Background: In addition to supportive therapy, antiviral therapy is an effective 
treatment for coronavirus disease 2019 (COVID-19). Objective: To compare the 
efficacy and safety of favipiravir and umifenovir (Arbidol) to treat COVID-19 
patients. Methods: We conducted a prospective, randomized, controlled, 
open-label multicenter trial involving adult patients with COVID-19. Enrolled 
patients with initial symptoms within 12 days were randomly assigned in a 1:1 
ratio to receive conventional therapy plus Arbidol (200 mg*3/day) or favipiravir 
(1600 mg*2/first day followed by 600 mg*2/day) for 7 days. The primary outcome 
was the clinical recovery rate at day 7 of drug administration (relief for 
pyrexia and cough, respiratory frequency ≤24 times/min; oxygen saturation ≥98%). 
Latency to relief for pyrexia and cough and the rate of auxiliary oxygen therapy 
(AOT) or noninvasive mechanical ventilation (NMV)/mechanical ventilation (MV) 
were the secondary outcomes. Safety data were collected for 17 days. Results: A 
total of 240 enrolled COVID-19 patients underwent randomization; 120 patients 
were assigned to receive favipiravir (116 assessed), and 120 patients were 
assigned to receive Arbidol (120 assessed). The clinical recovery rate at day 7 
of drug administration did not significantly differ between the favipiravir 
group (71/116) and Arbidol group (62/120) (p = 0.1396, difference in recovery 
rate: 0.0954; 95% CI: -0.0305∼0.2213). Favipiravir contributed to relief for 
both pyrexia (difference: 1.70 days, p < 0.0001) and cough (difference: 1.75 
days, p < 0.0001). No difference was observed in the AOT or NMV/MV rate (both p 
> 0.05). The most frequently observed favipiravir-associated adverse event was 
increased serum uric acid (16/116, OR: 5.52, p = 0.0014). Conclusion: Among 
patients with COVID-19, favipiravir, compared to Arbidol, did not significantly 
improve the clinical recovery rate at day 7. Favipiravir significantly improved 
the latency to relieve pyrexia and cough. Adverse effects caused by favipiravir 
are mild and manageable.