With all due-fairness (IF I can be, as REGN SH)
First, Kevzara is sound choice to try (anecdote and MoA comfort with pathology), but why PLACEBO as control? Why not antiviral (GILD), ot HCQ/CQ or maybe something else, as control? Those are serious late stage viral-infections patients and need all help they can get? Normally, one need to be careful not to administer something (MD choices) that may do WORSE/HARM!
Second, "Similar to the approach the company pursued for Mers and Ebola virus, we believe Regeneron’s Covid-19 antibody cocktail may offer efficacy in preventing and treating the virus,” SVB Leerink analyst Geoffrey Porges wrote in a note to investors."
I did not read Porges report, but what make him optimistic that REGN's Abs will be effective as preventive/treatment for nCoV?
latest from CELL: cell.com
All what we know about virus, and what is available in literature...virus undergo proteolytic transformation on S2-RBD of the Spike protein (by HOST transmembrane/surface proteases) before it can penetrate cell membrane. While, REGN approach in immunization humanized mice is by *natural* (unmodified) RBD-fragment or some other random Spike protein sequence? So, regardless how good are your mice and how good is immunization process, it is up to VALIDITY/IMMUNOGENICITY of the protein sequence that will generate Abs capable to attack and neutralize virus at CRITICAL MOMENT, at CRITICAL PLACE, and CRITICAL STAGE!
Is there other way to neutralize virus INSIDE CELLS (when multiple, non-standard anti-viral), or to neutralize virus before cells penetration is the only and best approach?
I am not virologist, and I am without any background knowledge on topic, but my concern is overwhelmed by *stage of the current knowledge*!
Coronavirus is not from *yesterday*, many worked on treatment approach, still very little progress.
Anaway, REGN mentioned Abs isolated from infected/exposed subjects, so they are aware of the limitation from their original approach (mice immunization). Hope Abs-combination (human and mice) may do trick. Also, I *like* TMPRSS2 inhibitors approach (also anti-Ab), as proteolytic activator of the RBD-Spike, but none talk about.
So, If anyone have something to add into this concern/view, please be free to attack/confront my perspective. Only by that way (me, and you) will learn where we stand.
Thanks,
Miljenko |
