Company Description
Mirum Pharmaceuticals, Inc. (NASDAQ: MIRM) is a biopharmaceutical and rare disease company focused on the identification, acquisition, development and commercialization of novel therapies for debilitating rare and orphan diseases. The company is described in its public communications as a rare disease specialist with a global footprint of approved products and a broad pipeline of investigational medicines, with particular depth in rare liver diseases and select neurodevelopmental conditions.
Core business focus
Mirum’s business centers on developing and commercializing medicines for rare diseases affecting children and adults. According to company disclosures, it is purpose-built to bring forward breakthrough medicines for people with overlooked conditions, combining scientific expertise with connections to rare disease communities. Its activities span late-stage clinical development, regulatory approvals and commercial launch of therapies in narrowly defined patient populations.
Commercial portfolio
Mirum reports three approved medications in its commercial portfolio:
- LIVMARLI (maralixibat) oral solution and tablets, an ileal bile acid transporter (IBAT) inhibitor. LIVMARLI is approved for the treatment of cholestatic pruritus in patients with Alagille syndrome (ALGS) in the United States and Europe at specified pediatric age ranges, and for cholestatic pruritus in patients with progressive familial intrahepatic cholestasis (PFIC) in both the United States and Europe, also with defined age ranges. Company communications state that LIVMARLI has received Breakthrough Therapy designation for ALGS and PFIC type 2 and orphan designation for ALGS and PFIC, and is being evaluated in the Phase 3 EXPAND study in additional settings of cholestatic pruritus.
- CHOLBAM (cholic acid) capsules, a bile acid indicated for treatment of bile acid synthesis disorders due to single enzyme defects and as adjunctive treatment of peroxisomal disorders, including Zellweger spectrum disorders, in patients who exhibit manifestations of liver disease, steatorrhea, or complications from decreased fat-soluble vitamin absorption. It is described as the first FDA-approved treatment for bile acid synthesis disorders due to single enzyme defects and for specified peroxisomal disorders.
- CTEXLI (chenodiol) tablets, FDA-approved for the treatment of adults with cerebrotendinous xanthomatosis (CTX), a rare progressive disease that can affect the brain, spinal cord, tendons, eyes and arteries. Company materials note that CTEXLI was evaluated in the Phase 3 RESTORE study, characterized as the first clinical trial for CTX.
Clinical-stage pipeline
Mirum also discloses a clinical-stage pipeline targeting additional rare liver and neurological conditions:
- Volixibat, an oral, minimally absorbed IBAT inhibitor designed to selectively inhibit the ileal bile acid transporter. It is being evaluated in Phase 2b studies for primary sclerosing cholangitis (PSC) in the VISTAS study and for primary biliary cholangitis (PBC) in the VANTAGE study. Company communications state that volixibat has been granted Breakthrough Therapy designation for the treatment of cholestatic pruritus in patients with PBC and may offer a novel approach in adult cholestatic diseases by reducing bile acids systemically and in the liver.
- Brelovitug, an investigational, highly potent, pan-genotypic, fully human IgG1 monoclonal antibody targeting the surface antigen on hepatitis D and hepatitis B viruses. Mirum has entered into a definitive agreement to acquire Bluejay Therapeutics, which would add worldwide rights to brelovitug for chronic hepatitis delta virus (HDV), subject to completion of the proposed acquisition. Company disclosures describe brelovitug as having FDA Breakthrough Therapy designation for HDV and PRIME and orphan designations from the European Medicines Agency, and being evaluated in the AZURE Phase 3 program for HDV.
- MRM-3379, an in-licensed, orally available, selective phosphodiesterase-4D (PDE4D) inhibitor being evaluated for Fragile X syndrome (FXS), a rare genetic neurocognitive and neurodevelopmental disorder. Mirum has initiated the BLOOM Phase 2 clinical study to assess safety, tolerability and potential clinical benefit in males with a confirmed genetic diagnosis of FXS, with endpoints that include cognition and behavioral measures.
Therapeutic areas and disease focus
Across its portfolio, Mirum concentrates on rare liver diseases and select neurological conditions. Its approved and investigational products target conditions such as:
- Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC), where cholestatic pruritus is a key symptom addressed by LIVMARLI.
- Bile acid synthesis disorders due to single enzyme defects and peroxisomal disorders, treated with CHOLBAM.
- Cerebrotendinous xanthomatosis (CTX), treated with CTEXLI.
- Primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), investigated indications for volixibat.
