Is Mirum Pharmaceuticals About to Soar in 2026?

Mirum Pharmaceuticals' (NASDAQ: MIRM) share price has more than doubled over the last 12 months. Is this biotech stock about to soar again in 2026? I think so – for two key reasons.

At an inflection point

In several important ways, Mirum is at an inflection point. It achieved positive cash flow from operations in 2025. That's a significant milestone for any small biotech company.

Mirum won two approvals from the U.S. Food and Drug Administration (FDA) last year. In February, the agency gave Ctexli a thumbs-up for the treatment of cerebrotendinous xanthomatosis (CTX), a rare genetic disorder of bile acid synthesis. The FDA also approved a tablet formulation of Livmarli in April for the treatment of cholestatic pruritus in patients with Alagille syndrome (ALGS) and Progressive Familial Intrahepatic Cholestasis (PFIC), both rare liver diseases.

On Jan. 26, 2026, Mirum completed the acquisition of Bluejay Therapeutics. This transaction adds brelovitug to Mirum's pipeline. Brelovitug is a promising therapy targeting chronic hepatitis delta virus (HDV), a rare liver disease with no approved treatment in the U.S.

Net product sales for Livmarli jumped 69% year over year in 2025 to $359 million. Sales for bile acid replacement therapies Cholbam and Ctexli increased 31% year over year to $161 million. Mirum also expects solid momentum this year, with overall revenue guidance of $630 million to $650 million.

Multiple potential catalysts ahead

2026 should also be loaded with catalysts for Mirum. The most important one, in my view, is the company's anticipated announcement in the second quarter of results from a Phase 2B clinical study evaluating volixibat for the treatment of primary sclerosing cholangitis (PSC). Mirum hopes to use these results to file for accelerated approval of the drug in the second half of 2026.

Volixibat holds the potential to be a blockbuster drug if approved. There are currently no approved therapies in the U.S. for PSC. Mirum is also evaluating volixibat in another clinical study targeting primary biliary cholangitis (PBC), the most prevalent type of cholestatic liver disease. Enrollment in this PBC study is expected to be completed in the second half of 2026.

Image source: Getty Images.

Results from a Phase 3 study of brelovitug in the treatment of HDV are also expected in the second half of the year. If the data are positive, Mirum could file for approval of the drug acquired from Bluejay in early 2027.

If that's not enough for you, Mirum has accelerated the timing of its Phase 3 study of Livmarli in the treatment of pruritus in rare cholestatic conditions. The company now expects to complete enrollment in this study in the first half of 2026 and report topline data before the end of the year.

Will Mirum's stock continue to soar in 2026? The odds look pretty good to me.

Keith Speights has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Mirum Pharmaceuticals. The Motley Fool has a disclosure policy.