COVID-19 InfectionPhase 1NCT06032000
Evaluation of Safety and Immunogenicity of a SARS-CoV-2(Severe Acute Respiratory Syndrome Coronavirus 2) Booster Vaccine (LEM-mR203)
A Phase 1 study testing LEM-mR203 in people with COVID-19 Infection and COVID-19 Vaccine Adverse Reaction, run by Lemonex at 1 site in South Korea.
Trial summary
A dose-escalation, double-blinded, randomized, placebo-controlled phase 1 study to assess the safety, reactogenicity, and immunogenicity of a SARS-CoV-2 Booster Vaccine (LEM-mR203) in healthy adults aged at 19 to 55 years Read more about this study
- Who is it for?
- Ages 19 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- COVID-19 Infection, COVID-19 Vaccine Adverse Reaction
- What is being tested?
- LEM-mR203
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- 1 siteSouth Korea
- Study dates
- 6 Nov 2023to 28 Mar 2025
- 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 19 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy volunteer aged 19 years or older but less than 55 years at the time of screening.
- Individuals falling into one of the following categories:
- Those who have completed their primary vaccination with a domestically approved COVID-19 vaccine and have elapsed more than 90 days but less than 48 weeks since the completion of the primary vaccination.
- Individuals who have completed their primary vaccination and received 1 or more additional doses; these individuals must have elapsed more than 4 months but less than 48 weeks since their last vaccination
- Individuals who do not exhibit clinically significant respiratory symptoms (e.g., cough, sore throat) and do not have clinically significant active lesions on chest X-ray.
- Individuals who agree to use medically accepted contraceptive methods during the entire study period before clinical trials
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- Individuals who agree not to donate blood or receive blood transfusions (including whole blood, plasma components, platelet components, and platelet plasma components) during the study period before clinical trials.
- Individuals who can participate in all study visit schedules and comply with all study procedures.
- Individuals who, after receiving detailed explanations about the clinical trial and fully comprehending it, voluntarily decide to participate, and provide written consent before the screening procedure.
Who cannot join
- Within 72 hours before administration of the investigational medicinal product, individuals with clinically significant respiratory symptoms (e.g., cough, sore throat), acute febrile illness with body temperature exceeding 38℃, suspicion of other infectious diseases, or individuals with symptoms suspected to be caused by other infectious diseases.
- Individuals who tested positive for SARS-CoV-2 genetic test (RT-PCR) or rapid antigen test during the screening.
- Individuals who have not elapsed 90 days since being diagnosed with COVID-19.
- Individuals with positive results in screening tests for Hepatitis B, Hepatitis C, Syphilis (RPR), or HIV conducted during the screening.
- Individuals with a smoking history within 12 weeks prior to administration of the investigational medicinal product or current smokers (smoking up to 10 cigarettes/month may be allowed based on the investigator's judgment ).
- Individuals with a history of malignant tumors within 5 years before administration of the investigational medicinal product.
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- Individuals with a history of generalized urticaria within 5 years before administration of the investigational medicinal product.
- Individuals with clinically significant conditions or medical history (e.g., respiratory diseases such as asthma, chronic obstructive pulmonary disease, active tuberculosis; cardiovascular diseases such as congestive heart failure, myocardial infarction, coronary artery disease, uncontrolled hypertension; gastrointestinal diseases such as chronic liver disease, inflammatory bowel disease; hematological and neoplastic diseases, endocrine diseases such as diabetes, hyperthyroidism; genitourinary diseases such as chronic urinary tract infections, chronic renal failure; musculoskeletal diseases such as muscular dystrophy; neurological and psychiatric diseases such as epilepsy, mood disorders, obsessive-compulsive disorder), not limited to the mentioned examples.
- Individuals with a history of solid organ or bone marrow transplantation.
- Individuals with a history of congenital or acquired immunodeficiency diseases or autoimmune diseases.
- Participants who have received any other vaccines within 4 weeks prior to the investigational medicinal product or who have planned to receive other vaccines within 28 days after the administration of the investigational medicinal product are excluded. However, exception applies to influenza vaccines
Trial locations and contacts
1 site in 1 country.
