COVID-19Phase 2NCT05067933
A Ph 2 Trial With an Oral Tableted COVID-19 Vaccine
A Phase 2 study testing VXA-CoV2-1.1-S in people with COVID-19, run by Vaxart at 4 sites in United States.
Trial summary
Part 1: An open label, dose and age escalation phase to evaluate the safety and immunogenicity of VXA-CoV2-1.1-S with a repeat-dose vaccination schedule in healthy adults aged 18 - 75 years old that are either vaccine naive or have received prior vaccination with an mRNA (messenger ribonucleic acid) vaccine for the… Read more about this study
- Who is it for?
- Ages 18 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- COVID-19
- What is being tested?
- VXA-CoV2-1.1-S
- Type of treatment
- Vaccines, Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 66 participants
- Where
- 4 sitesUnited States
- Study dates
- 22 Oct 2021to 9 May 2023
- Phase
- Phase 2
- 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 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 18 - 75 years of age (inclusive) at the time of signing the Informed Consent Form (ICF).
- Cohort 1 ONLY - Naive of any prior vaccination for the prevention of COVID-19 (tested using a rapid antibody test) at screening and within 7 days prior to the enrollment (Day 1).
- Cohort 2 ONLY - Have received prior immunizations (both doses) with an EUA or FDA approved mRNA vaccine for the prevention of COVID-19, at least 6 months prior to enrollment (Day 1).
- In stable and good health, without significant medical illness, based on medical history, physical examination, vital signs, and clinical laboratory tests as determined by the Investigator.
- Safety laboratory values1 within the following range criteria at screening:
- Laboratory values within normal range or grade 1 outside the range of normal with no clinical significance (NCS) for the following analytes:, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin, blood urea nitrogen (BUN), creatinine, glucose, potassium, and sodium
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- Laboratory values within normal range for platelet counts2 and the following coagulation tests: PT/INR, aPTT and fibrinogen
- Body mass index (BMI) between 17 and 32 kg/m2 at screening.
- Capable of providing signed informed consent.
- Available for all planned visits and phone calls, and willing to complete all protocol-defined procedures and assessments (including ability and willingness to swallow multiple small enteric-coated tablets per vaccine dose).
- Gender and Reproductive Considerations
- Male or female participants. Contraception use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. Refer to Appendix 4 (Section 9.4).
- Female participants must not be breastfeeding and must have a negative pregnancy test at screening and before each vaccination and fulfill one of the following criteria:
- At least 1 year post-menopausal (defined as amenorrhea for ≥12 consecutive months prior to Screening without an alternative medical cause).
- Women under 60 years will need to verify post-menopausal status via a follicle-stimulating hormone (FSH) test if another option to prevent potential pregnancy will not be utilized for 30 days prior to baseline vaccination and until 60 days after the last vaccination.
- Surgically sterile
- Use of oral, implantable, transdermal or injectable contraceptives for 30 days prior to initial vaccination and until 60 days after the last vaccination.
- A reliable form of contraception must be approved by the Investigator (e.g., double barrier method, Depo-Provera, intrauterine device, Norplant, oral contraceptives, contraceptive patches).
- Not be sexually active (abstinent) or be in a relationship with partner who is sterile (must be discussed with site staff and documented).
Who cannot join
- Clinically significant acute illness within 72 hours prior to vaccination defined as the presence of a moderate or severe illness (as determined by the Investigator through medical history and physical exam) (assessment may be repeated during screening period).
- Current or known previous infection with SARS-CoV-2 or receipt of any therapeutic for the prevention or treatment of COVID-19, Middle East Respiratory Syndrome (MERS), or severe acute respiratory syndrome (SARS). [EUA or FDA approved mRNA vaccines for the prevention of SARS-CoV-2 infection taken at least 6 months prior to enrollment are permitted in Cohort 2]
- Individuals with the following underlying medical conditions who are at higher risk (or might be at higher risk) of severe illness from COVID-19 per the guidance from the Centers for Disease Control and Prevention (CDC):
- Cancer, including history of cancer or treatment within past 3 years (excluding basal cell carcinoma or squamous cell carcinoma)
- Chronic kidney disease
- Chronic obstructive pulmonary disease (COPD)
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- Immunocompromised state from solid organ transplant, or other medical condition
- Serious heart conditions, such as heart failure, coronary artery disease, or cardiomyopathies
- Sickle cell disease
- Uncontrolled type 2 diabetes mellitus
- Asthma (moderate to severe)
- Cerebrovascular disease
- Cystic fibrosis
- Uncontrolled hypertension or high blood pressure
- Immunocompromised state from blood or bone marrow transplant, immune deficiencies, HIV, use of corticosteroids, or use of other immune weakening medicines
- Neurologic conditions, such as dementia
- Liver disease
- Pregnancy or breast feeding
- Pulmonary fibrosis
- Chronic smoking (≥ 1 cigarette per day)
- Thalassemia
- Type 1 diabetes mellitus
- Diagnosed bleeding disorder or significant bruising or bleeding difficulties that could make blood draws problematic.
