HealthyPhase 1NCT06137729
A Study to Learn How the Study Medicine PF-07899895 Are Tolerated and Act in the Body of Healthy Adults
A Phase 1 study testing PF-07899895 in people with Healthy, run by Pfizer at 1 site in Belgium.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- PF-07899895
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 37 participants
- Where
- 1 siteBelgium
- Study dates
- 17 Nov 2023to 24 Oct 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
Belgium1 site
Pfizer Clinical Research Unit - Brussels
Brussels, Bruxelles-capitale, Région de, B-1070
About this study
Official title: 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.
Read more
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.
- Conditions
- Healthy
- Being tested
- PF-07899895, Placebo
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PF-07899895Drug
Participants will receive oral ascending doses.
PlaceboDrug
Participants will receive matching placebo.
| Study group | Role | What they receive |
|---|---|---|
| PF-07899895 | Experimental | Participants will receive single or multiple ascending oral doses of PF-07899895. Receives: Drug: PF-07899895 |
| Placebo | Placebo comparator | Participants will receive matching placebo. Receives: Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
AE observed after single or multiple doses
number of participants experience AE or SAEs.
Measured: 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
Measured: 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
Measured: 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
Measured: 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)
Measured: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
Secondary outcomes (14)
Area under the concentration-time curve from time 0 to the time of the last quantifiable concentration (AUClast)
descriptive summary of AUClast by treatment
Measured: Day 1 up to Day 3 (Part A)
Dose normalized AUClast divided by dose (AUClast(dn))
descriptive summary of AUClast by treatment
Measured: Day 1 up to Day 3 (Part A)
Maximum Observed Plasma Concentration (Cmax)
descriptive summary of Cmax by treatment
Measured: 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
Measured: 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
Measured: 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
Measured: Day 1 up to Day 3 (Part A)
Dose normalized AUCinf divided by dose (AUCinf(dn))
descriptive summary of AUCinf,dn by treatment
Measured: 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
Measured: 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
Measured: 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
Measured: 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
Measured: Day 1 and Day 12 (Part B)
Dose normalized AUCtau divided by dose (AUCtau(dn))
descriptive summary of AUCtau,dn
Measured: Day 1 and Day 12 (Part B)
Observed accumulation ratio for Rac for AUC
descriptive summary of observed Rac for AUC
Measured: Day 1 and Day 12 (Part B)
Observed accumulation ratio for Cmax (Rac,Cmax)
descriptive summary of Rac,Cmax
Measured: Day 1 and Day 12 (Part B)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Nov 2023
- Study start17 Nov 2023
- Primary completion24 Oct 2025
- Study completion24 Oct 2025
Why it stopped: Study was terminated early . This decision was not due to any safety concerns associated with PF-07899895 but rather due to a business decision.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HealthyStudies 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 37 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06137729
- Sponsor's protocol ID
- C5471001
- Other IDs
- 2023-507354-32-00, 2023
- Status last verified
- Nov 2025
- First submitted
- 14 Nov 2023
- Last updated
- 25 Nov 2025
- 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 25 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT06137729
- Acronym / sponsor ID
- C5471001
- Conditions
- Healthy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Study was terminated early . This decision was not due to any safety concerns associated with PF-07899895 but rather due to a business decision.
- Enrolment
- 37 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 17 Nov 2023 (actual)
- Primary completion
- 24 Oct 2025 (actual)
- Study completion
- 24 Oct 2025 (actual)
- First posted
- 18 Nov 2023 (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 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 design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| PF-07899895 | Experimental | Drug: PF-07899895Participants will receive single or multiple ascending oral doses of PF-07899895. |
| Placebo | Placebo comparator | Drug: PlaceboParticipants will receive matching placebo. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 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.
Key exclusion criteria (8 listed)
- 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).
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 |
|---|---|---|
| PF-07899895Participants will receive oral ascending doses. | Drug | PF-07899895 |
| PlaceboParticipants will receive matching placebo. | Drug | Placebo |
Primary outcome
AE observed after single or multiple doses
Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
number of participants experience AE or SAEs.
Laboratory abnormalities following single or multiple ascending doses
Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
number of participants with laboratory abnormalities
Vital sign changes following single or multiple ascending doses
Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
Number of participants with change from baseline in vital signs
ECG changes following single or multiple ascending doses
Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
Number of participants with change from baseline in electrocardiogram (ECG) parameters
Changes in physical examination after single or multiple ascending doses
Time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)
Number of participants with change from baseline in physical examinations (PE)
14 secondary outcomes
Area under the concentration-time curve from time 0 to the time of the last quantifiable concentration (AUClast)
Time frame: Day 1 up to Day 3 (Part A)
Dose normalized AUClast divided by dose (AUClast(dn))
Time frame: Day 1 up to Day 3 (Part A)
Maximum Observed Plasma Concentration (Cmax)
Time frame: Day 1 (Part A)/Day 1 and Day 10 (Part B)
Dose normalized Cmax divided by dose (Cmax(dn))
Time frame: Day 1 (Part A)/Day 1 and Day 10 (Part B)
Time to Reach Maximum Observed Plasma Concentration (Tmax)
Time frame: Day 1 (Part A)/Day 1 and Day 10 (Part B)
Area under the concentration time-profile from time 0 extrapolated to infinity (AUCinf)
Time frame: Day 1 up to Day 3 (Part A)
Dose normalized AUCinf divided by dose (AUCinf(dn))
Time frame: 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)
Time frame: Day 1 up to Day 3 (Part A)/Day 10 up to Day 12 (Part B)
Apparent clearance (CL/F)
Time frame: 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)
Time frame: 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)
Time frame: Day 1 and Day 12 (Part B)
Dose normalized AUCtau divided by dose (AUCtau(dn))
Time frame: Day 1 and Day 12 (Part B)
Observed accumulation ratio for Rac for AUC
Time frame: Day 1 and Day 12 (Part B)
Observed accumulation ratio for Cmax (Rac,Cmax)
Time frame: Day 1 and Day 12 (Part B)
Results and safety
The study was stopped early (reason given: Study was terminated early . This decision was not due to any safety concerns associated with PF-07899895 but rather due to a business decision.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Nov 2025.
- 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. This study is not recruiting at the moment.
Pfizer CT.gov Call Center study director
Pfizer
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing PF-07899895 in people with Healthy, run by Pfizer at 1 site in Belgium.
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 3 inclusion and 8 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: stopped early, as of the sponsor's last update on 25 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. 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. Some participants in this study may receive a placebo. 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?
The study was stopped early (reason given: Study was terminated early . This decision was not due to any safety concerns associated with PF-07899895 but rather due to a business decision.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
AE observed after single or multiple doses (time frame: Day 1 up to Day 28 (Part A)/Day 1 up to Day 38 (Part B)). The study lists 5 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 25 Nov 2025.