Enrollment, randomization, populations for analysis, and study timeline in the AB023 phase 2 clinical trial. Thirty-seven patients were screened for study eligibility. Ten patients did not meet inclusion/exclusion criteria and were not enrolled in the study. An additional 3 patients terminated the study early, prior to randomization on study day 1. Twenty-four patients were randomized and all 24 patients completed the study. All randomized patients were confined to the clinic from study day −8 to study day 6, after which they returned to the clinic on study days 8, 10, and 12 to continue heparin-free hemodialysis. Predose hemodialysis occurred on study days −7, −5, and −3. Dosing occurred on study day 1, and postdosing hemodialysis occurred on study days 1, 3, 5, 8, 10, and 12. The red diamonds represent hemodialysis days in which data were collected, and the blue diamonds represent heparin-free hemodialysis sessions that were performed in the clinic, but no data were collected. Cohorts were dosed sequentially, starting with cohort 1 (0.25 mg/kg or matching placebo). Once cohort 1 was completed, dosing for cohort 2 began (0.5 mg/kg or matching placebo). Placebo from both cohorts were pooled together for analysis. All 24 patients randomized were included in the safety and efficacy analyses. Two patients from the 0.25 mg/kg group were excluded from the PK analysis; 1 patient was excluded because the percent of AUC_0-inf extrapolated (AUC_%extrap) was very high (63%) and therefore did not meet the prespecified criteria for inclusion of the PK analyses, and 1 patient was excluded from the summary statistics because the 0.17-hour AB023 concentration was an outlier. AEs, adverse events; SAE, serious adverse event.