Federal health officials said early Tuesday that results from a U.S. trial of AstraZeneca’s Covid-19 vaccine may have relied on “outdated information” that “may have provided an incomplete view of the efficacy data,” casting doubt on an announcement on Monday that had been seen as good news for the British-Swedish company as well as the global vaccination drive.
In a highly unusual statement released after midnight, the National Institute of Allergy and Infectious Diseases said that the data and safety monitoring board, an independent panel of medical experts under the National Institutes of Health that has been helping to oversee AstraZeneca’s U.S. trial, had notified government agencies and AstraZeneca late Monday that it was “concerned” by information the company had released that morning.
The institute urged AstraZeneca to work with the monitoring board “to review the efficacy data and ensure the most accurate, up-to-date efficacy data be made public as quickly as possible.”
AstraZeneca did not immediately return a request for comment early Tuesday.
In a news release on Monday announcing the results of the U.S. trial, the company said that the vaccine it developed with the University of Oxford was 79 percent effective against Covid-19, higher than observed in previous trials, and completely prevented the worst outcomes from the disease. The long-anticipated results were seen as encouraging global confidence in the vaccine, which was shaken this month when more than a dozen countries, mostly in Europe, temporarily suspended the shot’s use over concerns about possible rare side effects.
In recent days, the monitoring board’s analysis was delayed several times because the board had to ask for revised reports from those handling trial data on behalf of the company, according to a person familiar with the matter who was not authorized to discuss it publicly.
Companies sponsoring drug or vaccine trials typically wait for the monitoring board to run analyses and conclude that the study has yielded an answer before they announce trial results. During the trial, an unblinded statistical analysis group that is walled off from the company acts as an intermediary to handle data requests and many other interactions with the monitoring board.
Company executives are blinded to the results of the study until the monitoring board reports their study data back to them. The monitoring board ultimately conveyed the results of the study to AstraZeneca in a meeting over the weekend, leading to the company’s announcement Monday morning.
An AstraZeneca spokeswoman, whom the company declined to name, said last week that it was “completely incorrect” that the trial data had formatting problems or had not been submitted to the monitoring board in a clean fashion.
“As is often the case,” the spokeswoman said, monitoring boards “can request new or clarifying analyses of data from the trial. This would enable them to ensure the robustness of their determinations.”
Dr. Eric Topol, a clinical trials expert at Scripps Research in San Diego, said it was “highly irregular” to see such a public display of friction between a monitoring board and a study sponsor, which are typically in close concordance.
“I’ve never seen anything like this,” he said in an interview after the institute’s statement was released. “It’s so, so troubling.”
AstraZeneca’s relationship with the U.S. authorities has been fraught since last year, when senior health officials believed the company was not being forthright about the design of its clinical trials, its results and safety issues. That skepticism carried over to last week, when senior officials at a number of federal health agencies grew suspicious about why AstraZeneca had not announced data from its U.S. study.
That U.S. trial, which involved more than 32,000 participants, was the largest test of its kind for the shot. The results AstraZeneca released on Monday were from an interim look at the data after 141 Covid-19 cases had turned up among volunteers.
The company did not disclose how up-to-date the data are. If the analysis was conducted on data from a month or two ago, it is possible that a more current look would present a different picture of the vaccine’s effectiveness and safety. The company has said it will provide the Food and Drug Administration with a more comprehensive, recent set of data than what it disclosed on Monday. Although no clinical trial is large enough to rule out extremely rare side effects, AstraZeneca reported that its study had turned up no serious safety issues.
The data may have arrived too late to make much difference in the United States, where the vaccine is not yet authorized and is unlikely to become available before May. By then, federal officials predict, there will be enough vaccine doses for all of the nation’s adults from the three vaccines that have already been authorized: Pfizer-BioNTech, Moderna and Johnson & Johnson.
Even so, the better-than-expected results were seen as a heartening turn for AstraZeneca’s shot, whose low cost and simple storage requirements have made it a vital piece of the drive to vaccinate the world.
The results were also thought to ease concerns about the AstraZeneca vaccine in Europe. Regulators there said last week that the shot was “safe and effective,” having conducted a review after a small number of people who had recently been inoculated developed blood clots and abnormal bleeding. The U.S. trial did not turn up any sign of such problems, although some safety issues can only be detected in the real world, once a drug or vaccine has been widely used.
Many millions of people have received the AstraZeneca shot worldwide, including more than 17 million in Britain and the European Union, almost all without serious side effects. In an effort to increase public confidence, many European political leaders have gotten the injections in recent days. The AstraZeneca vaccine has also been administered in the past week to leaders in South Korea, Taiwan and Thailand.
AstraZeneca said on Monday that it would continue to analyze the new data and prepare to apply in the coming weeks for emergency authorization in the United States. The vaccine has already been approved in more than 70 countries, but clearance from American regulators would bolster its global reputation.
The statement from the infectious disease institute comes after a series of miscues and communication blunders by AstraZeneca dating to last year that have eroded American officials’ trust in the company.
