Nature Communications Publishes Pivotal Data Demonstrating Efficacy and Tolerability of CSL and Arcturus Therapeutics’ COVID-19 Vaccine

Rhea-AI Summary

CSL and Arcturus Therapeutics announced pivotal data published in Nature Communications demonstrating the efficacy and tolerability of their novel self-amplifying (sa-mRNA) COVID-19 vaccine, ARCT-154. The vaccine, the first of its kind approved in Japan, showed 100% efficacy against severe COVID-19 in healthy adults aged 18-59 and over 90% efficacy in older adults or those with comorbidities. The study, covering phases 1 through 3b, indicated that two 5 μg doses were well-tolerated and provided robust protection against multiple strains, including Omicron BA 4/5. The results underline the potential of the sa-mRNA technology to offer long-lasting immunity and superior protection compared to traditional mRNA vaccines.

Positive

• ARCT-154 showed 100% efficacy against severe COVID-19 in healthy adults aged 18-59.
• Over 90% efficacy in older adults or those with comorbidities.
• The vaccine demonstrated superior immunogenicity to Omicron BA 4/5 compared to conventional mRNA boosters.
• The study indicated that two 5 μg doses were well-tolerated.
• The vaccine provided robust protection against multiple strains.
• The data was published in the highly respected journal Nature Communications.
• Approval of the world’s first self-amplifying (sa-mRNA) COVID-19 vaccine in Japan.

Negative

• The press release did not provide specific data on the duration of immunity.
• Potential investor concerns about the actual commercial uptake and competitive landscape.
• Any adverse effects or complications beyond general tolerability were not disclosed.

Medical Research Analyst

The results of the study for ARCT-154 add substantial support to the vaccine's safety and effectiveness against COVID-19. The vaccine utilizes self-amplifying mRNA (sa-mRNA) technology, which represents a significant advancement over conventional mRNA vaccines. This new approach could potentially offer higher efficacy and longer-lasting immunity, as demonstrated by the study's outcome showing superior immunogenicity to the Omicron BA 4/5 variant and prolonged immunity duration.

The implications of these findings are noteworthy. A 100% efficacy rate in healthy adults aged 18-59 and over 90% in individuals at risk due to comorbidities or age underlines the robust protective capability of ARCT-154. Given these stats, the vaccine could play a pivotal role in managing the pandemic more effectively, especially in populations with higher vulnerability.

Retail investors should understand that this development could strongly position CSL and Arcturus in the global vaccine market, potentially leading to increased revenue streams through broader distribution and adoption. However, clinical outcomes in real-world settings post-approval will be key to maintaining momentum.

Financial Analyst

CSL and Arcturus Therapeutics are poised to benefit financially from the positive data on ARCT-154. The approval of the world's first sa-mRNA COVID-19 vaccine in Japan is already a significant milestone. This approval may pave the way for further regulatory endorsements globally, translating into increased market share and revenue growth for both companies.

Investors should note that CSL (ASX:CSL; USOTC:CSLLY) and Arcturus (Nasdaq: ARCT) could see a surge in stock prices as market confidence builds around the potential for sustained sales. The efficacy and tolerability of ARCT-154, combined with the innovative sa-mRNA technology, suggest a competitive edge in the vaccine market. Additionally, the publication of the study in a prestigious journal like Nature Communications reinforces the credibility of the results and can positively influence investor sentiment.

However, one should also consider the competitive landscape and the need for ongoing research to address new COVID-19 variants, which could influence long-term financial outcomes.

• Data follow the approval of the world’s first self-amplifying (sa-mRNA) COVID-19 vaccine for adults in Japan.
• These results add to recently published data on ARCT-154 demonstrating superior immunogenicity to Omicron BA 4/5 compared to conventional mRNA COVID-19 vaccine booster and follow-up data demonstrating longer duration of immunity compared to traditional COVID-19 mRNA vaccine booster.

