A Study to Learn How the Study Medicine Called Atirmociclib is Handled by the Body in People With Normal Liver Function and Different Levels of Liver Disease

A PHASE 1, NON-RANDOMIZED, OPEN-LABEL, SINGLE-DOSE, PARALLEL GROUP STUDY TO COMPARE THE PHARMACOKINETICS OF ATIRMOCICLIB IN ADULT PARTICIPANTS WITH VARYING DEGREES OF HEPATIC IMPAIRMENT RELATIVE TO PARTICIPANTS WITH NORMAL HEPATIC FUNCTION

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:

• Aged 18 years or older
• Have a BMI of 17.5 to 40 kg/m2, and body weight more than 50 kg.
• Have normal liver function or have stable mild, moderate, or severe liver disease

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Hepatic Impairment; Healthy Adults; Healthy, Hepatic Insufficiency
• Intervention / Treatment: Drug: Atirmociclib

• Study Type: Interventional
• Enrollment (Estimated): 28
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Pfizer CT.gov Call Center; Phone Number: 1-800-718-1021; Email: ClinicalTrials.gov_Inquiries@pfizer.com

Study Locations

• United States
  • Florida
    • Miami Lakes, Florida, United States, 33016
      • Floridian Clinical Research
    • Orlando, Florida, United States, 32809
      • Orlando Clinical Research Center
    • Tampa, Florida, United States, 33603
      • Genesis Clinical Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion criteria including but not limited to:

• BMI of 17.5-40 kg/m2; and a total body weight >50 kg (110 lb).
• Willing and able to comply with all scheduled visits, treatment plan, laboratory tests, lifestyle considerations, and other study procedures.
• Capable of giving signed informed consent.

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 Child-Pugh Class A, B, or C . Stable hepatic impairment is 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.

Exclusion criteria including but not limited to:

• Any condition or history of surgery 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, 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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group 1: Normal Hepatic Function; Atirmociclib administered as a single oral dose	Drug: Atirmociclib; atirmociclib administered as a single oral dose; Other Names: PF-07220060
Experimental: Group 2: Mild Hepatic Impairment; Atirmociclib administered as a single oral dose	Drug: Atirmociclib; atirmociclib administered as a single oral dose; Other Names: PF-07220060
Experimental: Group 3: Moderate Hepatic Impairment; Atirmociclib administered as a single oral dose	Drug: Atirmociclib; atirmociclib administered as a single oral dose; Other Names: PF-07220060
Experimental: Group 4: Severe Hepatic Impairment; Atirmociclib administered as a single oral dose	Drug: Atirmociclib; atirmociclib administered as a single oral dose; Other Names: PF-07220060

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	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	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 - ∞).	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 - ∞).	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

Secondary Outcome Measures

Outcome Measure	Time Frame
Number of Participants With Treatment-Emergent Adverse Events	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	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	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	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	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	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	Predose and at 4, 192 hours after a single oral dose of atirmociclib

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Estimated): July 9, 2026
• Primary Completion (Estimated): August 14, 2027
• Study Completion (Estimated): September 10, 2027

Study Registration Dates

• First Submitted: June 24, 2026
• First Submitted That Met QC Criteria: June 24, 2026
• First Posted (Actual): June 30, 2026

Study Record Updates

• Last Update Posted (Actual): June 30, 2026
• Last Update Submitted That Met QC Criteria: June 24, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System Diseases; Liver Diseases; Hepatic Insufficiency
• Other Study ID Numbers: C4391014

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No