Background: Halofuginone (PJS-539) is an oral prolyl-tRNA synthetase inhibitor that has a potent in vitro activity against SARS-CoV-2 virus. The safety and efficacy of halofuginone in Covid-19 patients has not been studied.
Methods: We conducted a phase II, randomized, double-blind, placebo-controlled, dose ranging, safety and tolerability trial of halofuginone in symptomatic (≤ 7 days), mostly vaccinated, non-hospitalized adults with mild to moderate Covid-19. Patients were randomized in a 1:1:1 ratio to receive halofuginone 0.5mg, 1mg or placebo orally once daily for 10 days. The primary outcome was the decay rate of the SARS-CoV-2 viral load logarithmic curve within 10 days after randomization.
Results: From September 25, 2021, to February 3, 2022, 153 patients were randomized. The mean decay rate in SARS-CoV-2 viral load log10 within 10 days was -3.75 (95% CI, -4.11; -3.19) in the placebo group, -3.83 (95% CI, -4.40; -2.27) in the halofuginone 0.5mg group and -4.13 (95% CI, -4.69; -3.57) in the halofuginone 1mg group, with no statistically significant difference in between placebo vs. halofuginone 0.5mg (mean difference -0.08; 95% CI -0.82 to 0.66, p = 0.96) and between placebo vs. halofuginone 1mg (mean difference -0.38; 95% CI, -1.11; 0.36, p = 0.41). There was no difference on bleeding episodes or serious adverse events at 28 days.
Conclusions: Among non-hospitalized adults with mild to moderate Covid-19 halofuginone treatment was safe and well tolerated but did not decrease SARS-CoV-2 viral load decay rate within 10 days.
Copyright: © 2024 Tomazini et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.