KING OF PRUSSIA, Pa. & SAN DIEGO--(BUSINESS WIRE)-- Global biotechnology leader CSL (ASX:CSL; USOTC:CSLLY) and Arcturus Therapeutics (Nasdaq: ARCT) today announce Nature Communications has published results from an integrated phase 1/2/3a/3b study evaluating the safety, immunogenicity, and efficacy of ARCT-154, a novel self-amplifying (sa-mRNA) COVID-19 vaccine and the world’s first approved sa-mRNA COVID-19 vaccine.

The results demonstrate that two 5 μg doses of ARCT-154, sa-mRNA vaccine, were well-tolerated, immunogenic and provided significant protection against multiple strains of COVID-19. The efficacy of ARCT-154 against severe COVID-19 was 100 percent in healthy persons aged 18-59 and more than 90 percent in persons at risk of severe consequences of the disease due to co-morbidities or older age.

“The results published in Nature Communications demonstrate the efficacy and tolerability of ARCT-154 and add to a growing body of evidence that our sa-mRNA vaccine has the potential to provide significant protection against the pervasive virus, reinforcing our promise to protect public health,” said Jon Edelman, M.D., Senior Vice President, Vaccines Innovation Unit, CSL.

“We are thrilled that the results of the ARCT-154 study have been published in the highly respected journal Nature Communications,” said Pad Chivukula, Ph.D., Chief Scientific Officer of Arcturus Therapeutics. “These data and the approval in Japan highlight the strength of our and CSL’s commitment to delivering innovative technology that protects the public from COVID-19.”

The Nature Communications 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” was published online.

About the study

During the observer-blind, randomized, controlled phase 1, 2, 3a and 3b integrated study, adults ≥18 years old receive two 5 μg doses of ARCT-154 or saline placebo 28 days apart. Phase 2/3a/3b participants were stratified by age (< 60 or ≥ 60 years of age) and by risk of severe COVID-19 prior to being randomized 3:1 (phase 1/2/3a) or 1:1 (phase 3b) to vaccine or placebo groups. The primary endpoints were vaccine efficacy up to 2 months after dose 2, reactogenicity within up to 7 days of each dose, safety within up to 28 days after each dose, and immunogenicity measured 28 days after each dose. From August 15 to January 12, 2023, 1,001 participants were randomized (748 ARCT-154 and 253 placebo) in the integrated phase 1/2/3a study, and 16,100 participants (8,056 ARCT-154 and 8,044 placebo) in the phase 3b study.

In the phase 1/2/3a studies, ARCT-154 was safe and well tolerated. Most solicited adverse events were mild or moderate and resolved quickly, and rates of related or severe unsolicited adverse events were similar in the ARCT-154 and placebo groups. The phase 3b study confirmed these observations.

Four weeks after the second ARCT-154 dose in phase 3b, the neutralizing antibody seroconversion rate was 94.1% (95% CI: 92.1–95.8). There were 640 confirmed, protocol-defined COVID-19 cases, mainly of the Delta variant, that were determined to be eligible for analysis, including 43 severe cases and 10 deaths attributed to COVID-19. ARCT-154 absolute efficacy was 56.6% (95% CI: 48.7–63.3) against any COVID-19, 95.3% (80.5–98.9) against severe COVID-19 and 86.5% (-7.4–98.3) against death due to COVID-19. Efficacy against severe COVID-19 was 100% in healthy 18-59-year-olds and 91.9% (37.9–98.9) in participants in that age group with underlying co-morbidities, which put them at risk for severe disease. In adults aged 60 years or older, efficacy was 54.3% (28.2–70.9) against COVID-19 of any severity and 94.4% (58.2–99.3) against severe COVID-19.

The study was co-funded by Vinbiocare Biotechnology Joint Stock Company in Hanoi, Vietnam, and Arcturus Therapeutics.

About sa-mRNA

mRNA vaccines help protect against infectious diseases by providing a blueprint for cells in the body to make a protein to help our immune systems recognize and fight the disease. Unlike standard mRNA vaccines, self-amplifying mRNA vaccines instruct the body to make more mRNA and protein to boost the immune response.

