Covid-19Phase 3NCT04446104
A Preventive Treatment for Migrant Workers at High-risk of COVID-19
A Phase 3 study testing Hydroxychloroquine Sulfate Tablets, Ivermectin 3mg Tab and Zinc in people with Covid-19, run by National University Hospital, Singapore at 1 site in Singapore.
Trial summary
In December 2019, a novel coronavirus, now called COVID-19, emerged as a global health threat from Wuhan, China. Within weeks, the contagious virus spread within and between communities, causing a lower respiratory tract infection dominated by symptoms of fever, cough and sore throat. Read more about this study
- Who is it for?
- Ages 21 to 60 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Covid-19
- What is being tested?
- Hydroxychloroquine Sulfate Tablets, Ivermectin 3mg Tab and Zinc
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 4,257 participants
- Where
- 1 siteSingapore
- Study dates
- 13 May 2020to 31 Aug 2020
- Phase
- Phase 3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 21 to 60 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Subjects must meet all the of following criteria to be included in this study:
- Men residing in dormitory aged 21-60 years
- Willing and able to give informed consent
- Able to understand instructions and consume study medications according to the study protocol.
- Weight more than 40kg
- Owns a mobile phone (with wireless fidelity and/or 3G connection and able to fill in online forms.
Who cannot join
- Subjects who have any of the following criteria at baseline will be excluded from participating in this study:
- Symptoms of acute respiratory illness (e.g. fever, runny nose, sore throat, cough, breathlessness, loss of smell and loss of taste) for the past 30 days
- Known current or history of SARS-CoV-2 infection
- Unable to read English or any of the available local languages used for this clinical trial
- History of cardiac or neurological diseases
- History of retinal diseases
Show all 16Show fewer
- History of diabetes on insulin treatment
- History of depression
- History of chronic alcohol use
- History of renal or hepatic dysfunction
- History of glucose-6-phosphate dehydrogenase deficiency
- History of anaemia, after exposure to any given medications
- History of thyroid disorder, hyperthyroidism, or sensitivity to iodine
- History of allergies with systemic presentation to any given medication (e.g.: swelling of the face, throat, eyes and lips, respiratory disturbances, asthmatic attacks, widespread skin blistering or urticaria (hives))
- Concomitant medication that may lead to cardiac arrhythmia (azithromycin, amitriptyline, cimetidine, citalopram, nortriptyline, pantoprazole, quetiapine etc).
- Unwilling to comply with study dosing, instructions or restrictions.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A Randomized Open-label Prophylaxis Trial Among Migrant Workers at High-risk of COVID-19 (DORM Trial)
In December 2019, a novel coronavirus, now called COVID-19, emerged as a global health threat from Wuhan, China. Within weeks, the contagious virus spread within and between communities, causing a lower respiratory tract infection dominated by symptoms of fever, cough and sore throat. The incubation period was estimated at between 5 to 7 days, but could last as long as 14 days. Although COVID-19 causes a mostly mild and self-limiting disease, respiratory involvement has been reported in about 5% of the population, requiring supplemental oxygen and even ventilatory support to relieve hypoxia. Alveolar damage, fibrosis and consolidation have been reported in radiologic and post-mortem studies. Existing data suggest a mortality rate of COVID-19 is approximately 1-2%, higher among individuals with pre-existing comorbidities and in healthcare systems with suboptimal access to ventilatory support.
Given its high transmissibility, COVID-19 has quickly spread across the globe within a short interval. By 27 April 2020, over 3 million people around the world have been diagnosed with COVID-19, and more 200,000 have succumbed to the disease. As a proportion of patients manifest mild or no symptoms, these numbers are likely an underestimate of the actual number of patients with COVID-19. More disconcertingly, patients are known to shed viruses despite mild or no symptoms, making it essential that a collective approach against COVID-19 incorporate active pharmacological treatment to prevent or mitigate virus pathogenesis prior to its potential evolution to cause respiratory distress. To date, clinical trials have focused on the treatment of hospitalised patients diagnosed with COVID-19; only few have examined the clinical benefits of pharmacological agents despite few compelling in vitro data.
