Healthy ParticipantsPhase 1NCT07231991
A Study to Learn How the Body Processes the Study Medicine Called Vepdegestrant in People With Loss of Liver Function
A Phase 1 study testing vepdegestrant in people with Healthy Participants, run by Pfizer at 4 sites in United States.
Trial summary
The purpose of the study is to look at how the body processes a study medicine called vepdegestrant in participants with loss of liver function relative to people with normal liver function. Read more about this study
- Who is it for?
- Ages 18 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Participants
- What is being tested?
- vepdegestrant
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 24 participants
- Where
- 4 sitesUnited States
- Study dates
- 18 Nov 2025to 23 Dec 2026
- Phase
- Phase 1
- 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 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Female participants of non-childbearing potential, or male participants between the age of 18 years (or the minimum age of consent in accordance with local regulations) and 70 years, inclusive, at screening.
- Body mass index of 17.5-38 kg/m2, inclusive, and a total body weight >50 kg (110 lb).
- Normal hepatic function group only:
- -Overtly healthy as determined by medical evaluations including medical history, physical examination, laboratory tests, vital signs and standard 12-lead ECGs.
- Hepatic impairment groups only:
- Satisfy the criteria for Class B (Group 2: moderate hepatic impairment) or C (Group 3: severe hepatic impairment) of the modified Child-Pugh Classification.
- Stable hepatic impairment, defined as no clinically significant change in disease status within the last 28 days prior to the screening visit, as documented by the participant's recent medical history.
Who cannot join
- Any condition possibly affecting drug absorption.
- Use of prohibited prior or concomitant medications.
- Normal hepatic function group only:
- -Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing).
- Hepatic impairment groups only:
- -A diagnosis of hepatic dysfunction secondary to any acute ongoing hepatocellular process that is documented by medical history, PE, liver biopsy, hepatic ultrasound, CT scan, or MRI.
Trial locations and contacts
4 sites in 1 country. Contact the study team or a site near you to ask about taking part.
United States4 sites, 4 recruiting
- Recruiting
Clinical Pharmacology of Miami
Miami, Florida, 33172
- Recruiting
Floridian Clinical Research, LLC
Miami Lakes, Florida, 33016
- Recruiting
Orlando Clinical Research Center
Orlando, Florida, 32809
- Recruiting
Genesis Clinical Research, LLC
Tampa, Florida, 33603
About this study
Official title: A PHASE 1, NON-RANDOMIZED, OPEN-LABEL, SINGLE-DOSE, PARALLEL GROUP STUDY TO COMPARE THE PHARMACOKINETICS OF VEPDEGESTRANT (PF-07850327) IN ADULT PARTICIPANTS WITH MODERATE AND SEVERE HEPATIC IMPAIRMENT RELATIVE TO HEALTHY PARTICIPANTS WITH NORMAL HEPATIC FUNCTION
The purpose of the study is to look at how the body processes a study medicine called vepdegestrant in participants with loss of liver function relative to people with normal liver function.
This study is seeking participants who are:
Read more
- females who cannot have children or males
- between 18 and 70 years of age
- weigh more than 50 Kilograms (110 pounds)
- either healthy with normal liver function or have loss of liver function
All participants in this study will take one dose of vepdegestrant by mouth. This study looks at how the medicine is changed and removed from the body after being taken by the participants. The amount of vepdegestrant in participants with loss of liver function will be compared to the amount of vepdegestrant in participants with normal liver function.
All participants will stay at the study clinic for about 11 days and 10 nights.
- Conditions
- Healthy Participants
- Being tested
- vepdegestrant
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
vepdegestrantDrug
Also called ARV-471, PF-07850327
Vepdegestrant administered as a single oral 200 mg dose
| Study group | Role | What they receive |
|---|---|---|
| Group 1 | Experimental | participants with normal hepatic function Receives: Drug: vepdegestrant |
| Group 2 | Experimental | participants with moderate hepatic impairment Receives: Drug: vepdegestrant |
| Group 3 | Experimental | participants with severe hepatic impairment Receives: Drug: vepdegestrant |
What is being measured
The primary outcome is the main question the study is designed to answer.
Maximum observed concentration (Cmax) for vepdegestrant
Measured: Pre-dose, and 1, 2, 4, 6, 8, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 192, and 216 hours post dose
Area under the curve from time zero to extrapolated infinite time [AUC (0 - ∞)] for vepdegestrant
AUC (0 - ∞)= Area under the plasma concentration versus time curve (AUC) from time zero (pre-dose) to extrapolated infinite time (0 - ∞). It is obtained from AUC (0 - t) plus AUC (t - ∞).
Measured: Pre-dose, and 1, 2, 4, 6, 8, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 192, and 216 hours post dose
Secondary outcomes (4)
Number of Participants With Treatment-Emergent Adverse Events
Measured: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
Number of Participants With Clinically Significant Clinical Laboratory Abnormalities
Measured: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Measured: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
Number of Participants With Clinically Significant Electrocardiogram (ECG) Abnormalities
Measured: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Nov 2025
- Study start18 Nov 2025
- Primary completion4 Dec 2026 (estimated)
- Study completion23 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy ParticipantsStudies 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 1
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 24 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Arvinas Estrogen Receptor, Inc.
