COVID-19Phase 1NCT05972993

A Safety and Immune Response Study to Evaluate Varying Doses of an mRNA Vaccine Against Coronavirus Disease 2019 (COVID-19) in Healthy Adults

A Phase 1 study testing mRNA-CR-04 vaccine 10μg, mRNA-CR-04 vaccine 30μg and mRNA-CR-04 vaccine 100μg in people with COVID-19, run by GlaxoSmithKline at 4 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

The purpose of this study is to evaluate the safety, reactogenicity and immune responses of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA-CR-04 vaccine construct when administered in healthy adults previously vaccinated with SARS-CoV-2 mRNA vaccines. Read more about this study

Who is it for?: Ages 18 to 49 yearsHealthy volunteers can take part
Conditions the study is for: COVID-19
What is being tested?: mRNA-CR-04 vaccine 10μg, mRNA-CR-04 vaccine 30μg and mRNA-CR-04 vaccine 100μg
Type of treatment: Vaccines, Injection or infusion
Could I receive a placebo?: Yes, some participants may receive a placebo
How many people: 114 participants
Where: 4 sitesUnited States
Study dates: 7 Aug 2023to 14 Oct 2024
Phase: Phase 1
Are there results?: Yes, posted in the registrySummary in the doctors' view

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 49 years
All sexes
Healthy volunteers accepted
Adult

Who may be able to join

Written or witnessed informed consent obtained from the participant prior to performance of any study-specific procedure.
Participants, who in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the eDiary and study procedures).
Has received 2 doses of primary series and booster dose(s) of an authorized or licensed mRNA COVID-19 vaccine (only Moderna or Pfizer vaccines) with the last booster dose administered between at least 6 and 18 months or more prior to screening and has provided documentation of receiving the vaccination series (e.g., vaccination card).
Negative for SARS-CoV-2 infection by RT-PCR test at screening within 7 days prior to study vaccination.
Is a male or nonpregnant female of 18 to 49 years, inclusive, at screening.
If the participant is a woman of childbearing potential (WOCBP), the participant agrees to practice true abstinence or use at least 1 highly effective form of contraception for at least 30 days prior to study vaccination up to 1 month after study vaccination.
Agrees to refrain from blood or plasma donation from screening and up to 6 months after vaccination.
Is healthy or medically stable as determined by investigator judgment based on medical history, clinical laboratory tests, vital sign measurements, and physical examination findings.

Who cannot join

Has a new onset, clinically significant, abnormal biochemistry or hematology finding [defined as greater than or equal to (>=) Grade 1] at screening (participants with Grade 1 laboratory abnormalities that have been stable for at least 6 months before enrollment may be included in the study).
Has any medical disease or condition that, in the opinion of the investigator, precludes study participation. This includes any acute, subacute, intermittent, or chronic medical disease or condition that would place the participant at an unacceptable risk of injury, render the participant unable to meet the requirements of the protocol, or may interfere with the evaluation of responses or the participant's successful completion of the trial.
Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
History of myocarditis, pericarditis, second- and third-degree heart block or idiopathic cardiomyopathy, or presence of any medical condition that increases risk of myocarditis or pericarditis, including cocaine abuse, cardiomyopathy, endomyocardial fibrosis, hypereosinophilic syndrome, hypersensitivity myocarditis eosinophilic granulomatosis with polyangiitis, persistent myocardial viral infection (e.g., due to enterovirus or adenovirus).
Has an acute febrile illness with a temperature >=38.0 degree Celsius (°C) or >=100.4 degree Fahrenheit (°F) observed by the participant or at the study site within 72 hours prior to study vaccination. Participants with suspected COVID-19 symptoms should be excluded and referred for medical care.
Has a history of hypersensitivity or severe allergic reaction, including anaphylaxis, generalized urticaria, angioedema, and other significant reactions to any previous vaccine, or any component of the study vaccine.

