Akston Biosciences Corporation, a developer of new classes of biologic therapeutics, announced it dosed the first set of volunteers in an open-label study of AKS-452, its protein subunit Covid-19 vaccine, as a booster. The Phase II booster study is designed to investigate the response of the immune system in up to 600 volunteers who have previously been vaccinated with EMA-registered vaccines from Pfizer, Moderna, Johnson & Johnson (Janssen) and AstraZeneca.

The study is being conducted at the University Medical Center Groningen (UMCG), one of the largest hospitals in the Netherlands. Schelto Kruijff, M.D., Ph.D., the principal investigator at the UMCG for the AKS-452 Phase I and Phase II primary vaccine trials, is serving in the same capacity for the booster trial.

“AKS-452 induced a Th1/Th2 mixed immune response against the Receptor Binding Domain (RBD) of the coronavirus spike protein, according to an analysis of the Phase II study of AKS-452 as a primary vaccine,” Dr. Kruijff said. “While we still need to vaccinate millions of people with a primary Covid-19 shot, it’s also clear that we’ll need an annual booster shot, and key characteristics of AKS-452, including low price and shelf stability, could make AKS-452 an ideal solution.”

The participants, healthy adults between the ages of 18 and 85, will have had their last Covid-19 vaccine shot at least three months earlier and will not have received a Covid-19 booster shot. To determine the efficacy of the AKS-452 as a booster, the study will divide participants into four groups, each of up to 150 subjects, based on having previously received the Pfizer, Moderna, Johnson & Johnson or AstraZeneca vaccine. Each participant will receive one dose of the AKS-452 antigen (90 µg). Antibody levels, virus neutralization activity, and T cell response will be measured over nine months from samples taken in several follow-on appointments to determine the effect over time. The primary efficacy endpoint will be the antibody titer level four weeks after receiving the booster.