A Phase 1 interventional study of Atirmociclib in Hepatic Impairment, Healthy, Hepatic Insufficiency and Healthy Adults, sponsored by Pfizer. Recruiting at 3 sites in United States. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Pfizer · Phase 1, Interventional, and Other
The purpose of this study to understand how the study medicine atirmociclib behaves in the body and how safe it is for people with different levels of liver health.
The study is seeking participants who are:
Participants will receive study medicine by mouth. Blood samples will be collected to see how much of the medicine is in the body over time. This will help understand whether liver disease changes how the medicine is handled.
Participants will be in the study for about 9 weeks. Those with normal liver function will stay in the clinic for about 7 days. People with liver disease will stay for about 9 days. After leaving the clinic, people may be contacted for follow-up. This may be done by phone or through a clinic visit.
113 studies on the registry are indexed under Hepatic Insufficiency; 15 are open to participants now.
This study's planned enrollment of 28 is close to the median of 29 across 100 interventional studies indexed under Hepatic Insufficiency.
Browse Hepatic Insufficiency studies →Pfizer is the lead sponsor of 3,334 studies on the registry; 149 are open to participants now.
Of its 601 completed or terminated interventional studies of FDA-regulated products, 391 (65%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
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:
- Stable hepatic impairment meeting the criteria for Class A, B, or C . Stable hepatic impairment is defined as no change in disease status within the last 28 days prior to the screening visit, as documented by the participant's recent medical history.
Exclusion criteria including but not limited to:
Normal hepatic function group only:
- Evidence or history of hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, 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 , hepatic ultrasound, CT scan, or MRI.
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Child-Pugh class
A score of how well the liver works in people with liver disease such as cirrhosis: class A is mild, B moderate and C severe.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Atirmociclib administered as a single oral dose
Drug: Atirmociclib
Atirmociclib administered as a single oral dose
Drug: Atirmociclib
Atirmociclib administered as a single oral dose
Drug: Atirmociclib
Atirmociclib administered as a single oral dose
Drug: Atirmociclib
atirmociclib administered as a single oral dose
Also known as: PF-07220060
Maximum Observed Plasma Concentration (Cmax) for atirmociclib in participants with normal hepatic function
Maximum observed plasma concentration (Cmax) for atirmociclib following a single oral dose in participants with normal hepatic function
Time frame: Pre-dose and at, 1, 2, 4, 6, 8, 12, and 24, 36, 48, 60, 72, 96, 120, 144 hours after a single oral dose
Maximum Observed Plasma Concentration (Cmax) for atirmociclib in participants with hepatic impairment
Maximum observed plasma concentration (Cmax) for atirmociclib following a single oral dose in participants with hepatic impairment
Time frame: Pre-dose and at, 1, 2, 4, 6, 8, 12, and 24, 36, 48, 60, 72, 96, 120, 144, 168, 192 hours after a single oral dose
Area under the curve from time zero to extrapolated infinite time [AUC (0 - ∞)] for atirmociclib in participants with normal hepatic function
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 - ∞).
Time frame: Pre-dose and at, 1, 2, 4, 6, 8, 12, and 24, 36, 48, 60, 72, 96, 120, 144 hours after a single oral dose
Area under the curve from time zero to extrapolated infinite time [AUC (0 - ∞)] for atirmociclib in participants with impaired hepatic function
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 - ∞).
Time frame: Pre-dose and at, 1, 2, 4, 6, 8, 12, and 24, 36, 48, 60, 72, 96, 120, 144, 168, 192 hours after a single oral dose
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 atirmociclib
Number of Participants With Normal Hepatic Function having Clinically Significant Clinical Laboratory Abnormalities
Time frame: Baseline and Day 2, Day 7 after a single oral dose of atirmociclib
Number of Participants With Impaired Hepatic Function having Clinically Significant Clinical Laboratory Abnormalities
Time frame: Baseline and Day 2, Day 9 after a single oral dose of atirmociclib
Number of Participants With Normal Hepatic Function having Clinically Significant Change From Baseline in Vital Signs
Time frame: Predose and at 4, 144 hours after a single oral dose of atirmociclib
Number of Participants With Impaired Hepatic function having Clinically Significant Change From Baseline in Vital Signs
Time frame: Predose and at 4, 192 hours after a single oral dose of atirmociclib
Number of Participants With Normal Hepatic Function having Clinically Significant Electrocardiogram (ECG) Abnormalities
Time frame: Predose and at 4, 144 hours after a single oral dose of atirmociclib
Number of Participants With Impaired Hepatic Function having Clinically Significant Electrocardiogram (ECG) Abnormalities
Time frame: Predose and at 4, 192 hours after a single oral dose of atirmociclib
Plan to share: 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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Studies of the drug tested here: Atirmociclib