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Has a body mass index greater than (>) 40 Kilograms meter per square (kg/m^2).
Has had known close contact with anyone who had a confirmed SARS-CoV-2 infection within 14 days before study vaccination.
Has a history of documented SARS-CoV-2 infection or COVID-19 within 6 months before the date of screening visit.
Has any self-reported or medically documented clinically significant medical or psychiatric condition. Significant medical conditions include, but are not limited to, the following:
Moderate or severe respiratory disease (e.g., chronic obstructive pulmonary disease, asthma).
Uncontrolled hypertension, defined as an average systolic blood pressure >= 140 millimeters of mercury (mmHg) or an average diastolic blood pressure >= 90 mmHg, based on an average of up to 3 blood pressure measurements.
Clinically significant cardiovascular disease (e.g., congestive heart failure, cardiomyopathy, ischemic heart disease).
Neurological or neurodevelopmental conditions (e.g., Down syndrome, dementia, chronic migraine not controlled by medication, epilepsy, stroke or seizures in the last 3 years, encephalopathy, focal neurologic deficits, Guillain- Barré syndrome, encephalomyelitis, or transverse myelitis).
Ongoing malignancy or recent diagnosis of malignancy in the last 5 years (excluding basal cell and squamous cell carcinoma of the skin).
Tuberculosis or non-tuberculosis mycobacterial infection.
Autoimmune disease, including hypothyroidism without a defined nonautoimmune cause.
Immunodeficiency of any cause, including from solid organ transplant, blood, or bone marrow transplant, or use of other immune-weakening medicine.
Type 1 or 2 diabetes mellitus regardless of disease control.
Has any of the following self-reported or medically documented risk factors for severe COVID-19:
Chronic kidney disease
Cerebrovascular disease
Cystic fibrosis
Chronic liver disease
Pulmonary fibrosis
Has participated or plans to participate in another investigational study involving any investigational drug or device within 60 days or 5 half-lives, whichever is longer, before study vaccination and throughout the study.
Has received a licensed or authorized non-mRNA COVID-19 vaccine (primary series or booster dose).
Has received or plans to receive any licensed vaccine within 4 weeks before or after study vaccination. Inactivated vaccines for influenza are permitted during the study if they are administered at least 14 days before or after study vaccination.
Is planning to receive an authorized or licensed COVID-19 booster vaccination for the duration of the study (for participants who are not covered by local recommendations to receive booster per current standard of care) OR is planning to receive an authorized or licensed COVID-19 booster vaccination on or before Day 31 of the study (for participants covered by local recommendations to receive booster).
Has received or plans to receive immunoglobulins or any blood or blood products within 90 days before study vaccination and throughout the study.
Reports chronic use (more than 14 continuous days) of any medication that may be associated with changes in immune function including, but not limited to, systemic corticosteroids exceeding 20 mg/day of prednisone equivalent, allergy injections, immunoglobulins, interferons, immunomodulators, cytotoxic drugs, or other similar or toxic drugs within 6 months of study vaccination. Note: The use of low-dose topical, ophthalmic, inhaled, intra-articular and intranasal steroid preparations is permitted.
Pregnant or lactating female.
Female participant planning to become pregnant or planning to discontinue contraceptive precautions within 1 month following study vaccination.
Participant is an employee or family member of the investigator or study site personnel.

Trial locations and contacts

4 sites in 1 country.

United States4 sites

GSK Investigational Site
Austin, Texas, 78705
GSK Investigational Site
Melbourne, Florida, 32934
GSK Investigational Site
Peoria, Illinois, 61614
GSK Investigational Site
San Diego, California, 92108

Other trials in United States

About this study

Official title: Exploratory, First Time in Human (FTIH), Observer-blind, Randomized, Controlled Study to Evaluate Safety, Reactogenicity and Immunogenicity of Various Doses of GlaxoSmithKline Biologicals SA's (GSK) Investigational Omicron Variant S Glycoprotein (mRNA-CR-04) Vaccine When Administered Intramuscularly in Healthy Adults 18 to 49 Years of Age

Read the detailed description

There will be dose-escalation in part A of the study with sentinel dosing strategy implemented in each of 3 dosing levels (Group 1; 2; 3). At start, enrollment in Group 1 and 2 will occur simultaneously with the enrolment of 1st participant in Group 1. Each group will consist of 8 sentinel participants, with 6 receiving the mRNA-CR-04 vaccine and 2 receiving a placebo. The safety data from the sentinel participants in both groups, up to Day 8 post-vaccination, will be reviewed by the Internal Safety Review Committee (iSRC).

