Pending advisory committee support and granted authorization, the adenovirus vaccine could become the first single-shot option in the US.
Janssen Biotech has submitted an application for Emergency Use Authorization (EUA) of its investigational single-dose coronavirus 2019 (COVID-19) vaccine candidate to the US Food and Drug Administration (FDA).
The submission comes a week following shared preliminary results of the vaccine’s ongoing phase 3 clinical trial, and puts the adenovirus prophylaxis in position to become the first single-shot COVID-19 vaccine available to prioritized members of the public.
The Ad26.COV2.S vaccine is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector encoding a full-length and stabilized SARS-CoV-2 spike (S) protein. Compatible with standards distribution channels, the single-dose vaccine has an estimated shelf-life of 2 years at -4°F (-20°C)—at least 3 months of which can be stored in most standard refrigerators at temperatures of 36°F–46°F (2°-8°C).
Janssen would intend to ship the vaccine using cold chain technologies—similar to the Pfizer COVID-19 mRNA vaccine, BNT162b2.
The Trial Data
Last week, investigators reported data showing the vaccine reached efficacy and safety endpoints in the ongoing phase 3 ENSEMBLE clinical trial, including protection of COVID-19 at 72% in US-based participants versus placebo 28 days after administration.
Investigators additionally reported an 85% overall efficacy in prevention of severe COVID-19 across all observed regions in the study program—including Latin American and South Africa, the latter of which has been associated with a highly transmissible SARS-CoV-2 variant which has since spread worldwide.
Per Janssen, the observed safety profile of the vaccine is consistent with other vaccines being made with their proprietary AdVac technology—used in 200,000-plus patients to date.
EUA decision for the vaccine, which will be considered on the strength of submitted data from the phase 3 ENSEMBLE clinical trial, will come after a scheduled hearing from the FDA’s Vaccines and Related Biologics Product Advisory Committee (VRBPAC) on Friday, February 26.
The expert panel previously ruled in favor of the data supporting the benefit-risk profile of Pfizer’s BNT162b2 and Moderna’s mRNA-1273 for the prevention of COVID-19 in adults in separate December 2020 meetings. Their supporting opinion led to the quick approval of their EUA applications, making them the lone FDA-regulated COVID-19 vaccines in the US.
Janssen confirmed it has begun rolling submissions with several other national health agencies, and will submit a European Medicines Agency-equivalent a Conditional Marketing Authorisation Application next week.
Paul Stoffels, MD, vice chairman of the Executive Committee and Chief Scientific Officer at Johnson & Johnson, expressed a readiness to begin contributing vaccination efforts in the US, pending FDA decision.
“Upon authorization of our investigational COVID-19 vaccine for emergency use, we are ready to begin shipping,” Stoffels said in a statement. “With our submission to the FDA and our ongoing reviews with other health authorities around the world, we are working with great urgency to make our investigational vaccine available to the public as quickly as possible."