Current data are insufficient to recommend either for or against using convalescent plasma to treat patients who have COVID-19, the National Institutes of Health’s (NIH) COVID-19 Treatment Guidelines Panel said Tuesday.
“Convalescent plasma should not be considered standard of care for the treatment of patients with COVID-19,” the committee said.
The NIH statement comes just more than a week after the US Food and Drug Administration (FDA) on August 23 issued an emergency use authorization (EUA) promoting the use of convalescent plasma in treating patients hospitalized with COVID-19. In the FDA statement announcing the EUA, Health & Human Services Secretary Alex Azar called it “a milestone achievement.”
The COVID-19 Treatment Guidelines Panel, made up of physicians, statisticians, and other experts, rejected that interpretation of the data.
“[T]hough data suggest that convalescent plasma with high antibody titers may be beneficial in nonintubated patients, uncertainty remains about the efficacy and safety of convalescent plasma due to the lack of a randomized control group and possible confounding,” the NIH panel concluded after reviewing published and unpublished data on convalescent plasma for treating COVID-19, including the FDA analyses that led to the EUA.
The panel notes that serious adverse reactions after the administration of COVID-19 convalescent plasma are infrequent, which is “consistent with the risks associated with plasma infusions for other indications.”
Panel members called for well-controlled, sufficiently powered trials to answer the question of whether convalescent plasma is safe and effective and said it will continue to evaluate emerging data regarding its use in the treatment of COVID-19.
“The shame here is that this far into the pandemic we do not have the evidence we need to make a clear determination about the role of convalescent sera as therapy for COVID-19,” Harlan Krumholz, MD, director of the Yale New Haven Hospital Center for Outcomes Research and Evaluation in Connecticut, told Medscape Medical News.
“We have lacked the will, the organization, and the funding to take promising therapies and rapidly evaluate them in rigorous ways. Moreover, the lack of clear standardization of the products is an additional issue mentioned by the NIH.”
Krumholz said that while he prefers trials, he believes observational studies can have a role. But the findings must be put in perspective, which the NIH panel did, he said.
He pointed out that even the authors of the key study on convalescent plasma refer, in their preprint, to their findings only as “signals consistent with efficacy.”
Tuesday’s announcement by the NIH follows an outpouring of concerns by physicians and public health experts that political motivations are unduly influencing decisions by federal agencies.
The FDA’s announcement of the EUA for convalescent plasma came just one day after President Donald Trump tweeted that “The deep state, or whoever, over at the FDA is making it very difficult for drug companies to get people in order to test the vaccines and therapeutics. Obviously, they are hoping to delay the answer until after November 3rd.”
That evening, the White House Press Secretary tweeted that there would be a news conference the next day with the president, Azar, and FDA Commissioner Stephen Hahn, MD, “concerning a major therapeutic breakthrough” in treating COVID-19.
At that press briefing, Azar incorrectly said patients given convalescent plasma experienced a 35% reduction in mortality, based on data from the Mayo Clinic Expanded Access Program that was posted on a preprint server.
Hahn reiterated the error at the briefing as well as on Twitter.
Discovery that the findings had been misrepresented at the briefing was followed by outrage, and the FDA later clarified that patients given plasma with higher antibody levels had “roughly a 35% relative improvement” in survival rates compared with those who received plasma with lower antibody levels.
Hahn acknowledged in a tweet that “the criticism was entirely justified,” admitted he misspoke at the briefing, and said that the 35% figure measured relative risk, not absolute risk.
He also emphasized that the EUA of convalescent plasma “is not a final approval.” The FDA will continue to monitor the research and “will revoke authorization if needed. We feel broader use of plasma will truly benefit many patients but will require further study.”
Krumholz has reported no relevant financial relationships.
Marcia Frellick is a freelance journalist based in Chicago. She has previously written for the Chicago Tribune, Science News, and Nurse.com and was an editor at the Chicago Sun-Times, the Cincinnati Enquirer, and the St. Cloud (Minnesota) Times. Follow her on Twitter at @mfrellick