SARS-CoV-2Phase 2NCT04728347

Open Label Extension Study to Assess the Safety and Long-Term Immunogenicity of ARCT-021

A Phase 2 study testing ARCT-021 in people with SARS-CoV-2, run by Arcturus Therapeutics, Inc. at 1 site in Singapore.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Trial 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. Read more about this study

Who is it for?: Ages 21 to 80 yearsHealthy volunteers can take part
Conditions the study is for: SARS-CoV-2
What is being tested?: ARCT-021
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 65 participants
Where: 1 siteSingapore
Study dates: 4 Jan 2021to 28 Dec 2021
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 21 to 80 years
All sexes
Healthy volunteers accepted
Adult, Older adult

Who may be able to join

Individuals who:
are able to give consent
must have completed Study ARCT-021-01
agree to comply with all study visits and procedures
Only for subjects that will receive ARCT-021 in this study:
are healthy and medically stable

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are not planning to donate blood or plasma until 28 days after the last dose of ARCT-021.
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.
are willing to adhere to contraception requirements if sexually active and/or are of child-bearing potential

Who cannot join

Individuals who:
are unable to comply with the study visits or procedures in Study ARCT-021-01
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:
have or will receive any of the SARS CoV-2 or another experimental coronavirus during this study.
have a diagnosis of new clinically significant abnormalities including but not limited to

Show all 24Show fewer

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
have abnormal screening laboratory results
have uncontrolled diabetes
use of any prescription or over-the-counter medications within 7 days prior to vaccination
have received immunoglobulins and/or any blood or blood products
have a bleeding disorder
have uncontrolled blood pressure
have been treated with another investigational drug, biological agent, or device since completion of the Parent Study
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
have traveled outside of Singapore within 30 days before the vaccination or plans to travel outside of Singapore within 60 days after vaccination.
other restrictions may apply

Trial locations and contacts

1 site in 1 country.

Singapore1 site

SingHealth Investigational Medicine Unit (IMU), Singapore General Hospital
Singapore, 169608

Other trials in Singapore

About this study

Official title: A Phase 2a, Open Label Extension Study to Assess the Safety and Long-Term Immunogenicity of ARCT-021

Read the 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.

Conditions: SARS-CoV-2
Being tested: ARCT-021

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

ARCT-021Biological
ARCT-021 single dose

Study groups in NCT04728347
Study group	Role	What they receive
ARCT-021	Experimental	Participants will receive a single dose of ARCT-021 on Day 1 Receives: Biological: ARCT-021
Long-term follow up from ARCT-021-01	No intervention	Participants will not receive intervention but will be followed for safety.

What is being measured

The primary outcome is the main question the study is designed to answer.

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.
Measured: Up to Day 7 (7 days after vaccine administration)
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.
Measured: Up to Day 29 (28 days after vaccine administration)
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.
Measured: Up to a maximum of approximately 12 months

Secondary outcomes (6)

Geometric Mean Titer (GMT) of Serum Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Neutralizing Antibodies
Measured: Cohorts 1a and 1b: Days 1, 29, 57, Cohort 2: Day 29
Geometric Mean Fold Rise (GMFR) in SARS-CoV-2 Neutralizing Antibody Titers
Measured: 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)
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.
Measured: Days 29, and 57
Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies
GMC data are reported for the S (spike binding antibodies) analyte.
Measured: Cohorts 1a and 1b: Days 1, 29, 57, Cohort 2: Day 29
GMFR in SARS-CoV-2 Binding Antibody Titers
GMFR data are reported for the S (spike binding antibodies) analyte.
Measured: 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 (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.
Measured: Days 29, and 57

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

4 Jan 202128 Dec 2021

First posted28 Jan 2021
Study start4 Jan 2021
Primary completion28 Dec 2021
Study completion28 Dec 2021

Why it stopped: A decision was made to terminate the study for operational/business reasons. This study was not terminated for reasons of safety or immunogenicity.