Last summer, at least some top F.D.A. officials learned only from news reports that AstraZeneca had paused its Phase 2/3 vaccine trial in Britain after a participant developed neurological symptoms. Then in September, after another participant in the British study fell ill with similar symptoms, AstraZeneca halted its trials globally but failed to promptly notify the U.S. authorities.
The U.S. study was ultimately paused for seven weeks last fall, in part because AstraZeneca was slow to provide the F.D.A. with evidence that the vaccine had not caused the neurological symptoms. Investigators ultimately concluded that the illnesses could not be linked to the vaccine. Still, the delay was a key reason that AstraZeneca fell so far behind the three other manufacturers whose vaccines have been granted emergency authorization in the United States.
Chancellor Angela Merkel of Germany, warning on Tuesday that her country is facing a significantly more deadly wave of the coronavirus, announced a five-day lockdown over Easter and the extension of existing restrictions until mid-April in an effort to break a spike in coronavirus cases.
Starting April 1, and until the following Monday, Germany will effectively shut down for an extended Easter break, with private meetings limited to no more than two groups of up to five adults and almost all stores ordered shuttered (supermarkets can open on the Saturday). Churches are asked to hold services online, and people are being asked to stay home and not travel.
“We are in a very, very serious situation,” Ms. Merkel told a news conference, after hours of deliberations with the leaders of the country’s 16 states over the Easter lockdown and extension of existing restrictions through April 18.
“After we were able to sharply bring down the number of new infections in January, we are now experiencing, through the spread of the more contagious British variant, a more dangerous variation — the numbers are going up and the intensive care beds are filling up,” she said.
Germany is the latest country in Europe to tighten restrictions as more contagious virus variants spread and the continent struggles to vaccinate its citizens. Poland, Italy and parts of France have ordered that residents stay home, and many businesses have shut before the holiday.
A resurgent virus and lagging vaccinations have forced governments to renege on promises that they would slowly reopen businesses and society as spring approached. That has spurred protests across Europe.
Europe’s vaccine campaign slowed after a small number of cases of blood clots and abnormal bleeding were reported in patients who received the AstraZeneca vaccine, dampening confidence in its safety. While the European drug regulator, the European Medicines Agency, cleared the vaccine for use last week and said it was “safe and effective,” the scare further complicated vaccination efforts.
Just three weeks ago, Ms. Merkel and state officials hammered out a road map to reopening that relied on a decline in case rates. But the number of new daily cases in Germany has increased by 69 percent in the past two weeks, to levels last seen in January.
A monoclonal antibody treatment developed by the drug maker Regeneron sharply cut the risk of hospitalization and death when given to high-risk Covid-19 patients in a large clinical trial, the company announced on Tuesday.
The results are the latest in a growing flurry of evidence that the infused drugs, meant to mimic the antibodies that the immune system generates naturally in fighting the coronavirus, can help infected patients avoid the worst outcomes if given early.
Regeneron’s treatment, a cocktail of two antibody drugs, was given last fall to President Donald J. Trump shortly after he got sick with Covid-19 and is now one of three such therapies available in the United States.
The new results come from a Phase 3 trial that enrolled more than 4,500 patients beginning in late September, around the time virus cases began to climb dangerously in the United States. The study found that patients who got the infused treatment within 10 days of developing symptoms or testing positive had a roughly 70 percent reduced risk of being hospitalized or dying compared with patients who were infused with a placebo.
“I think these are exciting data,” said Dr. Rajesh Gandhi, an infectious diseases physician at Massachusetts General Hospital who was not involved in the study.
Even as vaccinations speed up, antibody treatments are expected to be helpful for high-risk people who still get sick for many months at least, and longer still if the virus can’t be wiped out. While there are signs that emerging virus variants may in some cases make antibodies less potent, Regeneron’s cocktail has not shown such vulnerability in laboratory tests.
In the new findings, Regeneron’s treatment worked equally well when given at half the dosing at which it was authorized. Regeneron said that it planned to request that the Food and Drug Administration allow the treatment to be given at that reduced strength.
Such a change would bring several advantages: While the cocktail is safe, getting it at a lower dose reduces the odds of side effects, such as an infusion reaction.
It would also allow Regeneron to increase the supply it can provide the United States. The company said that it had expected to supply the country with about 750,000 doses at the originally authorized higher strength by the end of June. If the lower strength is authorized, the company expects to provide about 1.25 million doses by then.
The antibody treatments from Regeneron and the drug maker Eli Lilly, which makes the other two such drugs authorized in the United States, were expected to be in high demand and to serve as a bridge in fighting the pandemic before vaccinations ramped up. Instead, they ended up sitting on refrigerator shelves in many places even during recent surges.
Many patients and their doctors did not know to ask for them or where to find them. Overwhelmed hospitals lacked the bandwidth to prioritize giving out the treatments. And some doctors were unconvinced by the relatively weak evidence available last fall supporting their use.
That picture is gradually shifting, thanks to improved logistics and more awareness. And more solid evidence, like the new data from Regeneron, also appears to be helping the drugs get used more widely. “As the data get stronger and stronger, I would expect that use will increase,” Dr. Gandhi said.