- Any condition that resulted in the absence or removal of the spleen.
- Any other condition that in the clinical judgment of the Investigator would jeopardize the safety or rights of a participant participating in the study, would render the participant unable to comply with the protocol or would interfere with the evaluation of the study endpoints.
- Diagnostic Assessments
- Temperature ≥38.0ºC (100.4°F) within 24 hours prior to the planned study vaccination (assessment may be repeated during screening period).
- Positive HIV, Hepatitis B surface antigen (HBsAg) or HCV tests at the screening visit.
- History of gastrointestinal bleeding (e.g. melena or hematochezia) Prior/Concurrent Therapy Note: The Active Period is defined as the time period from Day 1 through Week 8, or 4 weeks post last vaccination.
- Receipt of a licensed influenza vaccine within 14 days prior to baseline vaccination or another licensed vaccine within 28 days prior to baseline vaccination, or planned administration during the study active period.
- Use of antiviral medications , including anti-retrovirals within 1 week before vaccination or planned use during the active study period.
- Use of antibiotics, proton pump inhibitors, H2 blockers or antacids within 1 week before vaccination or planned use during the active study period.
- Use of medications known to affect the immune function (e.g., systemic corticosteroids and others) within 14 days before vaccination or planned use during the active study period.
- Daily use of nonsteroidal anti-inflammatory drugs, sulfonylureas, and angiotensin II blockers within 1 week before vaccination or planned use during the active study period.
- Positive urine drug screen for drugs of abuse at screening (except for previous marijuana use); concurrent or planned use of marijuana during the active study period.
- Administration of any investigational vaccine, drug or device within 8 weeks preceding vaccination, or planned use within the duration of the study.
- Other Exclusions
- Donation or use of blood or blood products within 4 weeks prior to vaccination or planned donation during the study period.
- Any significant hospitalization within the last year which in the opinion of the Investigator or Sponsor could interfere with study participation.
- History of drug, alcohol or chemical abuse within 1 year of screening.
- History of hypersensitivity or allergic reaction to any component of the investigational vaccine, including but not limited to fish gelatin.
- Any of the following history or conditions that may lead to higher risk of clotting events and/or thrombocytopenia:
- Family or personal history of bleeding or thrombosis
- History of heparin-related thrombotic events, and/or receiving heparin treatments
- History of autoimmune or inflammatory disease
- Presence of any of the following conditions known to increase risk of thrombosis within 6 months prior to screening:
- Recent surgery other than removal/biopsy of cutaneous lesions
- Immobility (confined to bed or wheelchair for 3 or more successive days)
- Head trauma with loss of consciousness or documented brain injury
- Receipt of anticoagulants for prophylaxis of thrombosis
- Recent clinically significant infection
Trial locations and contacts
4 sites in 1 country.
United States4 sites
Velocity Clinical Research, Inc,
Cleveland, Ohio, 44122
AMR Knoxville
Knoxville, Tennessee, 37909
Ark Clinical Research
Long Beach, California, 90806
AMR Wichita East
Wichita, Kansas, 64114
About this study
Official title: A Phase 2, Double-Blind, Multi-Center, Randomized, Placebo-Controlled, Dose-Ranging Trial to Determine the Safety, Immunogenicity and Efficacy of an Adenoviral-Vector Based Vaccine Expressing Severe Acute Respiratory Syndrome (SARS-CoV-2) and dsRNA Adjuvant Administered Orally
Part 1: An open label, dose and age escalation phase to evaluate the safety and immunogenicity of VXA-CoV2-1.1-S with a repeat-dose vaccination schedule in healthy adults aged 18 - 75 years old that are either vaccine naive or have received prior vaccination with an mRNA (messenger ribonucleic acid) vaccine for the prevention of COVID-19.