The relatively high transmission of COVID-19 in a closed dormitory environment of migrant workers in Singapore presents a real-life scenario where a prophylaxis treatment could reduce the impact of the disease. In Singapore, there are well grounded concerns an excess in cases could pose the possibility of strain in healthcare system and mentally drain her workers. The availability of an effective prophylaxis treatment is highly desirable to potentially reduce this burden. Data from the current study could also have implications on how future outbreaks in high-density areas should be managed, especially when residents are subjected to quarantine and isolation.
Read the detailed description
This is a pragmatic, open-label, randomised study with 4 interventional and 1 control arms. Individuals will be recruited from migrant worker dormitories, and written informed consent taken prior to enrolment. Randomisation will be done by the level within the dormitory building and predetermined each day according to a randomisation schema done by an independent statistician. This will obviate the potential for bias due to drug exchange between study individuals.
The 5 arms consist of:
- Experimental arms
- Hydroxychloroquine tablet 400mg loading dose, followed by 200mg daily for 42 days (1,000 study subjects)
- Ivermectin tablet 12mg single dose (1,000 study subjects)
- Zinc tablet 80 mg/vitamin C 500mg daily for 42 days (1,000 study subjects)
- Povidone-iodine throat spray (3 times daily) for 42 days (1,000 study subjects)
- Control arm 5) Vitamin C tablet 500mg daily for 42 days (1,000 study subjects)
Study information sheet will be circulated in selected buildings within the dormitory 1-4 days before recruitment starts. All publicity materials and informed consent form will be translated to the different languages (e.g. Tamil, Bengali, Chinese, Burmese and Malay). A translator will be present to aid translation if necessary. Study subjects will be given ample time to ask questions relating to the study. Prospective participants will respond by showing up to recruitment stations at designated dates and times. Facilitators from the dormitory will be engaged to assist with the ground crowd-control. Prospective videos will be shown to inform the subject on the purpose, study inclusion and exclusion criteria, study medications, blood taking, reporting of adverse effects and follow-up visits. Informed consent will be taken before all study-related procedures are performed, including study eligibility. Translators will also help translate the daily questionnaires.
During the baseline recruitment,
- History of symptoms, comorbidities and prior illnesses will be asked. Specific questions include presence or absence of the following symptoms: Fever, chills, myalgia, headache, diarrhoea, running nose, anosmia, loss of taste, sore throat, dry cough, shortness of breath.
- Measurements of study subjects' parameters such as weight, height, temperature, pulse rate and blood pressure will be recorded. Subjects randomised to Ivermectin arm and subsequently found to weigh below 60 kg will be randomised to other treatment arms. Subjects randomised to hydroxychloroquine arm and found to have systolic blood pressure >150 mmHg and/or diastolic blood pressure >90 mmHg and/or heart rate >100 beats per minute will also be randomized to other treatment arms.
- 12-lead electrocardiogram (ECG) will be performed in patients randomised to receive hydroxychloroquine. Only those with corrected QT values less than 450 ms, no cardiac arrhythmia and no ventricular hypertrophy will be allowed to receive hydroxychloroquine. Those with corrected QT values more than 450 ms, cardiac arrhythmia and ventricular hypertrophy will be randomised to other treatment arms.
- Blood sample (20 mL) will be obtained to test Immunoglobulin G/M against SARS-CoV-2. Depending on the findings, additional tests will be performed to explore potential biological reasons underpinning these observations. The choice of markers may include pathway-specific biomarkers targeting inflammation, oxidative stress, lipid parameters, as well as organ-specific ones such as renal and liver parameters. Given the large sample size and high costs of analysis, the study team will prioritise more detailed investigations in a targeted group of patients depending on the final findings. None of these blood results is a screening criteria for study participation. The investigator will share abnormal to the study subjects abnormal results of their renal and liver parameters should these tests are tested following study completion. The extent on investigation, however, depends on funding support. In this study, renal and hepatic dysfunction will be based on physician-diagnosed and self-declaration on the part of the study subject. All clinical information will be verified by a senior physician on-site.
- Study medications will be packed with clear instructions written on the packing bag. The package will be distributed to each subject based on the randomised treatment assigned.
