J&J Begins Largest Global Phase 3 COVID-19 Vaccine Trial to Date

Johnson and Johnson (J&J) yesterday became the fourth drugmaker to begin a large-scale phase 3 trial of a COVID-19 vaccine candidate — and it will be the largest late-stage trial of a COVID-19 vaccine to date.

The ENSEMBLE trial will test the safety and efficacy of a single dose of Ad26.COV2.S vs. a placebo for preventing COVID-19 in 60,000 volunteers across more than 200 clinical research sites in the U.S., Argentina, South Africa, Brazil, Chile, Colombia, Mexico and Peru.

J&J’s trial is testing a single dose of AD26.COV2.S, while its competitors are testing two doses of their vaccines several weeks apart. J&J’s Chief Scientific Officer Paul Stoffels said that interim phase 1/2 data show that a single dose is “sufficient to protect the people for a long time.” Data from that trial is expected to be released within days. Stoffels said the company should know whether the vaccine works by the end of the year.

The global study is being carried out in collaboration with HHS’ Biomedical Advanced Research and Development Authority and the NIH’s National Institute for Allergy and Infectious Diseases. The company is also collaborating with the UK government on a separate phase 3 study evaluating a two-dose regimen of the vaccine (DID, Aug. 17).

Pfizer and BioNTech just reached their initial enrollment target of 30,000 participants and are now seeking to expand enrollment to 44,000 volunteers (DID, Sept. 17). In addition, both Moderna and AstraZeneca are aiming to enroll 30,000 volunteers for their trials. — Jordan Williams