Adults 18 to 75, any sex, with Coronavirus or Corona Virus Infection. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Substudy 1 - Number of COVID-19+ PCR Patients in Self-quarantine Who Are HospitalizedPrimary· Until completion of study, 29 to 31 days after beginning treatment.
Number of COVID-19+ PCR patients in self-quarantine who are hospitalized up to 31 days after beginning HCQ or Placebo
Group
Value
95% CI
Sub Study 1 Group 1 (HCQ)
0
Sub Study 1 Group 2 (Placebo)
0
Sub Study 2:Number of Health Care Workers Testing Positive at 2 MonthsPrimary· Until completion of study, 2 months after start of treatment.
Rate of COVID-19 infection (confirmed by accepted testing methods) at 2 months
Group
Value
95% CI
Sub Study 2 Group 1 (HCQ)
0
Sub Study 2 Group 2 (Placebo)
0
Sub Study 1 - Secondary Infection of Co-inhabitants of COVID-19 Positive PCR Patients in Self-quarantineSecondary· Until completion of study, 29 to 31 days after beginning treatment.
Co-inhabitants of COVID-19 positive PCR patients in self-quarantine that test positive up to 31 days after patient begins treatment with HCQ or Placebo
Group
Value
95% CI
Sub Study 1 Group 1 (HCQ)
0
Sub Study 1 Group 2 (Placebo)
0
Sub Study 1 - Rate of Negative Tests at End of Treatment for COVID-19 Positive PCR Patients in Self-quarantineSecondary· 15-17 days after completion of 14 day treatment
Rate of negative tests at end of treatment for COVID-19 positive PCR patients in self-quarantine
Group
Value
95% CI
Sub Study 1 Group 1 (HCQ)
6
Sub Study 1 Group 2 (Placebo)
0
Sub Study 1 - Rate of Negative Tests at End of Treatment for COVID-19 Positive PCR Patients in Self-quarantineSecondary· 1-3 days after completion of 14 day treatment
Rate of negative tests at end of treatment for COVID-19 positive PCR patients in self-quarantine
Group
Value
95% CI
Sub Study 1 Group 1 (HCQ)
4
Sub Study 1 Group 2 (Placebo)
0
Sub Study 2:Health Care Workers: Assessment of Any Medical Events That Occur During the ~60 Day Active PeriodSecondary· Until completion of study, 2 months (~60 days) after start of treatment.
Assessment of any medical events that occur during the \~60 day active period that is felt to be related to receipt of HCQ
moderate adverse events
Group
Value
95% CI
Sub Study 2 Group 1 (HCQ)
2
Sub Study 2 Group 2 (Placebo)
0
minor adverse events
Group
Value
95% CI
Sub Study 2 Group 1 (HCQ)
1
Sub Study 2 Group 2 (Placebo)
0
Sub Study 2:Health Care Workers:Rate of HospitalizationSecondary· Until completion of study, 2 months after start of treatment.
if the participant gets COVID and has severe symptoms and hospitalized, end point reached if before the end of the 2 month period
Group
Value
95% CI
Sub Study 2 Group 1 (HCQ)
0
Sub Study 2 Group 2 (Placebo)
0
Adverse events — posted to ClinicalTrials.gov
Time frame: Until completion of study, 2 months after start of treatment..
Reporting threshold: 0%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
The proposed hypothesis is that high doses of hydroxychloroquine (HCQ) for at least 2 weeks can be effective antiviral medication both as a treatment in ambulatory patients and prophylaxis/treatment in health care workers because it impairs lysosomal function and reorganizes lipid raft (cholesterol and sphingolipid rich microdomains in the plasma membrane) content in cells, which are both critical determinants of Emerging Viral Disease (EVD) infection. This hypothesis is based on a growing literature linking chloroquine to antiviral activity. It is estimated that enough information exists to launch a clinical trial of hydroxychloroquine for COVID-19.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by UnitedHealth Group
Last refreshed: 19 October 2021
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT04353037.