A Trial Evaluating the Safety and Effects of an RNA Vaccine ARCT-021 in Healthy Adults

NCT ID: NCT04668339

Last Updated: 2025-05-15

Study Results

Results available

Outcome measurements, participant flow, baseline characteristics, and adverse events have been published for this study.

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Basic Information

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Recruitment Status

TERMINATED

Clinical Phase

PHASE2

Total Enrollment

581 participants

Study Classification

INTERVENTIONAL

Study Start Date

2021-01-07

Study Completion Date

2022-03-01

Brief Summary

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This is a Phase 2, randomized, placebo-controlled, and observer-blind study in healthy adults.

The study will evaluate the safety, tolerability, and immunogenicity of the SARS-CoV-2 RNA vaccine candidate against COVID-19:

As 2 doses (at two different dose levels), separated by 28 days or as 1 dose

In adults 18 years of age and older

Detailed Description

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This is a multiregional, multicenter, Phase 2, randomized, observer-blind study designed to evaluate the safety, reactogenicity, and immunogenicity of the study vaccine in younger and older adult participants. Enrolled participants will be randomly assigned to receive either study vaccine ARCT-021 or placebo (sterile saline).

Approximately 600 participants (300 each in younger \[18 to \<56 years of age in United States or 21 to \<56 years of age in Singapore\] and older \[≥56 years of age\] participants) will be enrolled (including at least 50% of participants in the older cohort ≥65 years of age). Participants will be stratified by age and then randomly assigned (3 ARCT-021:1 placebo) to receive 2 doses of study vaccine separated by 28 days. At 180 days after second study vaccination (Day 208), participants in Study Groups 1, 2, and 3 will be randomly assigned again to receive a single booster dose of study vaccine (randomly assigned as 1 ARCT-021:1 placebo). Study Group 4 will not be randomized but will receive 1 dose of placebo at Day 208. Study Groups are summarized in Table 1. Study vaccine will be administered in an observer-blind fashion. Participants will be followed for safety and immunogenicity through 180 days after booster vaccination (Day 388). At a subset of clinical sites, all enrolled participants will also undergo blood sampling for evaluation of CMI responses.

Vaccine doses will be assigned as follows:

Younger Age Cohort:

Study Group 1: n= 75 participants, ARCT-021 7.5 µg (first dose), Placebo (second dose Study Group 2: n= 75 participants, ARCT-021 5.0 µg (first dose), 5.0 µg (second dose) Study Group 3: n= 75 participants, ARCT-021 7.5 µg (first dose), 7.5 µg (second dose) Study Group 4: n= 75 participants, Placebo (first dose), Placebo (second dose)

Booster Vaccine:

Study Groups 1, 2, 3: 113 participants, ARCT-021 5.0 µg or 7.5 µg, 112 participants, Placebo Study Group 4: n= 75 participants, Placebo

Older Age Cohort:

Study Group 1: n= 75 participants, ARCT-021 7.5 µg (first dose), Placebo (second dose Study Group 2: n= 75 participants, ARCT-021 5.0 µg (first dose), 5.0 µg (second dose) Study Group 3: n= 75 participants, ARCT-021 7.5 µg (first dose), 7.5 µg (second dose) Study Group 4: n= 75 participants, Placebo (first dose), Placebo (second dose)

Booster Vaccine:

Study Groups 1, 2, 3: 113 participants, ARCT-021 5.0 µg or 7.5 µg, 112 participants, Placebo Study Group 4: n= 75 participants, Placebo

A DSMB will be in place to independently review the safety data of participants. Pausing Rules are also utilized in this study to reduce risk to study participants.

The expected duration of participation for an individual participant is approximately 14 months, inclusive of the Screening period.

Conditions

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Covid19 SARS-CoV Infection Corona Virus Infection

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

sequential assignment
Primary Study Purpose

PREVENTION

Blinding Strategy

QUADRUPLE

Participants Caregivers Investigators Outcome Assessors
Observer blind

Study Groups

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Study Group 1, Younger Adult Participants

Participants will receive one dose of ARCT-021 on Day 0, one dose of Placebo (saline) on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo

Group Type EXPERIMENTAL

ARCT-021 single dose priming

Intervention Type BIOLOGICAL

ARCT-021 higher dose (one dose) + placebo (one dose)

Randomized booster

Intervention Type BIOLOGICAL

ARCT-021 (single dose) OR placebo, booster

Study Group 2, Younger Adult Participants

Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo

Group Type EXPERIMENTAL

ARCT-021 two lower dose priming

Intervention Type BIOLOGICAL

ARCT-021 lower dose (two doses, Day 0 and Day 28)

Randomized booster

Intervention Type BIOLOGICAL

ARCT-021 (single dose) OR placebo, booster

Study Group 3, Younger Adult Participants

Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo

Group Type EXPERIMENTAL

ARCT-021 two higher dose priming

Intervention Type BIOLOGICAL

ARCT-021 higher dose (two doses, Day 0 and Day 28)

Randomized booster

Intervention Type BIOLOGICAL

ARCT-021 (single dose) OR placebo, booster

Study Group 4, Younger Adult Participants

Participants will receive one of Placebo (Saline) on Day 0, one dose of Placebo on Day 28, and one dose of Placebo on Day 208

Group Type PLACEBO_COMPARATOR

Placebo (two doses), priming

Intervention Type BIOLOGICAL

Placebo (two doses, Day 0 and Day 28)