South Korea1 site
Seoul National University Hospital Clinical Trials Center
Seoul, 03080
About this study
Official title: A Dose-escalation, Double-blinded, Randomized, Placebo-controlled Phase 1 Study to Assess the Safety, Reactogenicity, and Immunogenicity of a SARS-CoV-2 Booster Vaccine (LEM-mR203) in Healthy Adults Aged at 19 to 55 Years
A dose-escalation, double-blinded, randomized, placebo-controlled phase 1 study to assess the safety, reactogenicity, and immunogenicity of a SARS-CoV-2 Booster Vaccine (LEM-mR203) in healthy adults aged at 19 to 55 years
Read the detailed description
The LEM-mR203 is a mRNA vaccine candidate using Lemonex's DDS (Drug Delivery System) named DegradaBALL, and is to be evaluated as a booster vaccine for the prevention of COVID-19 (Coronavirus Disease 2019) in healthy volunteers. DegradaBALL is porous silica nanoparticle-based Drug Delivery System and is resistant to heat and light and stable at room temperature. APIs (Active Pharmaceutical Ingredients) can be loaded by simply mixing into DegradaBALL at the point of use before administration unlike lipid nanoparticles (LNPs) that require drug loading through manufacturing at designated facilities. The LEM-mR203 has been developed to deliver Lemonex's mRNA using DegradaBALL to address the limitations of the existing mRNA COVID-19 vaccines using Lipid Nanoparticle (LNP). The development aims to overcome safety concerns associated with the components of LNP as well as challenges like the ultra-cold storage requirements.
This is the First-In-Human study of LEM-mR203 and consists of two dose cohorts, enrolling healthy adults who will receive a single intramuscular injection of LEM-mR203. The objectives of the trial are to evaluate the safety, reactogenicity, and immunogenicity of LEM-mR203. For each cohort, the first three participants will be dosed with LEM-mR203, followed by a safety review by the DSMB (Data Safety Monitoring Board) before enrolling the remaining participants. The follow-up period will continue for up to 12 months following the administration of a single dose of LEM-mR203.
- Being tested
- LEM-mR203, Placebo
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LEM-mR203Biological
mRNA vaccine using Lemonex's Drug Delivery System (DDS), DegradaBALL
PlaceboBiological
0.9% Sodium Chloride Solution
| Study group | Role | What they receive |
|---|---|---|
| LEM-mR203 | Active comparator | Drug: LEM-mR203
An intramuscular single injection prepared by mixing mRNA and DegradaBALL before administration Receives: Biological: LEM-mR203 |
| Placebo | Placebo comparator | Drug: 0.9% Sodium Chloride Solution
An intramuscular single injection prepared before administration Receives: Biological: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Safety and Reactogenicity Assessment
- Incidence rate of Acute Immediate Adverse Reactions(IAR) within 30 minutes post administration(sentinel group observed for 2 hours)
- Incidence rate of solicited local and systemic Adverse Events (AEs) within 7 days post-administration
- Incidence rate of unsolicited AEs within up to 28 days post-administration
- Incidence rate of Serious Adverse Events (SAEs), Medically Attended Adverse Events (MAAEs), Adverse Events of Special Interest (AESIs) within up to 366 days post-administration
Measured: Baseline, 1week, 4week and 3,6 and12 months post a booster injection
Secondary outcomes (7)
GMT(geometric mean titer) of Anti-SARS-CoV-2 RBD(receptor-binding domain) IgG
GMT of Anti-SARS-CoV-2 RBD IgG from baseline to 1,3,6 and12 months post a booster injection of LEM-mR203, measured by ECLIA(Electrochemiluminescence Immunoassay)
Measured: Baseline,1,3,6 and 12 months post a booster injection
GMFR(geometric mean fold rise) of Anti-SARS-CoV-2 RBD IgG
GMFR of Anti-SARS-CoV-2 RBD IgG from baseline to 1,3,6 and12 months post a booster injection of LEM-mR203, measured by ECLIA
Measured: Baseline,1,3,6 and 12 months post a booster injection
Proportion of participants achieving seroresponse of Anti-SARS-CoV-2 RBD IgG
Proportion of participants achieving seroresponse(SR defined as at least 2-fold increase fro baseline) of Anti-SARS-CoV-2 RBD IgG from baseline to 1,3,6 and 12 months post a booster injection, measured by ECLIA
Measured: Baseline,1,3,6 and 12 months post a booster injection
GMT(geometric mean titer) of neutralizing antibody to the SARS-CoV-2 (kappa variant)
GMT of neutralizing antibody measured by live virus neutralization assay from baseline to 1, 3, 6 and 12 months post a booster injection
Measured: Baseline,1,3,6 and 12 months post a booster injection
GMFR(geometric mean fold rise) of neutralizing antibody to the SARS-CoV-2 (kappa variant)
