Hydroxychloroquine as pre-exposure prophylaxis for COVID-19 in healthcare workers: a randomized trial
PrEP RCT showing HR 0.73,
p = 0.12. Trial halted after 47% enrollment,
p < 0.05 will be reached at ~75% enrollment if similar results continue.
HR 0.66/0.68 for full medication adherence, 0.72/0.74,
p = 0.18/0.22 overall (1x/2x dosing). Efficacy for first responders was higher, OR 0.32,
p = 0.01. First responders had a much higher incidence, allowing greater power, and reducing the effect of confounders such as misdiagnosis of other conditions or survey issues.
Performance is similar to placebo for the first 3 weeks. The effect may be greater with a dosage regimen that achieves therapeutic levels faster
[tandfonline.com]. ~40% of participants suspected they might have had COVID-19 before the trial, the effect in people without prior COVID-19 may be higher.
Authors note:
- the trial was underpowered
- investigation into more frequent dosing may be warranted
- insufficient dosing with no participants achieving more than the
in vitro EC
50Internet survey RCT subject to survey bias. There were no deaths or ICU admissions. Low risk healthcare workers, median age ~40. 494 1x/week dosing, 495 2x/week dosing, 494 control participants (1x and 2x participants received the same overall dosage). COVID PREP.
NCT04328467 (history).
risk of hospitalization, 50.1% lower, RR 0.50, p = 1.00, treatment 1 of 989 (0.1%), control 1 of 494 (0.2%), NNT 987.
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risk of case, 27.0% lower, HR 0.73, p = 0.12, treatment 58 of 989 (5.9%), control 39 of 494 (7.9%), NNT 49.
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Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates
|
Rajasingham et al., 21 Sep 2020, Randomized Controlled Trial, USA, peer-reviewed, 22 authors, trial
NCT04328467 (history) (COVID PREP).
Abstract: Clinical Infectious Diseases
MAJOR ARTICLE
Hydroxychloroquine as Pre-exposure Prophylaxis for
Coronavirus Disease 2019 (COVID-19) in Healthcare
Workers: A Randomized Trial
Radha Rajasingham,1, Ananta S. Bangdiwala,1 Melanie R. Nicol,1 Caleb P. Skipper,1 Katelyn A. Pastick,1, Margaret L. Axelrod,2 Matthew F. Pullen,1
Alanna A. Nascene,1 Darlisha A. Williams,1 Nicole W. Engen,1 Elizabeth C. Okafor,1 Brian I. Rini,2 Ingrid A. Mayer,2 Emily G. McDonald,3 Todd C. Lee,3
Peter Li,4 Lauren J. MacKenzie,5 Justin M. Balko,2 Stephen J. Dunlop,1,6 Katherine H. Hullsiek,1 David R. Boulware,1,a and Sarah M. Lofgren1,a; on behalf of
the COVID PREP team
(See the Editorial Commentary by Goldman on pages e844–7.)
Background. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a rapidly emerging virus causing the ongoing
coronavirus disease 2019 (COVID-19) pandemic with no known effective prophylaxis. We investigated whether hydroxychloroquine
could prevent SARS-CoV-2 in healthcare workers at high risk of exposure.
Methods. We conducted a randomized, double-blind, placebo-controlled clinical trial of healthcare workers with ongoing exposure to persons with SARS-CoV-2, including those working in emergency departments, intensive care units, COVID-19 hospital
wards, and first responders. Participants across the United States and in the Canadian province of Manitoba were randomized to
hydroxychloroquine loading dose then 400 mg once or twice weekly for 12 weeks. The primary endpoint was confirmed or probable
COVID-19–compatible illness. We measured hydroxychloroquine whole-blood concentrations.
Results. We enrolled 1483 healthcare workers, of whom 79% reported performing aerosol-generating procedures. The incidence
of COVID-19 (laboratory-confirmed or symptomatic compatible illness) was 0.27 events/person-year with once-weekly and 0.28
events/person-year with twice-weekly hydroxychloroquine compared with 0.38 events/person-year with placebo. For once-weekly
hydroxychloroquine prophylaxis, the hazard ratio was .72 (95% CI, .44–1.16; P = .18) and for twice-weekly was .74 (95% CI, .46–1.19;
P = .22) compared with placebo. Median hydroxychloroquine concentrations in whole blood were 98 ng/mL (IQR, 82–120) with onceweekly and 200 ng/mL (IQR, 159–258) with twice-weekly dosing. Hydroxychloroquine concentrations did not differ between participants
who developed COVID-19–compatible illness (154 ng/mL) versus participants without COVID-19 (133 ng/mL; P = .08).
Conclusions. Pre-exposure prophylaxis with hydroxychloroquine once or twice weekly did not significantly reduce laboratoryconfirmed COVID-19 or COVID-19–compatible illness among healthcare workers.
Clinical Trials Registration. NCT04328467.
Keywords. COVID-19; hydroxychloroquine; healthcare workers; pre-exposure prophylaxis.
Coronavirus disease 2019 (COVID-19) creates a substantial strain on the healthcare system, with frontline healthcare
workers at increased risk of infection, and yet they are simultaneously essential for sustaining an adequate emergency
response. Unfortunately, at present, no effective oral chemoprophylaxis or vaccination against COVID-19 exists. On 7 October
2020, the Centers for Disease Control and Prevention (CDC)
reported over 173 000 cases of COVID-19 among healthcare
Received 17 August 2020; editorial decision 10 October 2020; published online 17 October
2020.
a
D. R. B. and S.M. L. contributed equally to this work.
Correspondence: R. Rajasingham, 689 23rd Ave SE,..
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