Johnson & Johnson has announced that its phase 3 COVID-19 vaccine trial is fully enrolled, with approximately 45,000 participants involved in the late-stage study.
The phase 3 ENSEMBLE trial is being conducted in collaboration with the US Biomedical Advanced Research and Development Authority (BARDA) and the National Institute of Allergy and Infectious Diseases (NIAID).
In a statement, J&J said that it expects that the number of participants now enrolled in the study will be sufficient to generate the data needed to determine the safety and efficacy of its COVID-19 vaccine.
This is due in large part to the high levels of COVID-19 cases among the general populations in the locations where the phase 3 trial is being conducted – this includes the US, where cases have now surpassed a total of 17 million.
J&J is expecting interim data from the phase 3 trial to be available by the end of January 2021, although this depends on the number of COVID-19 cases observed across the study itself.
Depending on the outcome of the study, J&J said it could submit an emergency use authorisation to the US Food and Drug Administration (FDA) in February, with additional health regulatory applications set to be made ‘in parallel’.
Last week, J&J announced that it would decrease the size of the ENSEMBLE trial after cases surged 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.
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.
J&J’s COVID-19 candidate uses the company’s AdVac technology platform, which was also used to develop and manufacture its existing Ebola vaccine, as well as construct its other investigational candidates for Zika, RSV and HIV.
The company is also collaborating with the UK National Institute for Health Research (NIHR) on a phase 3 clinical trial – ENSEMBLE 2 – in multiple countries which will explore a two-dose regimen of the vaccine.
This trial is currently enrolling participants in Belgium, Colombia, France, Germany, the Philippines, South Africa, Spain, the UK and US.