AstraZeneca announced the start of a phase 3 study in the US investigating its experimental COVID-19 vaccine AZD1222 in up to 30,000 adults aged 18 years or over. Subjects in the trial, called D8110C00001, will be randomized to receive two doses of either AZD1222 or a saline control, 4 weeks apart, with twice as many participants receiving the potential vaccine than the saline control.
The US study, which is funded by the US Biomedical Advanced Development Authority (BARDA) as part of Operation Warp Speed, will include adults from diverse racial, ethnic and geographic groups who are healthy or have stable underlying medical conditions, including those living with HIV, and who are at increased risk of infection from the SARS-CoV-2 virus. The trial is assessing efficacy and safety of AZD1222in all participants, while local and systemic reactions and immune responses will be assessed in 3000 people.
Late-stage studies grow
The study joins ongoing late-stage trials in the UK, Brazil and South Africa, with further studies planned to start in Japan and Russia. The Phase III program for the vaccine, which is being co-developed with the University of Oxford, will enroll a total of up to 50,000 participants globally with results expected later this year.
In July, interim results from the ongoing phase 1/2 COV001 trial were published in The Lancet showing that AZD1222 was tolerated and generated robust immune responses against the SARS-CoV-2 virus in all evaluated participants. Mene Pangalos, executive vice president of biopharmaceuticals R&D at AstraZeneca, remarked “we are pleased that AZD1222 demonstrated safety and immunogenicity across all adult age groups.”
Start follows reported delay
A recent report suggested that the trial had been put on hold due to political pressure, although William Hartman, an investigator on the study, said the delay was due to unspecified operational issues. “There was a hold on enrollment. We don’t really know what the reason for that was. We were told it had nothing to do with safety and didn’t have anything to do with an [emergency use authorisation], it was just an operational issue,” Hartman remarked.
Hartman added “we are going to proceed with the trial independent of any political pressure.” FDA Commissioner Stephen Hahn recently said that the agency would be willing to consider granting emergency authorisation for a vaccine against SARS-CoV-2 before clinical trials have been completed if the benefits outweigh the risks. However, he insisted that the agency would not be pressured to rush out a vaccine by the Trump administration, commenting “we have a convergence of the COVID-19 pandemic with the political season, and we’re just going to have to get through that and stick to our core principles.”