Clinical trial resumes on AstraZeneca-Oxford University Covid-19 vaccine

PT Jyothi Datta

AstraZeneca has resumed clinical trials on the AZ- Oxford coronavirus vaccine (AZD1222) in the UK, the biopharmaceutical company said, indicating that similar trials that had been “paused” in other countries, including India, could also now restart.

In a weekend announcement, AZ said that it had resumed its clinical trials “following confirmation by the Medicines and Healthcare Products Regulatory Agency (MHRA) that it was safe to do so.”

Last week, the company had paused global trials due to an adverse event reported in one patient in the UK. However, the latest note added, “AstraZeneca and the University of Oxford, as the trial sponsor, cannot disclose further medical information.”

“On 6 September, the standard review process triggered a voluntary pause to vaccination across all global trials to allow review of safety data by independent committees, and international regulators,” the company said, adding, “The UK committee has concluded its investigations and recommended to the MHRA that trials in the UK are safe to resume.”

Close on the heels of the AZ statement, Serum Institute of India said, “Once (the) DCGI (Drug Controller General of India) gives us the permission to restart the trials in India, we will resume the trials.”

Serum Institute has a production and distribution alliance on this vaccine candidate in low- and middle-income countries. It too had “paused” clinical trials in India, albeit a day after AZ announced similar action globally. In fact, the vaccine-maker received a show-cause notice from the DCGI for not informing it immediately and halting the trial on the same day.

‘Wake-up call’

Drug regulators in the different countries where clinical trials are being done on this Covid-19 vaccine candidate will review details on the adverse event before giving their green signal to resume trials. Scientific voices point out that pausing clinical trials to review and redirect course, if need be, was in fact sound in science.

Calling it a “wake-up call” of sorts, Dr Soumya Swaminathan, Chief Scientist with the World Health Organisation, said the development was “perhaps a lesson for everyone to recognise the fact that there are ups and downs in research, ups and downs in clinical development and we have to be prepared for those. It’s not always a fast and straight road. But we don’t need to be overly discouraged, as these things happen.” The next steps on the vaccine trial would depend on details from the data safety monitoring board, she said, in a briefing before the MHRA had cleared the vaccine for trials.

In its statement, AZ said it would update all trial investigators and participants with relevant information, which would be disclosed on global clinical registries, according to the clinical trial and regulatory standards.

On the anticipation for an effective Covid-19 vaccine, she said, “we have to remember that clinical trials take time, we cannot rush them, because we have to collect enough data on enough numbers of people to satisfy ourselves and satisfy the regulatory agencies that a particular drug or vaccine is safe and having the effect that you want it to have.”

On the time lines and people involved in the trials, she explained, “If you look at some of the clinical trials that are enrolling today, they have a sample size of anything from 30,000 to 60,000 and usually half of them are given the vaccine and the other half are given a placebo. It’s a blinded study so that the participants and the doctors don’t know who has received what. They have to be followed up for a certain length of time, a minimum of six months to be able to assess both on the protective efficacy and safety,” she said, indicating that more details on the other Covid-19 vaccines in advanced trials would possibly be available by later this year or early next.