Influenza polymerase inhibitors in advanced clinical development or recently approveda

FeatureFavipiravir (T-705)Pimodivir (JNJ-63623872)Baloxavir (S-033188)
Viral targetPB1PB2PA
SpectrumIV-A, IV-B, IV-CIV-A onlyIV-A and IV-B (better than OTV against IV-B)
Synergy with NAIsYesYesYes
Activity against M2-resistant strains, activity against NAI-resistant strainsYesYesYes
Agent-resistant variantsNone to dateYesYes
AdministrationOral (i.v. in development)Oral (i.v. in development)Oral
Reduction in i.v. viral loadsModestGood (better than NAI)Strong (3.5-log10 reduction)
Development statusApproval in Japan, investigational in rest of worldPhase 2 ambulatory done, hospitalized study ongoingApproval in Japan and in USA, pending in Europe
  • a IV-A, influenza virus A; IV-B, influenza virus B; i.v., intravenous; NAI, neuraminidase inhibitors; OTV, oseltamivir.