APN01 is a recombinant human angiotensin-converting enzyme 2 (ACE2) molecule. ACE2 is the receptor that the SARS-CoV-2 spike protein binds in order for the virus to gain access to host cells. This treatment is thought to act as a competitive inhibitor against the virus by binding the spike protein and preventing binding to host cell ACE2.

AT-001 is an aldose reductase inhibitor that has demonstrated potential therapeutic effects on diabetic cardiomyopathy. Given the involvement of the heart in individuals with severe COVID-19 complications, AT-001 is being tested to see how it can impact the cardiac structure, function, and survival of COVID-19 patients.

BLD-2660, synthetic small-molecule inhibitor of calpain. Calpains are a class of non-lysosomal cysteine proteases involved in diverse cellular processes. Several publications indicate that specific host calpains are essential for the replication of multiple RNA viruses including Coronaviruses. BLD-2660 has also been shown to normalize interleukin (IL)-6, a pro-inflammatory cytokine demonstrated to be elevated in COVID-19 patients and is implicated in disease pathogenesis.

CM4620 is a calcium release-activated channel (CRAC) inhibitor which ultimately inhibits the proliferation of immune cells and prevents the release of various inflammatory cytokines. This may lead to a reduction of inflammatory responses in inflammatory-mediated diseases, such as those observed in severe cases of COVID-19.

IC14 is a recombinant chimeric monoclonal antibody that binds human CD14. Binding of CD14 by this antibody prevents its interaction with pathogen and damage-associated molecular patterns (PAMPs and DAMPs, respectively) which contribute to inflammation during SARS-CoV-2 infection.

IFX-1 is a monoclonal antibody that targets the proinflammatory complement component C5a.

MRx-4DP0004 is an immunomodulating Live Biotherapeutic Product (LBP) comprised of the bacterium Bifidobacterium breve which was isolated from a healthy human gut. This LBP is expected to prevent or reduce the hyperinflammatory response to SARS-CoV-2 infection without impairing viral clearance.

NKG2D-ACE2 CAR-NK Cells are engineered natural killer (NK) cells made from chord blood. NK cells are part of the innate immune system that helps your body to kill virally-infected cells. These cells were then engineered to secrete an interleukin (IL)-15 superagonist (soluble IL-15 plus IL-15 receptor alpha chimeric protein; IL-15 is required for NK cell long-term survival in the body) and a single-chain variable fragment (scFv; a single-chain protein comprised of only the variable [specific] fragment of an antibody) that binds granulocyte-macrophage colony-stimulating factor (GM-CSF; a cytokine, that when neutralized, helps prevent a dangerous cytokine release syndrome associated with other cell therapies). Along with these secretable factors, these cells are chimeric antigen receptor (CAR) engineered to express the NKG2D membrane protein (an activating receptor of NK cells, which can recognize and thus clear virus-infected cells) and angiotensin-converting enzyme 2 (ACE2; the surface protein recognized by the SARS-CoV-2 spike protein) so that they can no only target and kill virally-infected cells, but also competitively inhibit SARS-CoV-2 infection of other cells through its ACE2 expression.