The Oxford-AstraZeneca vaccine is 79% effective in preventing symptomatic COVID-19, according to the findings of the interim analysis for the US Phase 3 study released by AstraZeneca yesterday. But in a statement issued early today [March 23], the NIAID questioned the data surrounding the efficacy figures published by the Anglo-Swedish company.
“Late Monday, the Data and Safety Monitoring Board (DSMB) notified NIAID, BARDA, and AstraZeneca that it was concerned by information released by AstraZeneca on initial data from its COVID-19 vaccine clinical trial,” reads a statement released by NIAID today [March 23].
“The DSMB expressed concern that AstraZeneca may have included outdated information from that trial, which may have provided an incomplete view of the efficacy data.
"We urge the company to work with the DSMB to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible.”
The Phase 3 trial in the US covered 32,449 participants across the US, Peru and Chile. The NIAID has not specified what data have prompted its questions: only that its concern is related to efficacy figures.
The US trial’s interim data supported previous results observed in other trials for the vaccine, although also reported similar efficacy results in people aged 65+ for the first time (20% of the trial’s participants were aged 65+).
AstraZeneca has responded to the NIAID’s statement, emphasizing the primary analysis (yet to be published) supports the interim analysis released yesterday: pledging to share the data with the DSMB as soon as possible.
“The numbers published [on March 22] were based on a pre-specified interim analysis with a data cut-off of 17 February,” says the company.
“We have reviewed the preliminary assessment of the primary analysis and the results were consistent with the interim analysis. We are now completing the validation of the statistical analysis.
“We will immediately engage with the independent data safety monitoring board (DSMB) to share our primary analysis with the most up to date efficacy data. We intend to issue results of the primary analysis within 48 hours.”
EUA application in sight
While AstraZeneca has obtained authorization for its vaccine in a number of jurisdictions around the world – including the UK and EU – it is yet to receive authorization in the US.
It said yesterday that it would submit data for an Emergency Use Authorization application ‘in the coming weeks’, while submitting the primary analysis for publication in a peer-reviewed journal in parallel.
The US Phase III trial, D8110C00001, is led by AstraZeneca and funded by the US Biomedical Advanced Research and Development Authority (BARDA).