There was a small but statistically significant decrease in CrCl from baseline in the active arm , compared to placebo , which was first observed at week @ ( mean change : -@ vs. -@ ml/min ; P = @ ) , persisted through the last on-treatment visit ( mean change : +@ vs. +@ ml/min ; P = @ ) , and resolved after stopping pre-exposure prophylaxis ( mean change : -@ vs. @ ml/min ; P = @ ) .