Early high antibody-titre convalescent plasma for hospitalised COVID-19 patients: DAWn-plasma.

BACKGROUND: Several randomised clinical trials have studied convalescent plasma (CP) for COVID-19 using different protocols, with different SARS-CoV-2 neutralising-antibody-titres, at different time-points and severities of illness.

METHODS: In the prospective multicentre DAWN-plasma trial, adult patients hospitalised with COVID-19 were randomised to 4 units of open-label convalescent plasma combined with standard of care (intervention group) or standard of care alone (control group). Plasma from donors with neutralising-antibody-titres (NT50) ≥1/320 was the product of choice for the study.

RESULTS: Between May 2nd, 2020 and January 26th, 2021, 320 patients were randomised to convalescent plasma and 163 patients to the control group according to a 2:1 allocation scheme. A median volume of 884 mL convalescent plasma (IQR 806-906 mL) was administered, and 80.68% of the units came from donors with neutralising-antibody-titres (NT50) ≥1/320. Median time from onset of symptoms to randomisation was 7 days. The proportion of patients alive and free of mechanical ventilation on Day 15 was not different between both groups (convalescent plasma: 83.74% (n=267) control: 84.05% (n=137) - Odds ratio 0.99 (0.59-1.66) - p-value=0.9772). The intervention did not change the natural course of antibody titres. The number of serious or severe adverse events was similar in both study arms, and transfusion-related side effects were reported in 19/320 patients in the intervention group (5.94%).

CONCLUSIONS: Transfusion of 4 units of convalescent plasma with high neutralising-antibody-titres early in hospitalised COVID-19 patients did not result in a significant improvement of the clinical status, or a reduced mortality.