Mirum Pharmaceuticals Reports Second Quarter 2026 Financial Results and Provides Business Update
Mirum Pharmaceuticals, Inc. a leading rare disease company, reported financial results for the second quarter 2026 and provided a business update. Mirum delivered another strong quarter, with continued commercial momentum supporting an increase to our full-year net product sales guidance and launch readiness for the upcoming potential approval of zilurgisertib,” said Chris Peetz, Chief Executive Officer of Mirum.
The FDA’s decision to grant volixibat Breakthrough Therapy and Orphan Drug Designations underscores the strength of the VISTAS efficacy data and the serious unmet need in PSC. VISTAS was designed with FDA input as a pivotal study and met its primary endpoint with highly significant results. However, at our recent pre-NDA meeting, the agency recommended conducting a Phase 3 study. We intend to hold further discussions with the FDA before a potential NDA submission in the first half of 2027 based on VISTAS.
Q2 and Recent Highlights
Commercial: Raising Full Year Net Product Sales Guidance to $680 Million to $700 Million
- Second quarter 2026 global net product sales of $176.2 million.
- Second quarter 2026 LIVMARLI® net product sales were $128.7 million, representing 46% growth over second quarter 2025 net product sales.
- Second quarter 2026 Bile Acid Medicines net product sales were $47.5 million, representing 20% growth over second quarter 2025 net product sales.
Regulatory and Pipeline: Advancing Toward Multiple Milestones
- U.S. FDA granted volixibat Breakthrough Therapy Designation for the treatment of cholestatic pruritus due to primary sclerosing cholangitis (PSC) and Orphan Drug Designation for PSC.
- Participated in pre-NDA meeting with U.S. FDA for volixibat in cholestatic pruritus due to PSC; planning additional discussions with the FDA before potential NDA submission, now targeted in H1 2027.
- Brelovitug AZURE-1 and AZURE-4 Phase 3 studies in chronic hepatitis delta virus (HDV) topline results expected in Q3 and Q4 2026, respectively.
- LIVMARLI EXPAND Phase 3 study in cholestatic pruritus due to additional rare cholestatic conditions topline results expected in Q4 2026.
- Completed enrollment in the volixibat VANTAGE Phase 2b study in cholestatic pruritus due to primary biliary cholangitis (PBC); topline results expected in Q1 2027.
- Presented positive pivotal Phase 2 results from the PROGRESS study of zilurgisertib in fibrodysplasia ossificans progressiva (FOP) at ENDO 2026; Prescription Drug User Fee Act (PDUFA) target action date for the zilurgisertib NDA is September 26, 2026.
Corporate & Financial: Strong Balance Sheet and Financial Independence
- Total revenue for the quarter ended June 30, 2026 was $176.2 million compared to $127.8 million for the quarter ended June 30, 2025.
- Total operating expenses were $218.8 million for the quarter ended June 30, 2026 compared to $132.8 million for the quarter ended June 30, 2025. Total operating expenses for the quarter ended June 30, 2026 included:
- Cost of sales of $23.2 million, excluding intangible amortization and stock-based compensation expense.
- Non-recurring acquired in-process research and development (IPR&D) expense associated with the exclusive license of worldwide rights to zilurgisertib of $16.4 million.
- Research and development expense of $76.3 million, including $28.8 million for the development of brelovitug, excluding stock-based compensation expense.
- Selling, general, and administrative expense of $65.6 million, excluding stock-based compensation expense.
- $37.3 million of stock-based compensation, intangible amortization, and other non-cash expenses.
- Issued $690.0 million aggregate principal amount of 0.00% convertible senior notes due 2032.
- Settled $237.2 million aggregate principal amount of 4.00% convertible senior notes due 2029, which represented approximately 75% of the then-outstanding notes.
- As of June 30, 2026, Mirum had unrestricted cash, cash equivalents, and investments of $561.3 million compared to $391.4 million as of December 31, 2025.
About LIVMARLI® (maralixibat) oral solution and LIVMARLI® (maralixibat) tablets
LIVMARLI® (maralixibat) is an orally administered, ileal bile acid transporter (IBAT) inhibitor approved by the U.S. Food and Drug Administration for two pediatric cholestatic liver diseases. It is approved for the treatment of cholestatic pruritus in patients with Alagille syndrome (ALGS) in the U.S. three months of age and older and in Europe for patients two months of age and older. It is also approved in the U.S. for the treatment of cholestatic pruritus in patients with progressive familial intrahepatic cholestasis (PFIC) 12 months of age and older and in Europe for the treatment of PFIC in patients three months of age and older.
About Volixibat
Volixibat is an investigational oral, minimally absorbed agent designed to selectively inhibit the ileal bile acid transporter (IBAT). Volixibat may offer a novel approach in the treatment of adult cholestatic diseases by blocking the recycling of bile acids through inhibition of IBAT, thereby reducing bile acids systemically and in the liver. Volixibat is currently being evaluated in Phase 2b studies for primary sclerosing cholangitis (PSC) (VISTAS study), and primary biliary cholangitis (PBC) (VANTAGE study).