- Study participants will be given a study card to remind them to submit their symptoms daily and to record the times when they consume their medications. They will also be asked to present this card to doctors at the medical post or hospital should they seek medical assistance. In the events of acute respiratory infection and hospitalization, lab testing will be done as clinically indicated. Subjects on ventilator support who are not able to take oral medications may discontinue taking the study drug. However, subjects will remain in the study for collection of data on duration of mechanical ventilation for analysis.
During final study visit,
- The study team, including investigators, will be present at the dormitory. A repeated blood sample (20mL) will be collected for serological tests. Measurements of study subjects' parameters such as weight (using Tanita BC-418 and Tanita BC-420MA for bio-electrical impedance analysis), height, blood pressure will be taken. ECG will be done only for subjects in hydroxychloroquine arm. History will be taken including symptoms of fever, chills, myalgia, headache, diarrhoea, running nose, anosmia, loss of taste, sore throat, dry cough, shortness of breath and the duration of such symptoms, if any.
- Balance medication and packaging retrieval to do medication accounting and checking for adherence to assigned treatment arm
- Discharged from study if no adverse events to follow-up.
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hydroxychloroquine Sulfate TabletsDrug
Hydroxychloroquine tablet 400mg loading dose, followed by 200mg daily for 42 days
Ivermectin 3mg TabDrug
Ivermectin tablet 12mg single dose
ZincDrug
Zinc tablet 80 mg/vitamin C 500mg daily for 42 days
Povidone-IodineDrug
Povidone-iodine throat spray (3 times daily) for 42 days
Vitamin CDietary supplement
Vitamin C tablet 500mg daily for 42 days
| Study group | Role | What they receive |
|---|---|---|
| Hydroxychloroquine | Experimental | Participants will receive hydroxychloroquine tablet 400mg loading dose, followed by 200mg daily for 42 days Receives: Drug: Hydroxychloroquine Sulfate Tablets |
| Ivermectin | Experimental | Participants will receive ivermectin tablet 12mg single dose Receives: Drug: Ivermectin 3mg Tab |
| Zinc/ Vitamin C | Experimental | Participants will receive zinc tablet 80 mg/vitamin C 500mg daily for 42 days Receives: Drug: Zinc |
| Povidone-iodine throat spray | Experimental | Participants will receive povidone-iodine throat spray (3 times daily) for 42 days Receives: Drug: Povidone-Iodine |
| Vitamin C | Active comparator | Participants will receive vitamin C tablet 500mg daily for 42 days Receives: Dietary Supplement: Vitamin C |
What is being measured
The primary outcome is the main question the study is designed to answer.
Laboratory-confirmed COVID-19 in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Measured: At the end of study dosing, which is day 42
Secondary outcomes (9)
Acute respiratory illness in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Acute respiratory illness is defined by acute onset with any key respiratory symptoms including cough, shortness of breath, sore throat, runny nose and change in smell.
Measured: At the end of study dosing, which is day 42
Febrile respiratory illness in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Measured: At the end of study dosing, which is day 42
Rate of hospitalization for COVID-19 and non-COVID-19 related indications in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Measured: At the end of study dosing, which is day 42
Rate of oxygen supplementation and mechanical ventilation in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Measured: At the end of study dosing, which is day 42
Duration of oxygen supplementation and mechanical ventilation in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Measured: At the end of study dosing, which is day 42
Length of hospital stay in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Measured: At the end of study dosing, which is day 42
Rate of laboratory-confirmed COVID-19 in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Measured: At the end of study dosing, which is day 42
Adverse events and serious adverse events in control arm (Vitamin C)
Measured: At the end of study dosing, which is day 42
Drug discontinuation due to adverse events in control arm (Vitamin C)
Measured: At the end of study dosing, which is day 42
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Jun 2020
- Study start13 May 2020
- Primary completion31 Aug 2020
- Study completion31 Aug 2020
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Covid-19Studies of the same condition, open and under way.
- More trials run by National University Hospital, SingaporeThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 4,257 participants (actual)
Sponsor and investigators
- Lead sponsor
- National University Hospital, Singapore
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04446104
- Sponsor's protocol ID
- 2020/00561
- Status last verified
- May 2020
- First submitted
- 11 May 2020
- Last updated
- 19 Oct 2020
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Quek AML, Ooi DSQ, Teng O, Foon CH, Li PP, Er BGC, Mahmud NFB, Shunmuganathan B, MacAry PA, Lim ECH, Seet RCS. Adiposity shapes the immune architecture independent of antibody responses in mild SARS-CoV-2 infection. Int J Infect Dis. 2026 Sep;170:108932. doi: 10.1016/j.ijid.2026.108932. Epub 2026 Jun 26.