GMFR of neutralizing antibody measured by live virus neutralization assay from baseline to 1, 3, 6 and 12 months post a booster injection
Measured: Baseline,1,3,6 and 12 months post a booster injection
Proportion of participants achieving seroresponse of neutralizing antibody to the SARS-CoV-2 (kappa variant)
Proportion of participants achieving seroresponse(SR defined as at least 2-fold increase from baseline) of neutralizing antibody measured by live virus from baseline to 1, 3, 6 and 12 months post a booster injection
Measured: Baseline,1,3,6 and 12 months post a booster injection
Cell-mediated Immunity (CMI)
INF(Interferon)-γ(gamma) and IL(Interleukin)-4 confirmed using ELISPOT (Enzyme-Linked ImmunoSpot) assay, from baseline to 1 month post a booster injection
Measured: Baseline and 1 month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Sep 2023
- Study start6 Nov 2023
- Primary completion28 Mar 2025
- Study completion28 Mar 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for COVID-19 InfectionStudies of the same condition, open and under way.
- 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
- Parallel groups
- Model description
- LEM-mR203 vs placebo
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Lemonex
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Cheolhee Won, PhD, Study director, LemonexIn Jin Jang, MD, PhD, Principal investigator, Seoul National University Hospital Clinical Trials Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06032000
- Sponsor's protocol ID
- LEM-mR203-101
- Status last verified
- Apr 2025
- First submitted
- 29 Aug 2023
- Last updated
- 6 Apr 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 6 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Dose-escalation, Double-blinded, Randomized, Placebo-controlled Phase 1 Study to Assess the Safety, Reactogenicity, and Immunogenicity of a SARS-CoV-2 Booster Vaccine (LEM-mR203) in Healthy Adults Aged at 19 to 55 Years
- ClinicalTrials.gov ID
- NCT06032000
- Acronym / sponsor ID
- LEM-mR203-101
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- LemonexIndustry (pharma, biotech, devices)
- Study start
- 6 Nov 2023 (actual)
- Primary completion
- 28 Mar 2025 (actual)
- Study completion
- 28 Mar 2025 (actual)
- First posted
- 11 Sep 2023 (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.
A dose-escalation, double-blinded, randomized, placebo-controlled phase 1 study to assess the safety, reactogenicity, and immunogenicity of a SARS-CoV-2 Booster Vaccine (LEM-mR203) in healthy adults aged at 19 to 55 years
Detailed description
The LEM-mR203 is a mRNA vaccine candidate using Lemonex's DDS (Drug Delivery System) named DegradaBALL, and is to be evaluated as a booster vaccine for the prevention of COVID-19 (Coronavirus Disease 2019) in healthy volunteers. DegradaBALL is porous silica nanoparticle-based Drug Delivery System and is resistant to heat and light and stable at room temperature. APIs (Active Pharmaceutical Ingredients) can be loaded by simply mixing into DegradaBALL at the point of use before administration unlike lipid nanoparticles (LNPs) that require drug loading through manufacturing at designated facilities. The LEM-mR203 has been developed to deliver Lemonex's mRNA using DegradaBALL to address the limitations of the existing mRNA COVID-19 vaccines using Lipid Nanoparticle (LNP). The development aims to overcome safety concerns associated with the components of LNP as well as challenges like the ultra-cold storage requirements.
This is the First-In-Human study of LEM-mR203 and consists of two dose cohorts, enrolling healthy adults who will receive a single intramuscular injection of LEM-mR203. The objectives of the trial are to evaluate the safety, reactogenicity, and immunogenicity of LEM-mR203. For each cohort, the first three participants will be dosed with LEM-mR203, followed by a safety review by the DSMB (Data Safety Monitoring Board) before enrolling the remaining participants. The follow-up period will continue for up to 12 months following the administration of a single dose of LEM-mR203.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- LEM-mR203 vs placebo
| Arm | Type | Receives |
|---|---|---|
| LEM-mR203 | Active comparator | Biological: LEM-mR203Drug: LEM-mR203 An intramuscular single injection prepared by mixing mRNA and DegradaBALL before administration |
| Placebo | Placebo comparator | Biological: PlaceboDrug: 0.9% Sodium Chloride Solution An intramuscular single injection prepared before administration |
Who may qualify
- Ages
- 19 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Healthy volunteer aged 19 years or older but less than 55 years at the time of screening.
