HealthyPhase 1NCT07231978
A Study to Learn How Different Forms of the Study Medicine Called Prazosin Are Taken up Into the Blood in Healthy Adults
A Phase 1 study testing Prazosin HCl in people with Healthy, run by Pfizer at 1 site in Belgium.
Trial summary
Prazosin hydrochloride (HCl) is a medicine taken by mouth that helps lower high blood pressure. It's used to treat hypertension, as well as heart failure. The purpose of this clinical trial is to prove that the prazosin HCl capsules made at the manufacturing site at Barceloneta (Puerto Rico) work the same in the body… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Prazosin HCl
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 69 participants
- Where
- 1 siteBelgium
- Study dates
- 14 Nov 2025to 30 Apr 2026
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Male and female participants, 18 years of age or older and who are overtly healthy as determined by medical evaluation
- Willing to comply with all study procedures
- BMI of 16-32 kg/m2; and a total body weight >50 kg (110 lb)
- Capable of giving signed informed consent
Who cannot join
- Evidence or history of clinically significant disease
- Evidence of any active suicidal ideation in the past year or suicidal behavior in the past 5 years
- Use of drugs within 14 days or 5 half-lives (whichever is longer) prior to study intervention
- Previous administration of an investigational product (drug or vaccine) within 30 days or 5 half-lives preceding the first dose of study intervention
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 2 COHORT, SINGLE DOSE, OPEN-LABEL, RANDOMIZED, PIVOTAL BIOEQUIVALENCE STUDY TO QUALIFY MANUFACTURING SITE TRANSFER FROM BARCELONETA TO ASCOLI FOR PRAZOSIN HYDROCHLORIDE CAPSULES IN HEALTHY ADULT PARTICIPANTS UNDER FASTED CONDITIONS
Prazosin hydrochloride (HCl) is a medicine taken by mouth that helps lower high blood pressure. It's used to treat hypertension, as well as heart failure. The purpose of this clinical trial is to prove that the prazosin HCl capsules made at the manufacturing site at Barceloneta (Puerto Rico) work the same in the body, as those made at Ascoli (Italy). This will be done by understanding how the different capsules and doses of prazosin HCL are changed and eliminated from your body after you take them. The study will also check how safe these capsules are and how well people can handle them.
This study is seeking participants ≥ 18 years old, who are healthy and have a total body weight >50 kg (110 lb). Before starting, participants will be interviewed and examined by skilled personnel to make sure they qualify. This will happen up to 28 days before the first dose of the study drug. Those who are eligible will check into the clinical research unit (CRU) the day before first dose of the study drug and stay there until 24 hours after their last dose [for approximately 9 days and 8 nights for cohort (group) 1 and 5 days and 4 nights for cohort (group) 2].
Read more
While in CRU each participant will receive by mouth either 4 capsules (cohort 1) or 2 capsules (cohort 2) of prazosin HCL at different time points. The capsules will be taken with a glass of water after overnight fasting. No food is allowed until 4 hours after taking the dose. Water is allowed freely except for 1 hour before dosing and can be consumed again 1 hour after dosing. Blood samples will be taken from participants right before they take the medicine and again after they have taken it. Electrocardiogram and blood pressure will be closely monitored.
We will compare the experiences of people receiving capsules manufactured at Barceloneta to those manufactured at Ascoli. This will help us determine if capsules from Barceloneta and Ascoli are safe and effective.
After completing all tests, participants will leave the CRU. Then, about 28 to 35 days after their final dose, they'll receive a follow-up phone call to check on their health.
The total duration of participation from the initial ("screening") visit to discharge from the CRU will be approximately 5 weeks and from the initial visit to follow up phone call will be approximately 10 weeks.
- Conditions
- Healthy
- Being tested
- Prazosin HCl
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Prazosin HClDrug
Also called CP-012299
Administered Orally; available in capsule form
| Study group | Role | What they receive |
|---|---|---|
| Cohort 1 | Experimental | Participants will receive a single dose of Prazosin HCl in 4 treatments. Receives: Drug: Prazosin HCl |
| Cohort 2 | Experimental | Participants will receive a single dose of Prazosin HCl in 2 treatments. Receives: Drug: Prazosin HCl |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pharmacokinetics: Area under the plasma concentration (AUC) of prazosin
Measured: Predose, upto 5 weeks
PK: Maximum plasma concentration (Cmax) of prazosin
Measured: Predose, upto 5 weeks
Secondary outcomes (5)
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Measured: Through study completion, approximately 10 weeks
Number of Participants With Clinical Laboratory Abnormalities
Measured: Through study completion, approximately 10 weeks
Number of participants with change from baseline in physical examinations
Measured: Through study completion, approximately 10 weeks
Number of Participants With Clinically Significant Changes From Baseline in 12-Lead Electrocardiogram (ECG) Parameters
Measured: Through study completion, approximately 10 weeks
Number of Participants With Abnormalities in Vital Signs
Measured: Through study completion, approximately 10 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Nov 2025
- Study start14 Nov 2025
- Primary completion3 Apr 2026
- Study completion30 Apr 2026
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
- Crossover
- Masking
- None (open label)
- Enrolment
- 69 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
- NCT07231978
- Sponsor's protocol ID
- A0281007
- Status last verified
- May 2026
- First submitted
- 13 Nov 2025
- Last updated
- 14 May 2026
- 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 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A 2 COHORT, SINGLE DOSE, OPEN-LABEL, RANDOMIZED, PIVOTAL BIOEQUIVALENCE STUDY TO QUALIFY MANUFACTURING SITE TRANSFER FROM BARCELONETA TO ASCOLI FOR PRAZOSIN HYDROCHLORIDE CAPSULES IN HEALTHY ADULT PARTICIPANTS UNDER FASTED CONDITIONS
- ClinicalTrials.gov ID
- NCT07231978
- Acronym / sponsor ID
- A0281007
- Conditions
- Healthy
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 69 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 14 Nov 2025 (actual)
- Primary completion
- 3 Apr 2026 (actual)
- Study completion
- 30 Apr 2026 (actual)
- First posted
- 17 Nov 2025 (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.
