J&J trims the size of its phase 3 COVID-19 vaccine trial

According to a source familiar with the matter, the downsizing of the trial is due to the climbing COVID-19 case figures across the US.

As cases grow, participants will be more likely to come into contact with the virus, allowing J&J to evaluate its vaccine in a smaller population of volunteers.

“We continue to anticipate that interim data from the ENSEMBLE trial will be available by the end of January,” J&J said in a statement.

“If the vaccine is safe and effective, an emergency use authorisation application could be submitted to the FDA in February,” the company added.

In a press briefing on Wednesday, US official and head of the government’s Operation Warp Speed initiative Moncef Slaoui mentioned that over 38,000 people have now been recruited into the J&J study.

He added: “With J&J, we decided to cap the recruitment to around 40,000 subjects, which will happen by the end of this week, so in the next two [or] three days.”

J&J advanced its COVID-19 vaccine candidate into phase 3 testing in September following positive interim results from a phase 1/2a clinical study of the shot. The pivotal late-stage study is investigating the safety and efficacy of a single vaccine dose versus placebo in preventing COVID-19.

Interim results from the phase 1/2a ENSEMBLE trial demonstrated that the shot has a promising safety profile and immunogenicity after a single dose.