Ann: Confirmation of Preliminary COVID-19 Results, page-239

My My Lastly! What have you been reading?
Sounds plausible to a layperson like myself.
There may also be a limit to how much of the drug the body/immune system can utilise, and any excess amounts make it difficult for the system to deal with. Possibly using up resources to deal with the flood of drug, instead of dealing with the virus?
This is just a wild guess, but it is similar to what happened with LCT's NTCELL - the lower doses worked better than the higher ones because the body simply didn't have enough 'machinery' to process it all