Convalescent plasma in hospitalised patients with COVID-19

Background: Convalscent plasma (CP) was identified as a potential therapy for COVID-19 available early in the pandemic. Aims: To evaluate CP for the treatment of hospitalised adults with COVID-19 within the Australasian COVID-19 Trial (ASCOT). Methods: ASCOT is an investigator-initiated, international, open-label, randomised clinical trial. Adult patients hospitalised with confirmed SARS-CoV-2 within 12 days of symptom onset and not receiving intensive respiratory or vasopressor/inotropic support were randomised to two units of CP or standard care. The primary outcome was the proportion of participants who died or required intensive respiratory support (invasive or non-invasive ventilation) or vasopressors/inotropic support in the 28 days after randomisation. The trial steering committee decided to discontinue the study in January 2021 in response to external evidence suggesting the futility of CP. Results: Between May and November 2020, 33 participants were enrolled from eight sites across Australia and New Zealand. At baseline, nine (53%) in standard care and seven (47%) in CP arms required supplemental oxygen, three participants (all in the CP arm) required non-invasive ventilation or high-flow oxygen and over half were taking dexamethasone. The primary outcome was met by 23.5% (4/17) of standard care and 7% (1/15) of CP participants. One serious adverse event was reported in the CP arm, which was deemed not treatment-related. Conclusion: Fewer participants allocated to CP died or required new intensive respiratory or vasopressors/inotropic support in the 28 days after randomisation compared to standard care. However, our trial was stopped early in response to external evidence, and our sample size was small, limiting any definitive conclusions regarding the efficacy or safety of CP.