SARS-CoV-2
Conditions
Brief summary
This is an open-label study enrolling healthy adults that participated in Study ARCT-021-01 (the Parent Study). Participants will receive either a single injection of ARCT-021 or no injection and be followed for up to 365 days.
Detailed description
This is a phase 2a, open-label study enrolling up to 106 healthy adults that participated in Study ARCT-021-01 (the Parent Study). Participants will enter this study approximately 3 months after their final study visit in the Parent Study. Participants that received placebo in the Parent Study or who are seronegative for SARS-CoV-2 neutralizing antibodies at screening will receive a single dose of ARCT-021 and will be followed for 365 days. Participants that received two injections of ARCT-021 in the Parent Study will not receive any further injections of ARCT-021 and will be followed for 281 days.
Interventions
BIOLOGICALARCT-021
ARCT-021 single dose
Sponsors
Arcturus Therapeutics, Inc.
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
Individuals who: 1. are able to give consent 2. must have completed Study ARCT-021-01 3. agree to comply with all study visits and procedures Only for subjects that will receive ARCT-021 in this study: 4. are healthy and medically stable 5. are not planning to donate blood or plasma until 28 days after the last dose of ARCT-021. 6. are willing to refrain from strenuous exercise/activity and alcohol for at least 72 hours prior to study visits and until 28 days after the last dose of ARCT-021. 7. are willing to adhere to contraception requirements if sexually active and/or are of child-bearing potential
Exclusion criteria
Individuals who: 1. are unable to comply with the study visits or procedures in Study ARCT-021-01 2. received placebo in the Parent Study and who are not willing to receive ARCT-021 in this study. Only for subjects that will receive ARCT-021 in this study: 3. have or will receive any of the SARS CoV-2 or another experimental coronavirus during this study. 4. have a diagnosis of new clinically significant abnormalities including but not limited to * Respiratory disease requiring daily medications or oxygen currently or any treatment of respiratory disease exacerbations * Significant heart conditions * Significant neurological conditions * Significant blood disorders * Newly diagnosed autoimmune disease * Major surgery 5. have abnormal screening laboratory results 6. have uncontrolled diabetes 7. use of any prescription or over-the-counter medications within 7 days prior to vaccination 8. have received immunoglobulins and/or any blood or blood products 9. have a bleeding disorder 10. have uncontrolled blood pressure 11. have been treated with another investigational drug, biological agent, or device since completion of the Parent Study 12. have received or plan to receive: * A licensed, live vaccine within 4 weeks before or after study vaccination, or * A licensed, inactivated vaccine within 2 weeks before or after study vaccination 13. have traveled outside of Singapore within 30 days before the vaccination or plans to travel outside of Singapore within 60 days after vaccination. 14. other restrictions may apply
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Solicited Local and Systemic Adverse Events | Up to Day 7 (7 days after vaccine administration) | Solicited local adverse events were defined as pain, tenderness, erythema, or swelling at the injection site. Solicited systemic adverse events were defined as fever, fatigue, headache, chills, nausea, vomiting, diarrhoea, myalgia, and arthralgia. A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module. |
| Number of Participants With Unsolicited Adverse Events | Up to Day 29 (28 days after vaccine administration) | Unsolicited adverse events were defined as any spontaneously occurring adverse event (serious and non-serious). A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module. |
| Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | Up to a maximum of approximately 12 months | SAEs were defined as any event that resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in a persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions, a congenital anomaly or birth defect, or was an important medical event. A NOCD was defined as a MAAE that led to the new diagnosis of a chronic medical condition that was not present or suspected prior to enrollment. A MAAE was an adverse event that led to an unscheduled visit (including a telemedicine visit) to a healthcare practitioner. A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Cohorts 1a and 1b: Days 1, 29, 57, Cohort 2: Day 29 | GMC data are reported for the S (spike binding antibodies) analyte. |
| Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Cohorts 1a and 1b: Days 1, 29, 57, Cohort 2: Day 29 | — |
| Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Binding Antibodies) | Days 29, and 57 | Seroconversion was defined as a 4-fold increase in antibody titer/concentration from baseline. Data is presented for the number of participants seroconverting for binding antibodies and immunoglobulin G (IgG) antibodies against the full-length SARS-CoV-2 recombinant spike protein antigen and spike protein receptor binding domain of the SARS-CoV-2 spike glycoprotein (RBD). ARCT-021-naïve participants were those participants whose first ARCT-021 vaccine administration occurred in this study (Cohort 1a). As pre-specified, data is presented for participants in Cohort 1a only. |
| GMFR in SARS-CoV-2 Binding Antibody Titers | Cohort 1a: Days 29, 57, Cohort 1b: Days 1, 29, 57, and Cohort 2: Day 29 | GMFR data are reported for the S (spike binding antibodies) analyte. |
| Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Cohort 1a: Days 29, 57, Cohort 1b: Days 1, 29, 57, and Cohort 2: Day 29 | — |
| Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Neutralizing Antibodies) | Days 29, and 57 | Seroconversion was defined as a 4-fold increase in antibody titer/concentration from baseline. Data is presented for the number of participants seroconverting for neutralizing antibodies and immunoglobulin G (IgG) antibodies against the full-length SARS-CoV-2 recombinant spike protein antigen and spike protein receptor binding domain of the SARS-CoV-2 spike glycoprotein (RBD). ARCT-021-naïve participants were those participants whose first ARCT-021 vaccine administration occurred in this study (Cohort 1a). As pre-specified, data is presented for participants in Cohort 1a only. |
Countries
Singapore
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Cohort 1a Participants who participated in Study ARCT-021-01 (the Parent Study \[NCT04480957\]) and were without detectable neutralizing antibody responses at baseline received a single-dose primary injection of ARCT-021 on Day 1. | 12 |
| Cohort 1b Participants who participated in Study ARCT-021-01 (the Parent Study \[NCT04480957\]) and were without detectable neutralizing antibody responses at baseline received a single-dose booster injection of ARCT-021 on Day 1. | 12 |
| Cohort 2: Younger Adults Participants aged 21 to 55 years old who participated in Study ARCT-021-01 (the Parent Study \[NCT04480957\]) and were vaccinated with ARCT-021 who did not receive subsequent vaccination with ARCT-021 in this study. | 25 |
| Cohort 2: Older Adults Participants aged 56 to 80 years old who participated in Study ARCT-021-01 (the Parent Study \[NCT04480957\]) and were vaccinated with ARCT-021 who did not receive subsequent vaccination with ARCT-021 in this study. | 16 |
| Total | 65 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 |
|---|---|---|---|---|---|
| Overall Study | Sponsor decision | 0 | 0 | 1 | 0 |
Baseline characteristics
| Characteristic | Cohort 1a | Cohort 1b | Cohort 2: Younger Adults | Cohort 2: Older Adults | Total |
|---|---|---|---|---|---|
| Age, Continuous | 45.1 years STANDARD_DEVIATION 14.99 | 48.3 years STANDARD_DEVIATION 16.17 | 39.7 years STANDARD_DEVIATION 8.34 | 63.7 years STANDARD_DEVIATION 4.13 | 48.2 years STANDARD_DEVIATION 14.28 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 12 Participants | 12 Participants | 25 Participants | 16 Participants | 65 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Asian | 12 Participants | 11 Participants | 22 Participants | 16 Participants | 61 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) White | 0 Participants | 1 Participants | 1 Participants | 0 Participants | 2 Participants |
| Sex: Female, Male Female | 3 Participants | 2 Participants | 9 Participants | 4 Participants | 18 Participants |
| Sex: Female, Male Male | 9 Participants | 10 Participants | 16 Participants | 12 Participants | 47 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 12 | 0 / 12 | 0 / 25 | 0 / 16 |
| other Total, other adverse events | 3 / 12 | 1 / 12 | 3 / 25 | 0 / 16 |
| serious Total, serious adverse events | 0 / 12 | 1 / 12 | 0 / 25 | 0 / 16 |
Outcome results
Primary
Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs)
SAEs were defined as any event that resulted in death, was life threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in a persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions, a congenital anomaly or birth defect, or was an important medical event. A NOCD was defined as a MAAE that led to the new diagnosis of a chronic medical condition that was not present or suspected prior to enrollment. A MAAE was an adverse event that led to an unscheduled visit (including a telemedicine visit) to a healthcare practitioner. A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module.
Time frame: Up to a maximum of approximately 12 months
Population: Safety population for Cohort 1a, which included all participants who received Study vaccine in ARCT-021-02 only, and in the Longitudinal Safety population for Cohorts 1b and Cohort 2, which included all participants who received Study vaccine in ARCT- 021-01 and ARCT-021-02 (Cohort 1b) or ARCT-021-01 only (Cohort 2).
