NCT06602531

Safety and Immunogenicity Study of Self-Amplifying RNA Pandemic Influenza Vaccine in Adults

A Phase 1, First-in-human, Randomized, Observer-blind, Parallel Design, Controlled, Dose Level and Schedule-finding Study to Evaluate the Safety, Reactogenicity, and Immunogenicity of a Self-Amplifying mRNA Pandemic Influenza Vaccine (ARCT-2304) When Administered to Healthy Adults

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 212 (actual)
• Sponsor: Arcturus Therapeutics, Inc. · Industry
• Sex: All
• Age: 18 Years – 80 Years
• Healthy volunteers: Accepted

Summary

The goal of this clinical trial is to evaluate the safety and immune responses of three different dose levels a self-amplifying RNA pandemic influenza vaccine (ARCT-2304) in adults. The key objectives of the study are: * To evaluate safety and reactogenicity of different dose levels of the ARCT-2304 vaccine * To describe the Immune responses of different dose levels of the ARCT-2304 vaccine as measured by hemagglutination inhibition (HAI) and neuraminidase enzyme-linked lectin (ELLA) antibody responses Researchers will compare the results with licensed influenza vaccines to select the most optimal dose level and schedule for vaccine administration in terms of safety and immunogenicity for further development of the vaccine. Participants will receive 2 doses of the ARCT-2304 vaccine or 1 dose of licensed influenza vaccine and 1 dose of placebo. They will be asked: * to complete a daily diary for 7 days after each vaccination, answering questions how they have been feeling on that day. * to provide blood samples at each visit in the clinic * to comply with all study visits and procedures (e.g., be available for planned telephone contacts and unscheduled clinic visits, if required)

Detailed description

Phase 1, first-in-human, randomized, controlled, observer blind, dose level and schedule-finding study, to evaluate the safety, reactogenicity, and immunogenicity of a self-amplifying mRNA pandemic influenza (H5N1) vaccine (ARCT-2304) when administered as a 2-dose vaccination series to healthy adults in comparison with an inactivated influenza vaccine. Study drug (ARCT-2304 or control) will be administered as a 2-dose vaccination series as an intramuscular (IM) injection. The study comprises two parts. In Part 1, 120 participants (young adults) will be randomized to one of the three dose levels of the ARCT-2304 vaccine or control vaccine. Participants will be further randomized to one of the two different vaccination schedules. In Part 2, 80 participants (older adults) will be randomized to one of the three dose levels of the ARCT-2304 vaccine or control vaccine. Participants will be further randomized to one of the two different vaccination schedules. Investigational Vaccine: ARCT-2304 Control Vaccines: licensed influenza vaccines

Conditions

• Influenza, Human

Interventions

Type	Name	Description
BIOLOGICAL	ARCT-2304	Each participant will receive 2-dose regimen intramuscular (IM) dose into the deltoid muscle.
BIOLOGICAL	Control vaccine (licensed seasonal influenza vaccine) younger adults	Each participant will receive one intramuscular (IM) dose into the deltoid muscle.
BIOLOGICAL	Control vaccine (licensed seasonal influenza vaccine) older adults	Each participant will receive one intramuscular (IM) dose into the deltoid muscle.
OTHER	Placebo Vaccine	Each participant will receive one intramuscular (IM) dose into the deltoid muscle.

Timeline

• Start date: 2024-12-10
• Primary completion: 2025-06-13
• Completion: 2025-12-05
• First posted: 2024-09-19
• Last updated: 2026-04-03

Locations

4 sites across 1 country: United States

Regulatory

• FDA-regulated drug study