85% efficacy against symptomatic COVID-19 in participants aged 65 years and over
March 25, 2021:
Positive high-level results from the primary analysis of the Phase III trial of AZD1222 in the US have confirmed vaccine efficacy consistent with the pre-specified interim analysis announced on Monday 22 March 2021.
These results have been presented to the independent Data Safety Monitoring Board. The primary analysis is pre-specified in the protocol and will be the basis for a regulatory submission for Emergency Use Authorization to the US Food and Drug Administration in the coming weeks.
This primary efficacy analysis included the accrual of 190 symptomatic cases of COVID-19 from the 32,449 trial participants, an additional 49 cases to the previously announced interim analysis. Participants were randomised on a 2:1 ratio between the vaccine and placebo group.
The primary endpoint, vaccine efficacy at preventing symptomatic COVID-19 was 76% (confidence interval (CI): 68% to 82%) occurring 15 days or more after receiving two doses given four weeks apart.
In addition, results were comparable across age groups, with vaccine efficacy of 85% (CI: 58% to 95%) in adults 65 years and older. A key secondary endpoint, preventing severe or critical disease and hospitalisation, demonstrated 100% efficacy.
There were eight cases of severe COVID-19 observed in the primary analysis with all of those cases in the placebo group.
The vaccine was well tolerated, and no safety concerns related to the vaccine were identified.
Mene Pangalos, Executive Vice President, BioPharmaceuticals R&D, said: “The primary analysis is consistent with our previously released interim analysis, and confirms that our COVID-19 vaccine is highly effective in adults, including those aged 65 years and over.
We look forward to filing our regulatory submission for Emergency Use Authorization in the US and preparing for the rollout of millions of doses across America.”
There were 190 cases in the primary analysis. There are 14 additional possible or probable cases to be adjudicated so the total number of cases and the point estimate may fluctuate slightly.
AstraZeneca will also submit the primary analysis for peer-reviewed publication in the coming weeks.
D8110C00001
The US Phase III trial, called D8110C00001, was led by AstraZeneca and funded by the Biomedical Advanced Research and Development Authority (BARDA), part of the office of the Assistant Secretary for Preparedness and Response (ASPR) at the US Department of Health and Human Services (HHS) in collaboration with the Department of Defense Joint Program Executive Office for Chemical, Biological, Radiological and Nuclear Defense (JPEO-CBRND) and the Army Contracting Command, and the National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health.
The NIAID-supported COVID-19 Prevention Network (CoVPN) participated in the trial.
D8110C00001 is a randomised, double-blind, placebo-controlled multicentre Phase III trial assessing the safety, efficacy, and immunogenicity of AZD1222 compared to placebo for the prevention of COVID-19, in 32,449 participants across 88 trial centres in the US, Peru and Chile.
Trial participants aged 18 years or over who are healthy or have medically stable chronic diseases and are at increased risk for being exposed to the SARS-CoV-2 virus and COVID-19 were randomised in a 2:1 ratio to receive two intramuscular doses of either 5 x1010 viral particles of AZD1222 or saline placebo four weeks apart.
The pre-specified statistical analysis plan required at least 75 adjudicated cases at interim analysis, and at least 150 adjudicated cases at primary analysis.”
https://www.astrazeneca.com/content/astraz/media-centre/press-releases/2021/azd1222-us-phase-iii-primary-analysis-confirms-safety-and-efficacy.html
