Positive in Ames; negative in in vitro human lymphocyte micronucleus and in vivo mouse bone marrow micronucleus assays
“Fexinidazole was mutagenic (positive in strains TA98, TA100, and TA1535 in the presence and absence of S9 and TA1537, and TA102 in the presence of S9) but was negative in the in vitro micronucleus assays in cultured human peripheral blood lymphocytes up to 180 µg/mL (+/-S9), and the in vivo micronucleus assay in the bone marrow of treated mice (2 oral doses up to 2000 mg/kg).”
✓ VerifiedFDA multi-discipline review, p. 57Source ↗
Carcinogenicity
Not conducted; related nitroimidazoles are carcinogenic in rodents
“Carcinogenicity studies are not indicated for fexinidazole and were not conducted. However, structurally related compounds such as metronidazole have exhibited carcinogenic potential in lifetime animal studies.”
✓ VerifiedFDA multi-discipline review, p. 74Source ↗
Instead of carcinogenicity
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Instead of genotoxicity
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
DRG histopathology
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Reproductive & developmental
Rat EFD: delayed ossification, reduced fetal and placental weights at maternally toxic 800 mg/kg
“Delayed ossification-reduced fetal weights and reduced placental weights were observed at 800 mg/kg in the presence of maternal toxicity (reduced maternal body weights).”
✓ VerifiedFDA multi-discipline review, p. 58Source ↗
Safety pharmacology
hERG: sulfone metabolite reduced current by 33% at 9.3 µg/mL
“(hERG) assay showed that fexinidazole sulfone, the fexinidazole metabolite, reduced the residual current by 33 % at 9.3 µg/mL.”
✓ VerifiedFDA multi-discipline review, p. 57Source ↗
Genotox: Ames
Positive (fexinidazole and M2 metabolite mutagenic)
“Fexinidazole and the M2 metabolite were mutagenic in the Ames test.”
Negative: in vitro micronucleus in human peripheral blood lymphocytes
“Fexinidazole was negative in the in vitro micronucleus test in cultured human peripheral blood lymphocytes, the rat liver unscheduled DNA synthesis (UDS) assay, and the in vivo mouse micronucleus assay.”
Negative: mouse micronucleus and rat liver UDS assays
“Fexinidazole was negative in the in vitro micronucleus test in cultured human peripheral blood lymphocytes, the rat liver unscheduled DNA synthesis (UDS) assay, and the in vivo mouse micronucleus assay.”
Not conducted; related nitroimidazoles carcinogenic in lifetime rodent studies
“No carcinogenicity study was performed with fexinidazole. Carcinogenicity has been observed in mice and rats treated chronically with nitroimidazole-class drugs which are structurally similar to fexinidazole.”
Not indicated and not conducted (short-course therapy); related nitroimidazoles carcinogenic in lifetime studies
“Carcinogenicity studies are not indicated for fexinidazole and were not conducted. However, structurally related compounds such as metronidazole have exhibited carcinogenic potential in lifetime animal studies.”
✓ VerifiedFDA multi-discipline review, p. 74Source ↗
hERG / QT
Sulfone metabolite inhibits hERG; patient sulfone Cmax (19.6 µg/mL) about 2 times levels affecting hERG
“Plasma levels of fexinidazole sulfone in patients receiving the recommended dose of fexinidazole (Cmax 19.6 µg/mL) were about two times the levels shown to affect hERG potassium channels.”
✓ VerifiedFDA multi-discipline review, p. 57Source ↗
Not genotoxic overall: Ames negative; in vitro chromosome aberration positive without (not with) metabolic activation; rat micronucleus and comet negative