About CSL

CSL (ASX:CSL; USOTC:CSLLY) is a global biotechnology company with a dynamic portfolio of lifesaving medicines, including those that treat hemophilia and immune deficiencies, vaccines to prevent influenza, and therapies in iron deficiency and nephrology. Since our start in 1916, we have been driven by our promise to save lives using the latest technologies. Today, CSL – including our three businesses: CSL Behring, CSL Seqirus and CSL Vifor – provides lifesaving products to patients in more than 100 countries and employs 32,000 people. Our unique combination of commercial strength, R&D focus and operational excellence enables us to identify, develop and deliver innovations so our patients can live life to the fullest. For inspiring stories about the promise of biotechnology, visit CSLBehring.com/Vita and follow us on Twitter.com/CSL. For more information about CSL, visit www.CSL.com.

About Arcturus Therapeutics

Founded in 2013 and based in San Diego, California, Arcturus Therapeutics Holdings Inc. (Nasdaq: ARCT) is a global mRNA medicines and vaccines company with enabling technologies: (i) LUNAR® lipid-mediated delivery, (ii) STARR® mRNA Technology (sa-mRNA) and (iii) mRNA drug substance along with drug product manufacturing expertise. Arcturus developed the first self-amplifying messenger RNA (sa-mRNA) COVID vaccine (Kostaive®) in the world to be approved. Arcturus has an ongoing global collaboration for innovative mRNA vaccines with CSL Seqirus, and a joint venture in Japan, ARCALIS, focused on the manufacture of mRNA vaccines and therapeutics. Arcturus’ pipeline includes RNA therapeutic candidates to potentially treat ornithine transcarbamylase deficiency and cystic fibrosis, along with its partnered mRNA vaccine programs for SARS-CoV-2 (COVID-19) and influenza. Arcturus’ versatile RNA therapeutics platforms can be applied toward multiple types of nucleic acid medicines including messenger RNA, small interfering RNA, circular RNA, antisense RNA, self-amplifying RNA, DNA, and gene editing therapeutics. Arcturus’ technologies are covered by its extensive patent portfolio (over 400 patents and patent applications in the U.S., Europe, Japan, China, and other countries). For more information, visit www.ArcturusRx.com. In addition, please connect with us on Twitter and LinkedIn.

View source version on businesswire.com: https://www.businesswire.com/news/home/20240520772541/en/

CSL Media Contacts:

Sue Thorn

Mobile: 617 799 3151

Email: sue.thorn@cslbehring.com

Australia:

Kim O’Donohue

Mobile: 0449 884 603

Email: kim.odonohue@csl.com.au

Jimmy Baker

Mobile: +61 450 909 211

Email: Jimmy.Baker@csl.com.au

Arcturus Media Contact:

Neda Safarzadeh

VP, Head of IR/PR/Marketing

Email: IR@arcturusrx.com

Source: Arcturus Therapeutics

FAQ

What is the efficacy of ARCT-154 against severe COVID-19 in healthy adults?

ARCT-154 demonstrated 100% efficacy against severe COVID-19 in healthy persons aged 18-59.

How effective is ARCT-154 in older adults or those with comorbidities?

ARCT-154 showed over 90% efficacy in persons at risk of severe consequences due to comorbidities or older age.

What is the approval status of ARCT-154?

ARCT-154 is the world’s first approved self-amplifying (sa-mRNA) COVID-19 vaccine, with approval in Japan.

How does ARCT-154 compare to conventional mRNA COVID-19 vaccines?

ARCT-154 demonstrated superior immunogenicity to Omicron BA 4/5 compared to conventional mRNA COVID-19 vaccine boosters.

What does the Nature Communications publication say about ARCT-154?

Nature Communications published results demonstrating that ARCT-154 is well-tolerated, immunogenic, and provides significant protection against multiple strains of COVID-19.