Study Endpoints The primary endpoint was the proportion of patients with treatment failure (failure to prevent kidney dysfunction) at 24 months, which was a composite of graft loss, histologically confirmed acute rejection or cyclosporine toxicity, or a > 15% increase in the mean serum creatinine level from the baseline assessment. The mean of the current and two previous serum creatinine levels was used to determine the level at baseline, the level at the nadir (the time of the lowest serum creatinine measurement),and the level at 2 years.