AstraZeneca to Hasten Trial Update After U.S. Calls Results Outdated
A healthcare worker attaches an expiry date sticker on a vial of the AstraZeneca Plc Covid-19 vaccine at Chang Gung Memorial Hospital in Taipei. (Photographer: I-Hwa Cheng/Bloomberg)

AstraZeneca to Hasten Trial Update After U.S. Calls Results Outdated


AstraZeneca Plc plans to release up-to-date results from the U.S. study of its Covid-19 vaccine within 48 hours following criticism from a science agency that an analysis published Monday included old information.

The U.K. drugmaker will “immediately engage” with the independent panel monitoring the trial to share the latest efficacy information, AstraZeneca said Tuesday. The earlier results were based on data gathered through Feb. 17.

The stumble is the latest misstep for AstraZeneca, which had announced that the vaccine was found to be 79% effective in preventing Covid-19 in the U.S. clinical trial of more than 30,000 volunteers. The shot, developed with the University of Oxford and viewed as a frontrunner to help curb the pandemic, has been beset by complications.

In a brief statement last night, the National Institute for Allergy and Infectious Diseases said the monitoring board charged with ensuring the safety and accuracy of the vaccine trial had expressed concern that results may give an “incomplete” view of the shot’s efficacy.

Data Doubts

The institute, headed by Anthony Fauci, urged AstraZeneca to work with the data and safety monitoring board to “ensure the most accurate, up-to-date efficacy data be made public as quickly as possible.”

In an interview with ABC’s Good Morning America, Fauci said that after the company put out its release Monday with the trial data and its efficacy conclusions, the DSMB “got concerned” the data was outdated and might be “misleading a bit.” Fauci said Astra “better get back with the DSMB and make sure the correct data gets put into a press release.”

AstraZeneca shares fell as much as 1.6% in London.

The vaccine has had a rocky rollout, especially in Europe, where it’s currently at the center of a supply showdown between the European Union and the U.K. Concerns about blood clots just days ago prompted around a dozen countries to suspend immunizations, though most have since resumed using the vaccine.

Fresh Concern

“The last thing this vaccine needs is more concern when we kind of thought we were at that point now where we’d put to bed all the other concerns,” said Paul Griffin, an associate professor of medicine at the University of Queensland in Brisbane, who is conducting clinical studies in Australia on four Covid-19 vaccine candidates.

After the vaccine was cleared for use in the U.K. and many other nations, AstraZeneca is preparing to seek approval from the U.S. Food and Drug Administration.

Astra Really Doesn’t Need More Doubts on Its Vaccine Data

The efficacy rate in the U.S. trial was stronger than the 70% figure AstraZeneca reported from an earlier study. But those data were an average of different readings -- 62% and 90% -- from two arms of the trial. Because of a manufacturing error, one group of participants had received a lower first dose, which produced the higher reading, compared with those getting two standard doses. Further analysis suggested it was the greater dosing gap rather than amount that had created the difference.

AstraZeneca’s final-stage U.S. trial was funded by the U.S. Biomedical Advanced Research and Development Authority and conducted in collaboration with government agencies including NIAID, whose Covid-19 Prevention Network -- a group that studies vaccines and monoclonal antibodies -- participated in the trial.

The DSMB is a group of outside experts who monitor the study. While researchers running the trial are blinded to certain details while it’s ongoing to prevent bias, the board members can watch trial data accumulate. In some cases they may stop trials, either if it appears that there’s a safety issue, or if data show that experiment has yielded an answer early.

©2021 Bloomberg L.P.

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