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 SARS-CoV-2Studies 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: Treatment
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 65 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04728347
Sponsor's protocol ID: ARCT-021-02
Status last verified: Dec 2024
First submitted: 24 Jan 2021
Last updated: 30 Dec 2024
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

See locations

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Study at a glance

From the registry record, last updated by the sponsor on 30 Dec 2024. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase 2a, Open Label Extension Study to Assess the Safety and Long-Term Immunogenicity of ARCT-021
ClinicalTrials.gov ID: NCT04728347
Acronym / sponsor ID: ARCT-021-02
Conditions: SARS-CoV-2
Phase: Phase 2
Study type: Interventional
Recruitment status: TerminatedReason stopped: A decision was made to terminate the study for operational/business reasons. This study was not terminated for reasons of safety or immunogenicity.
Enrolment: 65 participants (actual)
Lead sponsor: Arcturus Therapeutics, Inc.Industry (pharma, biotech, devices)
Study start: 4 Jan 2021 (actual)
Primary completion: 28 Dec 2021 (actual)
Study completion: 28 Dec 2021 (actual)
First posted: 28 Jan 2021 (actual)
Results: Posted 30 Dec 2024

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Detailed description

Study design

Primary purpose: Treatment
Allocation: Non-randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 2

Arm	Type	Receives
ARCT-021	Experimental	Biological: ARCT-021Participants will receive a single dose of ARCT-021 on Day 1
Long-term follow up from ARCT-021-01	No intervention	–Participants will not receive intervention but will be followed for safety.

Who may qualify

Ages: 21 to 80 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult

Key inclusion criteria (9 listed)

are able to give consent
must have completed Study ARCT-021-01
agree to comply with all study visits and procedures
are healthy and medically stable
are not planning to donate blood or plasma until 28 days after the last dose of ARCT-021.

Key exclusion criteria (24 listed)

are unable to comply with the study visits or procedures in Study ARCT-021-01
received placebo in the Parent Study and who are not willing to receive ARCT-021 in this study.
have or will receive any of the SARS CoV-2 or another experimental coronavirus during this study.
have a diagnosis of new clinically significant abnormalities including but not limited to
have abnormal screening laboratory results

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
ARCT-021ARCT-021 single dose	Biological	ARCT-021

Primary outcome

Number of Participants With Solicited Local and Systemic Adverse Events
Time frame: 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
Time frame: 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)
Time frame: 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.

6 secondary outcomes

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
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
Number of ARCT-021-naïve Participants (Cohort 1a) With Seroconversion (Neutralizing Antibodies)
Time frame: Days 29, and 57
Geometric Mean Concentration (GMC) of Serum SARS-CoV-2 Binding Antibodies
Time frame: Cohorts 1a and 1b: Days 1, 29, 57, Cohort 2: Day 29
GMFR in SARS-CoV-2 Binding Antibody Titers
Time frame: 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 (Binding Antibodies)
Time frame: Days 29, and 57

Results and safety

Results posted to the registry on 30 Dec 2024, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Cohort 1a	12	12
Cohort 1b	12	12
Cohort 2 Younger Adults	25	24
Cohort 2: Older Adults	16	16

Primary outcome: Number of Participants With Solicited Local and Systemic Adverse Events

Time frame: Up to Day 7 (7 days after vaccine administration). Count of participants. Unit: Participants

Measure	Cohort 1a n = 12	Cohort 1b n = 12
Solicited Local	11	10
Solicited Systemic	11	8

Population analysed: 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.

Primary outcome: Number of Participants With Unsolicited Adverse Events

Time frame: Up to Day 29 (28 days after vaccine administration). Count of participants. Unit: Participants

Measure	Cohort 1a n = 12	Cohort 1b n = 12
Value	3	2

Primary outcome: 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)

Time frame: Up to a maximum of approximately 12 months. Count of participants. Unit: Participants

Measure	Cohort 1a n = 12	Cohort 1b n = 12	Cohort 2: Younger Adults n = 25
SAEs	0	1	0
Unsolicited Adverse Events Associated with NOCD	0	1	0
MAAEs	2	5	3

Population analysed: 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).

6 secondary outcomes are reported in the full results.

Adverse events

Time frame: Up to a maximum of approximately 12 months. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Cohort 1a	0 of 12 (0%)	3 of 12 (25%)	0 of 12
Cohort 1b	1 of 12 (8.3%)	1 of 12 (8.3%)	0 of 12
Cohort 2: Younger Adults	0 of 25 (0%)	3 of 25 (12%)	0 of 25
Cohort 2: Older Adults	0 of 16 (0%)	0 of 16 (0%)	0 of 16

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 30 Dec 2024.
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.

The record lists no contact. Use the official record to reach the sponsor.

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing ARCT-021 in people with SARS-CoV-2, run by Arcturus Therapeutics, Inc. at 1 site in Singapore.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 24 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 30 Dec 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Singapore. 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. 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 30 Dec 2024). 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 With Solicited Local and Systemic Adverse Events (time frame: Up to Day 7 (7 days after vaccine administration)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04728347.

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 30 Dec 2024.