Arcturus Therapeutics/CSL Partnered COVID-19 Vaccine Surpasses Pfizer's Comirnaty Shot, Even At Lower Doses

CSL Limited CSLLY and Arcturus Therapeutics ARCT announced the results of a Phase 3 head-to-head study of ARCT-154, a self-amplifying (sa-mRNA) COVID-19 vaccine, compared to Pfizer Inc’s PFE shot Comirnaty.

The study showed that the sa-mRNA COVID-19 vaccine maintained superior immunogenicity compared to the conventional mRNA vaccine Comirnaty for up to one year against Wuhan-Hu-1, Omicron BA.4-5 and certain other variants, and at one-sixth the dose of the comparator (5 μg vs. 30 μg, respectively).

Also Read: Arcturus’ Inhaled mRNA Therapeutic In Cystic Fibrosis Study Highlights Potential Amid Competitive Landscape: Analyst.

The COVID-19 vaccine from this sa-mRNA platform targeted against the JN.1 variant is approved in Japan for immunization against COVID-19 in adults 18 years and older. It is being sold under the trade name Kostaive.

At Day 29, neutralizing antibodies (GMTs unadjusted) against the Wuhan-Hu-1 strain in ARCT-154 recipients (n = 378) were superior to those in the Comirnaty group (n = 374)

• GMT = 5390 vs. 3738, a GMT ratio of 1.44. This advantage persisted through all time points.
• At Day 361 (unadjusted), GMTs were 3396 and 1771 in ARCT-154 (n = 272) and Comirnaty (n = 266) groups, with a GMT ratio of 1.92.
• Differences were also observed in responses against Omicron BA.4-5, with GMT ratios of 1.31 at Day 29 and 1.89 at Day 361.

Additional data presented by CSL and Arcturus finds that the bivalent formula ARCT-2301, developed on the same platform as ARCT-154, induces superior immunogenicity over conventional bivalent mRNA vaccine Comirnaty, which persists against key variants up to six months postvaccination.

• Data from 930 participants showed that ARCT-2301 (n = 398) induced superior neutralizing antibody responses vs. Comirnaty (n = 405) against Omicron BA.4-5 (GMT ratio 1·49), and against Wuhan-Hu-1 (GMT ratio 1.45).
• The difference persisted through six months with GMT ratios of 2.17 and 1.98, respectively.
• Antibody responses against Omicron XBB.1.5 were also higher after ARCT-2301 vs. Comirnaty.

Price Action: ARCT stock is up 4.70% at $23.07 at last check Monday.

Image via Unsplash

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