Mirum Pharmaceuticals raises $120m to advance Maralixibat for rare liver diseases

Mirum Pharmaceuticals, a clinical-stage pharmaceutical company, has successfully raised $120 million in a Series A funding round to propel the development of its lead drug, Maralixibat, aimed at treating rare cholestatic liver diseases. The round was spearheaded by New Enterprise Associates (NEA) and saw participation from other notable investors including Deerfield Management, Frazier Healthcare Partners, Novo Holdings, Rock Springs Capital, Pappas Capital, and RiverVest Venture Partners.

In conjunction with this funding, Mirum Pharmaceuticals has signed an agreement with Shire to acquire exclusive global rights for the development and commercialization of Maralixibat. Under the terms of the deal, Shire will receive an upfront payment, an equity stake in Mirum, and potential future milestone payments and royalties.

Maralixibat, an oral inhibitor of the apical sodium-dependent bile acid transporter (ASBT), is being developed to address Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC). The drug aims to prevent the accumulation of excess bile acids and control severe itching associated with these cholestatic liver diseases. Mirum Pharmaceuticals is positioning Maralixibat as a potential first-in-class oral treatment for these conditions, pending regulatory approvals.

Ed Mathers, a partner at New Enterprise Associates, emphasized the significance of the investment: “The substantial investment we have made in Mirum and the outstanding syndicate of savvy biotech investors underscores the value we ascribe to Maralixibat, as well as our confidence in the company’s management team to execute on an aggressive development plan.”

The company plans to focus initially on pediatric indications for Maralixibat. However, there is potential for the ASBT inhibitor to be explored for additional pediatric and adult cholestatic liver disease indications. To date, Maralixibat has been tested on over 230 cholestatic patients, providing a comprehensive safety data set.

A Phase 2b trial, named ICONIC, demonstrated favorable interim results for Maralixibat in ALGS patients. According to Mike Grey, Chairman and CEO of Mirum Pharmaceuticals, “The interim data from the Phase 2b ICONIC study underscores my continued confidence in Maralixibat and its potential to help patients with these severely debilitating liver diseases.”

In addition to Maralixibat, Mirum Pharmaceuticals has acquired global rights from Shire for another ASBT inhibitor, volixibat, further expanding its portfolio in cholestatic liver disease treatments.