Valneva, Arcturus add to bombardment of booster boasting for COVID-19 shots

It’s the battle of the boosters. A day after Sanofi and GlaxoSmithKline said their COVID-19 shot works well as a booster for other shot regimens, Valneva and Arcturus Therapeutics are adding to the chorus.

The slew of companies shouting “me too” represents a turning point in the COVID-19 vaccine market. Whereas companies previously were trying to develop shots that could be used as a primary inoculation, they are now attempting to show their candidates can be used after a primary course instead.

In the case of Valneva, the phase 1/2 results are from a test that used the biotech’s own shot as a primary course. VLA2001 showed “excellent” immune response after administration seven to eight months after a primary course of the same shot, according to a Thursday statement. The biotech said the shot “significantly” boosted immunity in the participants.

VLA2001 is an inactivated, adjuvanted COVID-19 vaccine that was administered at the same dose level as the shots delivered in the primary course. The study featured 77 of the original patients from Valneva’s trial that initially tested the vaccine.

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The company is working to get data on the omicron variant, which has emerged as the latest threat in the pandemic.

Up next, Valneva expects to report additional booster data from a phase 3 trial called Cov-Compare. Another study will be launched using VLA2001 as a booster after a course of another vaccine or in those who have had COVID-19. The study is expected to get underway in the New Year.

Valneva previously reported that VLA2001 topped AstraZeneca's Vaxzevria in a phase 3 trial. 

On to Arcturus, which is developing two self-amplifying mRNA vaccine candidates called ARCT-154 and ARCT-165 to tackle the coronavirus. In a phase 1/2 trial, the biotech is assessing the pair of shots in participants 65 and younger as a primary vaccine series and as a booster course following a round of Pfizer/BioNTech’s Comirnaty.

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The data is limited to just a handful of patients. For ARCT-154, Arcturus reported data from the first eight patients of 12, and for ARCT-165, nine of the 12 patients. In both cases, the participants received a primary course of Comirnaty. Arcturus saw “an encouraging increase in neutralizing antibody titers” after either booster shot.

Arcturus President and CEO Joseph Payne admitted that the data are preliminary, but said the information so far encourages continued development The biotech is awaiting data from an ongoing phase 1/2/3 trial of ARCT-154 being conducted in Vietnam before proceeding with rolling regulatory submissions there. Data should be available in the coming weeks and an emergency use authorization is expected in the first quarter of 2022.