Why carry out this study?

There is an urgent clinical need for approved treatments that target immune system dysregulation and consequent amplification of the terminal complement pathway in patients with severe acute respiratory distress syndrome related to coronavirus disease 2019 (COVID-19).

Ravulizumab, a humanized monoclonal antibody that binds with high affinity to C5 and inhibits terminal complement activation, is being evaluated in an ongoing phase 3 randomized controlled trial (ALXN1210-COV-305) in patients with COVID-19 severe pneumonia, acute lung injury, or acute respiratory distress syndrome.

This evaluation assesses whether the modified dosing regimen selected to mitigate the amplification of terminal complement results in immediate and complete terminal complement inhibition.

What was learned from the study?

The high baseline serum C5 levels observed in patients with severe COVID-19 contributes to the growing body of evidence that suggests this disease is marked by amplification of terminal complement activation.

This evaluation of preliminary pharmacokinetic/pharmacodynamic data from 22 patients with severe COVID-19 shows that the modified ravulizumab dosing regimen achieved immediate and complete terminal complement inhibition for up to 22 days and supports the continued use of the dosage regimen in the ongoing phase 3 study.