On Aug. 28, 2020, iBio announced that it had entered into an exclusive worldwide license agreement with Planet Biotechnology for the development of Planetﾒs COVID-19 therapeutic candidate, ACE2-Fc.

ACE2-Fc is a recombinant protein comprised of human angiotensin converting enzyme 2 (ACE2) fused to a human immunoglobulin G Fc fragment (Fc). As an immunoadhesin, ACE2-Fc targets the coronavirus virions directly by using the ACE2 extracellular domain as a decoy to bind the spike protein and block infection of healthy cells, while the fused Fc domain prolongs the life of the protein in circulation.