Prazosin hydrochloride (HCl) is a medicine taken by mouth that helps lower high blood pressure. It's used to treat hypertension, as well as heart failure. The purpose of this clinical trial is to prove that the prazosin HCl capsules made at the manufacturing site at Barceloneta (Puerto Rico) work the same in the body, as those made at Ascoli (Italy). This will be done by understanding how the different capsules and doses of prazosin HCL are changed and eliminated from your body after you take them. The study will also check how safe these capsules are and how well people can handle them.
This study is seeking participants ≥ 18 years old, who are healthy and have a total body weight >50 kg (110 lb). Before starting, participants will be interviewed and examined by skilled personnel to make sure they qualify. This will happen up to 28 days before the first dose of the study drug. Those who are eligible will check into the clinical research unit (CRU) the day before first dose of the study drug and stay there until 24 hours after their last dose [for approximately 9 days and 8 nights for cohort (group) 1 and 5 days and 4 nights for cohort (group) 2].
While in CRU each participant will receive by mouth either 4 capsules (cohort 1) or 2 capsules (cohort 2) of prazosin HCL at different time points. The capsules will be taken with a glass of water after overnight fasting. No food is allowed until 4 hours after taking the dose. Water is allowed freely except for 1 hour before dosing and can be consumed again 1 hour after dosing. Blood samples will be taken from participants right before they take the medicine and again after they have taken it. Electrocardiogram and blood pressure will be closely monitored.
We will compare the experiences of people receiving capsules manufactured at Barceloneta to those manufactured at Ascoli. This will help us determine if capsules from Barceloneta and Ascoli are safe and effective.
After completing all tests, participants will leave the CRU. Then, about 28 to 35 days after their final dose, they'll receive a follow-up phone call to check on their health.
The total duration of participation from the initial ("screening") visit to discharge from the CRU will be approximately 5 weeks and from the initial visit to follow up phone call will be approximately 10 weeks.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Cohort 1 | Experimental | Drug: Prazosin HClParticipants will receive a single dose of Prazosin HCl in 4 treatments. |
| Cohort 2 | Experimental | Drug: Prazosin HClParticipants will receive a single dose of Prazosin HCl in 2 treatments. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Male and female participants, 18 years of age or older and who are overtly healthy as determined by medical evaluation
- Willing to comply with all study procedures
- BMI of 16-32 kg/m2; and a total body weight >50 kg (110 lb)
- Capable of giving signed informed consent
Key exclusion criteria (4 listed)
- Evidence or history of clinically significant disease
- Evidence of any active suicidal ideation in the past year or suicidal behavior in the past 5 years
- Use of drugs within 14 days or 5 half-lives (whichever is longer) prior to study intervention
- Previous administration of an investigational product (drug or vaccine) within 30 days or 5 half-lives preceding the first dose of study intervention
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 |
|---|---|---|
| Prazosin HClAlso: CP-012299Administered Orally; available in capsule form | Drug | Cohort 1, Cohort 2 |
Primary outcome
Pharmacokinetics: Area under the plasma concentration (AUC) of prazosin
Time frame: Predose, upto 5 weeks
PK: Maximum plasma concentration (Cmax) of prazosin
Time frame: Predose, upto 5 weeks
5 secondary outcomes
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Time frame: Through study completion, approximately 10 weeks
Number of Participants With Clinical Laboratory Abnormalities
Time frame: Through study completion, approximately 10 weeks
Number of participants with change from baseline in physical examinations
Time frame: Through study completion, approximately 10 weeks
Number of Participants With Clinically Significant Changes From Baseline in 12-Lead Electrocardiogram (ECG) Parameters
Time frame: Through study completion, approximately 10 weeks
Number of Participants With Abnormalities in Vital Signs
Time frame: Through study completion, approximately 10 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 14 May 2026.
- 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 Prazosin HCl 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 4 inclusion and 4 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: finished, as of the sponsor's last update on 14 May 2026. 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. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Pharmacokinetics: Area under the plasma concentration (AUC) of prazosin (time frame: Predose, upto 5 weeks). The study lists 2 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 14 May 2026.