Favipiravir (T-705)

PubMed: 26711718      Antiviral Res.

Initial dose-ranging study of ribavirin/favipiravir treatment of JUNV-infected guinea pigs. Animals in each group (n=6) were infected with 100 PFU of JUNV and treated i.p. with the indicated doses of favipiravir, ribavirin, a combination of both compounds, or placebo twice daily for 2 weeks starting 3 days p.i. Kaplan-Meier survival curves are shown. **P < 0.01, ***P < 0.001, compared to placebo-treated animals. Tx, treatment; p.i., postinfection.

PubMed: 28848019      Antimicrob Agents Chemother.

Reduction of WNV yield and cytotoxicity of favipiravir. (B) Percentage of viable Vero cells after favipiravir treatment. The 50% cytotoxic concentration was determined by measuring the cellular ATP content at 48 h posttreatment. Data are presented as the mean ± standard deviation (SD) from three independent determinations of both IC50 and CC50.

PubMed: 29765101      Sci Rep.

Histopathology and immunohistochemistry. (a) Formalin fixed tissues were embedded in paraffin and H&E stained. Images represent brains, lungs, and spleens of vehicle control animals, favipiravir p.o. and favipiravir s.c.

PubMed: 29765101      Sci Rep.

Histopathology and immunohistochemistry. (b) Formalin fixed tissues were embedded in paraffin and stained with anti-NiV nucleoprotein antibodies. Images represent brains, lungs, and spleens of vehicle control animals, favipiravir p.o. and favipiravir s.c. V, blood vessels; Br, bronchioles; Fo, follicles; Arrows, NiV nucleoprotein antigens.

PubMed: 26456301      Sci Rep.

Immunohistochemical analysis of tissues from animals infected with GPA-LASV and treated daily with favipiravir, ribavirin or placebo. Tissue samples from infected guinea pigs treated daily with favipiravir (150 or 300 mg/kg/d), ribavirin (50 mg/kg/d) or placebo were collected at 12 days post-infection and examined for the presence of LASV antigen (glycoprotein, GP) using a GP-specific monoclonal antibody according to standard immunohistochemistry techniques.

PubMed: 33037151      Proc Natl Acad Sci U S A.

(F) Representative H&E images of lungs at day 4 pi of SARS-CoV-2−infected hamsters and treated with favipiravir. At day 4, lungs of untreated hamsters show significant inflammation in bronchial wall (blue arrows) with apoptotic bodies in respiratory epithelium and extension into adjacent alveoli (orange arrow) and inflammatory cells in arterial wall (red arrow). Lungs of infected hamsters treated with 600 mg⋅kg−1⋅d−1 favipiravir still show a few inflammatory cells in the bronchial wall (blue arrows) and a few focal perivascular lymphocytes (red arrow), whereas lungs of hamsters treated with 1,000 mg⋅kg−1⋅d−1 favipiravir contain even less inflammatory cells in the bronchial wall, but no perivascular inflammation. Apoptotic bodies (black circles) were present in bronchial walls of hamsters from all three groups (Scale bars, 100 µm.)

PubMed: 29765101      Sci Rep.

Delayed treatment in vitro efficacy of favipiravir against NiV infection. (a) Microscopic analysis of Vero cells infected with rNiV-Gluc-eGFP (MOI 0.01). Favipiravir (250 μM) was added at 1, 12, and 24 HPI; eGFP expression, development of syncytia, and cytopathic effect were monitored by microscopy at 24, 48 and 72 HPI.