J&J initiates second Phase III trial of COVID-19 vaccine candidate

Janssen, a part of Johnson & Johnson (J&J), has initiated the two-dose regimen ENSEMBLE 2 Phase III clinical trial to study JNJ-78436735, the investigational vaccine candidate for the prevention of COVID-19. 

This trial is a complementary, planned, pivotal, large-scale, multi-country Phase III trial that will study the safety and efficacy of a two-dose regimen of the investigational Janssen vaccine candidate for the prevention of COVID-19 in up to 30,000 participants worldwide. The study will assess efficacy of the investigational vaccine after both the first and second dose to evaluate protection against the virus and potential incremental benefits for duration of protection with a second dose.

The Phase III ENSEMBLE study has begun following the continuation of the Phase III ENSEMBLE study, evaluating a single-dose regimen of the COVID-19 vaccine candidate. The trial is proceeding to enrol up to 60,000 participants worldwide. 

The ENSEMBLE 2 study is a randomised, double-blind, placebo-controlled clinical trial designed to evaluate the safety and efficacy of a two-dose vaccine regimen versus placebo in adults 18 years old and older with and without comorbidities associated with an increased risk for severe COVID-19. Janssen will aim to enrol participants in Belgium, Colombia, France, Germany, the Philippines, South Africa, Spain, the UK and the US. ENSEMBLE 2 is being conducted in collaboration with the UK National Institute for Health Research (NIHR). The ENSEMBLE and ENSEMBLE 2 trials will run in parallel.

According to J&J, the Phase III ENSEMBLE and ENSEMBLE 2 trials follow positive interim results from the company’s ongoing Phase I/IIa clinical study, which is studying the safety profile and immunogenicity of both a single-dose and two-dose vaccination. The interim analysis showed that a single dose of the COVID-19 vaccine candidate induced a robust immune response and was generally well-tolerated. 

“Janssen’s COVID-19 vaccine programme has been designed to be extremely thorough and driven by science. As such, we are investigating multiple doses and dosing regimens to evaluate their long-term efficacy,” said the company in a statement.