Mirum Announces Publication of Phase 3 MARCH Data in The Lancet Demonstrating Benefits of LIVMARLI (maralixibat) in patients with PFIC

Mirum Pharmaceuticals, Inc. (Nasdaq: MIRM) today announced that data from the Phase 3 MARCH-PFIC study evaluating LIVMARLI (maralixibat) oral solution in patients with PFIC was published in The Lancet Gastroenterology and Hepatology.

The MARCH-PFIC study was the largest, randomized, double-blind, placebo-controlled study in patients with PFIC, confirming the efficacy and safety of LIVMARLI, an IBAT inhibitor, across a broad genetic range of PFIC types. The main efficacy analyses were performed in two groups which included the BSEP deficiency (BSEP or PFIC2) cohort and the All-PFIC cohort which included patients with BSEP (PFIC2), FIC1 (PFIC1), MDR3 (PFIC3), TJP2 (PFIC4), or MYO5B deficiencies.

The study met both the primary efficacy endpoint (mean change in pruritus severity score between baseline and the last 12 weeks of treatment [weeks 15-26]) and the key secondary endpoint (mean change in total serum bile acid concentration between baseline and the average of weeks 18, 22, and 26) with statistically significant and clinically meaningful improvements observed by Week 2 and sustained throughout the 26-week study in LIVMARLI-treated participants in both the BSEP and All-PFIC cohorts. Improvements in bilirubin concentrations, growth, and sleep disturbances with LIVMARLI versus placebo were also observed. There were no new safety signals for LIVMARLI throughout the treatment periods with the most common adverse event being diarrhea, which was mostly mild and transient.

The Phase 3 MARCH study presents the largest and most comprehensive dataset demonstrating the therapeutic benefit of an IBAT inhibitor across a broad range of PFIC types, including some which have not been previously studied. In addition to the clinical benefits observed, LIVMARLI significantly improved serum bile acids and bilirubin which are both known to be predictive of transplant-free survival. LIVMARLI represents a non-surgical, pharmacological option to improve outcomes for patients with PFIC.

“These data advance our understanding of LIVMARLI’s potential to provide meaningful improvements in pruritus and a number of parameters impacting patients with various PFIC types. The clinically meaningful reductions in serum bile acid and bilirubin levels also signify the potential for improvements in native liver survival in PFIC, a step forward in considering the long-term care and health of patients with PFIC,” said Dr. Alexander Miethke, Cincinnati Children’s Hospital and lead author on the publication. “LIVMARLI presents a new non-surgical treatment option in PFIC with strong efficacy data and safety demonstrated across a range of PFIC types, which is important for patients with PFIC types previously unstudied.”