Much of the illness associated with COVID-19 is due to the intense inflammatory and immune response that can occur with an infection. The most successful treatments so far have targeted this overzealous immune response.
Taken early in the disease, the inhaled corticosteroid budesonide has been shown to reduce the development of more severe disease.
In people hospitalised with COVID-19 requiring oxygen, the oral corticosteroid dexamethasone reduces the likelihood of death.
In the most severe cases — COVID patients admitted to ICU — the anti-inflammatory tocilizumab administered intravenously gives a person a better chance of survival.
But these treatments don't target SARS-CoV-2 itself; just the consequences of infection. Directly targeting the virus has proven to be more difficult
SARS-CoV-2 carries an enzyme, 3C-like protease (3CLpro), which plays a crucial role in the replication process. This protease is almost identical to the protease used by the SARS-CoV-1 (SARS) virus, and similar to the protease used by the Middle Eastern Respiratory Virus (MERS).
So a drug that could effectively target 3CLpro and prevent virus replication could be beneficial against multiple known coronaviruses, and possibly any that emerge in the future.
Pfizer/BioNtech are taking two drugs to clinical trials for COVID-19: PF-07304814, an intravenous injection for use in patients hospitalised with severe COVID-19 and PF-07321332, an oral agent, or pill, that could potentially be used earlier in the disease. Both are formulations of a 3CLpro inhibitor.
An Israeli biotechnology company has claimed a 100% success rate in the first 10 patients treated with its drug as part of an early-stage clinical trial at Rambam Health Care Campus in Haifa.
Bonus's MesenCure, which consists of activated Mesenchymal Stromal Cells (MSCs) that are isolated from the adipose tissue of healthy donors, was found to reduce inflammation and alleviate respiratory and other symptoms in patients suffering from life-threatening respiratory distress brought on by COVID-19.