18 and older, any sex, with Coronavirus or Acute Respiratory 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.
COVID Outcomes Scale Score on Study Day 15 (14 Days After Randomization)Primary· Assessed on study day 15
We will determine the COVID Ordinal Scale for all patients on study day 15
COVID Ordinal Scale defined as:
1. Death
2. Hospitalized on invasive mechanical ventilation or ECMO ( extracorporeal membrane oxygenation)
3. Hospitalized on non-invasive ventilation or high flow nasal cannula
4. Hospitalized on supplemental oxygen
5. Hospitalized not on supplemental oxygen
6. Not hospitalized with limitation in activity (continued symptoms)
7. Not hospitalized without limitation in activity (no symptoms)
Group
Value
95% CI
Hydroxychloroquine
6
4 – 7
Placebo
6
4 – 7
COVID Ordinal Outcomes Scale on Study Day 3 (2 Days After Randomization)Secondary· assessed on study day 3
We will determine the COVID Ordinal Scale for all patients on study day 3
COVID Ordinal Scale defined as:
1. Death
2. Hospitalized on invasive mechanical ventilation or ECMO ( extracorporeal membrane oxygenation)
3. Hospitalized on non-invasive ventilation or high flow nasal cannula
4. Hospitalized on supplemental oxygen
5. Hospitalized not on supplemental oxygen
6. Not hospitalized with limitation in activity (continued symptoms)
7. Not hospitalized without limitation in activity (no symptoms)
Group
Value
95% CI
Hydroxychloroquine
4
3 – 5
Placebo
4
3 – 5
COVID Ordinal Outcomes Scale on Study Day 8 (7 Days After Randomization)Secondary· assessed on study day 8
We will determine the COVID Ordinal Scale on study day 8
COVID Ordinal Scale defined as:
1. Death
2. Hospitalized on invasive mechanical ventilation or ECMO ( extracorporeal membrane oxygenation)
3. Hospitalized on non-invasive ventilation or high flow nasal cannula
4. Hospitalized on supplemental oxygen
5. Hospitalized not on supplemental oxygen
6. Not hospitalized with limitation in activity (continued symptoms)
7. Not hospitalized without limitation in activity (no symptoms)
Group
Value
95% CI
Hydroxychloroquine
5
4 – 7
Placebo
6
3 – 6
COVID Ordinal Outcomes Scale on Study Day 29 (28 Days After Randomization)Secondary· assessed on study day 29
We will determine the COVID Ordinal Scale on study day 29
COVID Ordinal Scale defined as:
1. Death
2. Hospitalized on invasive mechanical ventilation or ECMO ( extracorporeal membrane oxygenation)
3. Hospitalized on non-invasive ventilation or high flow nasal cannula
4. Hospitalized on supplemental oxygen
5. Hospitalized not on supplemental oxygen
6. Not hospitalized with limitation in activity (continued symptoms)
7. Not hospitalized without limitation in activity (no symptoms)
Group
Value
95% CI
Hydroxychloroquine
6
6 – 7
Placebo
6
6 – 7
All-location, All-cause Mortality Assessed on Study Day 15 (14 Days After Randomization)Secondary· assessed on study day 15
Vital status of the patient on day 15 will be determined using any of the following methods: medical record review, phone calls to patient or proxy.
There were two patients for whom we were unable to collect their vital status.
Group
Value
95% CI
Hydroxychloroquine
18
Placebo
14
All-location, All-cause Mortality Assessed on Study Day 29 (28 Days After Randomization)Secondary· assessed on study day 29
Vital status of the patient at day 28 will be determined using any of the following methods: medical record review, phone calls to patient or proxy.
There were two patients for whom we were unable to collect their vital status.
Group
Value
95% CI
Hydroxychloroquine
25
Placebo
25
Number of Patients Dead or With Receipt of ECMO Between Enrollment and Day 28Secondary· Enrollment to Day 28
We will determine the number of patients who are either dead or on ECMO ( extracorporeal membrane oxygenation) between enrollment and day 28
Group
Value
95% CI
Hydroxychloroquine
29
Placebo
28
Oxygen-free Days Through Day 28Secondary· 28 days after randomization
The number of calendar days between randomization and 28 days later that the patient is alive and without the use of oxygen therapy. Patients who die prior to day 28 are assigned zero oxygen free days.