If no safety signal is observed, vaccination of the non-sentinel participants in that group will continue. If there are no safety signals observed from the sentinel participants in Group 1 and Group 2, the enrollment and vaccination of the sentinel participants in Group 3 will begin.

Part B of the study will commence only after all Part A participants have completed their Day 15 study visits and the Day 15 interim analysis is completed. In Part B, 2 doses of the mRNA-CR-04 vaccine will be evaluated.

Conditions: COVID-19
Being tested: mRNA-CR-04 vaccine 10μg, mRNA-CR-04 vaccine 30μg, mRNA-CR-04 vaccine 100μg, Placebo, mRNA-CR-04 vaccine 3μg
Keywords: COVID-19, SARS-CoV-2, Master Protocol, Omicron, mRNA
Medical subject headings: COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

mRNA-CR-04 vaccine 10μgBiological
mRNA CR-04 vaccine, 10 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.
mRNA-CR-04 vaccine 30μgBiological
mRNA CR-04 vaccine, 30 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.
mRNA-CR-04 vaccine 100μgBiological
mRNA CR-04 vaccine, 100 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.
PlaceboDrug
Placebo is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.
mRNA-CR-04 vaccine 3μgBiological
mRNA CR-04 vaccine, 3 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.

Study groups in NCT05972993
Study group	Role	What they receive
Part A, Group 1: mRNA CR-04 10 µg	Experimental	Participants received mRNA 10 micrograms (µg) administered on Day 1. Receives: Biological: mRNA-CR-04 vaccine 10μg
Part A, Group 1: Placebo	Placebo comparator	Participants received placebo dose administered on Day 1. Receives: Drug: Placebo
Part A, Group 2: mRNA CR-04 30 µg	Experimental	Participants received placebo dose administered on Day 1. Receives: Biological: mRNA-CR-04 vaccine 30μg
Part A, Group 2: Placebo	Placebo comparator	Participants received placebo dose administered on Day 1. Receives: Drug: Placebo
Part A, Group 3: mRNA CR-04 100 µg	Experimental	Participants received mRNA 100 µg administered on Day 1 Receives: Biological: mRNA-CR-04 vaccine 100μg
Part A, Group 3: Placebo	Placebo comparator	Participants received placebo dose administered on Day 1. Receives: Drug: Placebo
Part B: mRNA CR-04 3 µg	Experimental	Participants received mRNA 3 µg administered on Day 1. Receives: Biological: mRNA-CR-04 vaccine 3μg
Part B: mRNA CR-04 10 µg	Experimental	Participants received mRNA 10 µg administered on Day 1. Receives: Biological: mRNA-CR-04 vaccine 10μg
Part B: Placebo	Placebo comparator	Participants received placebo dose administered on Day 1. Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

Number of Participants With Any Solicited Administration Site Events
The solicited administration site events are pain, redness, swelling and lymphadenopathy (axillary swelling/ tenderness on the same side of the body as the site of injection). Any = occurrence of the event regardless of intensity grade.
Measured: Day 1 to Day 7
Number of Participants With Any Solicited Systemic Events
The solicited systemic events are fever, headache, myalgia (muscle pain), arthralgia (joint pain), fatigue (tiredness), chills, abdominal pain, vomiting and diarrhea. Fever is defined as body temperature ≥38ºC; preferred location for measuring the temperature is oral. Any = occurrence of the event regardless of intensity grade.
Measured: Day 1 to Day 7
Number of Participants With Any Unsolicited Adverse Events (AEs)
An unsolicited AE is an AE that is either not included in the list of solicited events or can be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events. Unsolicited AEs include both serious and nonserious AEs. Any = occurrence of the event regardless of intensity grade.
Measured: Day 1 to Day 30
Number of Participants With Any Hematological and Biochemical Laboratory Abnormalities
The hematological and biochemical parameters included alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), total bilirubin, creatinine, direct bilirubin, basophils, eosinophils increase, erytrocytes, hemoglobin decrease, lymphocytes decrease, mean corpuscular hemoglobin, mean corpuscular volume, monocytes, neutrophils decrease, platelets decrease, white blood cells (WBC) increase. Below = value below the laboratory reference range defined for the specified visit and laboratory parameter; Within = value within the laboratory reference range defined for the specified visit and laboratory parameter; Above = value above the laboratory reference range defined for the specified visit and laboratory parameter.
Measured: Day 1 to Day 15
Number of Participants With Any Medically Attended Adverse Events (MAAEs)
A MAAE is an AE for which the participant received medical attention including any symptom or illness requiring hospitalization, or an emergency room visit, or visit to/by a healthcare professional. Any = occurrence of the event regardless of intensity grade.
Measured: Day 1 to Day 31
Number of Participants With Any Serious Adverse Events (SAEs)
An SAE is defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study participant, abnormal pregnancy outcome or any other situation as determined by the investigator. Any = occurrence of the event regardless of intensity grade.
Measured: Day 1 to Day 31
Number of Participants With Any Adverse Events of Special Interest (AESIs)
AESIs include potential immune-mediated diseases (pIMDs) which are autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology, myocarditis, and pericarditis, virologically confirmed COVID-19 cases, anaphylaxis, or severe hypersensitivity within 24 hours after study investigational product administration. Any = occurrence of the event regardless of intensity grade.
Measured: Day 1 to Day 31