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Cohort 1a | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | SAEs | 0 Participants |
| Cohort 1a | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | MAAEs | 2 Participants |
| Cohort 1a | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | Unsolicited Adverse Events Associated with NOCD | 0 Participants |
| Cohort 1b | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | SAEs | 1 Participants |
| Cohort 1b | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | MAAEs | 5 Participants |
| Cohort 1b | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | Unsolicited Adverse Events Associated with NOCD | 1 Participants |
| Cohort 2: Younger Adults | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | Unsolicited Adverse Events Associated with NOCD | 0 Participants |
| Cohort 2: Younger Adults | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | SAEs | 0 Participants |
| Cohort 2: Younger Adults | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | MAAEs | 3 Participants |
| Cohort 2: Older Adults | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | SAEs | 0 Participants |
| Cohort 2: Older Adults | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | MAAEs | 0 Participants |
| Cohort 2: Older Adults | Number of Participants With Serious Adverse Events (SAEs), Unsolicited Adverse Events Associated With New Onset of Chronic Disease (NOCD) or Medically Attended Adverse Events (MAAEs) | Unsolicited Adverse Events Associated with NOCD | 0 Participants |
Primary
Number of Participants With Solicited Local and Systemic Adverse Events
Solicited local adverse events were defined as pain, tenderness, erythema, or swelling at the injection site. Solicited systemic adverse events were defined as fever, fatigue, headache, chills, nausea, vomiting, diarrhoea, myalgia, and arthralgia. A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module.
Time frame: Up to Day 7 (7 days after vaccine administration)
Population: Safety population for Cohort 1a, which included all participants who received Study vaccine in ARCT-021-02 only, and in the Longitudinal Safety population for Cohort 1b, which included all participants who received Study vaccine in ARCT- 021-01 and ARCT-021-02. As pre-specified, data is reported for Cohort 1 only.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Cohort 1a | Number of Participants With Solicited Local and Systemic Adverse Events | Solicited Local | 11 Participants |
| Cohort 1a | Number of Participants With Solicited Local and Systemic Adverse Events | Solicited Systemic | 11 Participants |
| Cohort 1b | Number of Participants With Solicited Local and Systemic Adverse Events | Solicited Local | 10 Participants |
| Cohort 1b | Number of Participants With Solicited Local and Systemic Adverse Events | Solicited Systemic | 8 Participants |
Primary
Number of Participants With Unsolicited Adverse Events
Unsolicited adverse events were defined as any spontaneously occurring adverse event (serious and non-serious). A summary of serious and all other non-serious adverse events regardless of causality is located in the Reported Adverse Events module.
Time frame: Up to Day 29 (28 days after vaccine administration)
Population: Safety population for Cohort 1a, which included all participants who received Study vaccine in ARCT-021-02 only, and in the Longitudinal Safety population for Cohort 1b, which included all participants who received Study vaccine in ARCT- 021-01 and ARCT-021-02. As pre-specified, data is reported for Cohort 1 only.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Cohort 1a | Number of Participants With Unsolicited Adverse Events | 3 Participants |
| Cohort 1b | Number of Participants With Unsolicited Adverse Events | 2 Participants |
Secondary
Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies
GMC data are reported for the S (spike binding antibodies) analyte.
Time frame: Cohorts 1a and 1b: Days 1, 29, 57, Cohort 2: Day 29
Population: Immunogenicity population, which included all participants who received Study vaccine in either ARCT-021-01 or ARCT-021-02 who had evaluable immunogenicity data following first vaccine administration. Overall number of participants analyzed' = participants evaluable for endpoint. 'Number analyzed' = participants evaluable at specified timepoint.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Cohort 1a | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 29 | 1629.3 Arbitrary units per milliliter (AU/mL) |
| Cohort 1a | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 1 | 47.3 Arbitrary units per milliliter (AU/mL) |
| Cohort 1a | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 57 | 1013.5 Arbitrary units per milliliter (AU/mL) |
| Cohort 1b | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 57 | 3088.1 Arbitrary units per milliliter (AU/mL) |
| Cohort 1b | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 1 | 310.6 Arbitrary units per milliliter (AU/mL) |
| Cohort 1b | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 29 | 5319.8 Arbitrary units per milliliter (AU/mL) |
| Cohort 2: Younger Adults | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 29 | 802.8 Arbitrary units per milliliter (AU/mL) |
| Cohort 2: Older Adults | Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies | Day 29 | 713.2 Arbitrary units per milliliter (AU/mL) |
Secondary
Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers
Time frame: Cohort 1a: Days 29, 57, Cohort 1b: Days 1, 29, 57, and Cohort 2: Day 29
Population: Immunogenicity population, which included all participants who received Study vaccine in either ARCT-021-01 or ARCT-021-02 and had evaluable immunogenicity data following first vaccine administration. Overall number of participants analyzed' = participants evaluable for endpoint. 'Number analyzed' = participants evaluable at specified timepoint.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Cohort 1a | Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Day 57 | 1.1 Ratio |
| Cohort 1a | Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Day 29 | 1.2 Ratio |
| Cohort 1b | Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Day 29 | 4.3 Ratio |
| Cohort 1b | Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Day 1 | 0.9 Ratio |
| Cohort 1b | Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Day 57 | 3.6 Ratio |
| Cohort 2: Younger Adults | Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Day 29 | 1.6 Ratio |
| Cohort 2: Older Adults | Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers | Day 29 | 1.0 Ratio |
Secondary
Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies
Time frame: Cohorts 1a and 1b: Days 1, 29, 57, Cohort 2: Day 29
Population: Immunogenicity population, which included all participants who received Study vaccine in either ARCT-021-01 or ARCT-021-02 who had evaluable immunogenicity data following first vaccine administration. Overall number of participants analyzed' = participants evaluable for endpoint. 'Number analyzed' = participants evaluable at specified timepoint.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Cohort 1a | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 29 | 6.1 Titer |
| Cohort 1a | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 1 | 5.0 Titer |
| Cohort 1a | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 57 | 5.7 Titer |
| Cohort 1b | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 57 | 23.5 Titer |
| Cohort 1b | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 1 | 7.3 Titer |
| Cohort 1b | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 29 | 38.6 Titer |
| Cohort 2: Younger Adults | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 29 | 9.7 Titer |
| Cohort 2: Older Adults | Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies | Day 29 | 5.0 Titer |
Secondary
GMFR in SARS-CoV-2 Binding Antibody Titers
GMFR data are reported for the S (spike binding antibodies) analyte.
