Respiratory Syncytial Virus (RSV)Phase 3NCT07543380
A Study to Learn Safety and Immune Response to Study Vaccine -RSVpreF in Adults at High Risk of Severe RSV Disease.
A Phase 3 study testing RSVpreF in people with Respiratory Syncytial Virus (RSV), run by Pfizer at 5 sites in Japan.
Trial summary
The purpose of the study is to learn about the immune response after a RSVpreF vaccination. This study is being conducted in Japan. RSV is a common virus that can cause infections of the lungs and airways. Read more about this study
- Who is it for?
- Ages 18 to 59 years
- Conditions the study is for
- Respiratory Syncytial Virus (RSV)
- What is being tested?
- RSVpreF
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 130 participants
- Where
- 5 sitesJapan
- Study dates
- 11 May 2026to 25 Aug 2026
- Phase
- Phase 3
- 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 59 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Underlying health condition(s) that can put the participant at an increased risk of severe RSV/complications including chronic lung , heart, kidney, liver, nervous system, blood, or metabolic diseases
Who cannot join
- Received any kind of RSV vaccine before participating in this study
- Determined as not eligible by the investigator based on the participant's past and present health condition(s), medication(s) and treatment(s)
- Please refer to the study contact for further eligibility details.
Trial locations and contacts
5 sites in 1 country.
5 sites in 1 country
Japan5 sites
Nihonbashi Sakura Clinic
Chuo-ku, Tokyo, 103-0025
Tokyo-Eki Center-building Clinic
Chuo-ku, Tokyo, 103-0027
Fukuwa Clinic
Chuo-ku, Tokyo, 104-0031
Tenjin Sogo Clinic
Fukuoka, 810-0021
Tsuchiura Beryl Clinic
Tsuchiura, Ibaraki, 300-0062
About this study
Official title: A PHASE 3, MULTICENTER, SINGLE-ARM, OPEN-LABEL STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) PREFUSION F SUBUNIT VACCINE IN ADULTS CONSIDERED AT HIGH RISK OF SEVERE RSV DISEASE IN JAPAN
The purpose of the study is to learn about the immune response after a RSVpreF vaccination. This study is being conducted in Japan. RSV is a common virus that can cause infections of the lungs and airways.
The study is seeking participants who are:
- 18 to 59 years of age
- adults with health condition(s) that can put them at an increased risk of severe RSV disease
It will also learn about the safety of RSVpreF vaccination. The study lasts about 2 months. Adults need to visit the research site at least 2 times. The participant will receive a phone call 2 months after vaccination for health checks.
Read the detailed description
This is a Phase 3, multicenter, single-arm, open-label study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in adults 18 to 59 years of age considered to be at high risk of RSV disease due to certain chronic medical conditions in Japan.
Approximately 130 participants 18 to 59 years of age considered at high risk of RSV disease due to certain chronic medical conditions will be enrolled to receive RSVpreF.
The total duration of trial participation for each participant will be 2 months.
After screening and confirmation of eligibility, a prevaccination blood sample will be collected for immunogenicity assessments and a single dose of study intervention (RSVpreF) will be administered.
Participants will report daily reactogenicity data using an electronic device for 7-days or until resolution.
Participants will return approximately 1 month later for a follow-up blood draw for immunogenicity assessments and collection of safety information.
A telephone follow-up visit will be conducted approximately 2 months after vaccination to collect safety information.
- Conditions
- Respiratory Syncytial Virus (RSV)
- Being tested
- RSVpreF
- Keywords
- RESPIRATORY SYNCYTIAL VIRUS (RSV), ADULTS AT HIGH RISK
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
RSVpreFBiological
RSV Vaccine
| Study group | Role | What they receive |
|---|---|---|
| RSVpreF | Experimental | RSV Vaccine Receives: Biological: RSVpreF |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of participants reporting prompted local reactions within 7 days following investigational product administration
Describe prompted local reactions following investigational product administration
Measured: Day 7
Percentage of participants reporting prompted systemic events within 7 days following investigational product administration
Describe prompted systemic events following investigational product administration
Measured: Day 7
Percentage of participants reporting adverse events (AEs) through 1 month following investigational product administration
Describe AEs occurring through 1 month following administration of investigational product
Measured: 1 month after vaccination
Percentage of participants reporting serious adverse events (SAEs) throughout the study
Describe SAEs through 2 months following administration of investigational product
Measured: 2 months after vaccination
Geometric Mean Titer (GMT) ratio (GMR) , estimated by the ratio of the GMTs for RSV subgroup A (RSV A) and RSV subgroup B (RSV B) neutralizing titers (NTs) with RSVpreF in this study's participants to that in Study C3671013 Japanese older adults
Demonstrate that the immune responses to RSVpreF in this study participant are similar to those in Study C3671013 Japanese older adults
Measured: 1 month after vaccination
Secondary outcomes (3)
GMT of NTs for RSV A and RSV B
Describe the immune responses to RSVpreF with GMT of NTs for RSV A and RSV B before vaccination and at 1 month after vaccination.
Measured: 1 month after vaccination
Geometric mean fold rise (GMFR) of NTs for RSV A and RSV B
Describe the immune responses to RSVpreF with GMFR of NTs for RSV A and RSV B from before vaccination to 1 month after vaccination.
Measured: 1 month after vaccination
Seroresponse rate of NTs for RSV A and RSV B
Describe the immune responses to RSVpreF with seroresponse rate of NTs for RSV A and RSV B at 1 month after vaccination.
