AstraZeneca's U.S. COVID-19 trial is back on track after 45-day hold

It’s been a minute, but AstraZeneca has gotten the FDA’s all-clear to restart the U.S. study of its COVID-19 vaccine.

Although the agency couldn’t rule out a link between AstraZeneca’s vaccine and side effects observed in one patient, it did not find the vaccine was responsible for them, a person familiar with the matter told the The Wall Street Journal.

RELATED: Patient death casts a shadow on AstraZeneca's COVID-19 trial: report

The British pharma slammed the brakes on the program in early September when a patient in the U.K. developed an inflammatory side effect. The pause came just one week after the 30,000-patient U.S. trial had kicked off.

U.K. regulators OK’d the resumption of the study a week later, with their counterparts in Brazil, India and South Africa doing the same in the following weeks. However, the FDA kept the U.S. trial on hold as it reviewed data around that side effect—transverse myelitis, or inflammation of the spinal cord that can be triggered by infections.

Now, the FDA has finished that review and told AstraZeneca it can restart the U.S. trial, the pharma giant confirmed Friday.

The news comes days after reports emerged that the trial could restart as soon as this week, with Reuters reporting Wednesday that the FDA “has come to the same conclusion as the other drug regulators." On Wednesday, Brazil’s health authority Anvisa announced a patient participating in the study had died but that the trial would carry on.

RELATED: Why did J&J hit pause on its COVID-19 vaccine trial? Stay tuned, execs say

Since AstraZeneca's U.S. trial was put on hold, Johnson & Johnson has suspended a 60,000-patient study of its own COVID-19 vaccine because of an “unexplained illness in a study participant.” Unlike AstraZeneca’s hold, though, J&J’s pause was voluntary. The company did not immediately know whether the patient who fell ill received the vaccine or placebo, and it is waiting on an independent monitoring board to analyze the data.

On Monday, the Financial Times also reported that AstraZeneca's vaccines saw a "a robust immune response in elderly people," according to sources that have seen it speaking to the London newspaper. The data and more clinical details are set to be published shortly, but if this follows on from earlier results in older patients, it will be a needed positive for the Big Pharma.