FDA Approves Mirum's Livmarli For Liver Disease In Kids As Young As 5 Years: Analyst Bullish On Label Expansion Strategy

Wednesday, The FDA approved Mirum Pharmaceuticals Inc’s MIRM Livmarli (maralixibat) oral solution for cholestatic pruritus in patients five years of age and older with progressive familial intrahepatic cholestasis (PFIC). 

In people with PFIC, liver cells are less able to secrete bile, and the buildup of bile in liver cells causes liver disease.

The approval is based on data from the Phase 3 MARCH study, the largest randomized trial conducted in PFIC, with 93 patients across various genetic PFIC types.

Mirum has also submitted an additional supplemental new drug application to introduce a higher concentration formulation of Livmarli, used during the MARCH study, to enable label expansion for younger patients with PFIC later this year.

HC Wainwright rights after discussion with management, the company expects 2024 to be primarily focused on broad payor coverage, with about 20 patients currently on Livmarli in the ongoing Phase 3 open-label extension study, MARCH-ON, expected to rollover onto commercial drug by YE 2024. 

Hence, the analysts have increased the price target from $45 to $58 and reaffirmed Buy.

The analyst is surprised by the label’s age restriction of ≥5 years old for PFIC (Mirum applied for ≥3 months of age), given that the MARCH study enrolled patients ≥12 months old, and the Albireo Pharma Inc’s Bylvay (Odevixibat) label is indicated for PFIC patients ≥3 months old.

HC Wainwright notes the FDA’s worries regarding the potential inability of children, particularly those under the age of 5, to process certain additives in the current medication formulation fully.

Despite the current label indicating suitability for children aged ≥3 months, there are concerns about metabolization. 

However, a new formulation containing reduced levels of these additives is proposed. 

The analyst anticipates that submitting this new Supplemental New Drug Application will undergo a brief procedural delay. 

Given that the primary approval risk hinges on the Chemistry, Manufacturing, and Controls analytics review, this label expansion will likely be approved once optimal reimbursement arrangements with payors are established.

Price Action: MIRM shares are 1.55% at $28.20 on the last check Thursday.