In 2026, Mirum shared that the Phase 2b VISTAS study of volixibat in PSC met its primary endpoint, with statistically significant and clinically meaningful reductions in pruritus observed in patients treated with volixibat. Volixibat’s safety profile in the study was generally consistent with the known effects of IBAT inhibition. Volixibat has been granted FDA Breakthrough Therapy designation for the treatment of cholestatic pruritus due to PSC.
In 2024, Mirum announced positive interim results from the Phase 2b VANTAGE study of volixibat in PBC. No new safety signals were observed in the study. Volixibat has been granted FDA Breakthrough Therapy designation for the treatment of cholestatic pruritus due to PBC.
About Brelovitug
Brelovitug is an investigational, highly potent, pan-genotypic, fully human immunoglobulin G1 (IgG1) monoclonal antibody (mAb) that targets the surface antigen (anti-HBsAg) on both the hepatitis delta virus (HDV) and the hepatitis B virus (HBV). Brelovitug is designed to neutralize and remove hepatitis B and hepatitis D virions and deplete HBsAg-containing subviral particles. Brelovitug has FDA Breakthrough Therapy designation for the treatment of chronic HDV infection and PRIME and Orphan designations from the European Medicines Agency.
In 2026, Mirum announced that in the Phase 2b portion of the AZURE-1 study in HDV, treatment with brelovitug demonstrated strong antiviral activity in HDV and achieved the primary composite endpoint of virologic response and alanine aminotransferase (ALT) normalization at Week 24 in both brelovitug dose arms as compared to the delayed treatment arm. Favorable safety and tolerability profiles were observed. Brelovitug is currently being evaluated in the global Phase 3 AZURE clinical program. Mirum owns worldwide rights to brelovitug.
About Zilurgisertib
Zilurgisertib is an investigational, oral, small molecule, activin receptor-like kinase 2 (ALK2) inhibitor in development for the treatment of Fibrodysplasia Ossificans Progressiva (FOP). Zilurgisertib is designed to inhibit the ALK2 receptor, which is abnormally active in most patients with FOP and leads to bone formation in soft tissues, a process known as heterotopic ossification (HO). FOP is an ultra-rare genetic disease that affects approximately 300 patients in the U.S. and 900 worldwide, with diagnosis typically occurring in early childhood.
Zilurgisertib was evaluated in the PROGRESS pivotal Phase 2 study, which formed the basis of a new drug application (NDA). The FDA has accepted the NDA for zilurgisertib in FOP under Priority Review with a Prescription Drug User Fee Act (PDUFA) date of September 26, 2026.
Mirum Pharmaceuticals, Inc. licensed zilurgisertib from Incyte for worldwide development and commercialization.
About MRM-3379
MRM-3379 is an in-licensed investigational oral therapy being evaluated for the treatment of Fragile X syndrome (FXS). It is a selective phosphodiesterase-4D (PDE4D) inhibitor designed to enhance cAMP signaling. MRM-3379 may offer a novel approach to improving cognition, language, and daily function in individuals with FXS. MRM-3379 has been granted FDA Fast Track designation for the treatment of FXS.
The BLOOM Phase 2 clinical study of MRM-3379 is currently underway in FXS. Males ages 16 to 45 will be randomly assigned to receive one of three dose levels of MRM-3379 or placebo for 12 weeks. An open-label cohort of boys ages 13 to 16 will receive the lowest dose, in order to explore effects of treatment in younger boys, closer to the age of diagnosis. The study’s primary endpoint is safety and tolerability, the key secondary endpoint is the NIH Toolbox Crystallized Cognition Composite (CCC), and several exploratory endpoints will assess potential effects on mood, behavior, and other symptoms that are relevant to this population. Mirum owns worldwide rights to MRM-3379.
About Mirum Pharmaceuticals
Mirum Pharmaceuticals is a leading rare disease company with a global footprint of approved products and a broad pipeline of investigational medicines. Purpose-built to bring forward breakthrough medicines for people with overlooked conditions, Mirum focuses on rare liver and rare genetic diseases, where it has built deep expertise and strong connections to patient communities. The company’s commercial portfolio includes LIVMARLI® (maralixibat) for Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC), CHOLBAM® (cholic acid) for bile-acid synthesis disorders, and CTEXLI® (chenodiol) for cerebrotendinous xanthomatosis (CTX).
Mirum’s clinical-stage pipeline includes volixibat, an IBAT inhibitor in late-stage development for primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), brelovitug, a fully human monoclonal antibody in late-stage development for chronic hepatitis delta virus (HDV), zilurgisertib, an ALK2 inhibitor under regulatory review with the FDA for fibrodysplasia ossificans progressiva (FOP), and MRM-3379, a PDE4D inhibitor being evaluated for Fragile X syndrome (FXS).
