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Healthcare WorkersPhase 3NCT04405271

TAF/FTC for Pre-exposure Prophylaxis of COVID-19 in Healthcare Workers (CoviPrep Study)

A Phase 3 study testing Emtricitabine/Tenofovir Alafenamide 200 MG-25 MG Oral Tablet in people with Healthcare Workers and COVID-19, run by Hospital Italiano de Buenos Aires at 1 site in Argentina.

Terminated

Stopped early. The study ended before it was planned to and will not resume.

Official record
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Trial summary

A randomized parallel double-blinded placebo-controlled clinical trial to evaluate the effect of Emtricitabine/Tenofovir alafenamide (FTC/TAF) compared with placebo on the risk of developing SARS-CoV-2 disease (COVID-19) in healthcare workers with high transmission risk in addition to currently recommended control… Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Healthcare Workers, COVID-19, SARS-CoV 2
What is being tested?
Emtricitabine/Tenofovir Alafenamide 200 MG-25 MG Oral Tablet
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
1,378 participants
Where
1 siteArgentina
Study dates
31 Jul 2020to 15 Nov 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 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Healthcare workers voluntarily deciding to participate in the study
  • Understanding the study purpose
  • Having between 18 and 70 years old
  • Having a high transmission risk for Covid-19. Physicians, nurses, lab technicians, physical therapists, or cleaning personnel working at COVID-19 areas, hospital emergency areas, or Intensive care units from healthcare institutions with the direct assistance of patients with Covid-19.
  • Not having a prior diagnosis of SARS-CoV-2 infection (COVID-19)
  • Having a negative IgM/IgG antibodies test for SARS-CoV-2 (COVID-19) prior to study entry
  • Negative pregnancy test for childbearing age women within 7 days prior to study entry.
  • Childbearing age males and females should comply with the use of a proven contraceptive method (double barrier methods, oral contraceptives or contraceptive hormone implants) during the course of the study and at least one month after study completion.

Who cannot join

  • Having symptoms compatible with COVID-19
  • Diagnosed HIV infection
  • Current use of Pre-exposure prophylaxis for HIV
  • Diagnosed Hepatitis B infection.
  • Diagnosed renal insufficiency and or current hemodialysis need
  • Diagnosed osteoporosis under pharmacological treatment.
Show all 12Show fewer
  • Weight < 40kg
  • Current immunosuppressive or serious hematological condition
  • Prior use of pre-exposure prophylaxis for SARS-CoV-2
  • Current pregnancy or pregnancy plan within the study course.
  • Current breastfeeding
  • Known hypersensitivity to any of the study medication components.

Trial locations and contacts

1 site in 1 country.

Argentina1 site

  • Sociedad Argentina de Infectología, A. J. Carranza 974

    Buenos Aires, Buenos Aires F.D., C1085

Other trials in Argentina

About this study

Official title: Randomized, Double-blind, Placebo-controlled Trial of TAF/FTC for Pre-exposure Prophylaxis of COVID-19 in Healthcare Workers (CoviPrep Study)

A randomized parallel double-blinded placebo-controlled clinical trial to evaluate the effect of Emtricitabine/Tenofovir alafenamide (FTC/TAF) compared with placebo on the risk of developing SARS-CoV-2 disease (COVID-19) in healthcare workers with high transmission risk in addition to currently recommended control measures.

Read the detailed description

Randomized, double-blind, placebo-controlled clinical trial. Phase III clinical trial for a new indication

Rationale One of the most affected subgroups during the current pandemic is represented by healthcare workers. In Argentina between 14 and 17% of the total COVID-19 cases are represented by this subgroup. In this sense, it appears as an adequate strategy testing the efficacy of pharmacological PrEP approaches on top of the currently recommended control measures.

The use of placebo is warranted for two main reasons: all healthcare workers will be allowed and encouraged to comply with non-pharmacological infection control measures for the protection of viral transmission. On the other hand, the use of a blinded placebo is intended for avoiding relaxation of the non-pharmacological control measures.

Tenofovir has been identified by both docking and in vitro studies as an inhibitor of RdRp (RNA dependent RNA polymerase) of coronavirus.

FTC/TAF has the additional advantage that is already being used in a pre-exposure prophylaxis setting and its safety is widely known.

Main objective To evaluate the risk of developing SARS-CoV-2 disease (COVID-19) in healthcare workers with high transmission risk in addition to currently recommended control measures.

