December 22, 2021
Administration of high-titer COVID-19 convalescent plasma (CCP) within 8 days of COVID-19 symptom onset reduced the risk of hospitalization by more than 50%, according to findings posted Tuesday on the pre-print server medRxiv.
Investigators from Johns Hopkins Medicine and the Johns Hopkins Bloomberg School of Public Health led the study, which transfused 1,181 outpatients with polyclonal high-titer CCP or placebo control plasma between June 2020 and October 2021. The primary outcome was COVID-19-related hospitalization within 28 days of plasma transfusion.
Among 592 patients in the CCP group, 17 patients (2.9%) required hospitalization within 28 days of their transfusion. Out of the 589 patients in the placebo group, 37 (6.3%) were hospitalized. This translated to a risk reduction for hospitalization of 54%.
In a media release, study co-lead author David Sullivan, MD, emphasized that the pandemic demands multiple treatment options, especially in low- and middle-income nations where frontline therapies may not be available. “Our study provides solid evidence that antibody-rich convalescent plasma should be part of the outpatient arsenal,” he said.
According to co-lead author Kelly Gebo, MD, MPH, early outpatient CCP use may be “another effective treatment for COVID-19 with the advantages being low cost, wide availability and rapid resilience to the evolving SARS-CoV-2.”
In the United States, the Food and Drug Administration authorized CCP therapy under emergency use, but the agency has not authorized its use as an early treatment option for outpatients with COVID-19. On Dec. 21, a group of more than 90 health care providers from the National COVID-19 Convalescent Plasma Project urged FDA to extend the emergency use authorization for CCP to the outpatient setting.
In response to the findings, AABB’s Chief Medical Officer Claudia S. Cohn, MD, PhD, noted that the trial results confirm the findings from a previous trial in Argentina, which showed that early use of high-titer CCP reduced the risk of progression to advanced respiratory disease in patients with COVID-19.
“These results may seem confusing because nearly all other CCP trials found no benefit, however, the other trials were conducted with in-patients who had severe/advance COVID; this is a setting in which convalescent plasma is not expected to provide benefit,” Cohn said. “If FDA approves CCP use in the outpatient setting, then this will represent an important treatment option for patient populations that are at high risk for disease progression.”