Secondary outcomes (6)

Number of Participants With Any MAAEs
A MAAE is an AE for which the participant received medical attention including any symptom or illness requiring hospitalization, or an emergency room visit, or visit to/by a healthcare professional. Any = occurrence of the event regardless of intensity grade.
Measured: Throughout the study period (Day 1 to Month 6)
Number of Participants With Any SAEs
An SAE is defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study participant, abnormal pregnancy outcome or any other situation as determined by the investigator. Any = occurrence of the event regardless of intensity grade.
Measured: Throughout the study period (Day 1 to Month 6)
Number of Participants With Any AESIs
AESIs include potential immune-mediated diseases (pIMDs) which are autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology, myocarditis, and pericarditis, virologically confirmed COVID-19 cases, anaphylaxis, or severe hypersensitivity within 24 hours after study investigational product administration. Any = occurrence of the event regardless of intensity grade.
Measured: Throughout the study period (Day 1 to Month 6)
Geometric Mean Titers (GMT) of Neutralizing Titers Against Pseudovirus Bearing S Protein From Vaccine Encoded SARS-CoV-2 and Wild Type (WT) Strains
The analyzed neutralizing titers were SARS-CoV-2 Neutralizing Titer BA.5 and SARS-CoV-2 Neutralizing Titer D614G. D= Day; M= Month.
Measured: At Days 1, 15 and 31, and at Month 6
Geometric Mean Ratio (GMR) of Neutralizing Titers Against Pseudovirus Bearing S Protein From Vaccine Encoded SARS-CoV-2 and WT Strains
The analyzed neutralizing titers were SARS-CoV-2 Neutralizing Titer BA.5 and SARS-CoV-2 Neutralizing Titer D614G. D= Day; M= Month.
Measured: At Days 15 and 31, and at Month 6 (compared with baseline [Day 1])
Number of Participants With Vaccine Response Rate (VRR) Based on Neutralizing Titers Against Vaccine Encoded SARS-CoV-2 and WT Strains
VRR is expressed as the number of participants with a vaccine response, defined as at least a 4-fold greater neutralizing titer as compared to the titer at Day 1. D= Day; M= Month.
Measured: At Days 15 and 31, and at Month 6 (compared with baseline [Day 1])

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

7 Aug 202314 Oct 2024

First posted2 Aug 2023
Study start7 Aug 2023
Primary completion9 May 2024
Study completion14 Oct 2024

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for COVID-19Studies of the same condition, open and under way.
More trials run by GlaxoSmithKlineThe 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: Prevention
Allocation: Randomised
Intervention model: Sequential
Model description: Dose escalation with sentinel dosing.
Masking: Triple blind
Who is masked: Participant, Care provider, Investigator
Enrolment: 114 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT05972993
Sponsor's protocol ID: 219112
Status last verified: May 2025
First submitted: 1 Aug 2023
Last updated: 28 May 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: Yes: GSK will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer tohttps://www.gsk-studyregister.com/About\_GSK\_Patient\_Level\_Data\_Sharing\_Final\_13July2023.pdf.