- Chronic hepatitis delta virus (HDV), the focus of brelovitug in the AZURE Phase 3 program, subject to closing of the Bluejay acquisition.
- Fragile X syndrome (FXS), the focus of MRM-3379 in the BLOOM Phase 2 study.
Regulatory designations and development stage
Mirum’s disclosures highlight several regulatory designations associated with its programs. LIVMARLI has Breakthrough Therapy and orphan designations in specified ALGS and PFIC settings. Volixibat has Breakthrough Therapy designation for cholestatic pruritus in PBC. Brelovitug has FDA Breakthrough Therapy designation for HDV and PRIME and orphan designations from the European Medicines Agency. These designations reflect interactions with regulators for rare and serious diseases, as described in company press releases.
Corporate and capital markets profile
Mirum Pharmaceuticals, Inc. is listed on the Nasdaq Global Market under the trading symbol MIRM. The company has used equity financing and private placements to support clinical development and commercial activities, including subscription agreements with institutional investors and a planned private placement in connection with the proposed acquisition of Bluejay Therapeutics, as detailed in its press releases and Form 8-K filings. An 8-K filing also describes an Agreement and Plan of Merger and Reorganization under which Bluejay Therapeutics would become a wholly owned subsidiary of Mirum, subject to customary closing conditions.
Geographic and operational footprint
Company communications describe Mirum as having a global footprint of approved products, including LIVMARLI approvals in the United States, Europe and other regions, and CHOLBAM and CTEXLI approvals in the United States. Mirum reports commercial access for its products in multiple countries and ongoing global clinical programs, such as the AZURE Phase 3 program for brelovitug and multicountry trials for volixibat.
Research and development approach
Mirum’s disclosures emphasize late-stage development in rare and orphan indications, focusing on mechanisms such as IBAT inhibition in cholestatic liver disease and PDE4D inhibition in Fragile X syndrome. The company describes its success as driven by teams dedicated to advancing high impact medicines through strategic development, disciplined execution and collaboration across the rare disease ecosystem. It also notes that it may evaluate strategic options for additional investigational programs acquired through transactions, such as those associated with Bluejay Therapeutics.
Position within biotechnology and rare disease
Within the biotechnology and rare disease segment, Mirum is characterized in its own materials as a leading rare disease company, with emphasis on rare liver diseases and neurodevelopmental disorders. Its combination of marketed products, late-stage liver programs and a neurocognitive pipeline candidate positions it within the research and development segment of biotechnology and the broader professional, scientific and technical services sector.
Frequently asked questions about Mirum Pharmaceuticals (MIRM)
- What does Mirum Pharmaceuticals do?
Mirum Pharmaceuticals is a biopharmaceutical company focused on the identification, acquisition, development and commercialization of novel therapies for debilitating rare and orphan diseases, with an emphasis on rare liver and neurodevelopmental conditions.
- Which products are currently approved in Mirum’s portfolio?
According to company communications, Mirum has three approved medications: LIVMARLI (maralixibat) oral solution and tablets, CHOLBAM (cholic acid) capsules, and CTEXLI (chenodiol) tablets, each indicated for specific rare liver-related or metabolic conditions.
- What rare diseases does LIVMARLI treat?
LIVMARLI is an IBAT inhibitor approved for the treatment of cholestatic pruritus in patients with Alagille syndrome (ALGS) and in patients with progressive familial intrahepatic cholestasis (PFIC), within defined pediatric age ranges in the United States and Europe, as described in Mirum’s product information.
- What is volixibat and what conditions is it being studied for?
Volixibat is an oral, minimally absorbed IBAT inhibitor designed to selectively inhibit the ileal bile acid transporter. Mirum reports that it is being evaluated in Phase 2b studies for primary sclerosing cholangitis (PSC) in the VISTAS study and primary biliary cholangitis (PBC) in the VANTAGE study.
- Who are the target patients for CHOLBAM?
CHOLBAM (cholic acid) capsules are FDA-approved for treatment of bile acid synthesis disorders due to single enzyme defects and as adjunctive treatment of peroxisomal disorders, including Zellweger spectrum disorders, in patients who show manifestations of liver disease, steatorrhea, or complications from decreased fat-soluble vitamin absorption.
- What is CTEXLI used for?
CTEXLI (chenodiol) tablets are FDA-approved for the treatment of adults with cerebrotendinous xanthomatosis (CTX), a rare progressive disease that can affect multiple organ systems, as described in Mirum’s product information.
- What is MRM-3379 and how is it being evaluated?