PubMed 42361956Teng O, Quek AML, Ooi DSQ, Wang S, Fragata L, Ng IXQ, Cui J, Chen J, Hartman M, Hutchinson PE, Tambyah PA, Seet RCS. High CD4(+) T-cell responses in seronegative individuals following SARS-CoV-2 exposure during a dormitory outbreak. Int J Infect Dis. 2025 Oct;159:108024. doi: 10.1016/j.ijid.2025.108024. Epub 2025 Aug 20.
PubMed 40845939
Study at a glance
From the registry record, last updated by the sponsor on 19 Oct 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Open-label Prophylaxis Trial Among Migrant Workers at High-risk of COVID-19 (DORM Trial)
- ClinicalTrials.gov ID
- NCT04446104
- Acronym / sponsor ID
- 2020/00561
- Conditions
- Covid-19
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 4,257 participants (actual)
- Lead sponsor
- National University Hospital, SingaporeUniversity, hospital or other
- Study start
- 13 May 2020 (actual)
- Primary completion
- 31 Aug 2020 (actual)
- Study completion
- 31 Aug 2020 (actual)
- First posted
- 24 Jun 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In December 2019, a novel coronavirus, now called COVID-19, emerged as a global health threat from Wuhan, China. Within weeks, the contagious virus spread within and between communities, causing a lower respiratory tract infection dominated by symptoms of fever, cough and sore throat. The incubation period was estimated at between 5 to 7 days, but could last as long as 14 days. Although COVID-19 causes a mostly mild and self-limiting disease, respiratory involvement has been reported in about 5% of the population, requiring supplemental oxygen and even ventilatory support to relieve hypoxia. Alveolar damage, fibrosis and consolidation have been reported in radiologic and post-mortem studies. Existing data suggest a mortality rate of COVID-19 is approximately 1-2%, higher among individuals with pre-existing comorbidities and in healthcare systems with suboptimal access to ventilatory support.
Given its high transmissibility, COVID-19 has quickly spread across the globe within a short interval. By 27 April 2020, over 3 million people around the world have been diagnosed with COVID-19, and more 200,000 have succumbed to the disease. As a proportion of patients manifest mild or no symptoms, these numbers are likely an underestimate of the actual number of patients with COVID-19. More disconcertingly, patients are known to shed viruses despite mild or no symptoms, making it essential that a collective approach against COVID-19 incorporate active pharmacological treatment to prevent or mitigate virus pathogenesis prior to its potential evolution to cause respiratory distress. To date, clinical trials have focused on the treatment of hospitalised patients diagnosed with COVID-19; only few have examined the clinical benefits of pharmacological agents despite few compelling in vitro data.
The relatively high transmission of COVID-19 in a closed dormitory environment of migrant workers in Singapore presents a real-life scenario where a prophylaxis treatment could reduce the impact of the disease. In Singapore, there are well grounded concerns an excess in cases could pose the possibility of strain in healthcare system and mentally drain her workers. The availability of an effective prophylaxis treatment is highly desirable to potentially reduce this burden. Data from the current study could also have implications on how future outbreaks in high-density areas should be managed, especially when residents are subjected to quarantine and isolation.
Detailed description
This is a pragmatic, open-label, randomised study with 4 interventional and 1 control arms. Individuals will be recruited from migrant worker dormitories, and written informed consent taken prior to enrolment. Randomisation will be done by the level within the dormitory building and predetermined each day according to a randomisation schema done by an independent statistician. This will obviate the potential for bias due to drug exchange between study individuals.
