AstraZeneca has published a press release announcing that the Oxford-AstraZeneca COVID-19 vaccine US Phase III trial met primary efficacy endpoint in preventing COVID-19 at interim analysis.
Dr Andrew Garrett, Executive VP, Scientific Operations, ICON Clinical Research, said:
“This is clearly stated as an AstraZeneca-led trial, and it more closely follows the large phase III vaccine trials reported by other sponsors. In this respect it is a solid 30,000 plus participant study with a placebo control, and a simple 4 week dosing interval, such that interpretation is more straightforward than previous Oxford/AZ vaccine trials. It has a good age mix with more than 6,000 participants aged >65 years and also wide ethnic representation. Interim efficacy is clearly stated as being 79% against symptomatic COVID-19 and 100% effective against severe disease. Detailed numbers are not provided at this time and the lower confidence limit is not stated. Importantly the trial provides further support for efficacy in the elderly (80%) where previous clinical trial data, other than immunological data, had been lacking. The study randomized two subjects to receive vaccine for every subject that received placebo providing a large safety database of 20,000 plus participants who received active vaccine. As described, this has been used to investigate the potential association of the vaccine with thrombotic events and specifically cerebral venous sinus thrombosis, of which there were no cases detected. Overall it was reported that there was no increased risk of thrombosis. These data are therefore timely in further addressing any safety concerns that could undermine vaccine uptake.