Fluvoxamine for Outpatient Treatment of COVID-19: A Decentralized, Placebo-controlled, Randomized, Platform Clinical Trial

Background: The effectiveness of fluvoxamine to shorten symptom duration or prevent hospitalization among outpatients in the US with mild to moderate symptomatic coronavirus disease 2019 (COVID-19) is unclear. Design: ACTIV-6 is an ongoing, decentralized, double-blind, randomized, placebo-controlled platform trial testing repurposed medications in outpatients with mild to moderate COVID-19. A total of 1288 non-hospitalized adults aged >=30 years with confirmed COVID-19 experiencing >=2 symptoms of acute infection for <=7 days prior to randomization were randomized to receive fluvoxamine 50 mg or placebo twice daily for 10 days. The primary outcome was time to sustained recovery, defined as the third of 3 consecutive days without symptoms. Secondary outcomes included composites of hospitalization or death with or without urgent or emergency care visit by day 28. Results: Of 1331 participants randomized (mean [SD] age, 48.5 [12.8] years; 57% women; 67% reported receiving at least 2 doses of a SARS-CoV-2 vaccine), 1288 completed the trial (n=614 placebo, n=674 fluvoxamine). Median time to recovery was 13 days (IQR 12-13) in the placebo group and 12 days (IQR 11-14) in the fluvoxamine group (hazard ratio [HR] 0.96, 95% credible interval [CrI] 0.86-1.07; posterior probability for benefit [HR>1]=0.22). Twenty-six participants (3.9%) in the fluvoxamine group were hospitalized or had urgent or emergency care visits compared with 23 (3.8%) in the placebo group (HR 1.1, 95% CrI 0.6-1.8; posterior probability for benefit [HR<1]=0.340). One participant in the fluvoxamine group and 2 in the placebo group were hospitalized; no deaths occurred. Adverse events were uncommon in both groups. Conclusions: Treatment with fluvoxamine 50 mg twice daily for 10 days did not improve time to recovery, compared with placebo, among outpatients with mild to moderate COVID-19. These findings do not support the use of fluvoxamine at this dose and duration in patients with mild to moderate COVID-19.