Placebo booster

Intervention Type BIOLOGICAL

Placebo (single dose)

Study Group 1, Older Adult Participants

Participants will receive one dose of ARCT-021 on Day 0, one dose of Placebo (saline) on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo

Group Type EXPERIMENTAL

ARCT-021 single dose priming

Intervention Type BIOLOGICAL

ARCT-021 higher dose (one dose) + placebo (one dose)

Randomized booster

Intervention Type BIOLOGICAL

ARCT-021 (single dose) OR placebo, booster

Study Group 2, Older Adult Participants

Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo

Group Type EXPERIMENTAL

ARCT-021 two lower dose priming

Intervention Type BIOLOGICAL

ARCT-021 lower dose (two doses, Day 0 and Day 28)

Randomized booster

Intervention Type BIOLOGICAL

ARCT-021 (single dose) OR placebo, booster

Study Group 3, Older Adult Participants

Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo

Group Type EXPERIMENTAL

ARCT-021 two higher dose priming

Intervention Type BIOLOGICAL

ARCT-021 higher dose (two doses, Day 0 and Day 28)

Randomized booster

Intervention Type BIOLOGICAL

ARCT-021 (single dose) OR placebo, booster

Study Group 4, Older Adult Participants

Participants will receive one dose of Placebo (saline) on Day 0, a second dose of Placebo on Day 28 and a third dose of Placebo on Day 208

Group Type PLACEBO_COMPARATOR

Placebo (two doses), priming

Intervention Type BIOLOGICAL

Placebo (two doses, Day 0 and Day 28)

Placebo booster

Intervention Type BIOLOGICAL

Placebo (single dose)

Interventions

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ARCT-021 single dose priming

ARCT-021 higher dose (one dose) + placebo (one dose)

Intervention Type BIOLOGICAL

ARCT-021 two lower dose priming

ARCT-021 lower dose (two doses, Day 0 and Day 28)

Intervention Type BIOLOGICAL

ARCT-021 two higher dose priming

ARCT-021 higher dose (two doses, Day 0 and Day 28)

Intervention Type BIOLOGICAL

Placebo (two doses), priming

Placebo (two doses, Day 0 and Day 28)

Intervention Type BIOLOGICAL

Randomized booster

ARCT-021 (single dose) OR placebo, booster

Intervention Type BIOLOGICAL

Placebo booster

Placebo (single dose)

Intervention Type BIOLOGICAL

Eligibility Criteria

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Inclusion Criteria

Individuals who:

1. are able to provide consent
2. agree to comply with all study visits and procedures
3. are willing and able to adhere to study restrictions
4. are sexually active and willing to adhere to contraceptive requirements
5. are male or female ≥18 or (in Singapore) ≥21 years of age
6. are medically stable

Exclusion Criteria

Individuals who:

1. have had SARS-CoV-2 infection or COVID-19 disease.
2. have had cancer except for cancers that were treated and that have low risk of returning
3. have chronic kidney disease
4. have some chronic lung diseases
5. have some heart conditions
6. have compromised immune systems
7. are obese
8. have sickle cell disease or some other blood disorders
9. are current smokers and/or use illegal drugs
10. have Type 2 diabetics
11. are immunocompromised, immunodeficient or have had a transplant
12. have autoimmune disease
13. have other severe or uncontrolled diseases or disease that may interfere with the interpretation of the study
14. have a positive test for hepatitis B or C or human immunodeficiency virus
15. have had a severe reaction to previous investigational vaccines
16. have a fever or are feeling sick close to the time of the first vaccination of the study
17. have positive drug test at screening
18. are pregnant
19. are breastfeeding
20. have a bleeding disorder
21. have previously received an investigational coronavirus vaccine (SARS-CoV(1) or MERS) or who plan to be in other COVID-19 studies
22. have recently been vaccinated with other vaccines
23. have recently received blood products
24. who work at one of the clinic sites participating in this study, work at Arcturus, who work at other companies that monitor the study or close family members to the sites, Arcturus, or partners involved in study monitoring
25. other restrictions may apply
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Arcturus Therapeutics, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Arcturus Investigational Site 103

Chandler, Arizona, United States

Site Status

Arcturus Investigational Site 107

Tucson, Arizona, United States

Site Status

Arcturus Investigational Site 112

San Diego, California, United States

Site Status

Arcturus Investigational Site 104

Melbourne, Florida, United States

Site Status

Arcturus Investigational Site 105

Orlando, Florida, United States

Site Status

Arcturus Investigational Site 106

Pinellas Park, Florida, United States

Site Status

Arcturus Investigational Site 109

The Villages, Florida, United States

Site Status

Arcturus Investigational Site 101

Peoria, Illinois, United States

Site Status

Arcturus Investigational Site 110

Rockville, Maryland, United States

Site Status

Arcturus Investigational Site 102

Anderson, South Carolina, United States

Site Status

Arcturus Investigational Site 111

Austin, Texas, United States

Site Status

Arcturus Investigational Site 108

Dallas, Texas, United States

Site Status

Arcturus Investigational Site 204

Singapore, , Singapore

Site Status

Arcturus Investigational Site 201

Singapore, , Singapore

Site Status

Arcturus Investigational Site 203

Singapore, , Singapore

Site Status

Countries

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United States Singapore

Provided Documents

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Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

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ARCT-021-04

Identifier Type: -

Identifier Source: org_study_id

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