A Ph 2 Trial With an Oral Tableted COVID-19 Vaccine

NCT05067933 | Terminated Phase 2 Results DMC FDA Drug

• 1 other identifier: VXA-COV2-201
• Study Type: interventional
• Target: 66
• Locations: 1 country
• Sites: 4

Brief 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 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.

Conditions

COVID-19

Keywords

oral vaccine; SARS-CoV-2; tablet vaccine

Outcome Measures

Primary Outcomes (6)

• 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

  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.

  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.

  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.

  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.

  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.

  Day 1 to Day 57

Secondary Outcomes (15)

• Number of Participants Who Experienced a MAAE During the Safety Follow-up Period

  From last dose up to 12 months post-last dose

• Severity of MAAEs During the Safety Follow-up Period

  From last dose up to 12 months post-last dose

• Number of Participants Who Experienced a Serious TEAE During the Safety Follow-up Period

  From last dose up to 12 months post-last dose

• Severity of Serious TEAEs During the Safety Follow-up Period

  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

  Day 1, Day 29 and Day 57

Study Arms (10)

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

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

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

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

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

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

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

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

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

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

Other: Placebo Tablets

Interventions

VXA-CoV2-1.1-S DRUG

COVID-19 (SARS-CoV-2) E1-/E3-Deleted Replication Defective Recombinant Adenovirus 5 with dsRNA Adjuvant Oral Tablet Vaccine

Also known as: Oral Tableted Ad5 COVID-19 Vaccine

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 Tablets OTHER

Placebo tablets matching the active vaccine tablets

Part 2 Healthy Adults: Placebo control

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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
• 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.

You may not qualify if:

• 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)
• 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

Sponsors & Collaborators

• Vaxart: lead

Study Sites (4)

Ark Clinical Research

Long Beach, California, 90806, United States

Location

AMR Wichita East

Wichita, Kansas, 64114, United States

Location

Velocity Clinical Research, Inc,

Cleveland, Ohio, 44122, United States

Location

AMR Knoxville

Knoxville, Tennessee, 37909, United States

Location

MeSH Terms

Conditions

COVID-19

Interventions

VXA-CoV2-1.1-S vaccine

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Limitations and Caveats

Vaxart decided not to conduct Part 2 of this study, so results for Part 2 were not included in this summary.

Results Point of Contact

• Title: Melanie Drayton
• Organization: Vaxart

ClinicalTrials@Vaxart.com

650-392-3109

Study Officials

• James Cummings, MD

  Vaxart, Inc.

  STUDY DIRECTOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: Yes

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Masking Details: Double-Blind, Randomized (Part 2)
• Purpose: PREVENTION
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Open-label dose and age escalation lead in phase in naive and prior vaccinated subjects, followed by a multi-center, placebo-controlled efficacy phase.

Study Record Dates

• First Submitted: September 16, 2021
• First Posted: October 5, 2021
• Study Start: October 22, 2021
• Primary Completion: June 10, 2022
• Study Completion: May 9, 2023
• Last Updated: April 13, 2025
• Results First Posted: April 13, 2025

Record last verified: 2025-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (4)