Title

A Study to Evaluate the Efficacy and Safety of Maralixibat in Subjects With Progressive Familial Intrahepatic Cholestasis (MARCH-PFIC)
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
  • Phase

    Phase 3
  • Study Type

    Interventional
  • Study Participants

    93
The purpose of this study is to determine whether the investigational treatment (maralixibat) is safe and effective in pediatric participants with Progressive Familial Intrahepatic Cholestasis (PFIC).
This study was conducted at multiple sites in North America, Europe, Asia and South America.
Study Started
Jul 09
2019
Primary Completion
Sep 01
2022
Study Completion
Sep 01
2022
Results Posted
Dec 11
2023
Last Update
Dec 11
2023

Drug Maralixibat

Maralixibat oral solution (up to 600 mcg/kg) orally twice daily for 26 weeks.

  • Other names: Formerly LUM001 and SHP625

Other Placebo

Placebo matching to maralixibat orally twice daily for 26 weeks.

Maralixibat Experimental

Participants will receive Maralixibat oral solution (up to 600 microgram per kilogram [mcg/kg]) orally twice daily for 26 weeks.

Placebo Placebo Comparator

Participants will receive placebo matched to maralixibat oral solution twice daily for 26 weeks.

Criteria

Inclusion Criteria:

Informed consent and assent (as applicable) per Institutional Review Board/Ethics Committee (IRB/EC)
Male or female subjects with a body weight ≥5 kg, who are ≥12 months and <18 years of age at time of baseline
Cholestasis as manifested by total sBA ≥3× ULN (applies to primary cohort only)
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) (*valid = completed and not answered as "I don't know"; maximum allowed invalid reports = 7, no more than 2 invalid reports during the last 7 days before randomization)

Diagnosis of PFIC based on the following:

Chronic cholestasis as manifested by persistent (>6 months) pruritus in addition to biochemical abnormalities and/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 or with intermittent cholestasis as manifested by fluctuating sBA levels. iii. Subjects with PFIC after internal or external biliary diversion surgery or for whom internal or external biliary diversion surgery was reversed.
Male and females of non-childbearing potential. Males and non-pregnant, non-lactating females of childbearing potential who are sexually active must agree to use acceptable methods of contraception during the study and 30 days following the last dose of the study medication. Females of childbearing potential must have a negative pregnancy test
Access to email or phone for scheduled remote visits
Ability to read and understand the questionnaires (both caregivers and subjects above the age of assent)
Access to consistent caregiver(s) during the study
Subject and caregiver willingness to comply with all study visits and requirements.

Exclusion Criteria:

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 (applies to primary cohort only)
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, albumin <30 g/L, history or presence of clinically significant ascites, variceal hemorrhage, and/or encephalopathy)
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 phenylbutyrates during the screening period
Criterion has been deleted as of Amendment 3
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
Known hypersensitivity to maralixibat or any of its excipients.

Summary

Maralixibat

Placebo

All Events

Event Type Organ System Event Term Maralixibat Placebo

Mean Change in the Average Morning ItchRO(Obs) Severity Score in the Primary Cohort

The primary efficacy endpoint is the mean change in the average morning ItchRO(Obs) severity score between baseline and Weeks 15-26, using 4-week average morning ItchRO(Obs) severity scores (Mixed Model Repeated Measures). The baseline average morning ItchRO(Obs) severity score is defined as the 4-week average morning ItchRO(Obs) severity score prior to the first dose of the study medication. ItchRo(Obs) Severity Score = Itch Reported Outcome Observer assessment severity score; scale between 0 (not itchy at all) and 4 (extremely itchy); the lower the score the better.

Primary Cohort Maralixibat

-1.718
Score on a scale (Least Squares Mean)
95% Confidence Interval: -2.272 to -1.163

Primary Cohort Placebo

-0.628
Score on a scale (Least Squares Mean)
95% Confidence Interval: -1.136 to -0.121

Mean Change in Total sBA Level in the Primary Cohort.

Mean change in total sBA level between baseline and average of Weeks 18, 22 and 26.

