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TerminatedNCT06137729Updated Nov 25, 2025

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

A Phase 1 interventional study of PF-07899895 and Placebo in Healthy, sponsored by Pfizer. Terminated at 1 site in Belgium. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-25.

Sponsored by Pfizer · Phase 1, Interventional, and Basic science

Why this study was terminated
Study was terminated early . This decision was not due to any safety concerns associated with PF-07899895 but rather due to a business decision.
Phase
Phase 1
Study type
Interventional
Enrollment
37
Allocation
Randomized
Ages
18 Years to 65 Years
Sex
All
01

Study summary

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.
02

Conditions studied

  • Healthy
03

In context

Lead sponsor

Pfizer is the lead sponsor of 3,244 studies on the registry; 139 are open to participants now.

Of its 582 completed or terminated interventional studies of FDA-regulated products, 381 (65%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

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

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.
05

Study design

Phase
Phase 1
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
37 participants (actual)

Study arms

  • Experimental
    PF-07899895

    Participants will receive single or multiple ascending oral doses of PF-07899895.

    Drug: PF-07899895

  • Placebo comparator
    Placebo

    Participants will receive matching placebo.

    Drug: Placebo

Interventions

  • DrugPF-07899895

    Participants will receive oral ascending doses.

  • DrugPlacebo

    Participants will receive matching placebo.

06

What researchers measure

Primary outcomes

  1. AE observed after single or multiple doses

    number of participants experience AE or SAEs.

    Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)

  2. Laboratory abnormalities following single or multiple ascending doses

    number of participants with laboratory abnormalities

    Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)

  3. Vital sign changes following single or multiple ascending doses

    Number of participants with change from baseline in vital signs

    Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)

  4. ECG changes following single or multiple ascending doses

    Number of participants with change from baseline in electrocardiogram (ECG) parameters

    Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)

  5. Changes in physical examination after single or multiple ascending doses

    Number of participants with change from baseline in physical examinations (PE)

    Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)

Secondary outcomes

  1. Area under the concentration-time curve from time 0 to the time of the last quantifiable concentration (AUClast)

    descriptive summary of AUClast by treatment

    Time frame: Day 1 up to Day 3 (Part A)

  2. Dose normalized AUClast divided by dose (AUClast(dn))

    descriptive summary of AUClast by treatment

    Time frame: Day 1 up to Day 3 (Part A)

  3. Maximum Observed Plasma Concentration (Cmax)

    descriptive summary of Cmax by treatment

    Time frame: Day 1 (Part A)/Day 1 and Day 10 (Part B)

  4. Dose normalized Cmax divided by dose (Cmax(dn))

    descriptive summary of Cmax,dn by treatment

    Time frame: Day 1 (Part A)/Day 1 and Day 10 (Part B)

  5. Time to Reach Maximum Observed Plasma Concentration (Tmax)

    descriptive summary of Tmax by treatment

    Time frame: Day 1 (Part A)/Day 1 and Day 10 (Part B)

  6. Area under the concentration time-profile from time 0 extrapolated to infinity (AUCinf)

    descriptive summary of AUCinf by treatment

    Time frame: Day 1 up to Day 3 (Part A)

  7. Dose normalized AUCinf divided by dose (AUCinf(dn))

    descriptive summary of AUCinf,dn by treatment

    Time frame: Day 1 up to Day 3 (Part A)

  8. 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

    Time frame: Day 1 up to Day 3 (Part A)/Day 10 up to Day 12 (Part B)

  9. Apparent clearance (CL/F)

    descriptive summary of CL/F by treatment

    Time frame: Day 1 up to Day 3 (Part A)/Day 10 up to Day 12 (Part B)

  10. Apparent volume of distribution after oral dose is influenced by the fraction absorbed (Vz/F)

    descriptive summary of Vz/F

    Time frame: Day 1 up to Day 3 (Part A)/Day 10 up to Day 12 (Part B)

  11. Area under the concentration-time curve from time 0 to time tau, where tau=24 hrs (AUCtau)

    descriptive summary of AUCtau

    Time frame: Day 1 and Day 12 (Part B)

  12. Dose normalized AUCtau divided by dose (AUCtau(dn))

    descriptive summary of AUCtau,dn

    Time frame: Day 1 and Day 12 (Part B)

  13. Observed accumulation ratio for Rac for AUC

    descriptive summary of observed Rac for AUC

    Time frame: Day 1 and Day 12 (Part B)

  14. Observed accumulation ratio for Cmax (Rac,Cmax)

    descriptive summary of Rac,Cmax

    Time frame: Day 1 and Day 12 (Part B)

07

Study locations

1 site
  • Pfizer Clinical Research Unit - Brussels
    Brussels, Bruxelles-capitale, Région de B-1070, Belgium
08

References and documents

Individual participant data

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.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Nov 25, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06137729
Lead sponsor
Pfizer
Responsible party
Sponsor
First posted
Nov 18, 2023
Start date
Nov 17, 2023
Primary completion
Oct 24, 2025
Completion
Oct 24, 2025
Last update
Nov 25, 2025

Study contacts

Pfizer CT.gov Call Center
study director · Pfizer

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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