Convalescent Plasma Is Hardly A “Breakthrough”

On August 23, the FDA issued an emergency use authorization for convalescent plasma for the treatment of severe COVID-19. The Trump Administration hailed convalescent plasma as a “breakthrough” treatment for COVID-19. That is a bit of a stretch.

Convalescent plasma is the liquid portion of the blood of individuals who have recovered from COVID-19. In the plasma are hundreds of proteins, including the antibodies that are developed by the body after it has fought off the infection. It is assumed that the plasma of those who have recovered from COVID-19 will have antibodies against the SARS-CoV-2 virus.

The theory is that if we give the plasma of those who have recovered from COVID-19 to other people suffering from the disease, those antibodies will presumably help fight off the infection. Makes sense, right? The problem is, the studies conducted did not show that it worked.

The EUA was based on a number of studies, but there were only two of the gold standard: randomized, controlled trials. And those studies did not show a benefit for convalescent plasma.

In fact, in one study, there was a trend toward worse outcomes with plasma in patients with life-threatening COVID-19. I have spoken to colleagues who have seen that very outcome: their patients becoming worse — much worse — after getting plasma. Full disclosure, I have also had colleagues tell me that they have had patients get better with plasma as well.

And then there is the Mayo Clinic data. First of all, it is not even a controlled trial. And, if you read the fine print, the 7-day mortality rate was higher in those patients admitted to an intensive care unit vs not being in the ICU (10.5% vs 6.0%), and it was also higher in those patients on a ventilator compared to those not on a ventilator (12.1% vs 6.2%). So, how is this a “breakthrough”?

That’s why this move by the FDA — suddenly and curiously right before the Republican National Convention — is very concerning. They were right to be slow to authorize the emergency use of plasma because the data is not that great. This treatment can do some good, but it can also do a great deal of harm. We need better data, and I am very disappointed at the FDA for issuing this EUA. If they do this same move for an eventual COVID-19 vaccine, then count me out.