Codagenix is setting the foundation to capitalise on a year of success for respiratory syncytial virus (RSV) prophylactics with its RSV paediatric vaccine CodaVax-RSV, but study challenges persist.
In an interview with Pharmaceutical Technology, chief business officer Jeffrey Fu said the New York-headquartered company has faced unexpected challenges in a Phase I study of the vaccine causing a one-year alteration in its clinical development timeline.
The Phase I study (NCT04919109) began dosing in the US in May 2023, but Fu says that as the RSV season approaches in the US the study will shift to sites in South Africa.
He said: “We want to work in a time when there's less likelihood of natural RSV circulating in the environment because that will confound the study."
In the US, RSV season typically starts during autumn and peaks in winter.
Fu says that the trial is progressing at a slower pace than was initially expected with new estimates for the release of topline data landing in the second half of 2024. These results will comprise safety and immunogenicity data for the vaccine.
The reason for the trial delay was related to an issue with finding seropositive older toddlers due to the isolation of this age group during the Covid-19 pandemic. In the Phase I trial, the company is first dosing seropositive children who have been previously infected by RSV before moving on to the seronegative population.
This has been an eventful time for RSV vaccines after years of inactivity. In May 2023, the US Food and Drug Administration (FDA) approved GSK’s Arexvy as the first RSV vaccine available in the US. The vaccine was developed for the prevention of lower respiratory tract disease caused by RSV in individuals 60 years of age and older. Following this, Pfizer secured the first FDA approval for an RSV vaccine for pregnant individuals, with its Abrysvo vaccine.
The Phase I results would inform planning for a Phase II trial dose escalation study. Fu predicts that this trial will begin in 2025. Codagenix is using financing from its $25m Series B funding extension to push the development of its RSV clinical programme.
Codagenix’s CodaVax-RSV protects against the next wave of RSV that children experience in early life, being specifically developed for children aged from six months to five years. According to Fu, CodaVax-RSV is a live attenuated, intranasal vaccine, giving it a more durable immune effect.
Codagenix is also developing the vaccine for an adult patient population. In November 2022, the FDA granted the company fast track designation to expedite the development and review of the vaccine.
