Evaluate the Safety, Tolerability, and PK of EP547 in Healthy Subjects and Subjects With Cholestatic or Uremic Pruritus

Inclusion Criteria

Healthy Subjects:

• Age 18 to 60 years, inclusive
• Body mass index greater than or equal to 19 to less than or equal to 35 kg/m2
• Medically healthy with no clinically significant medical history, physical examination, vital sign, standard 12- lead ECG, chemistry, hematology, urinalysis, or coagulation results at Screening as deemed by the Investigator
• Male and female subjects must use adequate birth control and agree not to donate sperm or eggs for the time periods specified in the protocol

Subjects with Cholestatic Pruritus:

• Age 18 to 80 years, inclusive
• Has a cholestatic disorder
• Has experienced daily or near-daily moderate to severe pruritus for greater than 4 weeks before Screening and at study entry has itch scores indicative of moderate to severe pruritus
• If currently taking medications to treat the cholestatic disorder, must be on a stable dose for greater than 12 weeks before Screening and plans to maintain the regimen throughout the study
• If currently taking medications known to impact pruritus, must be on a stable dose for greater than 4 weeks before Screening and plans to maintain the regimen throughout the study
• Male and female subjects must use adequate birth control and agree not to donate sperm or eggs for the time periods specified in the protocol

Subjects with Uremic Pruritus

• Age 18 to 80 years, inclusive
• Has ESRD and is receiving hemodialysis 3× per week
• Has experienced daily or near-daily moderate to severe pruritus for greater than 4 weeks before Screening and at study entry has itch scores indicative of moderate to severe pruritus
• If currently taking medications known to impact pruritus, must be on a stable dose for greater than 4 weeks before Screening and plans to maintain the regimen throughout the study
• Male and female subjects must use adequate birth control and agree not to donate sperm or eggs for the time periods specified in the protocol

Exclusion Criteria

Healthy Subjects:

• Any prescription medications within 14 days of Screening
• Positive result for HIV HBV, or HCV at Screening
• History of malignancy within the past 5 years
• Tobacco product or electronic cigarette use within 90 days of Day -1
• Positive drug, alcohol, or cotinine screen results at Screening or Day -1
• Significant history of abuse of drugs, solvents, or alcohol in the past 2 years

Subjects with Cholestatic Pruritus:

• Scheduled to receive a liver transplant during the study (placement on a transplant waiting list is not exclusionary)
• Is receiving ongoing UVB treatment or anticipates receiving such treatment during the study
• Pruritus is secondary to biliary obstruction
• History or presence of hepatocellular carcinoma, hepatic abscess, or acute portal vein Thrombosis

Subjects with Uremic Pruritus:

• Scheduled to receive a kidney transplant during the study (placement on a transplant waiting list is not exclusionary)
• Is receiving ongoing UVB treatment or anticipates receiving such treatment during the study
• Known noncompliance with hemodialysis treatment that, in the opinion of the Investigator, would impede completion or validity of the study
• Pruritus is attributed mainly to any disease unrelated to kidney disease, is only present during the hemodialysis sessions, or is attributed to a skin disorder that occurs in this population with associated itch (eg, acquired perforating dermatosis)