Safety and Efficacy of Convalescent Plasma for Severe COVID-19: Interim Report of a Multicenter Phase II Study from Saudi Arabia.

OBJECTIVE

To present the interim findings from a national study investigating the safety and efficacy of convalescent plasma (CP) containing detectable IgG antibodies as a treatment strategy for severe coronavirus disease 2019 (COVID-19).

TRIAL DESIGN AND PARTICIPANTS

An open label, two-arm, phase-II clinical trial conducted across 22 hospitals from Saudi Arabia. The intervention group included 40 adults (aged ≥18 years) with confirmed severe COVID-19 and the control group included 124 patients matched using propensity score for age, gender, intubation status, and history of diabetes and/or hypertension. Intervention group included those (a) with severe symptoms (dyspnea; respiratory rate, ≥30/min; SpO, ≤93%, PaO2/FiO2 ratio, <300; and/or lung infiltrates >50% within 24-48 h), (b) requiring intensive care unit (ICU) care or (c) experiencing life-threatening conditions. The control group included confirmed severe COVID-19 patients of similar characteristics who did not consent for CP infusion or were not able to receive CP due to its nonavailability.

INTERVENTIONS

The intervention group participants were infused 300 ml (200-400 ml/treatment dose) CP at least once, and if required, daily for up to 5 sessions, along with receiving the best standard of care. The control group only received the best standard of care.

OUTCOMES

The primary endpoints were safety and ICU length of stay (LOS). The secondary endpoints included 30-day mortality, days on mechanical ventilation and days to clinical recovery.

RESULTS

CP transfusion did not result in any adverse effects. There was no difference in the ICU LOS (median 8 days in both groups). The mortality risk was lower in the CP group: 13% absolute risk reduction ( = 0.147), hazard ratio (95% confidence interval): 0.554 (0.299-1.027; = 0.061) by log-rank test. There was no significant difference in the days on mechanical ventilation and days to clinical recovery.

CONCLUSION

CP containing detectable antibodies is a safe strategy and may result in a decrease in mortality in patients with severe COVID-19. The results of the completed trial with a larger study sample would provide more clarity if this difference in mortality is significant.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04347681; Saudi Clinical Trials Registry No.: 20041102.