A Phase 1 interventional study of INT101 Low Dose and INT101 High Dose in Norovirus Infections and Norovirus Gastroenteritis, sponsored by InThera Inc. Korea. Recruiting at 1 site in South Korea. Open to participants aged 19 Years to 48 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-11-04.
Sponsored by InThera Inc. Korea · Phase 1, Interventional, and Prevention
Help build ClinicalTrials.gg — short surveys, remote interviews or testing, in your language. Take part →
This study is being conducted to evaluate the safety and immunogenicity of INT101, an investigational vaccine intended to prevent norovirus gastroenteritis, in healthy adults. INT101 contains multivalent norovirus antigens (GII.3, GII.4, and GII.17) and is administered as an intramuscular injection. Participants will receive either INT101 or a placebo, given three times at 4-week intervals. This is a single-center, single-blind, randomized, dose-escalation, placebo-controlled, multiple-dose, Phase 1 clinical trial. Approximately 30 healthy adult participants will be enrolled and randomly assigned to receive either a low dose or high dose of INT101, or a matching placebo, in a 2:1 ratio within each dose group. The primary objective is to evaluate the safety of multiple intramuscular doses of INT101 compared to placebo. The secondary objective is to evaluate the immunogenicity (antibody response) of INT101 compared to placebo. Participants will be followed for approximately 6 months after their last dose to monitor safety and immune response.
This is a single-center, single-blind, randomized, dose-escalation, placebo-controlled, multiple-dose, Phase 1 clinical trial designed to evaluate the safety and immunogenicity of INT101 intramuscular injection in healthy adults. INT101 is a vaccine candidate containing multivalent norovirus antigens (genotypes GII.3, GII.4, and GII.17), formulated at 20 μg per antigen (60 μg total) per 0.5 mL vial. The matching placebo is identical in formulation and appearance, excluding the active norovirus antigens. Approximately 30 participants will be enrolled into two dose groups: a low-dose group (30 μg/0.25 mL) and a high-dose group (60 μg/0.5 mL). Each dose group consists of a sentinel cohort followed by a main cohort. Within each cohort, participants are randomized in a 2:1 ratio to receive either INT101 or placebo. Enrollment proceeds in a staggered, dose-escalation manner: Sentinel A (low dose) is dosed first, followed by a Day 7 DSMB safety review before proceeding to Cohort A. DSMB (Data and Safety Monitoring Board) evaluations are conducted at Day 7 after the first and third (last) doses within Cohort A before advancing to the high-dose groups (Sentinel B and Cohort B). Each participant receives 3 intramuscular injections (into the deltoid muscle) at 4-week intervals (Visit 2/Baseline, Visit 4, Visit 6). The study includes a screening period (up to 4 weeks), a treatment period (8 weeks, 3 doses), and a follow-up period of approximately 6 months after the last dose, for a total of 9 study visits. Safety endpoints include immediate adverse events, solicited local and systemic adverse events, unsolicited adverse events, serious adverse events, and clinically significant changes in laboratory tests, physical examinations, and vital signs. Immunogenicity endpoints include seroconversion rate, geometric mean titer (GMT), and geometric mean ratio (GMR) of norovirus antibodies, assessed at Days 7, 28, 35, 56, 63, 84, and 224 relative to baseline.
20 studies on the registry are indexed under Caliciviridae Infections; 2 are open to participants now.
This study's planned enrollment of 30 is below the median of 71 across 18 interventional studies indexed under Caliciviridae Infections.
Browse Caliciviridae Infections studies →This is the only study on the registry with InThera Inc. Korea as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive INT101 (norovirus multivalent antigen \[GII.3, GII.4, GII.17\], total 30 μg/0.25 mL) via intramuscular injection into the deltoid muscle, administered 3 times at 4-week intervals.
Biological: INT101 Low Dose
Participants receive INT101 (norovirus multivalent antigen \[GII.3, GII.4, GII.17\], total 60 μg/0.5 mL) via intramuscular injection into the deltoid muscle, administered 3 times at 4-week intervals.
