Breast CancerPhase 2NCT05226871
Study for Participants Continuing From Pfizer-sponsored Palbociclib (a Study Medicine) Studies
A Phase 2 study testing Palbociclib, Cetuximab and Fulvestrant in people with Breast Cancer and Head and Neck Cancer, run by Pfizer at 23 sites in 7 countries.
Trial summary
The purpose of this clinical trial is to provide study medicine(s) and learn about their safety. This study is seeking participants who: Have benefited from ongoing study treatment as determined by the study doctor in a Pfizer-sponsored palbociclib Parent Study Must agree to follow the reproductive criteria Are… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Breast Cancer, Head and Neck Cancer
- What is being tested?
- Palbociclib, Cetuximab and Fulvestrant
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 35 participants
- Where
- 23 sitesin 7 countries
- Study dates
- 7 Jul 2022to 31 Dec 2029
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Any participant who is receiving study treatment and deriving clinical benefit as determined by the investigator in a Pfizer-sponsored palbociclib Parent Study
- Participants must agree to follow the reproductive criteria
- Participants who are willing and able to comply with all scheduled visits, treatment plans, and other study procedures
- Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent document and protocol
Who cannot join
- Any medical reason that, in the opinion of the investigator or sponsor, precludes the participant from inclusion in the study
Trial locations and contacts
23 sites in 7 countries.
23 sites in 7 countries
China11 sites
Beijing Cancer Hospital
Beijing, Beijing Municipality, 100142
Cancer Hospital Chinese Academy of Medical Science
Beijing, 100021
The First Hospital of Jilin University
Changchun, Jilin, 130021
Sun Yat-sen Memorial Hospital of Sun Yat-sen University
Guangzhou, Guangdong, 510000
Harbin Medical University Cancer Hospital
Harbin, Heilongjiang, 150081
The First Affiliated Hospital of Anhui Medical University
Hefei, Anhui, 230022
Ruijin Hospital, Shanghai Jiao Tong University School of Medicine
Shanghai, Shanghai Municipality, 200025
Liaoning Cancer Hospital and Institute
Shenyang, Liaoning, 110042
The First Hospital of China Medical University
Shenyang, Liaoning, 110167
Hubei Cancer Hospital
Wuhan, Hubei, 430079
Henan Cancer Hospital
Zhengzhou, Henan, 450003
South Korea3 sites
National Cancer Center
Goyang-si, Gyeonggi-do, 10408
Samsung Medical Center
Seoul, Seoul-teukbyeolsi [seoul], 06351
Seoul National University Hospital
Seoul, 03080
Ukraine3 sites
Regional Municipal Non-profit Enterprise "Bukovinian Clinical Oncology Center"
Chernivtsi, Chernivetska Oblast, 58013
Municipal Non-profit Enterprise "City Clinical Hospital #4" of Dnipro City Council
Dnipro, 49102
Municipal non-profit enterprise Regional Clinical Hospital of Ivano-Frankivsk Regional Council
Ivano-Frankivsk, 76000
Taiwan2 sites
National Cheng Kung University Hospital
Tainan, 704302
Mackay Memorial Hospital
Taipei, 10449
Thailand2 sites
Department of Medicine, Faculty of Medicine Siriraj Hospital
Bangkok, 10700
Faculty of Medicine, Ramathibodi Hospital, Mahidol University
Ratchathewi, Bangkok, 10400
United States1 site
UCSF Helen Diller Comprehensive Cancer Center at Mission Bay
San Francisco, California, 94158
Mexico1 site
Hospital Universitario "Dr. Jose Eleuterio Gonzalez"
Monterrey, Nuevo León, 64460
About this study
Official title: A TREATMENT PROTOCOL FOR PARTICIPANTS CONTINUING FROM PFIZER-SPONSORED PALBOCICLIB CLINICAL STUDIES
The purpose of this clinical trial is to provide study medicine(s) and learn about their safety. This study is seeking participants who:
- Have benefited from ongoing study treatment as determined by the study doctor in a Pfizer-sponsored palbociclib Parent Study
- Must agree to follow the reproductive criteria
- Are willing and able to comply with all scheduled visits, treatment plans, and other study procedures
- Can give signed informed consent documents
Participants in this study will continue to receive treatment as they were in the parent study. The time by which participants will take part in this study is retrospective (after completed parent study). We will examine the experiences of people receiving the study medicine(s). This will help us determine if the study medicine(s) are safe. During this time, the participants will be monitored for the safety of the study medicine(s).
