Arcturus Therapeutics Receives Clearance of an Investigational New Drug Application to U.S. Food and Drug Administration for ARCT-032, an Investigational Inhaled mRNA Therapeutic to Treat Cystic Fibrosis

Arcturus Therapeutics Holdings Inc. (the “Company”, “Arcturus”, Nasdaq: ARCT), a global messenger RNA medicines company focused on the development of infectious disease vaccines and addressing unmet medical needs within liver and respiratory rare diseases, today announced that the U.S. Food and Drug Administration (FDA) has issued a “Study May Proceed” notification for the Company’s Investigational New Drug (IND) application, ARCT-032, to treat cystic fibrosis (CF). FDA clearance of the ARCT-032 IND application enables the Company to initiate a Phase 2 multiple ascending dose study to evaluate the safety, tolerability and efficacy of ARCT-032 in people with Cystic Fibrosis.

“The Phase 2 Study May Proceed notification allows us to investigate ARCT-032 as a potential treatment for CF patients and provides the opportunity to further validate our LUNAR technology to deliver mRNA via inhalation,” said Dr. Juergen Froehlich, Chief Medical Officer of Arcturus Therapeutics. “The study is designed to evaluate the safety and effectiveness of ARCT-032 administered for several weeks at multiple dose levels in people with CF who do not qualify for, or benefit from, CFTR modulator therapy.”

About Cystic Fibrosis

Cystic fibrosis is a life-shortening disease with a worldwide prevalence. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene result in a reduction or absence of CFTR protein and/or function in the airways, causing insufficient chloride transport to maintain airway surface homeostasis. CF mucus is more difficult to clear, thus clogging the airways and leading to infection, inflammation, respiratory failure, or other life-threatening complications. Standard of care for many CF individuals include CFTR modulators. Nearly 40,000 people in the U.S. and more than 105,000 people worldwide are living with CF. Approximately 15% of individuals with CF do not benefit from CFTR modulator medicines due to dysfunctional or absent CFTR protein and/or drug intolerance.

About ARCT-032

ARCT-032 is an inhaled investigational mRNA therapeutic designed to express normal functional CFTR in the lungs of individuals with CF. ARCT-032 has received Orphan Medicinal Product Designation from the European Medicines Agency (EMA) and Orphan Drug Designation along with Rare Pediatric Disease Designation from the U.S. Food and Drug Administration (FDA) to treat cystic fibrosis. ARCT-032 utilizes Arcturus' LUNAR lipid-mediated aerosolized platform to deliver CFTR messenger RNA to the lungs. Lung disease is the leading cause of morbidity and mortality in people with CF. Expression of a functional copy of the CFTR mRNA in the lungs of people with CF has the potential to restore CFTR activity and mitigate the downstream effects that cause progressive lung disease. The ARCT-032 program is supported by preclinical data in rodents, ferrets and primates, as well as demonstrating restoration of CFTR expression and function in human bronchial epithelial cells.