Mirum Pharmaceuticals Raises $75 Million in Public Offering

Rare Daily Staff

Mirum Pharmaceuticals raised $75 million in a public offering to advance development of its pipeline of late-stage experimental therapies for rare liver diseases, selling 3.75 million shares of its common stock at $20 per share.

In addition, Mirum has granted the underwriters a 30-day option to purchase up to an additional 562,500 shares of common stock at the public offering price less underwriting discounts and commissions.

The offering comes one week after Mirum struck a development-based funding agreement with Oberland Capital Management that provides the company with $60 million upfront in cash and an equity investment, and up to another $150 million in development milestones that will be repaid based on revenues of maralixibat, Mirum’s lead experimental candidate in development for Alagille syndrome (ALGS), progressive familial intrahepatic cholestasis (PFIC), and biliary atresia.

ALGS is a rare, genetic disorder in which bile ducts are abnormally narrow, malformed, and reduced in number, leading to bile accumulation in the liver and ultimately progressive liver disease. The accumulation of bile acids prevents the liver from working properly to eliminate waste from the bloodstream and leads to progressive liver disease that may require liver transplantation. The severe itching, known as pruritus, that is experienced by patients with ALGS is among the most severe in any chronic liver disease and is present in most affected children by the third year of life.

Maralixibat is a novel, minimally absorbed, orally administered experimental drug being evaluated in several cholestatic liver diseases. Maralixibat inhibits the apical sodium-dependent bile acid transporter, resulting in more bile acids being excreted in the feces, leading to lower levels of bile acids systemically, thereby potentially reducing bile acid mediated liver damage and related effects and complications.

Mirum is currently submitting a rolling NDA to the FDA for maralixibat for the treatment of cholestatic pruritus in patients with ALGS, which it expects to complete in the first quarter of 2021, with launch planned in the second half of 2021. Mirum has also submitted a marketing authorization application to the European Medicines Agency (EMA) for maralixibat for the treatment of patients with progressive familial intrahepatic cholestasis type 2 (PFIC2), or bile salt export pump (BSEP) deficiency. The MAA was recently validated by the EMA and Mirum is preparing for launch in the European Union in the first quarter of 2022.