@article{Wawman:2026:10.1183/23120541.01560-2025,
author = {Wawman, RE and Shah, PL and Boffito, M and Tonkin, J and Conway, F and Tana, A and Santos, BR and Grinsztejn, B and Ramírez, BC and Pertinez, H and Owen, A and Curley, P and Arshad, U and Cox, H and Johnson, MR and Pozniak, A and Pelly, M and Orton, CM and Bhavsar, PK},
doi = {10.1183/23120541.01560-2025},
journal = {ERJ Open Research},
title = {The relationship between plasma favipiravir concentrations and clinical outcomes in COVID-19},
url = {http://dx.doi.org/10.1183/23120541.01560-2025},
volume = {12},
year = {2026}
}

Download

TY  - JOUR
AB  - BackgroundFavipiravir has shown efficacy against SARS-CoV-2 in patients <60years old, but data linking plasma concentrations to clinical outcomes are limited. This study investigated whether favipiravir plasma concentrations influence clinical efficacy and outcomes in patients hospitalised with COVID-19. The main research question was, How can antiviral dosing strategies be optimised to improve pandemic preparedness and treatment efficacy?MethodsAdult participants were drawn from the PIONEER trial, in which patients received oral favipiravir (1800mg twice daily for 1day, then 800mg twice daily for 9days) plus standard care. This analysis included patients with confirmed COVID-19 and ≥75% study adherence. Samples were collected between days 5 and 10 post-treatment initiation. The primary outcome was time to clinical improvement. Secondary outcomes included achievement of clinical improvement and mortality risk.ResultsOut of 140 patients (50% male; mean±sd age 59.5±14.8years), target plasma concentrations were reached in 29 (21%). Mean time to improvement was 7.7±5.9days in target achievers versus 9.1±7.2days in non-achievers (p=0.26). The target was more often achieved in female (34%) than male (7%) participants (p=0.0002). Plasma concentration inversely correlated with body mass index (r=–0.4, p<0.0001), and with lower body mass index in achievers (26.0±5.1kg·m−2 versus 30.5±6.9kg·m−2, p=0.003). Alkaline phosphatase and alanine aminotransferase levels were also lower in achievers (p=0.004 and p=0.02, respectively).ConclusionMost patients did not reach target favipiravir levels. Concentrations were influenced by sex, body mass index and liver function, confirming the need for pharmacokinetically guided dosing and therapeutic monitoring to optimise antiviral efficacy in future pandemic responses.
AU  - Wawman,RE
AU  - Shah,PL
AU  - Boffito,M
AU  - Tonkin,J
AU  - Conway,F
AU  - Tana,A
AU  - Santos,BR
AU  - Grinsztejn,B
AU  - Ramírez,BC
AU  - Pertinez,H
AU  - Owen,A
AU  - Curley,P
AU  - Arshad,U
AU  - Cox,H
AU  - Johnson,MR
AU  - Pozniak,A
AU  - Pelly,M
AU  - Orton,CM
AU  - Bhavsar,PK
DO  - 10.1183/23120541.01560-2025
PY  - 2026///
SN  - 2312-0541
TI  - The relationship between plasma favipiravir concentrations and clinical outcomes in COVID-19
T2  - ERJ Open Research
UR  - http://dx.doi.org/10.1183/23120541.01560-2025
UR  - https://doi.org/10.1183/23120541.01560-2025
VL  - 12
ER  - 

Download