A Study to Assess the Safety, Tolerability, and Immunogenicity of RSVpreF in Adults at High Risk of Severe RSV Disease

NCT05842967 | Completed Phase 3 Results DMC FDA Drug

• 2 other identifiers: C3671023NCT05842967
• Study Type: interventional
• Target: 885
• Locations: 1 country
• Sites: 36

Brief Summary

The purpose of this study is to learn about the safety and immunogenicity of a study vaccine (called RSVpreF) in several adult groups. Respiratory Syncytial Virus (RSV) is a common type of virus (germ) that can cause severe illness, where medical help is needed. RSV can lead to airway diseases in all ages. Vaccines help your body make antibodies which help fight against diseases. This is called an immune response. This study will measure how much antibody participants make after receiving RSVpreF (immunogenicity). The study consists of 2 groups (Substudy A and Substudy B). Substudy A is seeking approximately 675 participants who are:

• Between 18 and 60 years of age.
• Considered having a high likelihood of severe RSV disease due to certain long-term medical conditions. Such medical conditions do not include immunocompromising conditions. Participants will need to come to the study clinic at least 2 times. At the first clinic visit, participants will receive 1 shot of RSVpreF or placebo in the arm by chance. A placebo looks like the study vaccine but contains no active ingredients. At each clinic visit, a blood sample will be taken. A third (final) visit can be either completed in clinic or via telephone contact. This study is about 6 months long for each participant. Substudy B is seeking approximately 200 participants who are:
• At least 18 years of age. About half of the participants will be at least 60 years of age.
• Considered having a weakened immune system (immunocompromised). Participants will need to come to the study clinic at least 3 times. All participants will receive a shot of RSVpreF at the first study clinic visit. The second study clinic visit will be 1 month later. All participants will receive a second shot of the study vaccine at this second study clinic visit. Blood samples will be taken at the 3 study clinic visits. A fourth (final) visit can be either completed in clinic or via telephone contact. This study is about 7 months long for each participant.

Conditions

RESPIRATORY SYNCYTIAL VIRUS (RSV)

Keywords

RESPIRATORY SYNCYTIAL VIRUS (RSV); ADULTS AT HIGH RISK; IMMUNOCOMPROMISED ADULTS

Outcome Measures

Primary Outcomes (17)

• SSA: Percentage of Participants With Local Reactions Within 7 Days After Vaccination

  Local reactions included pain at injection site, redness and swelling, recorded by participants in an electronic diary (e-diary). Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit =0.5 centimeter (cm). Redness and swelling were graded as mild: \>2.5 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm; severe: \>10 cm.

  Within 7 Days after Vaccination (Vaccination on Day 1)

• SSA: Percentage of Participants With Systemic Events Within 7 Days After Vaccination

  Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.

  Within 7 Days after Vaccination (Vaccination on Day 1)

• SSA: Percentage of Participants With Adverse Events (AEs) From Vaccination Through 1 Month After Vaccination

  An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included. AEs included both serious and all non-serious adverse events.

  Within 1 Month after Vaccination (Vaccination on Day 1)

• SSA: Percentage of Participants With Newly Diagnosed Chronic Medical Conditions (NDCMCs) From Vaccination Throughout the Study

  A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions.

  Within 6 Months after Vaccination (Vaccination on Day 1)

• SSA: Percentage of Participants With Serious Adverse Events (SAEs) Throughout the Study

  An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical event were included in this outcome measure.

  Within 6 Months after Vaccination (Vaccination on Day 1)

• SSA: Geometric Mean Ratio (GMR) Estimated by Ratio of the Geometric Mean Titers (GMTs) at 1 Month After Vaccination in Study C3671023 Participants Compared to Study C3671013 Adults >= 60 Years

  In this outcome measure, GMTs for RSV A and RSV B neutralizing titers (NTs) are reported. In statistical section, GMT ratio estimated by the ratio of the GMTs for RSV A and RSV B serum NTs at 1 month after vaccination with RSVpreF in current study C3671023 participants to that in study C3671013 adults \>=60 years of age, is reported. GMTs and the corresponding 2-sided CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on Student t distribution).

