CSL (ASX:CSL; USOTC:CSLLY) and Arcturus Therapeutics (Nasdaq: ARCT) have announced the publication of groundbreaking findings in Nature Communications, revealing the results from a comprehensive phase 1/2/3a/3b study investigating the safety, immune response, and effectiveness of ARCT-154, a pioneering self-amplifying (sa-mRNA) COVID-19 vaccine. This vaccine marks a significant milestone as the world’s first approved sa-mRNA COVID-19 vaccine.
The study demonstrates that two 5 μg doses of ARCT-154 were well-tolerated, stimulated a robust immune response, and conferred substantial protection against various strains of COVID-19. Notably, the vaccine showed 100% efficacy against severe COVID-19 among healthy individuals aged 18-59 and over 90% efficacy among those at higher risk due to age or underlying health conditions.
Dr. Jon Edelman, Senior Vice President of CSL’s Vaccines Innovation Unit, emphasized the importance of these findings, stating that they contribute to a growing body of evidence supporting the potential of the sa-mRNA vaccine to offer significant protection against COVID-19, further reinforcing their commitment to public health.
Dr. Pad Chivukula, Chief Scientific Officer of Arcturus Therapeutics, expressed delight at the publication of the ARCT-154 study in Nature Communications, underscoring the strength of their collaboration with CSL and their dedication to delivering innovative solutions for combating COVID-19.
The article titled “Safety, Immunogenicity, and Efficacy of the Self-Amplifying mRNA ARCT-154 COVID-19 Vaccine: Pooled Phase 1, 2, 3a, and 3b Randomized Controlled Trials” has been published online in Nature Communications.
The integrated study involved adults aged 18 and above who received two 5 μg doses of ARCT-154 or a saline placebo 28 days apart. The primary endpoints included vaccine efficacy, reactogenicity, safety, and immune response. The study enrolled 1,001 participants in the phase 1/2/3a study and 16,100 participants in the phase 3b study.
Results from the phase 1/2/3a studies indicated that ARCT-154 was safe and well-tolerated, with most adverse events being mild to moderate and resolving quickly. The phase 3b study corroborated these findings.
Following the second dose of ARCT-154 in phase 3b, the seroconversion rate of neutralizing antibodies was 94.1%. The vaccine demonstrated an efficacy of 56.6% against any COVID-19, 95.3% against severe COVID-19, and 86.5% against COVID-19-related deaths. Notably, efficacy against severe COVID-19 was 100% among healthy individuals aged 18-59 and 91.9% among those with underlying health conditions in the same age group. In adults aged 60 and older, efficacy was 54.3% against any COVID-19 and 94.4% against severe COVID-19.
The study was co-funded by Vinbiocare Biotechnology Joint Stock Company in Hanoi, Vietnam, and Arcturus Therapeutics.
Self-amplifying mRNA vaccines differ from standard mRNA vaccines by instructing the body to produce more mRNA and protein to enhance the immune response.
CSL (ASX:CSL; USOTC:CSLLY) is a global biotechnology company renowned for its portfolio of life-saving medicines, including treatments for hemophilia, immune deficiencies, and vaccines for influenza. With a legacy dating back to 1916, CSL is dedicated to saving lives through cutting-edge technologies and operates through three business units: CSL Behring, CSL Seqirus, and CSL Vifor.
