Table 1.
Overview of influenza polymerase inhibitors
| Favipiravir | Pimodivir | Baloxavir marboxil | |
|---|---|---|---|
| Alternative name | T-705 | JNJ-63623872, VX-787 | S-033188 |
| Molecular formula | C5H4FN3O2 | C20H19F2N5O2 | C27H23F2N3O7S |
| Molecular weight | 157.1 | 399.4 | 571.6 |
| Active form | Favipiravir-RTP | – | Baloxavir acid |
| Target protein | PB1 | PB2 | PA |
| Target influenza viruses | Types A, B, C, D | Type A | Types A, B, C, D |
| Current status | Approved in Japan for influenza pandemic preparedness | In Phase III clinical trials | Approved in several countries (Japan, USA, etc.) |
| Route of administration | BID oral dose for 5 d | BID oral dose for 5 d | Single oral dose |
| Inhibition of M2 inhibitor–resistant viruses | Yes | Yes | Yes |
| Inhibition of NA inhibitor–resistant viruses | Yes | Yes | Yes |
| Emergence of variants with reduced susceptibility in vitro | Yes | Yes | Yes |
| Emergence of variants with reduced susceptibility in clinical trials | No | Yes | Yes |
(Favipiravir-RTP) Favipiravir-ribofuranosyl-5′-triphosphate, (PB1) polymerase basic protein 1, (PB2) polymerase basic protein 2, (PA) polymerase acidic protein, (BID) twice daily, (M2) matrix protein 2, (NA) neuraminidase.