Part 2: This phase will assess the efficacy of prophylactic VXA-CoV2-1.1-S against confirmed COVID-19 occurring from 7 days after second dose with a repeat-dose vaccination schedule in healthy adults compared to placebo. Safety and immunogenicity of VXA-CoV2-1.1-S will also be evaluated in this phase.
Read the detailed description
Part 1: This is an open-label, dose-ranging phase of the study to determine the safety and immunogenicity of an orally administered adenoviral-vector based vaccine (VXA-COV2-1.1-S) expressing a SARS-CoV-2 antigen and dsRNA adjuvant. Post screening activities, healthy adult volunteers, either naïve or prior vaccinated with an mRNA COVID-19 vaccine, aged 18 - 55 yrs old, and then 56 - 75 yrs old, will be enrolled into the study in 8 subgroups. Participants will receive either a low or a high dose of an oral tableted vaccine at Days 1 and Day 29. The total study period will last ~ 2 months during the active phase, with a total 12 month safety follow-up period post last vaccination. Safety, reactogenicity and immunogenicity assessments will be performed at set times during the study active and follow-up periods. Subjects will be monitored for symptoms of COVID-19 throughout the duration of the study follow-up period. An independent data monitoring committee (IDMC) will provide safety oversight through the duration of the trial. Safety and immunogenicity data will inform on the dose selection for Part 2.
Part 2: This will be a placebo-controlled phase with the vaccine dose level selected from Part 1. Subjects will receive two doses of vaccine or placebo at Days 1 and 29. Subjects will be followed as in Part 1 for safety and immunogenicity. They will also be followed for 6 months for efficacy.
- Conditions
- COVID-19
- Being tested
- VXA-CoV2-1.1-S, Placebo Tablets
- Keywords
- oral vaccine, SARS-CoV-2, tablet vaccine
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
VXA-CoV2-1.1-SDrug
Also called Oral Tableted Ad5 COVID-19 Vaccine
COVID-19 (SARS-CoV-2) E1-/E3-Deleted Replication Defective Recombinant Adenovirus 5 with dsRNA Adjuvant Oral Tablet Vaccine
Placebo TabletsOther
Placebo tablets matching the active vaccine tablets
| Study group | Role | What they receive |
|---|---|---|
| Part 1 Cohort 1a (Naïve, low dose, young adult) | Experimental | 1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who are vaccine naïve Receives: Drug: VXA-CoV2-1.1-S |
| Part 1 Cohort 1b (Naïve, high dose, young adult) | Experimental | 1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who are vaccine naïve Receives: Drug: VXA-CoV2-1.1-S |
| Part 1 Cohort 1c (Naïve, low dose, older adult) | Experimental | 1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who are vaccine naïve Receives: Drug: VXA-CoV2-1.1-S |
| Part 1 Cohort 1d (Naïve, high dose, older adult) | Experimental | 1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who are vaccine naïve Receives: Drug: VXA-CoV2-1.1-S |
| Part 1 Cohort 2a (Prior vaccinated, low dose, young adult) | Experimental | 1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who have received prior vaccinations with an mRNA vaccine Receives: Drug: VXA-CoV2-1.1-S |
| Part 1 Cohort 2b (Prior vaccinated, high dose, young adult) | Experimental | 1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who have received prior vaccinations with an mRNA vaccine Receives: Drug: VXA-CoV2-1.1-S |
| Part 1 Cohort 2c (Prior vaccinated, low dose, older adult) | Experimental | 1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who have received prior vaccinations with an mRNA vaccine Receives: Drug: VXA-CoV2-1.1-S |
| Part 1 Cohort 2d (Prior vaccinated, high dose, older adult) | Experimental | 1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who have received prior vaccinations with an mRNA vaccine Receives: Drug: VXA-CoV2-1.1-S |
| Part 2 Healthy Adults: Active vaccine | Experimental | Repeat dose vaccinations with VXA-CoV2-1.1-S at dose selected from Part 1 in healthy male and female adult volunteers 18 to 75 years old Receives: Drug: VXA-CoV2-1.1-S |
| Part 2 Healthy Adults: Placebo control | Placebo comparator | Repeat dose administration with matching placebo tablets in healthy male and female adult volunteers 18 to 75 years old Receives: Other: Placebo Tablets |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants Who Experienced a Solicited Symptom of Reactogenicity
Solicited symptoms of reactogenicity were predefined systemic signs and symptoms of reactogenicity for which the participant was specifically questioned, and which were noted by the participant in their daily Solicited Symptom Diary for 7 days after each vaccination, including:
- fever (any temperature 100°F or higher)
- headache
- myalgia (muscle pain)
- abdominal pain
- anorexia (defined and not eating)
- nausea
- vomiting
- diarrhea
- malaise/fatigue
Measured: Up to 7 days after Dose 1 (Days 1 to 8) and Dose 2 (Days 29 to 36)
