- AstraZeneca halted its Phase 3 coronavirus vaccine trial earlier this week following a severe reaction that may or may not have been induced by the vaccine.
- CEO Pascal Soriot addressed the matter in a private call with investors, explaining that a woman in the UK who received the vaccine candidate developed neurological issues. Her condition is improving, and she was expected to be discharged on Wednesday.
- Reports earlier this week said the British woman might have developed a condition called transverse myelitis, and that researchers are looking at whether it could have been caused by the experimental vaccine.
The AstraZeneca/Oxford coronavirus vaccine partnership is one of the frontrunners in the COVID-19 vaccine race. Oxford was among the first few companies to publish promising results for COVID-19 immunity, and the vaccine is one of the three advanced experimental drugs that have reached Phase 3 trials in America and Europe. AstraZeneca has already inked deals with the US government, Great Britain, and other countries to provide hundreds of millions of doses if the vaccine is found to be safe and effective. But AstraZeneca had to halt Phase 3 inoculations at all international testing sites earlier this week after one volunteer developed a severe medical condition. It’s currently unclear whether the vaccine candidate triggered an adverse effect or the patient’s diagnosis happened independently of the drug. That’s why vaccinations were paused, so experts can investigate the matter and determine whether the research process can continue. AstraZeneca explained that such events are typical in drug research, without elaborating on what happened.
A report that followed indicated that a patient developed a condition called transverse myelitis, which is a severe spinal inflammation that can follow a viral infection. AstraZeneca CEO Pascal Soriot addressed the matter in a private conference call with investors on Wednesday.
Three investors on the call shared the remarks with Stat, which first reported the incident that halted the AstraZeneca/Oxford trial.
Soriot said the participant who triggered the shutdown of the trial was a woman in the UK who experienced neurological symptoms consistent with transverse myelitis. The woman’s diagnosis has not been confirmed but her condition has been improving, and she was expected to be discharged on Wednesday. Transverse myelitis is a serious condition that can lead to muscle weakness, pain, bladder problems, and even paralysis, Stat explains. The condition can be triggered in rare instances by vaccines, and it is treatable.
Of note, Soriot also confirmed that the woman had received the vaccine candidate and not the placebo compound used in the study.
The exec said that the study was halted once before in July during a previous phase of the trial, when one other patient developed neurological symptoms. But that person was diagnosed with multiple sclerosis, which was unrelated to the experimental vaccine. One of the investors on the call said that Soriot’s comments were intended to reassure investors that the company was taking vaccine safety seriously, and to reverse the damage done to its stock. “A vaccine that nobody wants to take is not very useful,” Soriot reportedly said.
The exec made these comments during a private meeting and AstraZeneca has yet to share them with the general public. The company did say that the study was halted due to an unexplained illness and that such events are routine for clinical trials. But AstraZeneca never mentioned what sort of potential vaccine side effect it was studying.
Others have explained that clinical hold policies aren’t uncommon in clinical trials, like the director of the National Institutes of Health, Francis Collins. He told a Senate panel on Wednesday that “to have a clinical hold, as has been placed on AstraZeneca as of yesterday, because of a single serious adverse event is not at all unprecedented. This certainly happens in any large-scale trial where you have tens of thousands of people invested in taking part, some of them may get ill, and you always have to try to figure out: Is that because of the vaccine, or were they going to get that illness anyway?”