A Study to Learn How the Study Medicine PF-07899895 Are Tolerated and Act in the Body of Healthy Adults

A Phase 1, Randomized, Double-Blind, Sponsor-Open, Placebo-Controlled Study to Assess Safety, Tolerability, and Pharmacokinetics of Single and Multiple Ascending Oral Doses of PF-07899895 Administered as Immediate and Modified Release Formulations in Healthy Adult Participants

The purposes of the study are as follows:

• To understand how safe and tolerable are different amounts of study medicine (PF-07899895).
• To measure the amount of PF-07899895 in blood after the medicine is taken by mouth.

The study is seeking participants who:

• Are male or female of 18 to 65 years of age.
• Are in good health condition.
• Have not had viral infections (HIV, HBV, or HCV). HIV, human immunodeficiency virus. - HBV, human hepatitis B virus. HCV, human hepatitis C virus.
• Have tested negative for tuberculosis.

Participants will receive either PF-07899895 or placebo (dummy pill) by chance. In the first part of the study (Part A):

• each participant will receive a total of up to 5 doses of the medicine or placebo with at least 5 days between each dose.
• after each dose, participants will stay in study clinic for 3 to5 days.

In the second part of the study (Part B):

- each participant will need to take 10 days of dosing and will stay in the study clinic for clinical checks for 13 days.

In the third part of the study (Part C):

• In SD cohort, each participant will receive a total of up to 5 doses of the medicine or placebo with at least 7 days between each dose. After each dose, participants will stay in study clinic for 5 days.
• In MD cohorts, each participant will need to take 10 days of dosing and will stay in the study clinic for clinical checks for 13 days.

The planned duration of participation from screening to follow-up in:

• Part A of the study is up to 15 to 18 weeks.
• Part B of the study is up to 11 weeks.
• Part C of the study is up to 15 to 18 weeks. Participants will also have their blood collected by the study doctors for several times.

Study Overview

• Status: Terminated
• Conditions: Healthy
• Intervention / Treatment: Drug: Placebo; Drug: PF-07899895

• Study Type: Interventional
• Enrollment (Actual): 37
• Phase: Phase 1

Contacts and Locations

Study Locations

• Belgium
  • Bruxelles-capitale, Région de
    • Brussels, Bruxelles-capitale, Région de, Belgium, B-1070
      • Pfizer Clinical Research Unit - Brussels

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Participants, male or female, must be 18 to 65 years of age, inclusive, at the time of signing the ICD.
• BMI of 16 to 32 kg/m2; and a total body weight>50 kg (110 lb).
• Male and female participants who are overtly healthy as determined by medical evaluation including medical history, physical examination, vital signs assessments, oral temperature, 12-lead ECGs, and laboratory tests.

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease.
• Any condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy, bowel resection) or gastrointestinal (GI) transit time (eg, constipation).
• History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C; positive testing for HIV, hepatitis B surface antibody (HBsAb), hepatitis B core antibody (HBcAb), hepatitis B surface antigen (HBsAg), or hepatitis C antibody (HCVAb); positive or indeterminate QuantiFERON test for tuberculosis. Hepatitis B vaccination is allowed.
• Any medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality or other conditions that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• History of undesired reactions to the sun (photosensitivity).
• Recent exposure to live or attenuated vaccines within 28 days of the screening visit.
• Use of prescription or nonprescription drugs and dietary and herbal supplements within 7 days or 5 half-lives (whichever is longer) prior to the first dose of study intervention, with the exception of moderate or strong cytochrome P450 3A (CYP3A) inducers or inhibitors which are prohibited within 14 days plus 5 half-lives prior to the first dose of study intervention.
• Previous administration with an investigational product (drug or vaccine) within 30 days (or as determined by the local requirement) or 5 half-lives preceding the first dose of PF-07899895 used in this study (whichever is longer). Participation in studies of other investigational products (drug or vaccine) at any time during their participation in this study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Participants will receive matching placebo.	Drug: Placebo; Participants will receive matching placebo.
Experimental: PF-07899895; Participants will receive single or multiple ascending oral doses of PF-07899895.	Drug: PF-07899895; Participants will receive oral ascending doses.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AE observed after single or multiple doses	number of participants experience AE or SAEs.	Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
Laboratory abnormalities following single or multiple ascending doses	number of participants with laboratory abnormalities	Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
Vital sign changes following single or multiple ascending doses	Number of participants with change from baseline in vital signs	Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
ECG changes following single or multiple ascending doses	Number of participants with change from baseline in electrocardiogram (ECG) parameters	Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
Changes in physical examination after single or multiple ascending doses	Number of participants with change from baseline in physical examinations (PE)	Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area under the concentration-time curve from time 0 to the time of the last quantifiable concentration (AUClast)	descriptive summary of AUClast by treatment	Day 1 up to Day 3 (Part A)
Dose normalized AUClast divided by dose (AUClast(dn))	descriptive summary of AUClast by treatment	Day 1 up to Day 3 (Part A)
Maximum Observed Plasma Concentration (Cmax)	descriptive summary of Cmax by treatment	Day 1 (Part A)/Day 1 and Day 10 (Part B)
Dose normalized Cmax divided by dose (Cmax(dn))	descriptive summary of Cmax,dn by treatment	Day 1 (Part A)/Day 1 and Day 10 (Part B)
Time to Reach Maximum Observed Plasma Concentration (Tmax)	descriptive summary of Tmax by treatment	Day 1 (Part A)/Day 1 and Day 10 (Part B)
Area under the concentration time-profile from time 0 extrapolated to infinity (AUCinf)	descriptive summary of AUCinf by treatment	Day 1 up to Day 3 (Part A)
Dose normalized AUCinf divided by dose (AUCinf(dn))	descriptive summary of AUCinf,dn by treatment	Day 1 up to Day 3 (Part A)
Plasma elimination half-life is the time measured for the plasma concentration to decrease by one half (t½)	descriptive summary of t1/2 by treatment	Day 1 up to Day 3 (Part A)/Day 10 up to Day 12 (Part B)
Apparent clearance (CL/F)	descriptive summary of CL/F by treatment	Day 1 up to Day 3 (Part A)/Day 10 up to Day 12 (Part B)
Apparent volume of distribution after oral dose is influenced by the fraction absorbed (Vz/F)	descriptive summary of Vz/F	Day 1 up to Day 3 (Part A)/Day 10 up to Day 12 (Part B)
Area under the concentration-time curve from time 0 to time tau, where tau=24 hrs (AUCtau)	descriptive summary of AUCtau	Day 1 and Day 12 (Part B)
Dose normalized AUCtau divided by dose (AUCtau(dn))	descriptive summary of AUCtau,dn	Day 1 and Day 12 (Part B)
Observed accumulation ratio for Rac for AUC	descriptive summary of observed Rac for AUC	Day 1 and Day 12 (Part B)
Observed accumulation ratio for Cmax (Rac,Cmax)	descriptive summary of Rac,Cmax	Day 1 and Day 12 (Part B)

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 (Actual): November 17, 2023
• Primary Completion (Actual): October 24, 2025
• Study Completion (Actual): October 24, 2025

Study Registration Dates

• First Submitted: November 14, 2023
• First Submitted That Met QC Criteria: November 14, 2023
• First Posted (Actual): November 18, 2023

Study Record Updates

• Last Update Posted (Actual): November 25, 2025
• Last Update Submitted That Met QC Criteria: November 20, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: C5471001; 2023-507354-32-00 (Registry Identifier: CTIS (EU))

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