Being tested
Emtricitabine/Tenofovir Alafenamide 200 MG-25 MG Oral Tablet, Placebo
Keywords
SARS Virus, SARS-CoV-2, COVID-19, Health Personnel
Medical subject headings
COVID-19, Severe Acute Respiratory Syndrome

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Emtricitabine/Tenofovir Alafenamide 200 MG-25 MG Oral TabletDrug

    Also called FTC/TAF

    Emtricitabine/Tenofovir alafenamide (FTC/TAF) in 200 mg/25 mg tablets. A dose of 1 tablet per day will be administered for a total of 12 weeks

  • PlaceboDrug

    Also called Placebo comparator

    A dose of 1 tablet per day will be administered for a total of 12 weeks.

Study groups in NCT04405271
Study groupRoleWhat they receive
FTC/TAFExperimentalEmtricitabine/Tenofovir alafenamide (FTC/TAF) in 200 mg/25 mg tablets. A dose of 1 tablet per day will be administered for a total of 12 weeks.
Receives: Drug: Emtricitabine/Tenofovir Alafenamide 200 MG-25 MG Oral Tablet
PlaceboPlacebo comparatorIdentical tablets to the active experimental tablets with the same characteristics and packaging. A dose of 1 tablet per day will be administered for a total of 12 weeks
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. COVID-19 incident cases

    SARS-CoV-2 disease (COVID-19) with or without symptoms at week 12 of treatment as defined by the presence of specific antibodies against the virus. Positive cases will be confirmed by PCR

    Measured: During treatment (12 weeks)

Secondary outcomes (5)

  1. Number of asymptomatic SARS-CoV-2 (Covid-19) infections confirmed by serology

    Number of asymptomatic SARS-CoV-2 (Covid-19) infections confirmed by serology

    Measured: During treatment (12 weeks)

  2. Severity of symptomatic COVID-19

    Severity of symptomatic SARS-CoV-2 (Covid-19) infections as defined by the following categories:

    • Mild symptoms: malaise, fever, cough, arthralgia myalgias,
    • Moderate symptoms: same as above plus shortness of breath
    • Severe symptoms: clinical status requiring admission in Intensive care unit

    Measured: During treatment (12 weeks)

  3. Respiratory symptom duration in days

    Respiratory symptom duration in days

    Measured: During treatment (12 weeks)

  4. Relation between treatments and symptoms duration

    Relation between treatments and symptoms duration

    Measured: During treatment (12 weeks)

  5. Time course of specific IgM/IgG seroconversion

    Time course of specific IgM/IgG seroconversion

    Measured: During treatment (12 weeks)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted28 May 2020
  2. Study start31 Jul 2020
  3. Primary completion15 Nov 2020
  4. Study completion15 Nov 2020

Why it stopped: Vaccine availability precluded further recruitment

Resources

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
Model description
Randomized (1:1), double-blind, placebo-controlled clinical trial
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
1,378 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04405271
Sponsor's protocol ID
5616
Status last verified
Jul 2020
First submitted
26 May 2020
Last updated
9 Sep 2025
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Elfiky AA. Anti-HCV, nucleotide inhibitors, repurposing against COVID-19. Life Sci. 2020 May 1;248:117477. doi: 10.1016/j.lfs.2020.117477. Epub 2020 Feb 28.

    PubMed 32119961

  • Castillo-Mancilla JR, Meditz A, Wilson C, Zheng JH, Palmer BE, Lee EJ, Gardner EM, Seifert S, Kerr B, Bushman LR, MaWhinney S, Anderson PL. Reduced immune activation during tenofovir-emtricitabine therapy in HIV-negative individuals. J Acquir Immune Defic Syndr. 2015 Apr 15;68(5):495-501. doi: 10.1097/QAI.0000000000000529.

    PubMed 25763783

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Emtricitabine/Tenofovir Alafenamide 200 MG-25 MG Oral Tablet in people with Healthcare Workers and COVID-19, run by Hospital Italiano de Buenos Aires at 1 site in Argentina.

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 8 inclusion and 12 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: stopped early, as of the sponsor's last update on 9 Sep 2025. 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 Argentina. 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. Some participants in this study may receive a placebo. 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 was stopped early (reason given: Vaccine availability precluded further recruitment). Results are not available in the source record.

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?

COVID-19 incident cases (time frame: During treatment (12 weeks)). 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 NCT04405271, 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 9 Sep 2025.

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