Self-amplifying COVID-19 mRNA Vaccine Candidate Met Primary Efficacy Endpoint

California-based Arcturus Therapeutics Holdings Inc. today shared topline data from an ongoing Phase 1/2/3 trial evaluating ARCT-154, Arcturus’ self-amplifying mRNA vaccine candidate against COVID-19 disease caused by the SARS-CoV-2 coronavirus.

Data show that, in an analysis of COVID-19 cases accrued between 7 days and 56 days after completion of a two-dose vaccination series, two 5-mcg doses of ARCT-154 demonstrated 55% vaccine efficacy for protection against COVID-19.

The COVID-19 cases were detected in parallel with a SARS-CoV-2 outbreak in Vietnam from December 2021 to February 2022, where the Delta and Omicron dominated.

“We are very pleased with these results and see ARCT-154 protecting symptomatic COVID-19 and almost complete protection against severe disease in a placebo-controlled vaccine efficacy study,” said Joseph Payne, President, and CEO of Arcturus Therapeutics, in a press release issued on April 20, 2022.

The key secondary endpoint of severe COVID-19 disease (including deaths) demonstrates a point estimate of vaccine efficacy of 95% against severe/fatal COVID-19 disease.

Arcturus has also advanced ARCT-154 (5 mcg) toward a pivotal booster study that will involve approximately 2,400 participants. 

Founded in 2013 and based in San Diego, California, Arcturus Therapeutics Holdings Inc. is a clinical-stage mRNA medicines and vaccines company.

Note: This press release was edited for clarity and curated for mobile readership.