While this is not a clinical study, the results of this report on CRP apheresis in severe cases of COVID-19 are remarkable. Not only was the mortality rate significantly lower than the expected >40%, but also, usually progressing damage done to the lungs could be reversed.

The article Seven COVID-19 Patients Treated with C-Reactive Protein (CRP) Apheresis from the Journal of Clinical Medicine can be found here: https://doi.org/10.3390/jcm11071956