Regeneron, the company that makes the experimental treatment given to President Trump last week, told CNN their antibody treatment could have affected the blood test that shows Trump has antibodies to the coronavirus.
Earlier today the President’s physician, Dr. Sean Conley, released a memo on the President’s health. In it, he said Trump had "detectable levels" of coronavirus antibodies as of Monday.
“Of note today, the President’s labs demonstrated detectable levels of SARS-Cov-2 IgG antibodies from labs drawn Monday, October 5th; initial IgG levels drawn late Thursday were undetectable,” the memo read.
Trump received a single infusion of Regeneron’s dual monoclonal antibody treatment on Friday. The company said the IgG antibody test would have detected the engineered antibodies that were administered to Trump.
Those antibodies – laboratory versions of immune system proteins designed to home in directly on specific parts of the coronavirus – would remain detectable in his system for several months.
In a statement to CNN, Regeneron said:
"Most of the standard assays for IgG would not distinguish between endogenous (self-made) antibodies and the ones delivered by our therapy. However, given the volume of IgG antibodies delivered in our therapy, and the timing of these tests, it is likely that the second test is detecting REGN-COV2 antibodies.
Our early data announced last week shows that the patients most likely to benefit from this treatment have a similar profile to President Trump, in that they had undetectable antibodies at baseline (‘seronegative’) and were early in the course of disease. Treatment with REGN-COV2 had the greatest impact in viral load reduction and time to symptom alleviation in this seronegative group. We also know by looking at the placebo groups that these seronegative patients were at a much higher risk of requiring further medical attention than ‘seropositive’ patients when untreated with therapeutic antibodies."