Johnson & Johnson has begun a 60,000-subject phase 3 assessment of its COVID-19 vaccine. The trial will enroll participants in the U.S. and other countries with a high incidence of COVID-19 with a view to generating data to support emergency use authorization early next year.
J&J submitted details of the phase 3 to ClinicalTrials.gov last month. At that time, J&J aimed to start enrolling subjects in the first week of September. Today, around two weeks after the targeted start of recruitment, J&J said it has initiated a phase 3 trial of Ad26 vector-based vaccine Ad26.COV2.S, now also known as JNJ-78436735.
AstraZeneca, Moderna and Pfizer, in collaboration with BioNTech, got U.S. phase 3 COVID-19 vaccine trials underway before J&J reached that milestone. However, J&J has advantages that could see it come from behind to play a major role in the effort to end the pandemic.
Unlike its rivals, J&J is evaluating the safety and efficacy of a single dose of a COVID-19 vaccine. If the one-dose regimen is successful, J&J could eliminate the logistical complexity and dropouts associated with trying to get people to return for a second shot. A one-shot regimen would also enable J&J to vaccinate 1 billion people each year. Few manufacturers of two-dose regimens can match that figure.
J&J is covered in the event two doses are needed to confer immunity. Working with the U.K. government, J&J plans to run a second phase 3 trial that will evaluate the effects of giving two doses of the vaccine.
Janssen, the J&J unit developing the vaccine, moved the one-dose regimen into phase 3 after getting a look at early-phase data on the candidate. A preprint paper detailing the results of the phase 1/2 is due to be published imminently.
In disclosing the start of the phase 3, J&J also called out the storage requirements of its vaccine. The candidate is expected to be stable for two years at -20°C and for upward of three months in the 2°C to 8°C range used to store many biologics. J&J said the candidate is “compatible with standard vaccine distribution channels and would not require new infrastructure to get it to the people who need it.” Pfizer’s mRNA vaccine must be kept at -70⁰C and be used within 24 hours of being thawed.
Other COVID-19 vaccines have storage requirements more comparable to those of J&J’s shot. Storage will likely only become a factor if multiple vaccines post comparable phase 3 safety and efficacy data. For now, any vaccine that is shown to work is likely to be used as quickly as it can be produced.
J&J has contracts lined up in key markets around the world and expects to start selling the vaccine in the U.S. under an emergency use authorization early next year. That prediction, which J&J first made in March, suggests J&J will get its vaccine to market shortly after the leading candidates, if they work.