The 5 arms consist of:
- Experimental arms
- Hydroxychloroquine tablet 400mg loading dose, followed by 200mg daily for 42 days (1,000 study subjects)
- Ivermectin tablet 12mg single dose (1,000 study subjects)
- Zinc tablet 80 mg/vitamin C 500mg daily for 42 days (1,000 study subjects)
- Povidone-iodine throat spray (3 times daily) for 42 days (1,000 study subjects)
- Control arm 5) Vitamin C tablet 500mg daily for 42 days (1,000 study subjects)
Study information sheet will be circulated in selected buildings within the dormitory 1-4 days before recruitment starts. All publicity materials and informed consent form will be translated to the different languages (e.g. Tamil, Bengali, Chinese, Burmese and Malay). A translator will be present to aid translation if necessary. Study subjects will be given ample time to ask questions relating to the study. Prospective participants will respond by showing up to recruitment stations at designated dates and times. Facilitators from the dormitory will be engaged to assist with the ground crowd-control. Prospective videos will be shown to inform the subject on the purpose, study inclusion and exclusion criteria, study medications, blood taking, reporting of adverse effects and follow-up visits. Informed consent will be taken before all study-related procedures are performed, including study eligibility. Translators will also help translate the daily questionnaires.
During the baseline recruitment,
- History of symptoms, comorbidities and prior illnesses will be asked. Specific questions include presence or absence of the following symptoms: Fever, chills, myalgia, headache, diarrhoea, running nose, anosmia, loss of taste, sore throat, dry cough, shortness of breath.
- Measurements of study subjects' parameters such as weight, height, temperature, pulse rate and blood pressure will be recorded. Subjects randomised to Ivermectin arm and subsequently found to weigh below 60 kg will be randomised to other treatment arms. Subjects randomised to hydroxychloroquine arm and found to have systolic blood pressure >150 mmHg and/or diastolic blood pressure >90 mmHg and/or heart rate >100 beats per minute will also be randomized to other treatment arms.
- 12-lead electrocardiogram (ECG) will be performed in patients randomised to receive hydroxychloroquine. Only those with corrected QT values less than 450 ms, no cardiac arrhythmia and no ventricular hypertrophy will be allowed to receive hydroxychloroquine. Those with corrected QT values more than 450 ms, cardiac arrhythmia and ventricular hypertrophy will be randomised to other treatment arms.
- Blood sample (20 mL) will be obtained to test Immunoglobulin G/M against SARS-CoV-2. Depending on the findings, additional tests will be performed to explore potential biological reasons underpinning these observations. The choice of markers may include pathway-specific biomarkers targeting inflammation, oxidative stress, lipid parameters, as well as organ-specific ones such as renal and liver parameters. Given the large sample size and high costs of analysis, the study team will prioritise more detailed investigations in a targeted group of patients depending on the final findings. None of these blood results is a screening criteria for study participation. The investigator will share abnormal to the study subjects abnormal results of their renal and liver parameters should these tests are tested following study completion. The extent on investigation, however, depends on funding support. In this study, renal and hepatic dysfunction will be based on physician-diagnosed and self-declaration on the part of the study subject. All clinical information will be verified by a senior physician on-site.
- Study medications will be packed with clear instructions written on the packing bag. The package will be distributed to each subject based on the randomised treatment assigned.
- Study participants will be given a study card to remind them to submit their symptoms daily and to record the times when they consume their medications. They will also be asked to present this card to doctors at the medical post or hospital should they seek medical assistance. In the events of acute respiratory infection and hospitalization, lab testing will be done as clinically indicated. Subjects on ventilator support who are not able to take oral medications may discontinue taking the study drug. However, subjects will remain in the study for collection of data on duration of mechanical ventilation for analysis.
During final study visit,
- The study team, including investigators, will be present at the dormitory. A repeated blood sample (20mL) will be collected for serological tests. Measurements of study subjects' parameters such as weight (using Tanita BC-418 and Tanita BC-420MA for bio-electrical impedance analysis), height, blood pressure will be taken. ECG will be done only for subjects in hydroxychloroquine arm. History will be taken including symptoms of fever, chills, myalgia, headache, diarrhoea, running nose, anosmia, loss of taste, sore throat, dry cough, shortness of breath and the duration of such symptoms, if any.
