Clinical trials for the AstraZeneca-Oxford University coronavirus vaccine AZD1222 have today have been approved as safe to continue in the US by The Food and Drug Administration (FDA).

The FDA reviewed all safety data from trials globally and concluded it was safe to resume. In recent weeks, regulators in the UK, Brazil, South Africa and Japan had confirmed that it was safe to progress the trials.

As part of the standard review process for trial safety events, a voluntary pause to vaccination across all global trials was triggered on 6 September to allow the examination of safety data by independent monitoring committees. It is not unusual that in large scale vaccine trials, some participants will become unwell, and every case has to be evaluated to ensure the careful assessment of safety.

Pascal Soriot, Chief Executive Officer of AstraZeneca, said: “The restart of clinical trials across the world is great news as it allows us to continue our efforts to develop this vaccine to help defeat this terrible pandemic. We should be reassured by the care taken by independent regulators to protect the public and ensure the vaccine is safe before it is approved for use.”

AZD1222 was co-invented by the University of Oxford and its spin-out company, Vaccitech. It uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein. After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.

Results from the late-stage trials are anticipated later this year, depending on the rate of infection within the communities where the clinical trials are being conducted. 

Data readouts will be submitted to regulators and published in peer-reviewed scientific journals. Rolling reviews of the vaccine programme have already begun in countries where this regulatory pathway has been established, providing regulators access to data as soon as they become available.

While trials are ongoing, AstraZeneca and Oxford University will continue to provide information to regulators, study investigators and participants according to clinical trial and regulatory standards.

Cambridge, UK-headquartered AstraZeneca is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialisation of prescription medicines, primarily for the treatment of diseases in three therapy areas – Oncology, Cardiovascular, Renal & Metabolism, and Respiratory & Immunology.

Business Weekly reported earlier this month that the US government is laying out around $1/2 billion in new funding for a rapidly advanced antibody drug combination from AZ. This deal for AstraZeneca’s COVID-19 Long-Acting AntiBody (LAAB) combination AZD7442 follows the treatment’s surge into Phase III clinical trials.

AZD7442 is a combination of two LAABs derived from convalescent patients after SARS-CoV-2 infection. Discovered by Vanderbilt University Medical Center and licensed to AstraZeneca in June, the LAABs were optimised by AstraZeneca with half-life extension and reduced Fc receptor binding.

The half-life extended LAABs should afford six to 12 months of protection from COVID-19.

Two Phase III clinical trials of AZD7442 are due to start by the end of October. One will enrol over 6,000 adults for the prevention of COVID-19 with additional trials enrolling around 4,000 adults for the treatment of SARS-CoV-2 infections.

AstraZeneca plans to supply up to 100,000 doses starting towards the end of 2020 and the US Government can acquire up to an additional one million doses in 2021 under a separate agreement.

LAABs mimic natural antibodies and have the potential to treat and prevent disease progression in patients already infected with the virus, as well as to be given as a preventative intervention prior to exposure to the virus. 

A LAAB combination could be complementary to vaccines as a prophylactic agent, e.g. for people for whom a vaccine may not be appropriate or to provide added protection for high-risk populations. It could also be used to treat people who have been infected.

Should the Phase III trials prove successful and AZD7442 become an approved medicine the company anticipates providing doses at commercial terms during and after the current coronavirus pandemic.