They were just talking about this over on Medcram just a few days ago. About halfway through:
Various responses from Drs about this..some skeptical
https://texags.com/forums/84/topics/3142469
such as this
“I agree I am surprised Leronlimab was not used instead of REGN-COV2. Knowing that Covid-19 is a probable RANTES disease and Leronlimab disrupts the RANTES pathway in addition to decreasing the viral load like REGN-COV2.”