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 28 May 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Exploratory, First Time in Human (FTIH), Observer-blind, Randomized, Controlled Study to Evaluate Safety, Reactogenicity and Immunogenicity of Various Doses of GlaxoSmithKline Biologicals SA's (GSK) Investigational Omicron Variant S Glycoprotein (mRNA-CR-04) Vaccine When Administered Intramuscularly in Healthy Adults 18 to 49 Years of Age
ClinicalTrials.gov ID: NCT05972993
Acronym / sponsor ID: 219112
Conditions: COVID-19
Keywords: COVID-19, SARS-CoV-2, Master Protocol, Omicron, mRNA
Phase: Phase 1
Study type: Interventional
Recruitment status: Completed
Enrolment: 114 participants (actual)
Lead sponsor: GlaxoSmithKlineIndustry (pharma, biotech, devices)
Study start: 7 Aug 2023 (actual)
Primary completion: 9 May 2024 (actual)
Study completion: 14 Oct 2024 (actual)
First posted: 2 Aug 2023 (actual)
Results: Posted 28 May 2025

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Prevention
Allocation: Randomised
Intervention model: Sequential
Masking: Triple blind (participant, care provider, investigator)
Number of arms: 9
Model description: Dose escalation with sentinel dosing.

Arm	Type	Receives
Part A, Group 1: mRNA CR-04 10 µg	Experimental	Biological: mRNA-CR-04 vaccine 10μgParticipants received mRNA 10 micrograms (µg) administered on Day 1.
Part A, Group 1: Placebo	Placebo comparator	Drug: PlaceboParticipants received placebo dose administered on Day 1.
Part A, Group 2: mRNA CR-04 30 µg	Experimental	Biological: mRNA-CR-04 vaccine 30μgParticipants received placebo dose administered on Day 1.
Part A, Group 2: Placebo	Placebo comparator	Drug: PlaceboParticipants received placebo dose administered on Day 1.
Part A, Group 3: mRNA CR-04 100 µg	Experimental	Biological: mRNA-CR-04 vaccine 100μgParticipants received mRNA 100 µg administered on Day 1
Part A, Group 3: Placebo	Placebo comparator	Drug: PlaceboParticipants received placebo dose administered on Day 1.
Part B: mRNA CR-04 3 µg	Experimental	Biological: mRNA-CR-04 vaccine 3μgParticipants received mRNA 3 µg administered on Day 1.
Part B: mRNA CR-04 10 µg	Experimental	Biological: mRNA-CR-04 vaccine 10μgParticipants received mRNA 10 µg administered on Day 1.
Part B: Placebo	Placebo comparator	Drug: PlaceboParticipants received placebo dose administered on Day 1.

Who may qualify

Ages: 18 to 49 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult

Key inclusion criteria (8 listed)

Written or witnessed informed consent obtained from the participant prior to performance of any study-specific procedure.
Participants, who in the opinion of the investigator, can and will comply with the requirements of the protocol (e.g., completion of the eDiary and study procedures).
Has received 2 doses of primary series and booster dose(s) of an authorized or licensed mRNA COVID-19 vaccine (only Moderna or Pfizer vaccines) with the last booster dose administered between at least 6 and 18 months or more prior to screening and has provided documentation of receiving the vaccination series (e.g., vaccination card).
Negative for SARS-CoV-2 infection by RT-PCR test at screening within 7 days prior to study vaccination.
Is a male or nonpregnant female of 18 to 49 years, inclusive, at screening.

Key exclusion criteria (34 listed)

Has a new onset, clinically significant, abnormal biochemistry or hematology finding [defined as greater than or equal to (>=) Grade 1] at screening (participants with Grade 1 laboratory abnormalities that have been stable for at least 6 months before enrollment may be included in the study).
Has any medical disease or condition that, in the opinion of the investigator, precludes study participation. This includes any acute, subacute, intermittent, or chronic medical disease or condition that would place the participant at an unacceptable risk of injury, render the participant unable to meet the requirements of the protocol, or may interfere with the evaluation of responses or the participant's successful completion of the trial.
Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination (no laboratory testing required).
History of myocarditis, pericarditis, second- and third-degree heart block or idiopathic cardiomyopathy, or presence of any medical condition that increases risk of myocarditis or pericarditis, including cocaine abuse, cardiomyopathy, endomyocardial fibrosis, hypereosinophilic syndrome, hypersensitivity myocarditis eosinophilic granulomatosis with polyangiitis, persistent myocardial viral infection (e.g., due to enterovirus or adenovirus).
Has an acute febrile illness with a temperature >=38.0 degree Celsius (°C) or >=100.4 degree Fahrenheit (°F) observed by the participant or at the study site within 72 hours prior to study vaccination. Participants with suspected COVID-19 symptoms should be excluded and referred for medical care.