Severity of Solicited Symptoms of Reactogenicity
Solicited symptoms of reactogenicity were predefined systemic signs and symptoms of reactogenicity for which the participant was specifically questioned, and which were noted by the participant in their daily Solicited Symptom Diary for 7 days after each vaccination, including:
- fever (any temperature 100°F or higher)
- headache
- myalgia (muscle pain)
- abdominal pain
- anorexia (defined and not eating)
- nausea
- vomiting
- diarrhea
- malaise/fatigue
Participants were instructed to rate solicited symptoms of reactogenicity that were collected in their Solicited Symptom Diary with the below grades, against pre-defined criteria as noted in the protocol:
- Grade 1 - Mild
- Grade 2 - Moderate
- Grade 3 - Severe
- Grade 4 - Life Threatening
Participants with multiple solicited symptoms were only counted once, the highest severity of which was used.
Measured: Up to 7 days after Dose 1 (Days 1 to 8) and Dose 2 (Days 29 to 36)
Number of Participants Who Experienced an Unsolicited Treatment-emergent Adverse Event (TEAE) During the Active Treatment Period
A TEAE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention, occurring after first dose of study drug.
A serious TEAE was any TEAE that met any 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.
- Was a suspected transmission of any infectious agent via a medicinal product.
- Was a significant medical event, as judged by the investigator.
Measured: Day 1 to Day 57
Severity of Unsolicited TEAEs During the Active Treatment Period
All unsolicited TEAEs during the active treatment period were assessed by the investigator using the below scale:
- Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities.
- Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning.
- Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating.
- Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred.
Participants with multiple TEAEs during the active treatment period were only counted once, the highest severity of which was used.
Measured: Day 1 to Day 57
Number of Participants Who Experienced a Medically Attended Adverse Event (MAAE) During the Active Treatment Period
MAAEs were defined as TEAEs with medically-attended visits including hospital, emergency room, urgent care clinic, or other visits to or from medical personnel for any reason. Routine study visits were not considered medically-attended visits. New onset of chronic illness/diseases (NOCI) and adverse events of special interest (AESIs) were collected as part of the MAAEs. As defined in the protocol, adverse events for potential immune-mediated medical conditions as well as events associated with thrombosis and thrombocytopenia were considered AESIs.
Measured: Day 1 to Day 57
Severity of MAAEs During the Active Treatment Period
All MAAEs during the active treatment period were assessed by the investigator using the below scale:
- Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities.
- Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning.
- Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating.
- Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred.
Participants with multiple MAAEs during the active treatment period were only counted once, the highest severity of which was used.
Measured: Day 1 to Day 57
Secondary outcomes (15)
Number of Participants Who Experienced a MAAE During the Safety Follow-up Period
MAAEs were defined as TEAEs with medically-attended visits including hospital, emergency room, urgent care clinic, or other visits to or from medical personnel for any reason. Routine study visits were not considered medically-attended visits. NOCI and AESIs were collected as part of the MAAEs. As defined in the protocol, adverse events for potential immune-mediated medical conditions as well as events associated with thrombosis and thrombocytopenia were considered AESIs.
Measured: From last dose up to 12 months post-last dose
Severity of MAAEs During the Safety Follow-up Period
All MAAEs during the safety follow-up period were assessed by the investigator using the below scale:
- Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities.
- Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning.
- Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating.
- Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred.
Participants with multiple MAAEs during the safety follow-up period were only counted once, the highest severity of which was used.
Measured: From last dose up to 12 months post-last dose
Number of Participants Who Experienced a Serious TEAE During the Safety Follow-up Period
A TEAE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention, occurring after first dose of study drug.
A serious TEAE was any TEAE that met any 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.
- Was a suspected transmission of any infectious agent via a medicinal product.
- Was a significant medical event, as judged by the investigator.
