London, Nov 26 (efe-epa).- Drug-maker AstraZeneca may organize a new international trial of its prospective coronavirus vaccine after acknowledging problems with results showing the formula to be 90 percent, CEO Pascal Soriot said Thursday.
The company does not expect that the additional Phase 3 clinical trials will delay the process of obtaining regulatory approval in the United Kingdom and the European Union, he said in an interview with Bloomberg News.
On Monday, AstraZeneca and its partner in developing the vaccine, the University of Oxford, said that their drug proved 70 percent effective in preventing people from contracting Covid-19.
Subsequently, however, it emerged that they arrived at the 70 percent figure by averaging results from trials conducted among two separate groups of people using two different dosages.
One set of subjects received two full doses of the formula, while the other, smaller group got only half the normal dose in the first injection before getting a full dose in the second jab.
The vaccine was 62 percent effective for the people who received two full doses, but demonstrated 90 percent effectiveness among the test subjects given the half-dose in the initial shot.
Oxford said Thursday that the discrepancy in dosing was due to a “difference in the manufacturing process.”
Once researchers realized that the dose was smaller than planned, they changed the trial protocol in consultation with regulators, Oxford said.
“Now that we’ve found what looks like a better efficacy we have to validate this, so we need to do an additional study,” Soriot told Bloomberg, adding that the new trial “could be faster because we know the efficacy is high so we need a smaller number of patients.”
He said that the need to conduct another trial could delay securing approval for the drug in the United States.
“The question for us was, will we need the US data to get approval in the U.S. or can we get approval in the US with international data, and it was never clear. Now with those results it’s more likely that we will need the US data,” the AstraZeneca CEO said.
Moncef Slaoui, who leads the US government’s program to expedite development of a vaccine, Operation Warp Speed, said Tuesday that all of the test subjects who received the more effective dosage were under the age of 55.
People over 65 are the age group most at risk of dying from Covid-19.
Pfizer Inc. last week asked the US Food and Drug Administration to extend Emergency Use Authorization for its coronavirus vaccine candidate, which the company says proved 95 effective in clinical trials.
But the drug created by the US pharmaceutical giant in collaboration with Germany’s BioNTech has demanding storage and transportation requirements, unlike the AstraZeneca candidate.