tPAFrom wikipedia ...
"Tissue plasminogen activator (abbreviated
tPA or
PLAT) is a
protein involved in the breakdown of blood
clots. It is a
serine protease (
EC 3.4.21.68) found on
endothelial cells, the cells that line the
blood vessels.
As an enzyme, it catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for clot breakdown. Human tPA has a molecular weight of ~70 kDa in the single-chain form."
.....so tPA is a catalyst for the conversion of plasminogen to plasmin. This suggest's the patient would need decent levels of plasminogen for this to be successful. Ryplazim on the other hand is pure Plasminogen for those with deficient levels causing a bunch of health problems. Possibly administering both Plasminogen and tPA could be a home run .. but unless Ryplazim could be mass produced in quanity and low cost it would really only apply to those with a known deficiency. Likely tPA on its own makes more sense for COVID patients but certainly more interesting validation for Ryplazim's need.