Biological: INT101 High Dose
Participants receive INT101 Placebo (0.25 mL) via intramuscular injection into the deltoid muscle, administered 3 times at 4-week intervals.
Biological: INT101 Placebo (0.25 mL)
Participants receive INT101 Placebo (0.5 mL) via intramuscular injection into the deltoid muscle, administered 3 times at 4-week intervals.
Biological: INT101 Placebo (0.5 mL)
Norovirus multivalent antigen vaccine (GII.3, GII.4, GII.17), total 30 μg per 0.25 mL, administered via intramuscular injection into the deltoid muscle, 3 doses at 4-week intervals.
Norovirus multivalent antigen vaccine (GII.3, GII.4, GII.17), total 60 μg per 0.5 mL, administered via intramuscular injection into the deltoid muscle, 3 doses at 4-week intervals.
Matching placebo identical in formulation and appearance to INT101, excluding the active norovirus antigens; 0.25 mL, administered via intramuscular injection into the deltoid muscle, 3 doses at 4-week intervals.
Matching placebo identical in formulation and appearance to INT101, excluding the active norovirus antigens; 0.5 mL, administered via intramuscular injection into the deltoid muscle, 3 doses at 4-week intervals.
Incidence of Immediate Adverse Events (AEs)
Number and proportion of participants experiencing immediate adverse events occurring within 30 minutes after each administration of the investigational product.
Time frame: Within 30 minutes after each investigational product administration (up to 3 doses)
Incidence of Solicited Local Adverse Events
Number and proportion of participants experiencing solicited local adverse events (e.g., injection site pain, erythema, swelling) following each investigational product administration.
Time frame: Within 7 days after each investigational product administration
Incidence of Solicited Systemic Adverse Events
Number and proportion of participants experiencing solicited systemic adverse events (e.g., fever, fatigue, headache, myalgia) following each investigational product administration.
Time frame: Within 7 days after each investigational product administration
Incidence of Unsolicited Adverse Events
Number and proportion of participants experiencing unsolicited adverse events not specifically listed on the diary card, following each investigational product administration.
Time frame: Within 28 days after each investigational product administration, or occurring between Visit 8 and Visit 9
Incidence of Serious Adverse Events (SAEs)
Number and proportion of participants experiencing serious adverse events, regardless of causal relationship to the investigational product, from the first dose through the end of follow-up.
Time frame: From first investigational product administration up to Day 224 (approximately 32 weeks)
Incidence of Clinically Significant Abnormalities in Laboratory Tests, Physical Examinations, and Vital Signs
Number and proportion of participants with a shift from normal or not clinically significant abnormal at baseline to clinically significant abnormal at any post-baseline visit in laboratory test results, physical examination findings, or vital sign measurements.
Time frame: From baseline (Day 0, first investigational product administration) through Day 224 (end of study, approximately 32 weeks)
Seroconversion Rate of Norovirus Antibodies
Proportion of participants achieving seroconversion, defined as a ≥4-fold increase from baseline in norovirus IgG, IgA, or HBGA blocking antibody titer, at each post-baseline time point.
Time frame: Day 7, 28, 35, 56, 63, 84, and 224 after the first investigational product administration, compared to baseline
Geometric Mean Titer (GMT) of Norovirus Antibodies
Geometric mean titer of norovirus antibodies (IgG, IgA, and HBGA blocking antibody) at each post-baseline time point compared to baseline.
Time frame: Day 7, 28, 35, 56, 63, 84, and 224 after the first investigational product administration, compared to baseline
Geometric Mean Ratio (GMR) of Norovirus Antibodies
Geometric mean ratio (fold-rise from baseline) of norovirus antibody titers at each post-baseline time point compared to baseline.
Time frame: Day 7, 28, 35, 56, 63, 84, and 224 after the first investigational product administration, compared to baseline
Plan to share: Undecided — Data sharing plans have not yet been finalized. This is a single-site Phase 1 trial conducted in Korea; the decision will be determined at a later stage depending on publication plans and regulatory requirements.
No publications or documents are linked to this record.
Started Aug 2026 (actual). Primary completion is estimated for Aug 2027, 12 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.