Table 2.

COVID-19, SARS, and MERS therapies in development.

Name	MOA	Clinical Outcome(s)	Comments	Trial
COVID-19
Tocilizumab	Humanized monoclonal IL-6R antibody	Decreased patient temperature, oxygen intake, and CRP levels	Currently used to treat rheumatoid arthritis	Phase 2/3
Hydroxychloroquine	Unknown	Not significantly more effective than standard of care	Used to treat malaria and rheumatoid arthritis	Phase 3
Favipiravir	Viral RdRp inhibitor	Increased viral clearance and improved chest CT scans	Effective against Ebola virus and influenza	Phase 2/3
LPV/RTV	LPV: Protease inhibitor RTV: LPV metabolism inhibitor	Eliminated detectable SARS-CoV-2 viral titers (44% of patients)	No detectable side effects found	Phase 2
Arbidol	Viral entry inhibitor	Eliminated detectable SARS-CoV-2 viral titers Delayed the progression of pulmonary lesions	Currently used to treat prophylaxis and influenza in Russia and China	Phase 4
SARS
Remdesivir	Viral RdRp inhibitor	Reduces pulmonary SARS-CoV viral load	Broad-spectrum antiviral	Preclinical
LPV/RTV	LPV: Protease inhibitor RTV: LPV metabolism inhibitor	Reduces SARS-CoV viral load, mortality, and intubation rate	Possibly most effective as an initial therapy against infection	Preclinical
MERS
REGN 3048 and REGN 3051	Humanized mAbs	Clinical trial results not yet published	None	Phase 1
LPV/RTV and IFN-beta-1b	LPV/RTV: Protease inhibitors IFN-beta-1b: Antiviral protein activator	Contributed to a 40% decrease in early stage infection risk	None	Phase 1
SAB-301	Human polyclonal IgG	Clinical trial results not yet published	No reported tolerance issues	Phase 1

A summary of the current proposed therapies for the treatment of COVID-19, SARS, and MERS. Tocilizumab is a monoclonal IL-6R antibody that is undergoing phase 2/3 trials and has been effective in decreasing patient temperature, oxygen intake, and CRP levels. Hydroxychloroquine, an anti-malarial, is in phase 3; however, it has not been shown to be more effective than the standard of care. Favipiravir is a viral RdRp inhibitor in phase 2 and has been shown to eliminate detectable SARS-CoV-2 viral titers. Arbidol is in phase 4, and its mechanism of action inhibits viral entry and has shown to eliminate viral titers and delay the progression of pulmonary lesions. In regard to SARS, both remdesivir and LPV/RTV are in preclinical trials and have been shown to reduce viral load. REGN 3048, REGN 3051, and SAB-301 are all in phase 1 clinical trials for the treatment of MERS without any published results. LPV/RTV is a protease inhibitor, and IFN-beta-1b is an antiviral protein activator. When used in combination, they have been shown to reduce infection risk of MERS by 40% in a phase 1 clinical trial. Abbreviations: MOA = mechanism of action; IL-6R = interleukin 6 receptor; RdRp = RNA-dependent RNA polymerase; CRP= C-reactive protein; LPV/RTV = lopinavir-ritonavir; GI = gastrointestinal; mAbs = mouse antibodies; IFN = interferon; RBD = receptor-binding domain; IgG = immunoglobulin G Note: “Trial Phase” indicates the overall phase in development of the designated drug for the specified coronavirus; clinical outcomes reflect preclinical findings. The studies listed have no current updates on clinical trial results, which speaks to the delay in translating in vivo findings into tangible clinical applications.