WHO Skeptical Over FDA’s EUA for Convalescent Plasma

The World Health Organization (WHO) has expressed doubts about the FDA’s decision to grant an Emergency Use Authorization (EUA) for convalescent plasma as a COVID-19 treatment, claiming that the supporting evidence is weak.

WHO Chief Scientist Soumya Swaminathan suggested during a Monday news conference that the agency’s decision to allow the use of convalescent plasma in hospitalized COVID-19 patients was made too soon and that more research needs to be conducted on the experimental treatment.

“At the moment, it’s still very low-quality evidence,” she said. “There are a number of clinical trials going on around the world looking at convalescent plasma compared to standard of care. Only a few of them have reported out on results, and the results are not conclusive. The trials have been relatively small. We recommend that convalescent plasma is still an experimental therapy. It should be completely evaluated in well-designed, randomized clinical trials.”

Swaminathan also noted challenges in convalescent plasma as a treatment compared with  monoclonal antibodies, which are produced under good manufacturing practice (GMP) regulations. Unlike monoclonal antibodies, which have a set titer of antibodies and dosage when made under GMP, convalescent plasma is sourced from individuals who may have differing levels of neutralizing antibodies after they recover from infection.

“It’s very difficult to really test that and standardize that, and so it’s not one standardized therapy, because blood is being drawn from different patients and then being transfused,” she said.

Other experts have voiced concerns about the need for more research on convalescent plasma as a coronavirus treatment, including former FDA commissioners Mark McClellan, Margaret Hamburg, Robert Califf and Scott Gottlieb. The four ex-FDA chiefs have called for a “concerted effort” on plasma collection and for completion of randomized clinical trials to fully understand how the treatment works in COVID-19 patients.

Gottlieb has, however, defended the authorization from a regulatory perspective, saying “the available data seems to meet the bar for an EUA.”

Califf, similarly, said he agreed that the EUA met the legal standards, but added that he believed politics played a part in the FDA’s sudden turnaround on authorization (DID, Aug. 24). Previously, the agency had said it would hold off on issuing an EUA until more research was conducted.

“The law allows FDA to make this decision and the data are promising, but the majority of promising therapies turn out to fail when put to the proper test,” Califf said. “I believe the community will rally and get the trials done.” — James Miessler