Phase 3b dosing of ARCT-154 initiated; study designed to enroll approximately 20,000 participants

Initiation of Phase 3b study follows review of safety data from initial 1,000 Phase 1/2/3a participants

ARCT-154 remains on track for Emergency Use Authorization (EUA) filing in December 2021

SAN DIEGO, CA, USA I October 12, 2021 I Arcturus Therapeutics Holdings Inc. (the “Company”, “Arcturus”, Nasdaq: ARCT), a leading clinical-stage messenger RNA medicines company focused on the development of infectious disease vaccines and significant opportunities within liver and respiratory rare diseases, today announced that the Vietnam Ministry of Health has approved initiation of the Phase 3b part of the placebo-controlled, observer-blind Phase 1/2/3 clinical trial of ARCT-154 self-replicating RNA vaccine targeting the SARS-CoV-2 delta variant and other variants of concern. Arcturus Therapeutics and Vinbiocare remain on track to potentially file an Emergency Use Authorization (EUA) for ARCT-154 in Vietnam in December 2021.

ARCT-154 Phase 3b study dosing has been initiated and the trial is expected to enroll approximately 20,000 participants with half of the participants receiving ARCT-154 under a two-dose regimen with injections 28 days apart, while the other half will receive placebo. The Phase 1 part of the trial has completed the priming vaccination series with two administrations in 100 participants (75 in ARCT-154 arm). The Phase 2 and Phase 3a parts of the trial are ongoing with 300 (225 in ARCT-154 arm) and 600 (450 in ARCT-154 arm) participants, respectively.

The approval to proceed with the Phase 3b portion of the study follows the review of safety data from the initial 1,000 participants included in the Phase 1/2/3a cohorts of the ARCT-154 study.

“I am very pleased with the progress, including the rapid enrollment and dosing in the ARCT-154 trial. Initiation of dosing in the Phase 3b portion of the study brings us one step closer to our goal of filing for EUA and making it available as quickly as possible,” said Joseph Payne, President and CEO of Arcturus Therapeutics. “As a low dose vaccine targeting variants of concern, ARCT-154 has a differentiated profile compared to currently available vaccines and we believe that our program has the potential to become a best-in-class option for Vietnam and many other countries around the world.”

About Arcturus Therapeutics

Founded in 2013 and based in San Diego, California, Arcturus Therapeutics Holdings Inc. (Nasdaq: ARCT) is a clinical-stage mRNA medicines and vaccines company with enabling technologies: (i) LUNAR® lipid-mediated delivery, (ii) STARR™ mRNA Technology and (iii) mRNA drug substance along with drug product manufacturing expertise. Arcturus’ diverse pipeline of RNA therapeutic and vaccine candidates includes mRNA vaccine programs for SARS-CoV-2 (COVID-19) and Influenza, and other programs to potentially treat Ornithine Transcarbamylase (OTC) Deficiency, and Cystic Fibrosis along with partnered programs including Glycogen Storage Disease Type 3, Hepatitis B Virus, and non-alcoholic steatohepatitis (NASH). Arcturus’ versatile RNA therapeutics platforms can be applied toward multiple types of nucleic acid medicines including messenger RNA, small interfering RNA, replicon RNA, antisense RNA, microRNA, DNA, and gene editing therapeutics. Arcturus’ technologies are covered by its extensive patent portfolio (patents and patent applications issued in the U.S., Europe, Japan, China and other countries). Arcturus’ commitment to the development of novel RNA therapeutics has led to collaborations with Janssen Pharmaceuticals, Inc., part of the Janssen Pharmaceutical Companies of Johnson & Johnson, Ultragenyx Pharmaceutical, Inc., Takeda Pharmaceutical Company Limited, CureVac AG, Synthetic Genomics Inc., Duke-NUS Medical School, and the Cystic Fibrosis Foundation. For more information visit www.ArcturusRx.com. In addition, please connect with us on Twitter and LinkedIn.

SOURCE: Arcturus Therapeutics