Group
Value
95% CI
Hydroxychloroquine
21
0 – 27
Placebo
20
0 – 27
Ventilator-free Days Through Day 28Secondary· 28 days after randomization
Ventilator-free days is defined to be 28 days minus the duration of mechanical ventilation through day 28. Participants who do not survive to day 28 are assigned zero ventilator-free days.
Group
Value
95% CI
Hydroxychloroquine
28
28 – 28
Placebo
28
28 – 28
Vasopressor-free Days Through Day 28Secondary· 28 days after randomization
The number of calendar days between randomization and 28 days later that the patient is alive and without the use of vasopressor therapy. Patients who die prior to day 28 are assigned zero vasopressor free days.
Group
Value
95% CI
Hydroxychloroquine
28
28 – 28
Placebo
28
28 – 28
ICU-free Days to Day 28Secondary· 28 days after randomization
The number of days spent out of the ICU to day 28. Patients who die prior to day 28 are assigned zero ICU free days.
Group
Value
95% CI
Hydroxychloroquine
28
21 – 28
Placebo
28
18 – 28
Hospital-free Days to Day 28Secondary· 28 days after randomization
Defined as 28 days minus the number of days from randomization to discharge home.If a patient has not been discharged home prior to day 28 or dies prior to day 28, hospital free days will be zero.
Group
Value
95% CI
Hydroxychloroquine
21
11 – 24
Placebo
20
10 – 24
Adverse events — posted to ClinicalTrials.gov
Time frame: Subjects were assessed for adverse events from enrollment through study day 29 or discharge, whichever occurs first. Investigators will determine if the event is serious or related to study drug..
Reporting threshold: 0%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
ORCHID is a multicenter, blinded, placebo-controlled, randomized clinical trial evaluating hydroxychloroquine for the treatment of adults hospitalized with COVID-19. Patients, treating clinicians, and study personnel will all be blinded to study group assignment.
Publications & conference data
8 peer-reviewed publications reference this trial (live from Europe PMC):
NCT07343635 — The Efficacy and Safety of Anti-inflammation Treatment (Hirudoid Introduction Followed by Yellow Light Therapy) Combined
· NA
· recruiting
NCT07352566 — Utilization of a Microdevice for Psoriasis and Atopic Dermatitis
· Phase 4
· not yet recruiting
NCT05841758 — Hydroxychloroquine as a Steroid-sparing Agent in Extrapulmonary Sarcoidosis
· Phase 4
· recruiting
Other recruiting trials for Coronavirus
Currently open trials in the same condition.
NCT04772170 — Observational Digital Biomarker Discovery in Respiratory Virus Challenge Studies
· recruiting
NCT05868239 — Impact of Aerosol Box Use During Cardiopulmonary Arrest: A Multicenter Study
· NA
· recruiting
NCT04359836 — A Study to Explore the Role of Gut Flora in COVID-19 Infection
· recruiting
NCT04376034 — Convalescent Plasma Collection and Treatment in Pediatrics and Adults
· Phase 3
· recruiting
NCT04568148 — COVID-19 Biorepository
· active not recruiting
Other Massachusetts General Hospital trials
Trials by the same sponsor.
NCT03585946 — Outcomes in Stevens Johnsons Syndrome and Toxic Epidermal Necrolysis
· withdrawn
NCT07214831 — A Feasibility and Acceptability Study of a Large Language Model-based Chatbot for Brief Alcohol Intervention Among Emerg
· NA
· not yet recruiting
NCT06686901 — A Randomized Controlled Trial of a Smartphone Delivered Treatment for Suicidal Thoughts and Behavior
· NA
· not yet recruiting
NCT05854212 — Behavioral Economics to Implement Nutrition Ranking in Food Pantries
· NA
· not yet recruiting
NCT07323446 — The MIND Study: The MGH/MIT Investigation of NAC on Dysregulation
· EARLY_PHASE1
· not yet recruiting
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 Massachusetts General Hospital
Last refreshed: 17 March 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/NCT04332991.