J&J Looking to Enroll 60,000 Participants in Coronavirus Vaccine Trial

A phase 3 trial Johnson & Johnson is planning to get under way in September to test its coronavirus vaccine candidate Ad26.COV2.S is looking to recruit up to 60,000 participants globally, the company confirmed Thursday. The targeted enrollment, first reported on the ClinicalTrials.gov database, would make it double that of other studies that have either started recently or are expected soon for COVID-19 vaccines developed by AstraZeneca, Moderna, and an alliance between Pfizer and BioNTech.

Johnson & Johnson recently initiated a phase 1/2 trial of Ad26.COV2.S in healthy volunteers in the US and Belgium. According to the government database, the randomized phase 3 study will see participants administered either a single dose of Ad26.COV2.S or placebo, and will track rates of COVID-19 characterized moderate-to-severe symptoms between the two groups.

The trial will be conducted with healthy adults aged 18 years and older at nearly 180 locations in the US across 28 states, including those with high transmission rates such as Texas, Florida and California, which will each have multiple study sites. It will also be conducted in eight other countries where transmission rates are high, including Brazil, Chile, the Philippines and South Africa, according to the database.

Representative populations

While it is unclear why Johnson & Johnson is planning a much larger late-stage trial than other companies, spokesman Jake Sargent said it wants “to enroll a robust number of participants who are representative of those populations affected by COVID-19,” as well as to determine the safety, efficacy, durability and optimal dosing regimens of the vaccine. Sargent indicated that recruitment has already started, and “we are using epidemiology and modeling data to predict and plan where our studies should take place and expect that to be finalised soon.”

The study will follow the subjects for more than two years, although Johnson & Johnson might have a preliminary read-out by the end of this year, a company executive has said. If results prove the vaccine works safely and the US government clears the vaccine, Johnson & Johnson plans to make its first batches available for potential emergency use in early 2021, the spokesman said.

Earlier this month, Johnson & Johnson signed a $1-billion contract with the US government to supply 100 million doses of Ad26.COV2.S for the US, which also has an option to acquire additional doses that would be sufficient to vaccinate up to 300 million people. The company also recently agreed an initial sale of 30 million doses to the UK and has wrapped up exploratory advance purchase talks with the EU as well.