Study lengthAcceptedBeyond the letter
Animal data support only up to one month of dosing, while clinical treatment up to six weeks was permitted
Why: Longer treatment duration supported by clinical data · Human data
“The animal data supports safety of ceftobiprole medocaril sodium for up to 1 month duration, however, based on clinical data treatments for up to six weeks were permitted. We deferred to the clinical review team on the safety of ceftobiprole medocaril sodium administered for this extended duration.”
✓ VerifiedFDA integrated review, p. 293Source ↗ GenotoxicityAcceptedBeyond the letter
Positive in vitro mouse lymphoma and chromosomal assays (clastogenic potential); negative in vivo micronucleus and rat liver UDS
Why: Negative in vivo micronucleus and rat liver unscheduled DNA synthesis assays reduce the concern · Weight of evidence
“The genotoxicity profile of ceftobiprole medocaril sodium was mixed including a negative Ames assay, a positive mouse lymphoma assay, a negative forward mutation assay, and positive chromosomal assays for both the pro-drug and active metabolite suggesting clastogenic potential.”
✓ VerifiedFDA integrated review, p. 293Source ↗ “However, in vivo ceftobiprole medocaril sodium was negative in both the micronucleus assay and rat liver unscheduled DNA synthesis reducing concern for potential clastogenic activity.”
✓ VerifiedFDA integrated review, p. 293Source ↗ Impurity or metaboliteAcceptedBeyond the letter
Several drug substance and drug product impurities not adequately qualified in toxicology studies
Why: Impurity levels considered acceptable despite qualification limitations; no further safety evaluation warranted · Other reason
“The impurity qualification review indicates that the select individual impurities in the DS and DP are not adequately qualified based on the toxicology studies considered.”
✓ VerifiedFDA integrated review, p. 296Source ↗ “Although there are limitations in the qualification of impurities based on toxicological studies, the levels of impurities in ceftobiprole medocaril sodium are considered acceptable and no further evaluations of impurities for safety is warranted.”
✓ VerifiedFDA integrated review, p. 296Source ↗ Safety marginVerdict not stated
Convulsions and mortality in 13-week rat and marmoset studies at doses below the MRHD (0.2 times in marmosets)
“However, in the 13-week studies in the rats and marmosets at similar doses to those used in shorter term studies, convulsions and mortality were observed (≥50 mg/kg in marmosets, 0.2 times the MRHD; ≥250 mg/kg in rats, 0.94 times the MRHD, based on BSA comparisons).”
✓ VerifiedFDA integrated review, p. 125Source ↗