Seroresponse is defined as a postvaccination NT ≥4 times the lower limit of quantitation (LLOQ) if the baseline titer is below the LLOQ; or a ≥
Measured: 1 month after vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Apr 2026
- Study start11 May 2026
- Primary completion25 Aug 2026
- Study completion25 Aug 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Respiratory Syncytial Virus (RSV)Studies 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 3
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- This is a single-arm, open-label study.
- Masking
- None (open label)
- Enrolment
- 130 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
- NCT07543380
- Sponsor's protocol ID
- C3671060
- Status last verified
- Sep 2026
- First submitted
- 15 Apr 2026
- Last updated
- 24 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: 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 24 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A PHASE 3, MULTICENTER, SINGLE-ARM, OPEN-LABEL STUDY TO EVALUATE THE SAFETY, TOLERABILITY, AND IMMUNOGENICITY OF RESPIRATORY SYNCYTIAL VIRUS (RSV) PREFUSION F SUBUNIT VACCINE IN ADULTS CONSIDERED AT HIGH RISK OF SEVERE RSV DISEASE IN JAPAN
- ClinicalTrials.gov ID
- NCT07543380
- Acronym / sponsor ID
- C3671060
- Conditions
- Respiratory Syncytial Virus (RSV)
- Keywords
- RESPIRATORY SYNCYTIAL VIRUS (RSV), ADULTS AT HIGH RISK
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 130 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 11 May 2026 (actual)
- Primary completion
- 25 Aug 2026 (actual)
- Study completion
- 25 Aug 2026 (actual)
- First posted
- 21 Apr 2026 (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 purpose of the study is to learn about the immune response after a RSVpreF vaccination. This study is being conducted in Japan. RSV is a common virus that can cause infections of the lungs and airways.
The study is seeking participants who are:
- 18 to 59 years of age
- adults with health condition(s) that can put them at an increased risk of severe RSV disease
It will also learn about the safety of RSVpreF vaccination. The study lasts about 2 months. Adults need to visit the research site at least 2 times. The participant will receive a phone call 2 months after vaccination for health checks.
Detailed description
This is a Phase 3, multicenter, single-arm, open-label study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in adults 18 to 59 years of age considered to be at high risk of RSV disease due to certain chronic medical conditions in Japan.
Approximately 130 participants 18 to 59 years of age considered at high risk of RSV disease due to certain chronic medical conditions will be enrolled to receive RSVpreF.
The total duration of trial participation for each participant will be 2 months.
After screening and confirmation of eligibility, a prevaccination blood sample will be collected for immunogenicity assessments and a single dose of study intervention (RSVpreF) will be administered.
Participants will report daily reactogenicity data using an electronic device for 7-days or until resolution.
Participants will return approximately 1 month later for a follow-up blood draw for immunogenicity assessments and collection of safety information.
A telephone follow-up visit will be conducted approximately 2 months after vaccination to collect safety information.
Study design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- This is a single-arm, open-label study.
| Arm | Type | Receives |
|---|---|---|
| RSVpreF | Experimental | Biological: RSVpreFRSV Vaccine |
Who may qualify
- Ages
- 18 to 59 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Underlying health condition(s) that can put the participant at an increased risk of severe RSV/complications including chronic lung , heart, kidney, liver, nervous system, blood, or metabolic diseases
Key exclusion criteria (3 listed)
- Received any kind of RSV vaccine before participating in this study
- Determined as not eligible by the investigator based on the participant's past and present health condition(s), medication(s) and treatment(s)
- Please refer to the study contact for further eligibility details.
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 |
|---|---|---|
| RSVpreFRSV Vaccine | Biological | RSVpreF |
Primary outcome
Percentage of participants reporting prompted local reactions within 7 days following investigational product administration
Time frame: Day 7
Describe prompted local reactions following investigational product administration
Percentage of participants reporting prompted systemic events within 7 days following investigational product administration
Time frame: Day 7
Describe prompted systemic events following investigational product administration
Percentage of participants reporting adverse events (AEs) through 1 month following investigational product administration
Time frame: 1 month after vaccination
Describe AEs occurring through 1 month following administration of investigational product
Percentage of participants reporting serious adverse events (SAEs) throughout the study
Time frame: 2 months after vaccination
Describe SAEs through 2 months following administration of investigational product
Geometric Mean Titer (GMT) ratio (GMR) , estimated by the ratio of the GMTs for RSV subgroup A (RSV A) and RSV subgroup B (RSV B) neutralizing titers (NTs) with RSVpreF in this study's participants to that in Study C3671013 Japanese older adults
Time frame: 1 month after vaccination
Demonstrate that the immune responses to RSVpreF in this study participant are similar to those in Study C3671013 Japanese older adults
3 secondary outcomes
GMT of NTs for RSV A and RSV B
Time frame: 1 month after vaccination
Geometric mean fold rise (GMFR) of NTs for RSV A and RSV B
Time frame: 1 month after vaccination
Seroresponse rate of NTs for RSV A and RSV B
Time frame: 1 month after vaccination
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 24 Sep 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: Yes. 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
5 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing RSVpreF in people with Respiratory Syncytial Virus (RSV), run by Pfizer at 5 sites in Japan.
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 1 inclusion and 3 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 24 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 5 sites in Japan. 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
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?
Percentage of participants reporting prompted local reactions within 7 days following investigational product administration (time frame: Day 7). 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 24 Sep 2026.