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
mRNA-CR-04 vaccine 10μgmRNA CR-04 vaccine, 10 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.	Biological	Part A, Group 1: mRNA CR-04 10 µg, Part B: mRNA CR-04 10 µg
mRNA-CR-04 vaccine 30μgmRNA CR-04 vaccine, 30 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.	Biological	Part A, Group 2: mRNA CR-04 30 µg
mRNA-CR-04 vaccine 100μgmRNA CR-04 vaccine, 100 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.	Biological	Part A, Group 3: mRNA CR-04 100 µg
PlaceboPlacebo is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.	Drug	Part A, Group 1: Placebo, Part A, Group 2: Placebo, Part A, Group 3: Placebo, Part B: Placebo
mRNA-CR-04 vaccine 3μgmRNA CR-04 vaccine, 3 µg, is administered intramuscularly into the deltoid muscle of the non-dominant arm on day 1.	Biological	Part B: mRNA CR-04 3 µg

Primary outcome

Number of Participants With Any Solicited Administration Site Events
Time frame: Day 1 to Day 7
The solicited administration site events are pain, redness, swelling and lymphadenopathy (axillary swelling/ tenderness on the same side of the body as the site of injection). Any = occurrence of the event regardless of intensity grade.
Number of Participants With Any Solicited Systemic Events
Time frame: Day 1 to Day 7
The solicited systemic events are fever, headache, myalgia (muscle pain), arthralgia (joint pain), fatigue (tiredness), chills, abdominal pain, vomiting and diarrhea. Fever is defined as body temperature ≥38ºC; preferred location for measuring the temperature is oral. Any = occurrence of the event regardless of intensity grade.
Number of Participants With Any Unsolicited Adverse Events (AEs)
Time frame: Day 1 to Day 30
An unsolicited AE is an AE that is either not included in the list of solicited events or can be included in the list of solicited events but with an onset outside the specified period of follow-up for solicited events. Unsolicited AEs include both serious and nonserious AEs. Any = occurrence of the event regardless of intensity grade.
Number of Participants With Any Hematological and Biochemical Laboratory Abnormalities
Time frame: Day 1 to Day 15
The hematological and biochemical parameters included alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), total bilirubin, creatinine, direct bilirubin, basophils, eosinophils increase, erytrocytes, hemoglobin decrease, lymphocytes decrease, mean corpuscular hemoglobin, mean corpuscular volume, monocytes, neutrophils decrease, platelets decrease, white blood cells (WBC) increase. Below = value below the laboratory reference range defined for the specified visit and laboratory parameter; Within = value within the laboratory reference range defined for the specified visit and laboratory parameter; Above = value above the laboratory reference range defined for the specified visit and laboratory parameter.
Number of Participants With Any Medically Attended Adverse Events (MAAEs)
Time frame: Day 1 to Day 31
A MAAE is an AE for which the participant received medical attention including any symptom or illness requiring hospitalization, or an emergency room visit, or visit to/by a healthcare professional. Any = occurrence of the event regardless of intensity grade.
Number of Participants With Any Serious Adverse Events (SAEs)
Time frame: Day 1 to Day 31
An SAE is defined as any untoward medical occurrence that results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study participant, abnormal pregnancy outcome or any other situation as determined by the investigator. Any = occurrence of the event regardless of intensity grade.
Number of Participants With Any Adverse Events of Special Interest (AESIs)
Time frame: Day 1 to Day 31
AESIs include potential immune-mediated diseases (pIMDs) which are autoimmune diseases and other inflammatory and/or neurologic disorders of interest which may or may not have an autoimmune etiology, myocarditis, and pericarditis, virologically confirmed COVID-19 cases, anaphylaxis, or severe hypersensitivity within 24 hours after study investigational product administration. Any = occurrence of the event regardless of intensity grade.