Measured: From last dose up to 12 months post-last dose
Severity of Serious TEAEs During the Safety Follow-up Period
All serious TEAEs during the active treatment period were assessed by the investigator using the below scale:
- Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities.
- Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning.
- Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating.
- Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred.
Participants with multiple serious TEAEs during the active treatment period were only counted once, the highest severity of which was used.
Measured: From last-dose up to 12 months post-last dose
Levels of SARS-CoV2-specific Immunoglobulin G Spike (IgG-S) Antibodies by Mesoscale Discovery (MSD) Assay
SARS-CoV2-specific IgG-S antibody levels were measured on specific timepoints via MSD assay. For results below the lower limit of quantification (LLOQ), the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the upper limit of quantification (ULOQ), the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin G Nucleocapsid (IgG-N) Antibodies by MSD Assay
SARS-CoV2-specific IgG-N antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin G Receptor-binding Domain (IgG-RBD) Antibodies by MSD Assay
SARS-CoV2-specific IgG-RBD antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin A Spike (IgA-S) Antibodies by MSD Assay
SARS-CoV2-specific IgA-S antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin A Nucleocapsid (IgA-N) Antibodies by MSD Assay
SARS-CoV2-specific IgA-N antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin A Receptor-binding Domain (IgA-RBD) Antibodies by MSD Assay
SARS-CoV2-specific IgA-RBD antibody levels were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Levels of Neutralizing Serum Antibody Titers to SARS-CoV-2
Neutralizing Serum Antibody Titers to SARS-CoV-2 were measured on specific timepoints via qualified pseudovirus assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Mean Percentage of Cluster of Differentiation 8 (CD8) T-cells Making Tumor Necrosis Factor (TNF) Alpha+ Spike (S) as Measured by Intracellular Cytokine Cytometry (ICC)
Mean Percentage of CD8 T-cells making TNF alpha+S were measured on specific timepoints via ICC. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 8, Day 29 and Day 36
Mean Percentage of CD8 T-cells Making Interferon (IFN) Gamma+S as Measured by ICC
Mean Percentage of CD8 T-cells making IFN gamma+S were measured on specific timepoints via ICC. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 8, Day 29 and Day 36
Levels of SARS-CoV2-specific IgA-S Antibodies in Nasal Swabs
SARS-CoV2-specific IgA-S antibody levels in nasal swabs were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific IgA-S Antibodies in Saliva Swabs
SARS-CoV2-specific IgA-S antibody levels in saliva swabs were measured on specific timepoints via MSD assay. For results below the LLOQ, the value was replaced with 1/2 the numeric portion of the original result rounded up to nearest integer. For results above the ULOQ, the value was replaced with the numeric portion of the original result.
Measured: Day 1, Day 29 and Day 57
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Oct 2021
- Study start22 Oct 2021
- Primary completion10 Jun 2022
- Study completion9 May 2023
Why it stopped: The study drug was no longer available.
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.
- 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 2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Sequential
- Model description
- Open-label dose and age escalation lead in phase in naive and prior vaccinated subjects, followed by a multi-center, placebo-controlled efficacy phase.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 66 participants (actual)
Sponsor and investigators
- Lead sponsor
- Vaxart
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- James Cummings, MD, Study director, Vaxart, Inc.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05067933
- Sponsor's protocol ID
- VXA-COV2-201
- Status last verified
- Mar 2025
- First submitted
- 16 Sep 2021
- Last updated
- 13 Apr 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 2, Double-Blind, Multi-Center, Randomized, Placebo-Controlled, Dose-Ranging Trial to Determine the Safety, Immunogenicity and Efficacy of an Adenoviral-Vector Based Vaccine Expressing Severe Acute Respiratory Syndrome (SARS-CoV-2) and dsRNA Adjuvant Administered Orally
- ClinicalTrials.gov ID
- NCT05067933
- Acronym / sponsor ID
- VXA-COV2-201
- Conditions
- COVID-19
- Keywords
- oral vaccine, SARS-CoV-2, tablet vaccine
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: The study drug was no longer available.
- Enrolment
- 66 participants (actual)
- Lead sponsor
- VaxartIndustry (pharma, biotech, devices)
- Study start
- 22 Oct 2021 (actual)
- Primary completion
- 10 Jun 2022 (actual)
- Study completion
- 9 May 2023 (actual)
- First posted
- 5 Oct 2021 (actual)
- Results
- Posted 13 Apr 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Part 1: An open label, dose and age escalation phase to evaluate the safety and immunogenicity of VXA-CoV2-1.1-S with a repeat-dose vaccination schedule in healthy adults aged 18 - 75 years old that are either vaccine naive or have received prior vaccination with an mRNA (messenger ribonucleic acid) vaccine for the prevention of COVID-19.
