A multicenter randomized open-label clinical trial for convalescent plasma in patients hospitalized with COVID-19 pneumonia.

Background Passive immunotherapy with convalescent plasma (CP) is a potential treatment for COVID-19 for which evidence from controlled clinical trials is inconclusive. Methods We conducted a randomized, open-label, controlled clinical trial at 27 hospitals in Spain. Patients had to be admitted for COVID-19 pneumonia within 7 days from symptom onset and not on mechanical ventilation or high flow oxygen devices. Patients were randomized 1:1 to treatment with CP in addition to standard of care (SOC) or to the control arm receiving only SOC. The primary endpoint was the proportion of patients in categories 5 (non-invasive ventilation or high-flow oxygen), 6 (invasive mechanical ventilation or extracorporeal membrane oxygenation [ECMO]), or 7(death) at 14 days, and primary analysis was performed in the intention-to-treat population. Results Between April 4, 2020 and February 5, 2021, 350 patients were randomly assigned to either CP (n=179) or SOC (n=171). At 14 days, proportion of patients on categories 5, 6 or 7 was 11.7% in CP group versus 16.4% in control group (p=0.205). The difference was greater at 28 days, with 8.4% of patients in categories 5-7 in CP group versus 17.0% in control group (p=0.021). The difference in overall survival did not reach statistical significance (HR 0.46, 95%CI 0.19-1.14, log-rank p=0.087). Conclusion CP showed a significant benefit in preventing progression to non-invasive ventilation or high-flow oxygen, invasive mechanical ventilation or ECMO, or death at 28 days. The effect on the predefined primary endpoint at 14 days and the effect on overall survival were not statistically significant. Trial registration clinicaltrials.gov, NCT04345523FUNDING. Government of Spain, Instituto de Salud Carlos III.