Akston Biosciences has dosed the first subjects in a Phase II open-label clinical trial of its protein subunit Covid-19 vaccine candidate, AKS-452.

AKS-452 is based on the company’s Fc fusion protein platform and stimulates a Th1/Th2 mixed immune response against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein.

Performed at University Medical Center Groningen (UMCG) in the Netherlands and managed by contract research organisation TRACER Europe , the Phase II trial will enrol 52 subjects.

The participants in the trial will be administered either a single 90μg or two 45μg doses of the vaccine 28 days apart.

Data readout from the trial is anticipated in the third quarter of this year, Akston noted.

In a Phase I trial, AKS-452 was demonstrated to be safe and well-tolerated.

Furthermore, the vaccine generated a complete seroconversion rate in both the 90μg single-dose and 45μg two-dose regimens.

Mild adverse events reported in the trial were comparable to existing registered vaccines.

Akston Biosciences president and CEO Todd Zion said: “The extended shelf stability, the clinical data that show a single injection of the 90μg dose provides 100% seroconversion at significantly higher titers than confirmed Covid-19-positive convalescent serum samples, and the ease of manufacturing relative to currently approved vaccines, indicate that our second-generation vaccine has the potential to more easily safeguard the health of populations worldwide against Covid.”

The company noted that the AKS-452 vaccine is shelf-stable for a minimum of six months at 25°C and remains potent for a month at 37°C.

Trial principal investigator Schelto Kruijff said: “From Phase I, we know the AKS-452 showed limited side-effects, comparable to the current registered anti-Covid-19 vaccines.

“The new data that this vaccine candidate is shelf-stable at room temperature for at least six months makes it ideal for countries such as Malawi and Kenya, where I volunteer because it can be transported and stored for months without refrigeration.”

AKS-452 is designed to leverage conventional, cost-effective antibody production methods so that a single manufacturing line can generate more than one billion doses annually.