- Balance medication and packaging retrieval to do medication accounting and checking for adherence to assigned treatment arm
- Discharged from study if no adverse events to follow-up.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Hydroxychloroquine | Experimental | Drug: Hydroxychloroquine Sulfate TabletsParticipants will receive hydroxychloroquine tablet 400mg loading dose, followed by 200mg daily for 42 days |
| Ivermectin | Experimental | Drug: Ivermectin 3mg TabParticipants will receive ivermectin tablet 12mg single dose |
| Zinc/ Vitamin C | Experimental | Drug: ZincParticipants will receive zinc tablet 80 mg/vitamin C 500mg daily for 42 days |
| Povidone-iodine throat spray | Experimental | Drug: Povidone-IodineParticipants will receive povidone-iodine throat spray (3 times daily) for 42 days |
| Vitamin C | Active comparator | Dietary Supplement: Vitamin CParticipants will receive vitamin C tablet 500mg daily for 42 days |
Who may qualify
- Ages
- 21 to 60 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Men residing in dormitory aged 21-60 years
- Willing and able to give informed consent
- Able to understand instructions and consume study medications according to the study protocol.
- Weight more than 40kg
- Owns a mobile phone (with wireless fidelity and/or 3G connection and able to fill in online forms.
Key exclusion criteria (16 listed)
- Subjects who have any of the following criteria at baseline will be excluded from participating in this study:
- Symptoms of acute respiratory illness (e.g. fever, runny nose, sore throat, cough, breathlessness, loss of smell and loss of taste) for the past 30 days
- Known current or history of SARS-CoV-2 infection
- Unable to read English or any of the available local languages used for this clinical trial
- History of cardiac or neurological diseases
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hydroxychloroquine Sulfate TabletsHydroxychloroquine tablet 400mg loading dose, followed by 200mg daily for 42 days | Drug | Hydroxychloroquine |
| Ivermectin 3mg TabIvermectin tablet 12mg single dose | Drug | Ivermectin |
| ZincZinc tablet 80 mg/vitamin C 500mg daily for 42 days | Drug | Zinc/ Vitamin C |
| Povidone-IodinePovidone-iodine throat spray (3 times daily) for 42 days | Drug | Povidone-iodine throat spray |
| Vitamin CVitamin C tablet 500mg daily for 42 days | Dietary supplement | Vitamin C |
Primary outcome
Laboratory-confirmed COVID-19 in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
9 secondary outcomes
Acute respiratory illness in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
Febrile respiratory illness in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
Rate of hospitalization for COVID-19 and non-COVID-19 related indications in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
Rate of oxygen supplementation and mechanical ventilation in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
Duration of oxygen supplementation and mechanical ventilation in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
Length of hospital stay in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
Rate of laboratory-confirmed COVID-19 in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine)
Time frame: At the end of study dosing, which is day 42
Adverse events and serious adverse events in control arm (Vitamin C)
Time frame: At the end of study dosing, which is day 42
Drug discontinuation due to adverse events in control arm (Vitamin C)
Time frame: At the end of study dosing, which is day 42
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Oct 2020.
- Derived from this study: PubMed 42361956Quek AML, Ooi DSQ, Teng O, Foon CH, Li PP, Er BGC, Mahmud NFB, Shunmuganathan B, MacAry PA, Lim ECH, Seet RCS. Adiposity shapes the immune architecture independent of antibody responses in mild SARS-CoV-2 infection. Int J Infect Dis. 2026 Sep;170:108932. doi: 10.1016/j.ijid.2026.108932. Epub 2026 Jun 26.
- Derived from this study: PubMed 40845939Teng O, Quek AML, Ooi DSQ, Wang S, Fragata L, Ng IXQ, Cui J, Chen J, Hartman M, Hutchinson PE, Tambyah PA, Seet RCS. High CD4(+) T-cell responses in seronegative individuals following SARS-CoV-2 exposure during a dormitory outbreak. Int J Infect Dis. 2025 Oct;159:108024. doi: 10.1016/j.ijid.2025.108024. Epub 2025 Aug 20.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing Hydroxychloroquine Sulfate Tablets, Ivermectin 3mg Tab and Zinc in people with Covid-19, run by National University Hospital, Singapore at 1 site in Singapore.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Oct 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Singapore. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Laboratory-confirmed COVID-19 in treatment arms (hydroxychloroquine, ivermectin, zinc and povidone iodine) (time frame: At the end of study dosing, which is day 42). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04446104, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Oct 2020.