Part 2: This phase will assess the efficacy of prophylactic VXA-CoV2-1.1-S against confirmed COVID-19 occurring from 7 days after second dose with a repeat-dose vaccination schedule in healthy adults compared to placebo. Safety and immunogenicity of VXA-CoV2-1.1-S will also be evaluated in this phase.
Detailed description
Part 1: This is an open-label, dose-ranging phase of the study to determine the safety and immunogenicity of an orally administered adenoviral-vector based vaccine (VXA-COV2-1.1-S) expressing a SARS-CoV-2 antigen and dsRNA adjuvant. Post screening activities, healthy adult volunteers, either naïve or prior vaccinated with an mRNA COVID-19 vaccine, aged 18 - 55 yrs old, and then 56 - 75 yrs old, will be enrolled into the study in 8 subgroups. Participants will receive either a low or a high dose of an oral tableted vaccine at Days 1 and Day 29. The total study period will last ~ 2 months during the active phase, with a total 12 month safety follow-up period post last vaccination. Safety, reactogenicity and immunogenicity assessments will be performed at set times during the study active and follow-up periods. Subjects will be monitored for symptoms of COVID-19 throughout the duration of the study follow-up period. An independent data monitoring committee (IDMC) will provide safety oversight through the duration of the trial. Safety and immunogenicity data will inform on the dose selection for Part 2.
Part 2: This will be a placebo-controlled phase with the vaccine dose level selected from Part 1. Subjects will receive two doses of vaccine or placebo at Days 1 and 29. Subjects will be followed as in Part 1 for safety and immunogenicity. They will also be followed for 6 months for efficacy.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 10
- Model description
- Open-label dose and age escalation lead in phase in naive and prior vaccinated subjects, followed by a multi-center, placebo-controlled efficacy phase.
| Arm | Type | Receives |
|---|---|---|
| Part 1 Cohort 1a (Naïve, low dose, young adult) | Experimental | Drug: VXA-CoV2-1.1-S1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who are vaccine naïve |
| Part 1 Cohort 1b (Naïve, high dose, young adult) | Experimental | Drug: VXA-CoV2-1.1-S1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who are vaccine naïve |
| Part 1 Cohort 1c (Naïve, low dose, older adult) | Experimental | Drug: VXA-CoV2-1.1-S1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who are vaccine naïve |
| Part 1 Cohort 1d (Naïve, high dose, older adult) | Experimental | Drug: VXA-CoV2-1.1-S1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who are vaccine naïve |
| Part 1 Cohort 2a (Prior vaccinated, low dose, young adult) | Experimental | Drug: VXA-CoV2-1.1-S1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who have received prior vaccinations with an mRNA vaccine |
| Part 1 Cohort 2b (Prior vaccinated, high dose, young adult) | Experimental | Drug: VXA-CoV2-1.1-S1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in young adults (18-55 yrs) who have received prior vaccinations with an mRNA vaccine |
| Part 1 Cohort 2c (Prior vaccinated, low dose, older adult) | Experimental | Drug: VXA-CoV2-1.1-S1E10 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who have received prior vaccinations with an mRNA vaccine |
| Part 1 Cohort 2d (Prior vaccinated, high dose, older adult) | Experimental | Drug: VXA-CoV2-1.1-S1E11 repeat-dose vaccinations with VXA-CoV2-1.1-S at Days 1 and 29 in older adults (56-75 yrs) who have received prior vaccinations with an mRNA vaccine |
| Part 2 Healthy Adults: Active vaccine | Experimental | Drug: VXA-CoV2-1.1-SRepeat dose vaccinations with VXA-CoV2-1.1-S at dose selected from Part 1 in healthy male and female adult volunteers 18 to 75 years old |
| Part 2 Healthy Adults: Placebo control | Placebo comparator | Other: Placebo TabletsRepeat dose administration with matching placebo tablets in healthy male and female adult volunteers 18 to 75 years old |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (19 listed)
- 18 - 75 years of age (inclusive) at the time of signing the Informed Consent Form (ICF).