  At 1 Month after Vaccination (Vaccination on Day 1)

• SSA: Percentage of Participants With Seroresponse Rate and Difference in Seroresponse Rates of RSV A and RSV B Serum NTs at 1 Month After Vaccination for Participants in Study C3671023 and C3671013 Adults >= 60 Years

  Seroresponse was defined as achieving a \>=4-fold rise from baseline (before vaccination), if the baseline measurement was above the lower limit of quantitation (LLOQ). If the baseline measurement was below the LLOQ, a postvaccination assay result \>=4\* LLOQ was considered a seroresponse.

  At 1 Month after Vaccination (Vaccination on Day 1)

• SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 1

  Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit=0.5 cm. Redness and swelling were graded as mild: \> 2.0 cm to 5.0 cm; moderate: \> 5.0 cm to 10.0 cm and severe: \> 10 cm.

  Within 7 Days after Vaccination 1 (Vaccination 1 on Day 1)

• SSB: Percentage of Participants With Local Reactions Within 7 Days After Vaccination 2

  Local reactions included pain at injection site, redness and swelling, recorded by participants in an e-diary. Pain at injection site was graded as mild: did not interfere with activity; moderate: interfered with activity and severe: prevented daily activity. Redness and swelling were measured and recorded in measuring device units, where 1 measuring device unit = 0.5 cm. Redness and swelling were graded as mild: \>2.0 cm to 5.0 cm; moderate: \>5.0 cm to 10.0 cm and severe: \>10 cm.

  Within 7 Days after Vaccination 2 (Vaccination 2: 1-month post-vaccination 1 on Day 1)

• SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 1

  Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.

  Within 7 Days after Vaccination 1 (Vaccination 1 on Day 1)

• SSB: Percentage of Participants With Systemic Events Within 7 Days After Vaccination 2

  Systemic events included fever, fatigue, headache, vomiting, nausea, diarrhea, muscle pain and joint pain. These were recorded by participants in an e-diary. Fever defined as oral temperature \>=38.0 degrees Celsius (deg C) and categorized as mild: \>=38.0 to 38.4 deg C, moderate: \>38.4 to 38.9 deg C and severe: \>38.9 to 40.0 deg C. Vomiting categorized as mild: 1-2 times in 24 hours (h); moderate: \>2 times in 24h; severe: required intravenous (IV) hydration. Diarrhea categorized as mild: 2-3 loose stools in 24h; moderate: 4-5 loose stools in 24h; severe: 6 or more loose stools in 24h. Headache, fatigue, nausea, muscle pain and joint pain were categorized as mild: didn't interfere with activity; moderate: some interference with activity; severe: prevented daily routine activity.

  Within 7 Days after Vaccination 2 (Vaccination 2: 1-month post-vaccination 1 on Day 1)

• SSB: Percentage of Participants With AEs From Vaccination 1 Through 1 Month After Vaccination 2

  An AE was defined as any untoward medical occurrence in a participant temporally associated with the use of study intervention, whether or not considered related to the study intervention. Only AEs collected by non-systematic assessment (i.e. excluding local reactions and systemic events) were included. AEs included both serious and all non-serious adverse events.

  From Vaccination 1 (on Day 1) through 1 month after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 2 months]

• SSB: Percentage of Participants With NDCMCs From Vaccination Throughout the Study

  A NDCMC was defined as a disease or medical condition that was not identified prior to study start and was expected to be persistent or otherwise long-lasting in its effects. Newly diagnosed chronic medical condition did not include illnesses considered to be temporary conditions.

