FDA Allows COVID Convalescent Plasma for Some Outpatients

 The FDA on Tuesday both limited and expanded the emergency use authorization (EUA) for convalescent plasma as a treatment for COVID-19.

In its updated EUA, the agency restricted the use of high-titer COVID-19 convalescent plasma to immunocompromised patients, but stated that "these patients may be treated in outpatient or inpatient settings." (Previously, use of the once-promising therapy allowed for the treatment of any hospitalized COVID-19 patient early on in their disease course.)

To inform their decision, FDA reviewed multiple studies, including randomized trials in both hospitalized and non-hospitalized patients, and determined that convalescent plasma transfusion in hospitalized immunocompetent patients with COVID-19 is "unlikely to be associated with clinical benefit," wrote Jacqueline O'Shaughnessy, PhD, the FDA's acting chief scientist, in the updated authorization letter.

"However, evidence supports a potential clinical benefit of transfusion of COVID-19 convalescent plasma with high titers of anti-SARS-CoV-2 antibodies to treat COVID-19 in patients with immunosuppressive disease or receiving immunosuppressive treatment," O'Shaughnessy added.

Arturo Casadevall, MD, PhD, of Johns Hopkins Bloomberg School of Public Health in Baltimore, praised the agency's decision, noting that most of the monoclonal antibodies authorized for COVID-19 are no longer effective against the Omicron variant.

"We have lost most mAbs and the antiviral pills are not here yet," he told MedPage Today.

"FDA has moved very rapidly in response," he said via email. "The availability of plasma in the outpatient space compensates for the loss of the monoclonals and allows plasma to be used in an optimal way -- early in disease."

On Twitter, Casadevall -- a COVID-19 convalescent plasma trialist who has advocated for its increased use -- suggested that recently reported trial results from Johns Hopkins may have informed FDA's decision.

The Convalescent Plasma to Limit SARS-CoV-2 Associated Complications (CSSC-004) trial from Casadevall and colleagues showed a greater than 50% reduction in hospitalization risk for outpatients with COVID-19 who received high-titer convalescent plasma within 9 days of symptom onset. Among more than 1,100 patients in the study, 6.3% of those receiving placebo required hospitalization as compared with 2.9% of those who received convalescent plasma (relative risk 0.46, P=0.004). There were three deaths in the placebo arm versus none in the convalescent plasma arm.

"The change in the EUA allows physicians and blood bankers to put the system for plasma collection and testing back in operation, which had essentially come to a halt. This means very high quality plasma will be available without all the concerns about titer," Casadevall tweeted. "Once the supply line is re-established for the immunosuppressed and the ongoing work defining effective titer for omicron is completed, we will see additional changes to the EUA, possibly extending to the outpatient immunocompetent."

FDA noted that the clinical evidence for convalescent plasma in immunosuppressed patients with COVID-19 remains limited, and data from additional randomized trials are needed.

https://www.medpagetoday.com/infectiousdisease/covid19/96430