Balapiravir Explained

Balapiravir (R-1626, Ro4588161) is an experimental antiviral drug which acts as a polymerase inhibitor. There were efforts to develop it as a potential treatment for hepatitis C, and it was subsequently also studied in Dengue fever, but was not found to be useful. Lower doses failed to produce measurable reductions in viral load, while higher doses produced serious side effects such as lymphopenia which precluded further development of the drug.^[1] Subsequent research found that excess cytokine production triggered by Dengue virus infection prevented the conversion of the balapiravir prodrug to its active form, thereby blocking the activity of the drug.^[2]

Notes and References

1. A randomized, double-blind placebo controlled trial of balapiravir, a polymerase inhibitor, in adult dengue patients. . 22807519 . 10.1093/infdis/jis470 . 207 . 9 . 3610419 . Nguyen NM, Tran CN, Phung LK, Duong KT, Huynh Hle A, Farrar J, Nguyen QT, Tran HT, Nguyen CV, Merson L, Hoang LT, Hibberd ML, Aw PP, Wilm A, Nagarajan N, Nguyen DT, Pham MP, Nguyen TT, Javanbakht H, Klumpp K, Hammond J, Petric R, Wolbers M, Nguyen CT, Simmons CP . J Infect Dis . 1442–50. 2013 .
2. Chen Y, etal . 2014 . Activation of Peripheral Blood Mononuclear Cells by Dengue Virus Infection Depotentiates Balapiravir . J. Virol. . 88 . 3. 1740–1747 . 10.1128/JVI.02841-13 . 24257621 . 3911617 .