  From Vaccination 1 (on Day 1) through 6 months after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 7 months]

• SSB: Percentage of Participants With SAEs Throughout the Study

  An AE was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention. An SAE was defined as any untoward medical occurrence that, at any dose, met one or more of the following criteria - resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital anomaly/birth defect and was a suspected transmission via a Pfizer product of an infectious agent, pathogenic or non-pathogenic and other important medical event were included in this outcome measure.

  From Vaccination 1 (on Day 1) through 6 months after Vaccination 2 (1 month after Vaccination 1) [approximately up to maximum of 7 months]

• SSB: GMT of NT for RSV A and RSV B Before Vaccination 1

  GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5\*LLOQ. GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).

  Before Vaccination 1 (on Day 1)

• SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 1

  GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5\*LLOQ. GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).

  1 Month After Vaccination 1 (on Day 1)

• SSB: GMT of NT for RSV A and RSV B 1 Month After Vaccination 2

  GMT of RSV A and RSV B before vaccination were reported in this outcome measure. Assay results below the lower limit of quantification (LLOQ) were set to 0.5\*LLOQ. GMTs and 2-sided 95% CIs were calculated by exponentiating the mean logarithm of the titers and the corresponding CIs (based on the Student t distribution).

  1 Month After Vaccination 2 (1-month post Vaccination 1)

Secondary Outcomes (4)

• SSB: Geometric Mean Fold Rise (GMFR) of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 1

  At 1 Month After Vaccination 1 (on Day 1) to 1 Month Post-Vaccination 1

• SSB: GMFR of NTs for RSV A and RSV B From Vaccination 1 to 1 Month Post-Vaccination 2

  At 1 Month After Vaccination 1 (on Day 1) to 1 Month Post-Vaccination 2

• SSA: GMT of NTs for RSV A and RSV B Before Vaccination and 1 Month After Vaccination

  SSA: Before Vaccination (on Day 1) and 1 Month After Vaccination

• SSA: GMFR of NTs for RSV A and RSV B From Before Vaccination to 1 Month After Vaccination

  SSA: Before Vaccination (on Day 1) and 1 Month After Vaccination

Study Arms (3)

Substudy A - RSVpreF

EXPERIMENTAL

Participants will receive a single 120-µg dose of RSVpreF at Visit 1

Biological: RSVpreF

Substudy A - Placebo

PLACEBO COMPARATOR

Participants will receive placebo at Visit 1

Other: Placebo

Substudy B - RSVpreF

EXPERIMENTAL

Participants will receive 120-µg doses of RSVpreF at Visit 1 and Visit 2 (open label, single arm only)

Biological: RSVpreF

Interventions

RSVpreF BIOLOGICAL

120-µg

Substudy A - RSVpreF; Substudy B - RSVpreF

Placebo OTHER

Placebo

Substudy A - Placebo

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Capable of giving signed informed consent as described per protocol.
• Participants ≥18 to \<60 years of age at study enrollment.
• Life expectancy ≥12 months (365 days) in the opinion of the investigator at enrollment.
• Participants who are willing and able to comply with all scheduled visits, vaccination plan, lifestyle considerations, and other study procedures.
• Participants who are considered at high risk of RSV disease by virtue of the following:
• Adults with chronic pulmonary (including asthma), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus).
• Chronic medical conditions for this substudy are defined as:
• \- Duration greater than 6 months.
• Stable disease not requiring a significant change in therapy in the previous 6 weeks or hospitalization for worsening disease within 12 weeks before receipt of study intervention.
• Requires regular medical follow-up or ongoing medication or hospitalization in the previous year.
• Additional groups at high risk include:
• Residents of nursing homes and other long-term care facilities.