6 secondary outcomes

Number of Participants With Any MAAEs
Time frame: Throughout the study period (Day 1 to Month 6)
Number of Participants With Any SAEs
Time frame: Throughout the study period (Day 1 to Month 6)
Number of Participants With Any AESIs
Time frame: Throughout the study period (Day 1 to Month 6)
Geometric Mean Titers (GMT) of Neutralizing Titers Against Pseudovirus Bearing S Protein From Vaccine Encoded SARS-CoV-2 and Wild Type (WT) Strains
Time frame: At Days 1, 15 and 31, and at Month 6
Geometric Mean Ratio (GMR) of Neutralizing Titers Against Pseudovirus Bearing S Protein From Vaccine Encoded SARS-CoV-2 and WT Strains
Time frame: At Days 15 and 31, and at Month 6 (compared with baseline [Day 1])
Number of Participants With Vaccine Response Rate (VRR) Based on Neutralizing Titers Against Vaccine Encoded SARS-CoV-2 and WT Strains
Time frame: At Days 15 and 31, and at Month 6 (compared with baseline [Day 1])

Results and safety

Results posted to the registry on 28 May 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Part A, Group 1: mRNA CR-04 10 µg	18	16
Part A, Group 1: Placebo	6	6
Part A, Group 2: mRNA CR-04 30 µg	18	17
Part A, Group 2: Placebo	6	6
Part A, Group 3: mRNA CR-04 100 µg	18	18
Part A, Group 3: Placebo	6	6
Part B: mRNA CR-04 3 µg	18	18
Part B: mRNA CR-04 10 µg	18	16
Part B: Placebo	6	6

Primary outcome: Number of Participants With Any Solicited Administration Site Events

Time frame: Day 1 to Day 7. Count of participants. Unit: Participants

Measure	Part A, Group 1: mRNA CR-04 10 µg n = 18	Part A, Group 2: mRNA CR-04 30 µg n = 17	Part A, Group 2: Placebo n = 6	Part A, Group 3: mRNA CR-04 100 µg n = 18	Part B: mRNA CR-04 3 µg n = 18	Part B: mRNA CR-04 10 µg n = 18	Part B: Placebo n = 6
Pain at administration site	8	10	1	15	9	6	1
Redness at administration site	0	0	0	4	0	0	0
Swelling at administration site	0	1	0	3	0	0	0
Lymphadenopathy	0	2	0	2	2	3	0

Population analysed: Analysis was performed on Solicited Safety Set (SSS) which includes all participants who received at least one dose of investigational products and had solicited events data at the specified timepoints.

Primary outcome: Number of Participants With Any Solicited Systemic Events

Time frame: Day 1 to Day 7. Count of participants. Unit: Participants

Measure	Part A, Group 1: mRNA CR-04 10 µg n = 18	Part A, Group 1: Placebo n = 6	Part A, Group 2: mRNA CR-04 30 µg n = 17	Part A, Group 2: Placebo n = 6	Part A, Group 3: mRNA CR-04 100 µg n = 18	Part A, Group 3: Placebo n = 6	Part B: mRNA CR-04 3 µg n = 18	Part B: mRNA CR-04 10 µg n = 18	Part B: Placebo n = 6
Fever	0	0	0	0	3	0	0	0	0
Headache	5	1	4	1	8	2	6	4	2
Myalgia	4	0	4	2	11	0	6	8	0
Arthralgia	1	0	3	0	2	1	1	2	0
Fatigue	8	1	7	1	8	2	7	5	1
Chills	2	0	3	0	3	1	0	2	1
Abdominal Pain	0	0	1	0	1	1	1	1	0
Vomiting	0	0	1	0	0	0	0	2	0

Population analysed: Analysis was performed on SSS which includes all participants who received at least one dose of investigational products and had solicited events data at the specified timepoints.

Primary outcome: Number of Participants With Any Unsolicited Adverse Events (AEs)

Time frame: Day 1 to Day 30. Count of participants. Unit: Participants

Measure	Part A, Group 1: mRNA CR-04 10 µg n = 18	Part A, Group 1: Placebo n = 6	Part A, Group 2: mRNA CR-04 30 µg n = 18	Part A, Group 2: Placebo n = 6	Part A, Group 3: mRNA CR-04 100 µg n = 18	Part A, Group 3: Placebo n = 6	Part B: mRNA CR-04 3 µg n = 18	Part B: mRNA CR-04 10 µg n = 18	Part B: Placebo n = 6
Value	6	0	5	0	4	3	8	2	1

Population analysed: Analysis was performed on Exposed set, which included all participants who received the dose of the investigational products.