Primary Cohort Maralixibat

-175.536
μmol/L (Least Squares Mean)
95% Confidence Interval: -256.716 to -94.356

Primary Cohort Placebo

11.187
μmol/L (Least Squares Mean)
95% Confidence Interval: -58.073 to 80.446

Mean Change in the Average Morning ItchRO(Obs) Severity Score in Participants With PFIC (PFIC1, Nt-PFIC2, PFIC3, PFIC4 and PFIC6)

Mean change in the average morning ItchRO(Obs) severity score between baseline and Week 15 through Week 26 in participants with PFIC (PFIC1, PFIC2, PFIC3, PFIC4 and PFIC6). ItchRo(Obs) Severity Score = Itch Reported Outcome Observer assessment severity score; scale between 0 (not itchy at all) and 4 (extremely itchy); the lower the score the better.

PFIC Cohort Maralixibat

-1.811
score on a scale (Least Squares Mean)
95% Confidence Interval: -2.178 to -1.444

PFIC Cohort Placebo

-0.61
score on a scale (Least Squares Mean)
95% Confidence Interval: -1.0 to -0.221

Mean Change in Total sBA Level in Participants With PFIC (PFIC1, PFIC2, PFIC3, PFIC4 and PFIC6)

Mean change in total sBA level between baseline and average of Weeks 18, 22, and 26 in participants with PFIC (PFIC1, PFIC2, PFIC3, PFIC4 and PFIC6)

PFIC Cohort Maralixibat

-157.489
μmol/L (Least Squares Mean)
95% Confidence Interval: -200.276 to -114.703

PFIC Cohort Placebo

2.913
μmol/L (Least Squares Mean)
95% Confidence Interval: -42.32 to 48.146

Proportion of ItchRO(Obs) Responders in the Primary Cohort

Proportion of ItchRO(Obs) responders from Week 15 to Week 26 in participants with PFIC2 using the average value from the three 4-week periods (Weeks 15-18, 19-22 and 23-26). The number in the Subject Analysis Set refers to the number of responders. ItchRO responders are defined as a subject having a 4-week average morning ItchRO(Obs) severity change from baseline of ≤-1.0 or an average severity score of ≤1.0.

Primary Cohort Maralixibat

8.0
Number of responders

Primary Cohort Placebo

4.0
Number of responders

Proportion of sBA Responders in the Primary Cohort

Proportion of sBA responders from Week 18 to Week 26 in participants with PFIC2, using the average value from Weeks 18, 22 and 26 values. The number in the Subject Analysis Set refers to the number of responders. sBA responders are defined as a subject having an average sBA level of <102 umol/L (applies only if baseline sBA level was ≥102 umol/L), OR a ≤-75% average percent change from baseline.

Primary Cohort Maralixibat

5.0
Number of responders

Primary Cohort Placebo

1.0
Number of responders

Proportion of ItchRO(Obs) Responders PFIC (PFIC1, PFIC2, PFIC3, PFIC4 and PFIC6)

Proportion of ItchRO(Obs) responders from Week 15 to Week 26 in participants with PFIC (PFIC1, PFIC2, PFIC3, PFIC4 and PFIC6). The number in the Subject Analysis Set refers to the number of responders. ItchRO responders are defined as a subject having a 4-week average morning ItchRO(Obs) severity change from baseline of ≤-1.0 OR an average severity score of ≤1.0.

PFIC Cohort Maralixibat

21.0
Number of responders

PFIC Cohort Placebo

8.0
Number of responders

Proportion of sBA Responders PFIC (PFIC1, PFIC2, PFIC3, PFIC4 and PFIC6)

Proportion of sBA responders from Week 18 to Week 26 in participants with PFIC (PFIC1, PFIC2, PFIC3, PFIC4 and PFIC6). The number in the Subject Analysis Set refers to the number of responders. sBA responders are defined as a subject having an average sBA level of <102 umol/L (applies only if baseline sBA level was ≥102 umol/L), or a ≤-75% average percent change from baseline.

PFIC Cohort Maralixibat

15.0
Number of responders

PFIC Cohort Placebo

2.0
Number of responders

Total

93
Participants

Age, Categorical

Age, Categorical

Age, Categorical

Age, Continuous

Age, Continuous

Ethnicity (NIH/OMB)

Ethnicity (NIH/OMB)

Ethnicity (NIH/OMB)

Race (NIH/OMB)

Race (NIH/OMB)

Race (NIH/OMB)

Region of Enrollment

Sex: Female, Male

Sex: Female, Male

Sex: Female, Male

Overall Study

Maralixibat

Placebo