You may not qualify if:

• Bleeding diathesis or condition associated with prolonged bleeding that would, in the opinion of the investigator, contraindicate intramuscular injection.
• History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (eg, anaphylaxis) to any component of the study intervention(s) or any related vaccine.
• Participants who do not have adequate deltoid muscle mass to allow intramuscular vaccination, in the opinion of the investigator.
• Serious chronic disorder, including metastatic malignancy, end-stage renal disease with or without dialysis, clinically unstable cardiac disease, or any other disorder that, in the investigator's opinion, excludes the participant from participating in the study.
• Immunocompromised individuals with known or suspected immunodeficiency, as determined by history and/or laboratory/physical examination.
• Other medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality that may increase the risk of study participation or, in the investigator's judgment, make the participant inappropriate for the study.
• Note: Specific criteria for participants with known stable infection with HIV can be found in protocol.
• Individuals who receive chronic systemic treatment with immunosuppressive therapy, including cytotoxic agents, immunosuppressive monoclonal antibodies, systemic corticosteroids\*, eg, for cancer or an autoimmune disease, or radiotherapy, from 60 days before study intervention administration or planned receipt throughout the study.
• \*Applies to systemic corticosteroids administered for ≥14 days at a dose of ≥20 mg/day of prednisone or equivalent (eg, for cancer or an autoimmune disease). Systemic corticosteroids administered at a dose of \<20 mg/day of prednisone or equivalent are permitted. Inhaled/nebulized, intra-articular, intrabursal, or topical (skin, eyes, or ears) corticosteroids are permitted.
• Receipt of blood/plasma products or immunoglobulin within 60 days before study intervention administration or planned receipt of these medications prior to the final blood draw.
• Previous vaccination with any licensed or investigational RSV vaccine or planned receipt during study participation.
• Participation in other studies involving an investigational product within 28 days prior to consent and/or through and including the 6-month follow-up visit.
• Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members.
• Capable of giving signed informed consent as described per protocol.
• Participants ≥18 years of age at study enrollment.

Sponsors & Collaborators

• Pfizer: lead

Study Sites (36)

North Alabama Research Center

Athens, Alabama, 35611, United States

Location

Central Research Associates

Birmingham, Alabama, 35205, United States

Location

Medical Affiliated Research Center

Huntsville, Alabama, 35801, United States

Location

Hope Research Institute

Phoenix, Arizona, 85018, United States

Location

The Pain Center of Arizona

Phoenix, Arizona, 85018, United States

Location

Hope Research Institute

Tempe, Arizona, 85284, United States

Location

Orange County Research Center

Lake Forest, California, 92630, United States

Location

Kaiser Permanente

Los Angeles, California, 90027, United States

Location

Diablo Clinical Research, Inc.

Walnut Creek, California, 94598, United States

Location

New England Research Associates, LLC

Bridgeport, Connecticut, 06606, United States

Location

GW Medical Faculty Associates

Washington D.C., District of Columbia, 20037, United States

Location

GW Vaccine Research Unit

Washington D.C., District of Columbia, 20037, United States

Location

Alliance for Multispecialty Research, LLC

Coral Gables, Florida, 33134, United States

Location

Proactive Clinical Research,LLC

Fort Lauderdale, Florida, 33308, United States

Location

Clinical Neuroscience Solutions - Orlando - South Delaney Avenue

Orlando, Florida, 32806, United States

Location

University of Iowa

Iowa City, Iowa, 52242, United States

Location

Alliance for Multispecialty Research, LLC

Wichita, Kansas, 67207, United States

Location

Institute of Human Virology (IHV)

Baltimore, Maryland, 21201, United States

Location

Jadestone Clinical Research

Silver Spring, Maryland, 20904, United States

Location

Bio-Kinetic Clinical Applications, LLC dba QPS-MO

Springfield, Missouri, 65802, United States

Location

Bio-Kinetic Clinical Applications LLC dba QPS-MO (Patient Screening Only)

