Safety of sipavibart as a pre-exposure prophylaxis for COVID-19 in individuals at high risk of developing severe disease: results of the NOVELLA clinical study conducted in the Russian population

Aim. To evaluate the safety of sipavibart (AZD3152) for pre-exposure prophylaxis of COVID-19 in Russian population of participants at increased risk of developing severe COVID-19. Materials and methods. Randomized, double-blind phase 2 NOVELLA study included adults who had an increased risk of severe COVID-19 and inadequate response to vaccination against COVID-19. Participants were randomly assigned in a 3:1 ratio to receive a single IM injection of sipavibart (300 mg) or placebo, and they were followed for up to 181 days. The primary safety end point was the incidence of adverse events (AEs) after a single dose of sipavibart. Results. 116 participants were randomized (87 in the sipavibart group and 29 in the placebo group). Overall, 51.7% of participants in the sipavibart group and 58.6% of participants in the placebo group had at least one AE, most of which were Grade 1–2 in severity. AEs were well balanced between groups, with no meaningful differences for any categories. The overall frequency, severity and types of AEs do not suggest any safety concerns and are considered to be reflective of events generally observed in this immunocompromised population. The most commonly reported AEs were associated with infections and infestations (34.5% in both groups). There were no immediate AE or AE of special interest reported in the study. There were no related cases of ≥ grade 3 AEs or SAEs reported. Conclusion. The safety data in NOVELLA demonstrated that the safety profile of sipavibart for pre-exposure prophylaxis of COVID-19 in Russian participants is considered to be acceptable.