Following NYT report, Mayo researchers say they welcome further review of plasma data

Mayo Clinic researchers leading a nationwide study into convalescent plasma therapy are signaling cautious optimism about its use for treating patients with Covid-19, even as federal health officials reportedly express concern about whether the Mayo-led plasma program is growing too fast with too little evidence about its efficacy.

The New York Times reported Wednesday that top U.S. health officials, including Dr. Anthony Fauci, the nation’s top infectious disease expert, recently intervened to pause a proposed emergency authorization that would have expanded the use of blood plasma as a treatment for Covid-19. The health officials, according to The Times, argued the data presented by Mayo was “too weak” to warrant an emergency approval.

The paper also stated that officials have “privately expressed concern about the rapid growth of the Mayo program and the perceived rush to declare plasma effective without the affirmation of results from randomized trials, which scientists have long relied on as the gold standard of evidence.”

The concerns may not have stemmed as much from the data presented by Mayo, but rather from political pressures to accelerate the use of plasma in clinical settings. Following The Times report on Wednesday, President Trump suggested that health regulators may be delaying the emergency authorization of plasma in an attempt to hurt him politically.

“It could be a political decision because you have a lot of people over there that don’t want to rush things because they want to do it after November 3rd,” said Trump. The president also stated, without evidence, that plasma treatment has a success rate “way over 50 percent.”

But according to Mayo researchers, the data presented to the federal government was never meant to supplant a clinical trial. Instead, the data — the results of which Mayo researchers say they remain confident in — was presented in an effort to demonstrate the safety of plasma therapy and to inform future clinical trials on its use to treat Covid-19. In May, the government contributed $26 million toward the investigation.

“The program is not intended to be a clinical trial to determine the efficacy of convalescent plasma, in the course of our work, we observed possible signals of efficacy and chose to share that data,” said Drs. Scott Wright and Michael Joyner, study leaders of the Mayo convalescent plasma program, in a statement to Med City Beat. “The data could advance the discussion about the efficacy of convalescent plasma treatment, and we acknowledge that additional scientific investigation is needed.”

The Mayo-led study suggested that convalescent plasma treatment was associated with reduced mortality among the 35,000-plus patients hospitalized with Covid-19. Still, because there was no control group, more investigation is needed to determine whether other factors — such as higher quality care at better hospitals — played a role in the outcomes.

The F.D.A is now working with Mayo to further analyze the plasma data. The Mayo researchers said they welcome the additional review.

“We believe the data from the [convalescent plasma Expanded Access Program] is significant and could be used to provide evidence to conduct [randomized controlled trials] going forward,” said Drs. Wright and Joyner. “We will always support bolstering the best science that will result in the most effective treatment for patients and welcome methodical scrutiny of our data.”

Sean Baker is a Rochester journalist and the founder of Med City Beat.

Cover photo via Getty