Read the detailed description
This is an open-label study to provide continued access to treatment for eligible participants who continue to derive clinical benefit as determined by the investigator from study intervention(s) in a Pfizer-sponsored palbociclib clinical study (Parent Study)
- Conditions
- Breast Cancer, Head and Neck Cancer
- Being tested
- Palbociclib, Cetuximab, Fulvestrant, Letrozole
- Keywords
- Hormone Receptor Positive Advanced Breast Cancer, Squamous Cell Carcinoma of the Head and Neck
- Medical subject headings
- Breast Neoplasms, Head and Neck Neoplasms, Squamous Cell Carcinoma of Head and Neck
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PalbociclibDrug
Also called IBRANCE
oral
CetuximabDrug
Intravenous (IV) infusion
FulvestrantDrug
Intramuscular (IM)
LetrozoleDrug
oral
| Study group | Role | What they receive |
|---|---|---|
| Arm 2 | Experimental | Palbociclib plus Cetuximab Receives: Drug: Palbociclib; Drug: Cetuximab |
| Arm 3 | Other | Palbociclib plus Fulvestrant Receives: Drug: Palbociclib; Drug: Fulvestrant |
| Arm 1 | Other | Cetuximab Receives: Drug: Cetuximab |
| Arm 4 | Other | Palbociclib plus Letrozole Receives: Drug: Palbociclib; Drug: Letrozole |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number/Percentage of Participants with Treatment-Emergent Adverse Events (AEs) Leading to Permanent Discontinuation of Study Treatment and Serious Adverse Events (SAEs)
An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study drug and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.
Measured: Baseline up to 28 days after last dose of study intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Feb 2022
- Study start7 Jul 2022
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 35 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05226871
- Sponsor's protocol ID
- A5481173
- Other IDs
- 2021-005735-22
- Status last verified
- Sep 2026
- First submitted
- 26 Jan 2022
- Last updated
- 9 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A TREATMENT PROTOCOL FOR PARTICIPANTS CONTINUING FROM PFIZER-SPONSORED PALBOCICLIB CLINICAL STUDIES
- ClinicalTrials.gov ID
- NCT05226871
- Acronym / sponsor ID
- A5481173
- Conditions
- Breast Cancer, Head and Neck Cancer
- Keywords
- Hormone Receptor Positive Advanced Breast Cancer, Squamous Cell Carcinoma of the Head and Neck
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 35 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 7 Jul 2022 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 7 Feb 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this clinical trial is to provide study medicine(s) and learn about their safety. This study is seeking participants who:
- Have benefited from ongoing study treatment as determined by the study doctor in a Pfizer-sponsored palbociclib Parent Study
- Must agree to follow the reproductive criteria
- Are willing and able to comply with all scheduled visits, treatment plans, and other study procedures
- Can give signed informed consent documents
Participants in this study will continue to receive treatment as they were in the parent study. The time by which participants will take part in this study is retrospective (after completed parent study). We will examine the experiences of people receiving the study medicine(s). This will help us determine if the study medicine(s) are safe. During this time, the participants will be monitored for the safety of the study medicine(s).
Detailed description
This is an open-label study to provide continued access to treatment for eligible participants who continue to derive clinical benefit as determined by the investigator from study intervention(s) in a Pfizer-sponsored palbociclib clinical study (Parent Study)
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Arm 2 | Experimental | Drug: Palbociclib, Drug: CetuximabPalbociclib plus Cetuximab |
| Arm 3 | Other | Drug: Palbociclib, Drug: FulvestrantPalbociclib plus Fulvestrant |
| Arm 1 | Other | Drug: CetuximabCetuximab |
| Arm 4 | Other | Drug: Palbociclib, Drug: LetrozolePalbociclib plus Letrozole |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Any participant who is receiving study treatment and deriving clinical benefit as determined by the investigator in a Pfizer-sponsored palbociclib Parent Study
- Participants must agree to follow the reproductive criteria
- Participants who are willing and able to comply with all scheduled visits, treatment plans, and other study procedures
- Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent document and protocol
Key exclusion criteria (1 listed)
- Any medical reason that, in the opinion of the investigator or sponsor, precludes the participant from inclusion in the study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PalbociclibAlso: IBRANCEoral | Drug | Arm 2, Arm 3, Arm 4 |
| CetuximabIntravenous (IV) infusion | Drug | Arm 1, Arm 2 |
| FulvestrantIntramuscular (IM) | Drug | Arm 3 |
| Letrozoleoral | Drug | Arm 4 |
Primary outcome
Number/Percentage of Participants with Treatment-Emergent Adverse Events (AEs) Leading to Permanent Discontinuation of Study Treatment and Serious Adverse Events (SAEs)
Time frame: Baseline up to 28 days after last dose of study intervention
An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study drug and up to 28 days after last dose that were absent before treatment or that worsened relative to pretreatment state.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Pfizer CT.gov Call Center study director
Pfizer
23 sites in 7 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Palbociclib, Cetuximab and Fulvestrant in people with Breast Cancer and Head and Neck Cancer, run by Pfizer at 23 sites in 7 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 9 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 23 sites in China, South Korea, Ukraine, Taiwan, Thailand and 2 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number/Percentage of Participants with Treatment-Emergent Adverse Events (AEs) Leading to Permanent Discontinuation of Study Treatment and Serious Adverse Events (SAEs) (time frame: Baseline up to 28 days after last dose of study intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Sep 2026; AzTrials last refreshed its copy on 28 Oct 2026.