A Study to Evaluate the Safety and Efficacy of CR845 in Hemodialysis Patients With Moderate-to-Severe Pruritus (KALM-1)

Key Inclusion Criteria: To be eligible for inclusion into the Double-blind Phase of the study, a patient must meet the following criteria: * Has end-stage renal disease (ESRD) and has been on hemodialysis 3 times per week for at least 3 months prior to the start of screening; * Has at least 2 single-pool Kt/V measurements ≥1.2, or at least 2 urea reduction ratio measurements ≥65%, or 1 single pool Kt/V measurement ≥1.2 and 1 urea reduction ratio measurement ≥65% on different dialysis days during the 3 months period prior to screening; * Prior to randomization: * Has completed Worst Itching Intensity NRS worksheets up to 8 days prior to 1st dose; * Has a mean baseline Worst Itching Intensity NRS indicative of moderate to severe uremic pruritus. * To be eligible for inclusion into the Open-label Extension Phase of the study, each patient will have to fulfill the additional key following criteria at the time of entry into the Open-label Extension Phase: * Has received at least 30 doses of the planned 36 doses of study drug during the Double-blind Phase of this study; * Continues to meet inclusion criteria. Key Exclusion Criteria: A patient will be excluded from the Double-blind Phase of the study if any of the following criteria are met: * Known noncompliance with dialysis treatment that in the opinion of the investigator would impede completion or validity of the study; * Scheduled to receive a kidney transplant during the study; * New or change of treatment received for itch including antihistamines and corticosteroids (oral, IV, or topical) within 14 days prior to screening; * Received another investigational drug within 30 days prior to the start of screening or is planning to participate in another clinical study while enrolled in this study; * Has pruritus only during the dialysis session (by patient report); * Is receiving ongoing ultraviolet B and anticipates receiving such treatment during the study; * Participated in a previous clinical study with CR845. * A patient will be excluded from the Open-label Extension Phase of the study if any of the additional key following criteria are met at the time of entry into the Open-label Extension Phase: * Completed the Double-blind Phase of this study but exhibited adverse events during the course of the Treatment Period that may preclude continued exposure to the study drug; * Was noncompliant with protocol procedures during the Double-blind Phase of this study which is indicative of an inability to follow protocol procedures.