Polo R, Garcia-Albeniz X, Teran C, Morales M, Rial-Crestelo D, Garcinuno MA, Garcia del Toro M, Hita C, Gomez-Sirvent JL, Buzon L, Diaz de Santiago A, Perez Arellano JL, Sanz J, Bachiller P, Martinez Alfaro E, Diaz-Brito V, Masia M, Hernandez-Torres A, Guerra J, Santos J, Arazo P, Munoz L, Arribas JR, Martinez de Salazar P, Moreno S, Hernan MA, del Amo J. Daily tenofovir disoproxil fumarate/emtricitabine and hydroxychloroquine for pre-exposure prophylaxis of COVID-19: a double-blind placebo controlled randomized trial in healthcare workers. Clin Microbiol Infect. 2022 Aug 5. doi: 10.1016/j.cmi.2022.07.006.


OBJECIVE: To assess the effect of hydroxychloroquine (HCQ), Tenofovir disoproxil fumarate/Emtricitabine (TDF/FTC), and their combination as pre-exposure prophylaxis on the risk of symptomatic COVID-19.

METHODS: EPICOS is a double-blind, placebo-controlled randomized trial conducted in 51 hospitals in Spain, Bolivia, and Venezuela. Healthcare workers with negative SARS-CoV-2 IgM/IgG test were randomly assigned to: daily TDF/FTC plus HCQ for 12 weeks, TDF/FTC plus HCQ placebo, HCQ plus TDF/FTC placebo and TDF/FTC placebo plus HCQ placebo. The primary outcome was laboratory-confirmed, symptomatic COVID-19. We also studied any (symptomatic or asymptomatic) COVID-19 infection. We compared group-specific 14-week risks via differences and ratios with 95% confidence intervals (CI).

RESULTS: Of 1002 individuals screened, 926 (92.4%) were eligible; 64.2% recruited in Spain, 22.3% in Bolivia, and 13.6% in Venezuela. Median age was 38 years (range 18 - 68), 62.5% were female, 62.3% worked at inpatient care, and comorbidities were rare. Compared with the placebo group, 14-week risk ratios (95% CI) of symptomatic COVID-19 were 0.39 (0.00, 1.98) for TDF+HCQ, 0.34 (0.00, 2.06) for TDF, and 0.49 (0.00, 2.29) for HCQ. Corresponding risk ratios of any COVID-19 were 0.51 (0.21, 1.00) for TDF+HCQ, 0.81 (0.44, 1.49) for TDF, and 0.73 (0.41, 1.38) for HCQ. Adverse events were generally mild.

CONCLUSION: A beneficial effect of TDF/FTC and HCQ, alone or in combination, as pre-exposure prophylaxis for COVID-19 cannot be ruled out but effect estimates are imprecise because the target sample size was not met. These findings support launching randomized trials of TDF/FTC for the early treatment of COVID-19.

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