LUNAR-H5N1 becomes the third STARR® mRNA vaccine candidate to enter clinic First Phase 1 participant injected December 2024 Interim Phase 1 data expected H2 2025 SAN DIEGO--(BUSINESS WIRE)-- Arcturus Therapeutics Holdings Inc. (the "Company", "Arcturus", Nasdaq: ARCT ), a commercial messenger RNA medicines company focused on the development of infectious disease vaccines and opportunities within liver and respiratory rare diseases, today announced the initiation of the Company's Phase 1 study of ARCT-2304, a self-amplifying mRNA (sa-mRNA) vaccine candidate, also known as LUNAR-H5N1, for active immunization to prevent pandemic influenza disease caused by H5N1 virus. The randomized placebo-controlled Phase 1 trial ( NCT06602531 ) is being conducted at multiple sites in the U.S. and designed to enroll approximately 200 healthy adults (120 participants 18-59 years old; 80 participants 60-80 years old).