Arcturus Therapeutics Receives U.S. FDA Fast Track Designation for ARCT-810, mRNA Therapeutic Candidate for Ornithine Transcarbamylase Deficiency

Arcturus Therapeutics Holdings Inc. (the “Company”, “Arcturus”, Nasdaq: ARCT), a global late-stage clinical messenger RNA medicines company focused on the development of infectious disease vaccines and opportunities within liver and respiratory rare diseases, today announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to ARCT-810, the Company’s mRNA therapeutic candidate for ornithine transcarbamylase (OTC) deficiency.

Fast Track Designation is designed to facilitate development and expedite review of new therapeutics intended to treat serious or life-threatening conditions that demonstrate the potential to address important unmet medical needs. Programs granted Fast Track Designation may receive important benefits including more frequent interactions with FDA review teams and the ability to obtain rolling review of a Biologics License Application (BLA). In addition, BLA applications may receive a priority review, with the FDA aiming to complete its review within six months, instead of the standard ten months review timeline.

“ARCT-810 has the potential to be an important new medicine for individuals living with OTC deficiency and we are very pleased to have obtained Fast Track Designation for this program. This FDA designation provides several meaningful benefits that we expect will accelerate development and, hopefully, support the approval of this investigational therapy,” said Juergen Froehlich, MD, MBA, FCP, Chief Medical Officer, of Arcturus Therapeutics. “We look forward to more frequent interactions with the FDA and to acceleration of ARCT 810 as a potential new treatment option that addresses the root cause of OTC deficiency.”

About Ornithine Transcarbamylase (OTC) Deficiency

OTC deficiency is a serious urea cycle disorder with a prevalence of approximately 10,000 people worldwide. A lack of OTC, a critical urea cycle enzyme in liver cells, results in high blood ammonia levels that can cause diminished cognitive ability, seizures, coma and death. The current standard of care for OTC-deficient patients is a low-protein diet, nutritional supplements and ammonia scavengers to help prevent the accumulation of ammonia. These treatments do not address the underlying cause of OTC deficiency, for which there are no FDA approved medicines.