Sources Say US Study of AstraZeneca’s COVID-19 Vaccine May Restart This Week

According to a report Tuesday citing four sources, the US trial of AstraZeneca’s COVID-19 vaccine AZD1222 is expected to resume as early as this week after the FDA completed its review of a serious adverse event that had prompted a hold on global testing of the candidate last month. The phase 3 trial has been suspended in the US since September 6, after a participant in the company’s UK trial fell ill with what was suspected to be transverse myelitis, and while testing has since started up again in the UK and some other countries, it remains stalled in the US, where the FDA was conducting its own review of the incident.

The sources were briefed on the matter and said they have been told the US trial could resume later this week, although it is unclear how the FDA would characterise the illness. However, one of the sources indicated that the agency is requiring researchers conducting the trial to add information about the incident to consent forms signed by study participants. The FDA declined to comment on the report.

Re-do from scratch?

The US portion of AstraZeneca’s trial was launched at the start of September and is expected to enroll 30,000 participants in all to test the administration of two doses of AZD1222, given about a month apart. The study was put on hold just days later because of the adverse event. However, with the US study still paused some six weeks later, some participants have missed the window to receive their second dose, and researchers may now have to start from scratch.

William Hartman, principal investigator at one of the 80 trial sites across the US, said “several of those participants have reached out, asking, ‘What’s the deal?’…We just don’t have anything to tell them.”

Last week, Johnson & Johnson also suspended further dosing in a phase 3 trial of its coronavirus vaccine candidate JNJ-78436735 due to an “unexplained illness” in a participant. Meanwhile, Eli Lilly, which is evaluating LY-CoV555 as a potential treatment of COVID-19, also recently paused a phase 3 study of the experimental monoclonal antibody because of a “potential safety concern.”