A Study to Learn Safety and Immune Response to Study Vaccine -RSVpreF in Adults at High Risk of Severe RSV Disease.

NCT07543380 | Not Yet Recruiting Phase 3 FDA Drug

• 1 other identifier: C3671060
• Study Type: interventional
• Target: 130
• Locations: 1 country
• Sites: 5

Brief 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. 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.

Conditions

Respiratory Syncytial Virus (RSV)

Keywords

RESPIRATORY SYNCYTIAL VIRUS (RSV); ADULTS AT HIGH RISK

Outcome Measures

Primary Outcomes (5)

• Percentage of participants reporting prompted local reactions within 7 days following investigational product administration

  Describe prompted local reactions following investigational product administration

  Day 7

• Percentage of participants reporting prompted systemic events within 7 days following investigational product administration

  Describe prompted systemic events following investigational product administration

  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

  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

  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

  1 month after vaccination

Secondary Outcomes (3)

• GMT of NTs for RSV A and RSV B

  1 month after vaccination

• Geometric mean fold rise (GMFR) of NTs for RSV A and RSV B

  1 month after vaccination

• Seroresponse rate of NTs for RSV A and RSV B

  1 month after vaccination

Study Arms (1)

RSVpreF

EXPERIMENTAL

RSV Vaccine

Biological: RSVpreF

Interventions

RSVpreF BIOLOGICAL

RSV Vaccine

RSVpreF

Eligibility Criteria

• Age: 18 Years - 59 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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.

Sponsors & Collaborators

• Pfizer: lead

Study Sites (5)

Tsuchiura Beryl Clinic

Tsuchiura, Ibaraki, 300-0062, Japan

Location

Nihonbashi Sakura Clinic

Chuo-ku, Tokyo, 103-0025, Japan

Location

Tokyo-Eki Center-building Clinic

Chuo-ku, Tokyo, 103-0027, Japan

Location

Fukuwa Clinic

Chuo-ku, Tokyo, 104-0031, Japan

Location

Tenjin Sogo Clinic

Fukuoka, 810-0021, Japan

Location

Related Links

• To obtain contact information for a study center near you, click here.

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Central Study Contacts

Pfizer CT.gov Call Center

CONTACT

1-800-718-1021; ClinicalTrials.gov_Inquiries@pfizer.com

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: NA
• Masking: NONE
• Masking Details: This is an open label study. Participant, investigators and other site staff, and sponsor staff will be unblinded to the participant's assigned study intervention.
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: This is a single-arm, open-label study.

Study Record Dates

• First Submitted: April 15, 2026
• First Posted: April 21, 2026
• Study Start (Estimated): May 11, 2026
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): August 31, 2026
• Last Updated: April 21, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share

Locations

JP (5)