FDA Greenlights Restart of AstraZeneca’s Phase III COVID-19 Vaccine Study


After nearly a month in limbo, AstraZeneca will resume Phase III testing of its COVID-19 vaccine candidate in the United States.

AstraZeneca announced the restart of the Phase III trial of AZD1222 has been greenlit by the U.S. Food and Drug Administration (FDA). The trial had resumed elsewhere in the world, but had remained paused since September following reports that a patient in the United Kingdom who received the vaccine was hospitalized due to a serious spinal inflammatory disorder thought to be transverse myelitis. After an investigation into that case, as well as the case of a woman who developed neurological issues earlier this year that was determined to be multiple sclerosis, the FDA concluded it was safe to resume the trial.

“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,” AstraZeneca Chief Executive Officer Pascal Soriot said in a statement.

The FDA came to the same conclusion regarding the safety of the vaccine as the U.K.’s Medicines Health Regulatory Authority (MHRA). Earlier this month, the trial was allowed to begin again in Britain after the MHRA came to the conclusion there was not sufficient evidence the woman’s illness was directly caused by the vaccine. According to the Mayo Clinic, transverse myelitis can be caused by infections and immune system disorders.

Earlier this week there were reports of a patient death involved in a Brazilian study of the vaccine. However, it was determined that patient had likely received a placebo, as opposed to the vaccine candidate.

AstraZeneca’s COVID-19 vaccine candidate AZD1222 is a viral vector-based, weakened version of adenovirus containing the genetic material of SARS-CoV-2 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. In July, the company published positive Phase I data from its vaccine candidate that showed the preventative medication generated both neutralizing antibodies and immune T-cells that target the virus that causes COVID-19.

If the vaccine makes it through regulatory trials, AstraZeneca plans to manufacture two billion doses of its vaccine, with 400 million slated for the U.S. and UK, and one billion allotted for low- and middle-income countries. The vaccine candidate has been backed in the United States through a $1 billion investment from the federal government’s Operation Warp Speed program aimed at developing a vaccine for the novel coronavirus as quickly as possible.

The month-long pause in the 30,000 Phase III trial has put AstraZeneca and its developmental partner Oxford University behind other drugmakers working on a vaccine for the novel coronavirus. Both Moderna and Pfizer and BioNTech anticipate data from their Phase III studies within the next several weeks. Pfizer CEO Albert Boula said his company could seek Emergency Use Authorization in late November if the data is positive. Moderna CEO Stephane Bancel anticipates seeking EUA in December. AstraZeneca said results from its Phase III study are anticipated later this year, depending on the rate of infection within the communities where the clinical trials are being conducted. Rolling reviews of the vaccine have begun in some countries, AstraZeneca said.

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