- Individuals falling into one of the following categories:
- Individuals who do not exhibit clinically significant respiratory symptoms (e.g., cough, sore throat) and do not have clinically significant active lesions on chest X-ray.
- Individuals who agree to use medically accepted contraceptive methods during the entire study period before clinical trials
- Individuals who agree not to donate blood or receive blood transfusions (including whole blood, plasma components, platelet components, and platelet plasma components) during the study period before clinical trials.
Key exclusion criteria (11 listed)
- Within 72 hours before administration of the investigational medicinal product, individuals with clinically significant respiratory symptoms (e.g., cough, sore throat), acute febrile illness with body temperature exceeding 38℃, suspicion of other infectious diseases, or individuals with symptoms suspected to be caused by other infectious diseases.
- Individuals who tested positive for SARS-CoV-2 genetic test (RT-PCR) or rapid antigen test during the screening.
- Individuals who have not elapsed 90 days since being diagnosed with COVID-19.
- Individuals with positive results in screening tests for Hepatitis B, Hepatitis C, Syphilis (RPR), or HIV conducted during the screening.
- Individuals with a smoking history within 12 weeks prior to administration of the investigational medicinal product or current smokers (smoking up to 10 cigarettes/month may be allowed based on the investigator's judgment ).
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 |
|---|---|---|
| LEM-mR203mRNA vaccine using Lemonex's Drug Delivery System (DDS), DegradaBALL | Biological | LEM-mR203 |
| Placebo0.9% Sodium Chloride Solution | Biological | Placebo |
Primary outcome
Safety and Reactogenicity Assessment
Time frame: Baseline, 1week, 4week and 3,6 and12 months post a booster injection
1. Incidence rate of Acute Immediate Adverse Reactions(IAR) within 30 minutes post administration(sentinel group observed for 2 hours) 2. Incidence rate of solicited local and systemic Adverse Events (AEs) within 7 days post-administration 3. Incidence rate of unsolicited AEs within up to 28 days post-administration 4. Incidence rate of Serious Adverse Events (SAEs), Medically Attended Adverse Events (MAAEs), Adverse Events of Special Interest (AESIs) within up to 366 days post-administration
7 secondary outcomes
GMT(geometric mean titer) of Anti-SARS-CoV-2 RBD(receptor-binding domain) IgG
Time frame: Baseline,1,3,6 and 12 months post a booster injection
GMFR(geometric mean fold rise) of Anti-SARS-CoV-2 RBD IgG
Time frame: Baseline,1,3,6 and 12 months post a booster injection
Proportion of participants achieving seroresponse of Anti-SARS-CoV-2 RBD IgG
Time frame: Baseline,1,3,6 and 12 months post a booster injection
GMT(geometric mean titer) of neutralizing antibody to the SARS-CoV-2 (kappa variant)
Time frame: Baseline,1,3,6 and 12 months post a booster injection
GMFR(geometric mean fold rise) of neutralizing antibody to the SARS-CoV-2 (kappa variant)
Time frame: Baseline,1,3,6 and 12 months post a booster injection
Proportion of participants achieving seroresponse of neutralizing antibody to the SARS-CoV-2 (kappa variant)
Time frame: Baseline,1,3,6 and 12 months post a booster injection
Cell-mediated Immunity (CMI)
Time frame: Baseline and 1 month
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 6 Apr 2025.
- Individual participant dataSharing planned: No
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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.
Cheolhee Won, PhD study director
Lemonex
In Jin Jang, MD, PhD principal investigator
Seoul National University Hospital Clinical Trials Center
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 LEM-mR203 in people with COVID-19 Infection and COVID-19 Vaccine Adverse Reaction, run by Lemonex at 1 site in South Korea.
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 9 inclusion and 11 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 6 Apr 2025. 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 South Korea. 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?
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?
Safety and Reactogenicity Assessment (time frame: Baseline, 1week, 4week and 3,6 and12 months post a booster injection). 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 6 Apr 2025.