Convalescent Plasma Might not Benefit Hospitalised COVID Patients: Lancet

Consequently, convalescent plasma has been widely used for COVID-19 outside of clinical trials. Although observational studies have suggested that convalescent plasma might reduce mortality in severe viral respiratory infections, evidence from randomized trials remains scarce and inconclusive. Therefore, investigators of the RECOVERY trial evaluated the safety and efficacy of convalescent plasma therapy in patients admitted to the hospital with COVID-19.

RECOVERY trial (Randomised Evaluation of COVID-19 Therapy) is a randomized, controlled, open-label platform trial of several possible treatments in patients hospitalized with COVID-19 at 177 NHS hospitals from across the UK. The researchers include a total of 11558 patients and randomly assigned them to receive either usual care alone (usual care group, n=5763) or usual care plus high-titre convalescent plasma (convalescent plasma group, n=5795). The major outcome assessed was 28-day mortality, analyzed on an intention-to-treat basis.

Key findings of the study were:

• Upon analysis, the researchers found no significant difference in 28-day mortality between the two groups.
• They noted that 1399 (24%) patients in the convalescent plasma group and 1408 (24%) patients in the usual care group died within 28 days (rate ratio 1·00).
• They also found that the 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomization.
• They reported that allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99).
• Further, they found no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99), among those not on invasive mechanical ventilation at randomization.

The authors concluded, "The results of this large, randomized trial show that convalescent plasma did not improve survival or other clinical outcomes in patients hospitalized with COVID-19."

For further information:

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00897-7/fulltext