MRM-3379 is an in-licensed investigational oral therapy and selective PDE4D inhibitor being evaluated for Fragile X syndrome (FXS). Mirum has initiated the BLOOM Phase 2 clinical study, which will assess safety, tolerability and potential effects on cognition and behavior in males with a confirmed genetic diagnosis of FXS.
- What is brelovitug and how is Mirum involved?
Brelovitug is an investigational fully human monoclonal antibody targeting the surface antigen on hepatitis D and B viruses. Mirum has entered into a definitive agreement to acquire Bluejay Therapeutics, which would add worldwide rights to brelovitug for chronic hepatitis delta virus (HDV), subject to completion of the acquisition, as described in Mirum’s press releases and 8-K filing.
- On which exchange does Mirum Pharmaceuticals trade and what is its ticker?
Mirum Pharmaceuticals’ common stock is listed on the Nasdaq Global Market under the ticker symbol MIRM, as reported in its Form 8-K filing.
- How does Mirum describe its role in the rare disease space?
In its public communications, Mirum describes itself as a leading rare disease company with a global footprint of approved products and a broad pipeline of investigational medicines, focused on bringing breakthrough medicines to people with overlooked conditions.
Stock Performance
Mirum Pharmaceuticals (MIRM) stock last traded at $89.43, up 0.98% from the previous close. Over the past 12 months, the stock has gained 90.2%. At a market capitalization of $5.3B, MIRM is classified as a mid-cap stock with approximately 60.3M shares outstanding.
Latest News
Mirum Pharmaceuticals has 10 recent news articles, with the latest published 7 days ago. Of the recent coverage, 5 articles coincided with positive price movement and 5 with negative movement. Key topics include clinical trial, conferences, earnings date, acquisition. View all MIRM news →
SEC Filings
Mirum Pharmaceuticals has filed 5 recent SEC filings, including 5 Form 4. The most recent filing was submitted on March 17, 2026. SEC filings provide transparency into a company's financial condition, material events, and regulatory compliance. View all MIRM SEC filings →
Insider Radar
Insider buying activity at Mirum Pharmaceuticals over the past 90 days may reflect management confidence in the company's direction. Institutional investors and analysts often monitor insider purchases as a potential bullish indicator for the stock.
Financial Highlights
Mirum Pharmaceuticals generated $521.3M in revenue over the trailing twelve months, operating income reached -$22.1M (-4.3% operating margin), and net income was -$23.4M, reflecting a -4.5% net profit margin. Diluted earnings per share stood at $-0.47. The company generated $55.8M in operating cash flow. With a current ratio of 2.67, the balance sheet reflects a strong liquidity position.
Upcoming Events
VISTAS topline data
VISTAS PSC topline readout
VISTAS topline readout
VISTAS study topline results
Proposed Bluejay acquisition
AZURE HDV data release
Phase 3 topline readout
Topline 24-week results
AZURE HDV readouts
AZURE Phase 3 top-line data
Mirum Pharmaceuticals has 31 upcoming scheduled events. The next event, "VISTAS topline data", is scheduled for April 1, 2026 (in 8 days). 2 of the upcoming events are financial in nature, such as earnings calls or quarterly results. Investors can track these dates to stay informed about potential catalysts that may affect the MIRM stock price.
Short Interest History
Short interest in Mirum Pharmaceuticals (MIRM) currently stands at 7.8 million shares, up 2.7% from the previous reporting period, representing 15.3% of the float. Over the past 12 months, short interest has increased by 18.5%. This moderate level of short interest indicates notable bearish positioning. The 9.6 days to cover indicates moderate liquidity for short covering.
Days to Cover History
Days to cover for Mirum Pharmaceuticals (MIRM) currently stands at 9.6 days, up 12.9% from the previous period. This moderate days-to-cover ratio suggests reasonable liquidity for short covering, requiring about a week of average trading volume. The days to cover has decreased 36.4% over the past year, suggesting improved liquidity for short covering. The ratio has shown significant volatility over the period, ranging from 7.3 to 21.5 days.
MIRM Company Profile & Sector Positioning
Mirum Pharmaceuticals (MIRM) operates in the Biotechnology industry within the broader Pharmaceutical Preparations sector and is listed on the NASDAQ.
Investors comparing MIRM often look at related companies in the same sector, including Protagonist Ther (PTGX), Ascentage Pharma Group International (AAPG), Krystal Biotech (KRYS), Metsera (MTSR), and Zai Lab Limited (ZLAB). Comparing financial metrics, valuation ratios, and stock performance across these peers can help investors evaluate MIRM's relative position within its industry.