Johnson & Johnson (J&J) and AstraZeneca have announced plans to resume clinical trials in the US for their respective COVID-19 vaccine candidates after earlier pausing trials due to an unexpected illness of a study participant in their respective trials.

Earlier this month (October 2020), J&J paused all dosing in its COVID-19 vaccine trials due to an unexpected illness in a study participant. J&J reports that an independent data safety and monitoring board overseeing its Phase III Ensemble trial recommended resuming trial recruitment. The Ensemble trial is evaluating the safety and efficacy of a single dose of its vaccine versus placebo in up to 60,000 adults.

Following consultation with the US Food and Drug Administration (FDA), preparations to resume the trial in the US, including submissions for approval by the Institutional Review Boards, are now underway. The company says discussions with other regulators globally to resume the clinical trial program are progressing.

The company said that no clear cause for the incident was established. “After a thorough evaluation of a serious medical event experienced by one study participant, no clear cause has been identified,” said J&J in an October 23, 2020 statement. “There are many possible factors that could have caused the event. Based on the information gathered to date and the input of independent experts, the Company has found no evidence that the vaccine candidate caused the event.”

In a separate development, AstraZeneca reported that it is resuming its Phase III trial in the US for its COVID-19 vaccine candidate, AZD1222. In September (September 2020), AstraZeneca temporarily paused its clinical trials for the vaccine to allow an independent committee to review the safety data of a single event of an unexplained illness that occurred in a Phase III trial in the UK. The company said the incident was found during standard review of the trial.

The company reported that the FDA has authorized the restart of the trials in the US following the resumption of trials in other countries in recent weeks (as reported on October 23, 2020). Regulators in the UK, Brazil, South Africa, Japan, and India earlier deemed the trials to be safe and could resume

AstraZeneca says results from the late-stage trials are anticipated later in 2020, depending on the rate of infection within the communities where the clinical trials are being conducted and that data readouts will be submitted to regulators and published in peer-reviewed scientific journals. Rolling reviews of the vaccine program have already begun in countries where this regulatory pathway has been established.

Source: Johnson & Johnson and AstraZeneca