Akston Biosciences has dosed the first set of participants in the Phase II clinical trial of its protein subunit Covid-19 vaccine, AKS-452, as a booster.

The open-label trial will analyse the response of the immune system following boosting with AKS-452 in up to 600 subjects.

Being carried out at the University Medical Center Groningen (UMCG) in the Netherlands and managed by TRACER Europe BV, the trial will enrol healthy adult subjects aged between 18 and 85 years.

Trial subjects should have priorly received vaccines of either Pfizer, Moderna, Johnson & Johnson or AstraZeneca, which are registered by the European Medicines Agency.

They should have taken their last Covid-19 vaccine a minimum of three months earlier and should not have taken a booster.

The study will categorise subjects into four groups based on the vaccines they have received earlier for analysing the efficacy of AKS-452 administered as a booster.

Each subject will be given a single 90µg dose of AKS-452 antigen.

Furthermore, to establish the effect of booster over time, antibody levels, virus neutralisation activity and T cell response will be assessed for more than nine months. 

The antibody titer level four weeks following booster administration will be the trial’s primary efficacy endpoint. 

The dosing of all subjects is anticipated by the middle of next month. 

Akston Biosciences president and CEO Todd Zion said: “Because immunity to Covid-19 wanes over time and because new variants arise, the world will need an ongoing supply of booster vaccines. 

“AKS-452 is cost-effective to manufacture at scale and does not require the cold-chain necessary for mRNA vaccines.”

A Phase II/III trial of AKS-452 as a two-dose primary vaccination regimen in 1,600 subjects is progressing in India.

The company intends to seek Emergency Use Authorization (EUA) for the vaccine in the third quarter of this year.