Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Reviewer's view of the efficacy data
FDA: no consistent bacterial reduction for isolates with MIC ≥32 µg/mL; activity may be inconsistent against them
“For isolates with MIC ≥32 µg/mL, there was no consistent significant change from baseline, as some of the isolates did not show any change from baseline, suggesting that cefepime/zidebactam may not have consistent activity against isolates with an MIC of ≥32 µg/mL”