Springfield, Missouri, 65807, United States

Location

Bozeman Health Deaconess Hospital

Bozeman, Montana, 59715, United States

Location

University of Nebraska Medical Center

Omaha, Nebraska, 68105, United States

Location

University Of Nebraska Medical Center

Omaha, Nebraska, 68198, United States

Location

NYU Langone Health

New York, New York, 10016, United States

Location

Columbia University Irving Medical Center

New York, New York, 10032, United States

Location

Rochester Clinical Research, LLC

Rochester, New York, 14609, United States

Location

Accellacare - Wilmington

Wilmington, North Carolina, 28401, United States

Location

University Hospitals Cleveland Medical Center

Cleveland, Ohio, 44106, United States

Location

Alliance for Multispecialty Research, LLC

Knoxville, Tennessee, 37909, United States

Location

Orion Clinical Research

Austin, Texas, 78759, United States

Location

AIM Trials, LLC

Plano, Texas, 75093, United States

Location

Epic Medical Research

Red Oak, Texas, 75154, United States

Location

Clinical Trials of Texas, LLC

San Antonio, Texas, 78229, United States

Location

Charlottesville Medical Research

Charlottesville, Virginia, 22911, United States

Location

Alliance for Multispecialty Research, LLC

Norfolk, Virginia, 23502, United States

Location

Related Publications (2)

• Almeida NC, Parameswaran L, DeHaan EN, Wyper H, Rahman F, Jiang Q, Li W, Patton M, Lino MM, Majid-Mahomed Z, Malkin E, Davis M, Towner WJ, Saharia K, Ilangovan K, Kalinina E, Cooper D, Swanson KA, Anderson AS, Gurtman A, Munjal I. Immunogenicity and Safety of the Bivalent Respiratory Syncytial Virus Prefusion F Subunit Vaccine in Immunocompromised or Renally Impaired Adults. Vaccines (Basel). 2025 Mar 19;13(3):328. doi: 10.3390/vaccines13030328.

  PMID: 40266222 DERIVED

• Davis M, Towner W, DeHaan E, Jiang Q, Li W, Rahman F, Patton M, Wyper H, Lino MM, Sarwar UN, Majid-Mahomed Z, Mehta S, Howitt W, Cannon K, Kalinina E, Cooper D, Swanson KA, Anderson AS, Gurtman A, Munjal I; MONeT Study Team. Bivalent RSVpreF Vaccine in Adults 18 to <60 Years Old With High-Risk Conditions. Clin Infect Dis. 2025 Apr 30;80(4):911-920. doi: 10.1093/cid/ciae550.

  PMID: 39523547 DERIVED

Related Links

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

Results Point of Contact

• Title: Pfizer ClinicalTrials.gov Call Center
• Organization: Pfizer Inc

ClinicalTrials.gov_Inquires@pfizer.com

1-800-718-1021

Study Officials

• Pfizer CT.gov Call Center

  Pfizer

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restriction Type: OTHER
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Masking Details: Substudy A is double blind therefore all parties (participant, site staff and sponsor) will be blinded to study intervention. Substudy B is open-label therefore no blinding requirements are in place since all participants will receive RSVpreF.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Substudy A: Phase 3, multicenter, randomized, double-blinded, placebo-controlled study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in adults 18 to \<60 years of age considered to be at high risk of RSV disease due to certain chronic medical conditions. Approximately 675 participants ≥18 to \<60 years of age considered at high risk of RSV disease due to certain chronic medical conditions, excluding immunocompromising conditions, will be randomized to receive a single 120-µg dose of RSVpreF or placebo in a 2:1 ratio. Substudy B: Phase 3, single-arm, open-label, multicenter study that will assess the safety, tolerability, and immunogenicity of Pfizer's RSVpreF in immunocompromised adults. Approximately 200 immunocompromised adults ≥18 years of age will receive 2 120-µg doses of RSVpreF with an interval of 1 month. Approximately 100 participants will be ≥60 years of age and approximately 100 participants will be ≥18 to 60 years of age.

Study Record Dates

• First Submitted: April 24, 2023
• First Posted: May 6, 2023
• Study Start: May 11, 2023
• Primary Completion: March 18, 2024
• Study Completion: March 18, 2024
• Last Updated: August 8, 2025
• Results First Posted: August 8, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will share

Locations

US (36)