- Cohort 1 ONLY - Naive of any prior vaccination for the prevention of COVID-19 (tested using a rapid antibody test) at screening and within 7 days prior to the enrollment (Day 1).
- Cohort 2 ONLY - Have received prior immunizations (both doses) with an EUA or FDA approved mRNA vaccine for the prevention of COVID-19, at least 6 months prior to enrollment (Day 1).
- In stable and good health, without significant medical illness, based on medical history, physical examination, vital signs, and clinical laboratory tests as determined by the Investigator.
- Safety laboratory values1 within the following range criteria at screening:
Key exclusion criteria (51 listed)
- Clinically significant acute illness within 72 hours prior to vaccination defined as the presence of a moderate or severe illness (as determined by the Investigator through medical history and physical exam) (assessment may be repeated during screening period).
- Current or known previous infection with SARS-CoV-2 or receipt of any therapeutic for the prevention or treatment of COVID-19, Middle East Respiratory Syndrome (MERS), or severe acute respiratory syndrome (SARS). [EUA or FDA approved mRNA vaccines for the prevention of SARS-CoV-2 infection taken at least 6 months prior to enrollment are permitted in Cohort 2]
- Individuals with the following underlying medical conditions who are at higher risk (or might be at higher risk) of severe illness from COVID-19 per the guidance from the Centers for Disease Control and Prevention (CDC):
- Diagnosed bleeding disorder or significant bruising or bleeding difficulties that could make blood draws problematic.
- Any condition that resulted in the absence or removal of the spleen.
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 |
|---|---|---|
| VXA-CoV2-1.1-SAlso: Oral Tableted Ad5 COVID-19 VaccineCOVID-19 (SARS-CoV-2) E1-/E3-Deleted Replication Defective Recombinant Adenovirus 5 with dsRNA Adjuvant Oral Tablet Vaccine | Drug | Part 1 Cohort 1a (Naïve, low dose, young adult), Part 1 Cohort 1b (Naïve, high dose, young adult), Part 1 Cohort 1c (Naïve, low dose, older adult), Part 1 Cohort 1d (Naïve, high dose, older adult), Part 1 Cohort 2a (Prior vaccinated, low dose, young adult), Part 1 Cohort 2b (Prior vaccinated, high dose, young adult), Part 1 Cohort 2c (Prior vaccinated, low dose, older adult), Part 1 Cohort 2d (Prior vaccinated, high dose, older adult), Part 2 Healthy Adults: Active vaccine |
| Placebo TabletsPlacebo tablets matching the active vaccine tablets | Other | Part 2 Healthy Adults: Placebo control |
Primary outcome
Number of Participants Who Experienced a Solicited Symptom of Reactogenicity
Time frame: Up to 7 days after Dose 1 (Days 1 to 8) and Dose 2 (Days 29 to 36)
Solicited symptoms of reactogenicity were predefined systemic signs and symptoms of reactogenicity for which the participant was specifically questioned, and which were noted by the participant in their daily Solicited Symptom Diary for 7 days after each vaccination, including: * fever (any temperature 100°F or higher) * headache * myalgia (muscle pain) * abdominal pain * anorexia (defined and not eating) * nausea * vomiting * diarrhea * malaise/fatigue
Severity of Solicited Symptoms of Reactogenicity
Time frame: Up to 7 days after Dose 1 (Days 1 to 8) and Dose 2 (Days 29 to 36)
Solicited symptoms of reactogenicity were predefined systemic signs and symptoms of reactogenicity for which the participant was specifically questioned, and which were noted by the participant in their daily Solicited Symptom Diary for 7 days after each vaccination, including: * fever (any temperature 100°F or higher) * headache * myalgia (muscle pain) * abdominal pain * anorexia (defined and not eating) * nausea * vomiting * diarrhea * malaise/fatigue Participants were instructed to rate solicited symptoms of reactogenicity that were collected in their Solicited Symptom Diary with the below grades, against pre-defined criteria as noted in the protocol: * Grade 1 - Mild * Grade 2 - Moderate * Grade 3 - Severe * Grade 4 - Life Threatening Participants with multiple solicited symptoms were only counted once, the highest severity of which was used.
Number of Participants Who Experienced an Unsolicited Treatment-emergent Adverse Event (TEAE) During the Active Treatment Period
Time frame: Day 1 to Day 57
A TEAE was any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention, occurring after first dose of study drug. A serious TEAE was any TEAE that met any 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. * Was a suspected transmission of any infectious agent via a medicinal product. * Was a significant medical event, as judged by the investigator.
