TABLE 2.

Repurposing of potential candidate drugs for COVID-19.

Therapy/Mechanism	Authors	Country	Phase of trails	Methods	Primary outcome	Report findings
Remdesivir (RDV)/RNA polymerase inhibitor	Wang et al	China	III	Double-blinded RCT; RDV (n = 158) vs. placebo (n = 79)	Clinical improvement up to 28 days	RDV was not associated with a difference in time to clinical improvement (hazard ratio 1.23 [95% CI 0.87–1.75])
	Beigel et al	United States	III	Double-blinded; RDV (n = 538) vs. placebo (n = 521); hospitalized patients; favorable outcome in preliminary report	Time to recovery	Median recovery time: 11 days vs. 15 days, recovery rate ratio, 1.32; 95% CI, 1.12–1.55; p < 0.001
Lopinavir-ritonavir (LPV/r)/protease inhibitor	Cao et al	China	N/A	Hospitalized patients with COVID-19 and respiratory illness a ; open-label RCT; LPV/r (n = 99) vs. placebo (n = 100)	Time to clinical improvement	Modified intention-to-treat population b : Median time to clinical improvement: 15 days vs. 16 days (hazard ratio, 1.39; 95% CI, 1.00–1.91)
Favipiravir (FPV)/RNA polymerase inhibitor	Chen et al	China	N/A	Adults with COVID-19 pneumonia; open-label RCT; FPV (n = 120, 116 accessed) vs. UFV (n = 120)	Clinical recovery rate on day 7	Clinical recovery rate on day 7: 71.4% vs. 55.9%; rate ratio (95% CI): 0.16 (0.03–0.28)
Ribavirin (RBV)/Guanosine analog	Tong et al	China	N/A	Adults with severe COVID-19; retrospective study; RBV (n = 44) vs. none (n = 71)	Time to viral negative conversion	12.8 ± 4.1 vs. 14.1 ± 3.5 days (p = 0.314)
Interferon (IFN) β-1b, RBV, LPV/r/Combination therapy	Hung et al	Hong Kong	II	Adults with admitted COVID-19 patients; open-label RCT	Time to viral negative conversion	7 days vs. 12 days (hazard ratio,4.37; 95% CI (1.85 ∼ 10.24), p = 0.0010)
Chloroquine (CQ) and hydroxychloroquine (HCQ)	Gautret et al	France	III	Hospitalized patients with COVID-19 (age >12 years) regardless of their clinical status; open-label, non-RCT; HCQ ± AZI (n = 26) vs. none (n = 16)	Viral clearance at day 6	70.0% vs. 12.5%, p = 0.001
	Mehra et al	Multinational	N/A	Hospitalized patients with COVID-19 received treatment of interest within 48 h; multinational registry analysis, CQ or HCQ ± macrolide (n = 14,888) vs. none (n = 81,144)	In-hospital mortality and de novo ventricular arrhythmias	Retracted owing to suspicious data sources
Tocilizumab (TCZ)/Interleukin-6 inhibitors	Klopfenstein et al	France	II	Hospitalized adult patients with COVID-19; TCZ (n = 20) vs. control (n = 25)	Death and/or ICU admission	Patients with TCZ presented with severe form; death and/or ICU admission: TCZ 25% vs. control 72%, p = 0.002
	Campochiaro et al	Italy	II	Severe non-ICU adult patients with COVID-19; TCZ (n = 32) vs. control (n = 33)	Survival and clinical improvement at 28 days	Clinical improvement: TCZ 69% vs. control 61%, p = 0.61; mortality rate: TCZ 15% vs. control 33%, p = 0.15
	Price et al	United States	II	Hospitalized patients with COVID-19; observational study; TCZ (n = 153) vs. control (n = 86)	—	TCZ-treated patients with similar survival rates to non-severe patients (83% vs. 91%, p = 0.11)
Convalescent plasma (CP)/Neutralizing antibodies	Li et al	China	II	Severe and life-threatening COVID-19; RCT; CP (n = 52) vs. standard treatment (n = 51)	Clinical improvement within 28 days	28-days clinical improvement: CP 51.9% vs. standard treatment 43.1%; hazard ratio, 1.40 (95% CI, 0.79–2.49), p = 0.26. Patients without life-threatening disease: 28-days clinical improvement, hazard ratio, 2.15 (95% CI, 1.07–4.32); 72-h negative conversion rate of viral nucleic acid detection was higher in the CP group (87.2% vs. 37.5%, p < 0.001)
	Hegerova et al	United States	II	Adult patients with severe or critical COVID-19; case-control; CP (n = 20) vs. matched control (n = 20)	Clinical outcomes up to 14 days	Mortality rate: CP 10% vs. control 30%, p = 0.11; mechanical ventilation: CP 30% vs. control 5%, p = 0.1
	Zeng et al	China	II	Adult patients with COVID-19 and respiratory failure; case series, observational; CP (n = 6) vs. control (n = 15)	Primary outcome: Fatality and secondary outcome: Virus shedding	Mortality rate: CP 83.3% vs. control 93.3%; duration of virus shedding: CP 23.5 days vs. control 20.0 days, p = 0.38
Qingfei paidu qecoction (QPD)/Traditional Chinese medicine	Xin et al	China	II	COVID-19 patients admitted to the hospital (>15 years old); retrospective study; QPD + western medicines (interferon, lopinavir, or arbidol; n = 37) vs. Western medicine (n = 26)	Improvement of inflammatory markers at the end of treatment	% Of normal CRP,TLC, LDH level: Combined group > control group (p < 0.05)

AZI, Azithromycin; RCT, randomized-controlled trial; UFV, umifenovir; CRP, C-reaactive protein; TLC, total lymphocyte count; LDH, lactate dehydrogenase; N/A, not applicable.

^aOxygen saturation ≤94% in room air or arterial oxygen partial pressure/fractional inspired oxygen (PaO2/FiO2) ≤300 mmHg.

^bExclude three early deaths.