatment discontinuation rate is the percentage of participants who do not complete the palbociclib treatment per protocol for reasons due to toxicity, withdrawal of consent to be treated, or other events related to tolerability in uncensored participants. Participants who discontinued palbociclib early for reasons that were not treatment-related were censored.

Secondary

Measure	Time frame	Description
2-year Treatment Discontinuation Rate by Aromatase Inhibitor and Tamoxifen-based Therapy Subgroup	Evaluate upon completion of palbociclib, up to 2 years of treatment completion.	The 2-year treatment discontinuation rate is the percentage of participants who do not complete the palbociclib treatment per protocol for reason due to toxicity, withdrawal of consent to be treated, or other events related to tolerability of all enrolled participants.
Grade 3-4 Treatment-Related Neutropenia Toxicity Rate	AE data collected every cycle from the time of the first dose of study treatment, through the study and until 30 days after removal from study or death, whichever occurs first. Therefore, AEs were observed up to 2 years plus 30 days.	Grade 3-4 treatment-related neutropenia toxicity rate is the percentage of participants experiencing at least one grade 3-4 neutropenia AE with treatment attribution of possible, probable or definite based on NCI Common Toxicity Criteria for Adverse Events version 4 (CTCAEv4) during the time of observation on treatment as reported on case report forms.
All Grade Treatment-Related Fatigue Toxicity Rate	AE data collected every cycle from the time of the first dose of study treatment, through the study and until 30 days after removal from study or death, whichever occurs first. Therefore, AEs were observed up to 2 years plus 30 days.	All grade treatment-related fatigue toxicity rate is the percentage of participants experiencing at least one grade 1-4 fatigue AE with treatment attribution of possible, probable or definite based on NCI Common Toxicity Criteria for Adverse Events version 4 (CTCAEv4) during the time of observation on treatment as reported on case report forms.
All GradeTreatment-Related Alopecia Toxicity Rate	AE data collected every cycle from the time of the first dose of study treatment, through the study and until 30 days after removal from study or death, whichever occurs first. Therefore, AEs were observed up to 2 years plus 30 days.	All grade treatment-related alopecia toxicity rate is the percentage of participants experiencing at least one grade 1-4 alopecia AE with treatment attribution of possible, probable or definite based on NCI Common Toxicity Criteria for Adverse Events version 4 (CTCAEv4) during the time of observation on treatment as reported on case report forms.

Countries

United States

Participant flow

Participants by arm

Arm	Count
Palbociclib With Adjuvant Endocrine Therapy * Palbociclib 125 mg PO qd 21 days on, 7 days off * Endocrine Therapy: Tamoxifen 20mg, Letrozole 2.5mg, Anastrozole 1mg, or Exemestane 25mg PO qd	162
Total	162

Withdrawals & dropouts

Period	Reason	FG000
Overall Study	Adverse Event	14
Overall Study	ineligible	1
Overall Study	Lost to Follow-up	2
Overall Study	patient non-compliance	3
Overall Study	Physician Decision	5
Overall Study	recurrence	4
Overall Study	Withdrawal by Subject	31

Baseline characteristics

Characteristic	Palbociclib With Adjuvant Endocrine Therapy
Age, Customized Age, <50 years	69 Participants
Age, Customized Age, >50 years	93 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants
Race (NIH/OMB) Asian	3 Participants
Race (NIH/OMB) Black or African American	7 Participants
Race (NIH/OMB) More than one race	0 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants
Race (NIH/OMB) Unknown or Not Reported	8 Participants
Race (NIH/OMB) White	144 Participants
Region of Enrollment United States	162 participants
Sex: Female, Male Female	157 Participants
Sex: Female, Male Male	5 Participants
Type of prior neo/adjuvant chemotherapy Adjuvant	63 Participants
Type of prior neo/adjuvant chemotherapy Both	4 Participants
Type of prior neo/adjuvant chemotherapy Neoadjuvant	60 Participants
Type of prior neo/adjuvant chemotherapy None	33 Participants
Type of prior neo/adjuvant chemotherapy Unknown	2 Participants

Adverse events

Event type	EG000 affected / at risk
deaths Total, all-cause mortality	0 / 162
other Total, other adverse events	162 / 162
serious Total, serious adverse events	96 / 162

Outcome results

Primary

2-Year Treatment Discontinuation Rate

The 2-year treatment discontinuation rate is the percentage of participants who do not complete the palbociclib treatment per protocol for reasons due to toxicity, withdrawal of consent to be treated, or other events related to tolerability in uncensored participants. Participants who discontinued palbociclib early for reasons that were not treatment-related were censored.

Time frame: Evaluate upon completion of palbociclib, up to 2 years of treatment completion.

Population: The analysis population is comprised of all uncensored participants.

Arm	Measure	Value (NUMBER)
Palbociclib With Adjuvant Endocrine Therapy	2-Year Treatment Discontinuation Rate	31 percentage of participants

Comparison: Primary objective is treatment discontinuation rate at 2 yr for patients receiving Palbociclib therapy. If the true rate of discontinuation by two years is 48% or higher, treatment duration will be considered not feasible and not worthy of further study. If the rate of discontinuation is 33.3% or less, the 2 yr duration will be deemed feasible and worthy of further study. Using a one-sided alpha = 0.025, there is \> 90% power to reject the null hypothesis in favor of feasibility.p-value: 0.0011Exact binomial test

Secondary

2-year Treatment Discontinuation Rate by Aromatase Inhibitor and Tamoxifen-based Therapy Subgroup

The 2-year treatment discontinuation rate is the percentage of participants who do not complete the palbociclib treatment per protocol for reason due to toxicity, withdrawal of consent to be treated, or other events related to tolerability of all enrolled participants.

Time frame: Evaluate upon completion of palbociclib, up to 2 years of treatment completion.