for people ages 1-17 (full criteria)
at San Francisco, California and other locations
study started
estimated completion



The purpose of this study is to determine if the investigational treatment (maralixibat) is safe and effective in pediatric participants with Progressive Familial Intrahepatic Cholestasis (PFIC).

Official Title

MRX-502: Randomized Double-blind Placebo-controlled Phase 3 Study to Evaluate the Efficacy and Safety of Maralixibat in the Treatment of Subjects With Progressive Familial Intrahepatic Cholestasis (PFIC) - MARCH-PFIC


This study will be conducted at multiple sites in North America, Europe, Asia, and South America.


Progressive Familial Intrahepatic Cholestasis (PFIC) Cholestasis Maralixibat Mutation PFIC PFIC2 Bile Duct Diseases Liver Diseases Biliary Tract Diseases Digestive System Diseases Pediatric Cholestasis, Intrahepatic


You can join if…

Open to people ages 1-17

  • Informed consent and assent (as applicable) per Institutional Review Board/Ethics Committee (IRB/EC)
  • Male or female subjects with a body weight ≥ 5.0 kg, who are ≥ 12 months and < 18 years of age at time of consent
  • Cholestasis as manifested by total sBA ≥ 3× Upper Limit of Normal (ULN)
  • An average AM ItchRO(Obs) score ≥ 1.5 during 4 consecutive weeks of the screening period, leading to the baseline visit (Visit 1)
  • Completion of at least 21 valid morning ItchRO(Obs) entries during 4 consecutive weeks of the screening period, leading to the baseline visit (Visit 1)
  • Diagnosis of PFIC based on:
  • Chronic cholestasis as manifested by persistent (>6 months) pruritus, biochemical abnormalities or pathological evidence of progressive liver disease and
  • Primary Cohort: Subjects with genetic testing results consistent with biallelic disease-causing variation in ABCB11 (PFIC2), based on standard of care genotyping
  • Supplemental Cohort: i. Subjects with genetic testing results consistent with biallelic disease-causing variation in ATP8B1 (PFIC1), ABCB4 (PFIC3), or TJP2 (PFIC4), based on standard of care genotyping ii. Subjects with PFIC phenotype without a known mutation or with another known mutation not described above iii. Subjects with PFIC after internal or external biliary diversion surgery or for whom internal or external biliary diversion surgery was reversed

You CAN'T join if...

  • Predicted complete absence of bile salt excretion pump (BSEP) function based on the type of ABCB11 mutation (PFIC2), as determined by a standard of care genotyping (applies to primary cohort only). Subjects can enter the study in the Supplemental Cohort (under inclusion criteria 6.ii or 6.iii).
  • Recurrent intrahepatic cholestasis, indicated by a history of sBA levels <3x ULN or intermittent pruritus
  • Current or recent history (<1 year) of atopic dermatitis or other non-cholestatic diseases associated with pruritus
  • History of surgical disruption of the enterohepatic circulation (applies to primary cohort only)
  • Chronic diarrhea requiring intravenous fluid or nutritional intervention for the diarrhea and/or its sequelae at screening or during the 6 months prior to screening
  • Previous or need for imminent liver transplant
  • Decompensated cirrhosis (international normalized ratio [INR] > 1.5, and/or albumin < 30 g/L, history or presence of clinically significant ascites, and/or variceal hemorrhage, and/or encephalopathy)
  • Alanine aminotransferase (ALT) or total serum bilirubin (TSB) > 15× ULN at screening
  • Presence of other liver disease
  • Presence of any other disease or condition known to interfere with the absorption, distribution, metabolism or excretion of drugs, including bile salt metabolism in the intestine (e.g., inflammatory bowel disease), per Investigator discretion
  • Possibly malignant liver mass on imaging, including screening ultrasound
  • Known diagnosis of human immunodeficiency virus (HIV) infection
  • Any prior cancer diagnosis (except for in situ carcinoma) within 5 years of the screening visit (Visit 0)
  • Any known history of alcohol or substance abuse
  • Administration of bile acids or lipid binding resins, or sodium phenylbutyrate during the screening period
  • Administration of growth hormones at any time before or during the study
  • Administration of any investigational drug, biologic, or medical device during the screening period
  • Previous use of an ileal bile acid transporter inhibitor (IBATi)
  • History of non-adherence to medical regimens, unreliability, medical condition, mental instability or cognitive impairment that, in the opinion of the Investigator or Sponsor medical monitor, could compromise the validity of informed consent, compromise the safety of the subject, or lead to nonadherence with the study protocol or inability to conduct the study procedures.


  • UCSF Medical Center accepting new patients
    San Francisco California 94143 United States
  • Children Hospital LA accepting new patients
    Los Angeles California 90027 United States


accepting new patients
Start Date
Completion Date
Mirum Pharmaceuticals, Inc.
Genetics Home Reference - PFIC Mirum Pharmaceuticals homepage
Phase 3
Study Type
Last Updated