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07231991
- Sponsor's protocol ID
- C4891004
- Status last verified
- Mar 2026
- First submitted
- 13 Nov 2025
- Last updated
- 3 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: 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 3 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A PHASE 1, NON-RANDOMIZED, OPEN-LABEL, SINGLE-DOSE, PARALLEL GROUP STUDY TO COMPARE THE PHARMACOKINETICS OF VEPDEGESTRANT (PF-07850327) IN ADULT PARTICIPANTS WITH MODERATE AND SEVERE HEPATIC IMPAIRMENT RELATIVE TO HEALTHY PARTICIPANTS WITH NORMAL HEPATIC FUNCTION
- ClinicalTrials.gov ID
- NCT07231991
- Acronym / sponsor ID
- C4891004
- Conditions
- Healthy Participants
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 24 participants (estimated)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Collaborators
- Arvinas Estrogen Receptor, Inc.
- Study start
- 18 Nov 2025 (actual)
- Primary completion
- 4 Dec 2026 (estimated)
- Study completion
- 23 Dec 2026 (estimated)
- First posted
- 17 Nov 2025 (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 the study is to look at how the body processes a study medicine called vepdegestrant in participants with loss of liver function relative to people with normal liver function.
This study is seeking participants who are:
- females who cannot have children or males
- between 18 and 70 years of age
- weigh more than 50 Kilograms (110 pounds)
- either healthy with normal liver function or have loss of liver function
All participants in this study will take one dose of vepdegestrant by mouth. This study looks at how the medicine is changed and removed from the body after being taken by the participants. The amount of vepdegestrant in participants with loss of liver function will be compared to the amount of vepdegestrant in participants with normal liver function.
All participants will stay at the study clinic for about 11 days and 10 nights.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Group 1 | Experimental | Drug: vepdegestrantparticipants with normal hepatic function |
| Group 2 | Experimental | Drug: vepdegestrantparticipants with moderate hepatic impairment |
| Group 3 | Experimental | Drug: vepdegestrantparticipants with severe hepatic impairment |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Female participants of non-childbearing potential, or male participants between the age of 18 years (or the minimum age of consent in accordance with local regulations) and 70 years, inclusive, at screening.
- Body mass index of 17.5-38 kg/m2, inclusive, and a total body weight >50 kg (110 lb).
- -Overtly healthy as determined by medical evaluations including medical history, physical examination, laboratory tests, vital signs and standard 12-lead ECGs.
- Satisfy the criteria for Class B (Group 2: moderate hepatic impairment) or C (Group 3: severe hepatic impairment) of the modified Child-Pugh Classification.
- Stable hepatic impairment, defined as no clinically significant change in disease status within the last 28 days prior to the screening visit, as documented by the participant's recent medical history.
Key exclusion criteria (6 listed)
- Any condition possibly affecting drug absorption.
- Use of prohibited prior or concomitant medications.
- -Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing).
- -A diagnosis of hepatic dysfunction secondary to any acute ongoing hepatocellular process that is documented by medical history, PE, liver biopsy, hepatic ultrasound, CT scan, or MRI.
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 |
|---|---|---|
| vepdegestrantAlso: ARV-471, PF-07850327Vepdegestrant administered as a single oral 200 mg dose | Drug | Group 1, Group 2, Group 3 |
Primary outcome
Maximum observed concentration (Cmax) for vepdegestrant
Time frame: Pre-dose, and 1, 2, 4, 6, 8, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 192, and 216 hours post dose
Area under the curve from time zero to extrapolated infinite time [AUC (0 - ∞)] for vepdegestrant
Time frame: Pre-dose, and 1, 2, 4, 6, 8, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 192, and 216 hours post dose
AUC (0 - ∞)= Area under the plasma concentration versus time curve (AUC) from time zero (pre-dose) to extrapolated infinite time (0 - ∞). It is obtained from AUC (0 - t) plus AUC (t - ∞).
4 secondary outcomes
Number of Participants With Treatment-Emergent Adverse Events
Time frame: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
Number of Participants With Clinically Significant Clinical Laboratory Abnormalities
Time frame: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
Number of Participants With Clinically Significant Electrocardiogram (ECG) Abnormalities
Time frame: Time from baseline through and including follow-up contact occurring 28 to 35 calendar days after the last administration of the study intervention.
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 3 Apr 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. 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.
Pfizer CT.gov Call Center study director
Pfizer
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing vepdegestrant in people with Healthy Participants, run by Pfizer at 4 sites in United States.
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 7 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 3 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in United States. 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 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
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?
Contact Pfizer CT.gov Call Center (1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Maximum observed concentration (Cmax) for vepdegestrant (time frame: Pre-dose, and 1, 2, 4, 6, 8, 12, 24, 36, 48, 60, 72, 96, 120, 144, 168, 192, and 216 hours post dose). The study lists 2 primary outcomes in all. 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 3 Apr 2026.