Severity of Unsolicited TEAEs During the Active Treatment Period
Time frame: Day 1 to Day 57
All unsolicited TEAEs during the active treatment period were assessed by the investigator using the below scale: * Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities. * Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning. * Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating. * Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred. Participants with multiple TEAEs during the active treatment period were only counted once, the highest severity of which was used.
Number of Participants Who Experienced a Medically Attended Adverse Event (MAAE) During the Active Treatment Period
Time frame: Day 1 to Day 57
MAAEs were defined as TEAEs with medically-attended visits including hospital, emergency room, urgent care clinic, or other visits to or from medical personnel for any reason. Routine study visits were not considered medically-attended visits. New onset of chronic illness/diseases (NOCI) and adverse events of special interest (AESIs) were collected as part of the MAAEs. As defined in the protocol, adverse events for potential immune-mediated medical conditions as well as events associated with thrombosis and thrombocytopenia were considered AESIs.
Severity of MAAEs During the Active Treatment Period
Time frame: Day 1 to Day 57
All MAAEs during the active treatment period were assessed by the investigator using the below scale: * Mild: Events that required minimal or no treatment and did not interfere with the participant's daily activities. * Moderate: Events that resulted in a low level of inconvenience or concern with the therapeutic measures. Moderate events may have caused some interference with functioning. * Severe: Events that interrupted a participant's usual daily activity and may have required systemic drug therapy or other treatment. Severe events were usually incapacitating. * Life Threatening: Any adverse drug experience that placed the participant, in the view of the investigator, at immediate risk of death from the reaction as it occurred. Participants with multiple MAAEs during the active treatment period were only counted once, the highest severity of which was used.
15 secondary outcomes
Number of Participants Who Experienced a MAAE During the Safety Follow-up Period
Time frame: From last dose up to 12 months post-last dose
Severity of MAAEs During the Safety Follow-up Period
Time frame: From last dose up to 12 months post-last dose
Number of Participants Who Experienced a Serious TEAE During the Safety Follow-up Period
Time frame: From last dose up to 12 months post-last dose
Severity of Serious TEAEs During the Safety Follow-up Period
Time frame: From last-dose up to 12 months post-last dose
Levels of SARS-CoV2-specific Immunoglobulin G Spike (IgG-S) Antibodies by Mesoscale Discovery (MSD) Assay
Time frame: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin G Nucleocapsid (IgG-N) Antibodies by MSD Assay
Time frame: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin G Receptor-binding Domain (IgG-RBD) Antibodies by MSD Assay
Time frame: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin A Spike (IgA-S) Antibodies by MSD Assay
Time frame: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin A Nucleocapsid (IgA-N) Antibodies by MSD Assay
Time frame: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific Immunoglobulin A Receptor-binding Domain (IgA-RBD) Antibodies by MSD Assay
Time frame: Day 1, Day 29 and Day 57
Levels of Neutralizing Serum Antibody Titers to SARS-CoV-2
Time frame: Day 1, Day 29 and Day 57
Mean Percentage of Cluster of Differentiation 8 (CD8) T-cells Making Tumor Necrosis Factor (TNF) Alpha+ Spike (S) as Measured by Intracellular Cytokine Cytometry (ICC)
Time frame: Day 1, Day 8, Day 29 and Day 36
Mean Percentage of CD8 T-cells Making Interferon (IFN) Gamma+S as Measured by ICC
Time frame: Day 1, Day 8, Day 29 and Day 36
Levels of SARS-CoV2-specific IgA-S Antibodies in Nasal Swabs
Time frame: Day 1, Day 29 and Day 57
Levels of SARS-CoV2-specific IgA-S Antibodies in Saliva Swabs
Time frame: Day 1, Day 29 and Day 57
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Apr 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- 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.
James Cummings, MD study director
Vaxart, Inc.
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing VXA-CoV2-1.1-S in people with COVID-19, run by Vaxart 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 19 inclusion and 51 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: stopped early, as of the sponsor's last update on 13 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 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 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
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 13 Apr 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 Who Experienced a Solicited Symptom of Reactogenicity (time frame: Up to 7 days after Dose 1 (Days 1 to 8) and Dose 2 (Days 29 to 36)). The study lists 6 primary outcomes in all. 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 13 Apr 2025.