Primary outcome: Number of Participants With Any Hematological and Biochemical Laboratory Abnormalities

Time frame: Day 1 to Day 15. Count of participants. Unit: Participants

Measure	Part A, Group 1: mRNA CR-04 10 µg n = 18	Part A, Group 1: Placebo n = 6	Part A, Group 2: mRNA CR-04 30 µg n = 17	Part A, Group 2: Placebo n = 6	Part A, Group 3: mRNA CR-04 100 µg n = 18	Part A, Group 3: Placebo n = 6	Part B: mRNA CR-04 3 µg n = 18	Part B: mRNA CR-04 10 µg n = 18	Part B: Placebo n = 6
ALT: Below (Baseline) - Below (Day 15)	0	0	0	2	0	0	1	0	1
ALT: Within (Baseline) - Below (Day 15)	2	0	0	0	0	1	0	2	0
ALT: Above (Baseline) - Below (Day 15)	0	0	0	0	0	0	0	0	0
ALT: Below (Baseline) - Within (Day 15)	1	0	1	1	0	0	0	1	0
ALT: Within (Baseline) - Within (Day 15)	10	4	13	3	14	4	14	14	4
ALT: Above (Baseline) - Within (Day 15)	1	1	0	0	1	0	1	1	0
ALT: Below (Baseline) - Above (Day 15)	0	0	0	0	0	0	0	0	0
ALT: Within (Baseline) - Above (Day 15)	1	0	2	0	1	1	1	0	0

Population analysed: Analysis was performed on Exposed set. Only participants with data available at specified timepoints were included in analysis.

6 secondary outcomes are reported in the full results.

Adverse events

Time frame: Solicited AEs: Day 1 to Day 7; Unsolicited AEs: Day 1 to Day 30. SAEs, MAAEs, AESIs: Day 1 up to study end (6 months post-investigational products administration).. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Part A, Group 1: mRNA CR-04 10 µg	1 of 18 (5.6%)	12 of 18 (66.7%)	0 of 18
Part A, Group 1: Placebo	0 of 6 (0%)	2 of 6 (33.3%)	0 of 6
Part A, Group 2: mRNA CR-04 30 µg	1 of 18 (5.6%)	15 of 18 (83.3%)	0 of 18
Part A, Group 2: Placebo	0 of 6 (0%)	3 of 6 (50%)	0 of 6
Part A, Group 3: mRNA CR-04 100 µg	0 of 18 (0%)	16 of 18 (88.9%)	0 of 18
Part A, Group 3: Placebo	0 of 6 (0%)	4 of 6 (66.7%)	0 of 6
Part B: mRNA CR-04 3 µg	0 of 18 (0%)	16 of 18 (88.9%)	0 of 18
Part B: mRNA CR-04 10 µg	0 of 18 (0%)	10 of 18 (55.6%)	0 of 18
Part B: Placebo	0 of 6 (0%)	4 of 6 (66.7%)	0 of 6

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 28 May 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Individual participant dataSharing planned: Yes. GSK will assess requests from qualified researchers for anonymized individual patient-level data and related study documents. Data sharing is subject to certain criteria, conditions, and exceptions. For further information, refer tohttps://www.gsk-studyregister.com/About_GSK_Patient_Level_Data_Sharing_Final_13July2023.pdf.

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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.

The record lists no contact. Use the official record to reach the sponsor.

4 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing mRNA-CR-04 vaccine 10μg, mRNA-CR-04 vaccine 30μg and mRNA-CR-04 vaccine 100μg in people with COVID-19, run by GlaxoSmithKline at 4 sites in United States.

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 8 inclusion and 34 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 28 May 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites in United States. 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?

Yes. Results are posted in the registry (first posted 28 May 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Number of Participants With Any Solicited Administration Site Events (time frame: Day 1 to Day 7). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05972993.

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 28 May 2025.