Efficacy of oral amantadine among patients hospitalised with COVID-19: A randomised, double-blind, placebo-controlled, multicentre study

Background: Amantadine has been proposed as a treatment for COVID-19 because it shows anti-SARS-CoV-2 activity in vitro. However, to date, no controlled study has assessed the safety and efficacy of amantadine in COVID-19. Research question: Whether amantadine is effective and safe among patients with different COVID-19 severity classifications. Study design: and Methods: This was multi-centre, randomised, placebo-controlled study.Patients with oxygen saturation <= 94% and no need for high-flow oxygen or ventilatory support were randomly allocated to receive oral amantadine or placebo (1:1) for 10 days in addition to standard care. The primary endpoint was time to recovery assessed over 28 days since randomisation, defined as discharge from hospital or no need for supple-mental oxygen. Results: The study was terminated early due to a lack of efficacy after an interim analysis. Final data from 95 patients who received amantadine (mean age, 60.2 years; 65% male; 66% with comorbidities) and 91 patients who received placebo (mean age, 55.8 years; 60% male; 68% with comorbidities) were obtained. The median (95% CI) time to recovery was 10 days both in the amantadine (9-11) and placebo arms (8-11; subhazard ratio = 0.94 [95%CI 0.7-1.3]). The percentage of deaths and percentage of patients who required intensive care at 14 and 28 days did not significantly differ between the amantadine and placebo groups. Interpretation: Adding amantadine to standard care in patients hospitalised with COVID-19 did not increase the likelihood of recovery.Clinical trial registration: ClinicalTrials.gov; No.: NCT04952519; www.clinicaltrials.gov.