Regulators in the U.S. are broadening their investigation into an adverse event that occurred in the clinical trial of AstraZeneca’s vaccine against Covid-19, according to a news report.
Citing three sources familiar with the situation, Reuters reported Wednesday that the Food and Drug Administration would look at data from previous clinical trials that came from the same scientists. Reuters reported that the data the FDA is reviewing are expected to arrive this week, and that it will take time for the agency to analyze it. The vaccine, AZD1222, originated at the University of Oxford, where it was known as ChAdOx1 nCoV-19. The company, like most others, has received funding from the U.S. government for the development of AZD1222, amounting to more than $1 billion, in exchange for providing hundreds of millions of doses to the U.S. if trials are successful.
Clinical studies of the vaccine were put on hold early last month after a participant developed spinal inflammation, a disorder known as transverse myelitis. Trials of the vaccine resumed less than a week later in the U.K., following a clearance by that country’s drug regulatory agency, but they have remained on hold in the U.S., where a Phase III study of 30,000 participants was to test it.
In July, AstraZeneca said interim results from its Phase I/II study showed the vaccine was tolerated and produced “robust” immune responses – antibody as well as T-cell responses – in participants.
The hold plus the extra time for review means AstraZeneca will likely fall behind other companies whose vaccines against the virus that causes Covid-19, SARS-CoV-2, are already in late-stage development. These include Moderna, Johnson & Johnson as well as Pfizer and BioNTech, which are working under a partnership. On Tuesday, Moderna published data in The New England Journal of Medicine showing that its vaccine, mRNA-1273, showed immune responses among older and elderly participants in a Phase I study that were comparable to those seen in younger participants and that had continued a month after they received their second dose.
Another company with a vaccine in late-stage development, Inovio Pharmaceuticals, said this week that the FDA had placed a partial hold on its Phase II/III study of its vaccine, INO-4800, though that was because of questions about the delivery device rather than any safety issues.
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