Time frame: Cohort 1a: Days 29, 57, Cohort 1b: Days 1, 29, 57, and Cohort 2: Day 29
Population: Immunogenicity population, which included all participants who received Study vaccine in either ARCT-021-01 or ARCT-021-02 and had evaluable immunogenicity data following first vaccine administration. Overall number of participants analyzed' = participants evaluable for endpoint. 'Number analyzed' = participants evaluable at specified timepoint.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Cohort 1a | GMFR in SARS-CoV-2 Binding Antibody Titers | Day 29 | 34.4 Ratio |
| Cohort 1a | GMFR in SARS-CoV-2 Binding Antibody Titers | Day 57 | 20.4 Ratio |
| Cohort 1b | GMFR in SARS-CoV-2 Binding Antibody Titers | Day 1 | 7.2 Ratio |
| Cohort 1b | GMFR in SARS-CoV-2 Binding Antibody Titers | Day 57 | 104.9 Ratio |
| Cohort 1b | GMFR in SARS-CoV-2 Binding Antibody Titers | Day 29 | 136.5 Ratio |
| Cohort 2: Younger Adults | GMFR in SARS-CoV-2 Binding Antibody Titers | Day 29 | 13.3 Ratio |
| Cohort 2: Older Adults | GMFR in SARS-CoV-2 Binding Antibody Titers | Day 29 | 29.6 Ratio |
Secondary
Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Binding Antibodies)
Seroconversion was defined as a 4-fold increase in antibody titer/concentration from baseline. Data is presented for the number of participants seroconverting for binding antibodies and immunoglobulin G (IgG) antibodies against the full-length SARS-CoV-2 recombinant spike protein antigen and spike protein receptor binding domain of the SARS-CoV-2 spike glycoprotein (RBD). ARCT-021-naïve participants were those participants whose first ARCT-021 vaccine administration occurred in this study (Cohort 1a). As pre-specified, data is presented for participants in Cohort 1a only.
Time frame: Days 29, and 57
Population: Immunogenicity population, which included all participants who received Study vaccine in either ARCT-021-01 or ARCT-021-02 and had evaluable immunogenicity data following first vaccine administration. Overall number of participants analyzed' = participants evaluable for endpoint. 'Number analyzed' = participants evaluable at specified timepoint.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Cohort 1a | Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Binding Antibodies) | Day 29 | 10 Participants |
| Cohort 1a | Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Binding Antibodies) | Day 57 | 9 Participants |
Secondary
Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Neutralizing Antibodies)
Seroconversion was defined as a 4-fold increase in antibody titer/concentration from baseline. Data is presented for the number of participants seroconverting for neutralizing antibodies and immunoglobulin G (IgG) antibodies against the full-length SARS-CoV-2 recombinant spike protein antigen and spike protein receptor binding domain of the SARS-CoV-2 spike glycoprotein (RBD). ARCT-021-naïve participants were those participants whose first ARCT-021 vaccine administration occurred in this study (Cohort 1a). As pre-specified, data is presented for participants in Cohort 1a only.
Time frame: Days 29, and 57
Population: Immunogenicity population, which included all participants who received Study vaccine in either ARCT-021-01 or ARCT-021-02 and had evaluable immunogenicity data following first vaccine administration. Overall number of participants analyzed' = participants evaluable for endpoint. 'Number analyzed' = participants evaluable at specified timepoint.
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Cohort 1a | Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Neutralizing Antibodies) | Day 29 | 1 Participants |
| Cohort 1a | Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Neutralizing Antibodies) | Day 57 | 0 Participants |