Mirum Pharmaceuticals Reports Third Quarter 2026 Financial Results and Provides Business Update - MIRUM PHARMACEUTICALS INC

Explicit Guidance:

• Full-year 2026 net product sales guidance increased to $715–$720 million (previously lower; driven by strong performance in Q1–Q3).
• Q4 2026 revenue expected to maintain a sequential cadence of $10–$15 million quarter-over-quarter growth.
• 2027 revenue growth trajectory expected to continue the Q1–Q3 cadence of $10–$15 million sequential increases.
• Cash contribution margin for the commercial business remained in the high 50% of sales in Q3 2026.
• R&D expenses are expected to remain at approximately 50% of revenues for the next two quarters (Q4 2026 and Q1 2027), after which R&D spending is projected to decrease rapidly as late-stage trials conclude.
• The company projects to be cash flow positive in 2027 following the launch of new products and continued commercial scale.
• Peak revenue potential for the total portfolio is estimated at greater than $4 billion.
• Specific segment peak revenue outlooks include greater than $1 billion for the HDV (Brilovotug) program.

Business-Segment Outlook:

• Livmarly:
  • Primary growth driver; Q3 2026 sales of $133 million.
  • Growth supported by steady uptake in Alagile Syndrome (now termed Allergy Health Syndrome in transcript) and increasing diagnoses in PFIC (Progressive Familial Intrahepatic Cholestasis), specifically adults.
  • Addressable adult PFIC patient population in the US estimated at at least 2,000; management believes the majority remain undiagnosed.
  • Expansion of commercial efforts to improve PFIC diagnosis rates to lay foundation for 2027 growth.
  • Supplemental New Drug Application (sNDA) expected for Etebrios (Etebrios) expansion into pediatric FOP patients ages 6–<12.
• Etebrios (Etebrios):
  • Approved in September 2026 for adults and pediatric FOP patients (12+); U.S. launch commenced in October 2026.
  • Expected adoption curve projected to be faster than Livmarly due to higher receptivity and established diagnostic pathways.
  • Near-term focus on patient identification, access, and strong early engagement with caregivers and physicians.
• Pipeline & Regulatory Submissions (Expected in H1 2027):
  • NDA Submission (Velixibat): For Primary Sclerosing Cholangitis (PSC) and Pruritus in cholestatic liver disease.
  • NDA Submission (Velixibat): For PSC and Pruritus (specific mention of PDC in transcript, likely a transcription error for PSC).
  • BLA Submission (Brilovotug): For Hepatitis Delta Virus (HDV).
  • BLA Submission (Brilovotug): For Biliary Atresia.
  • sNDA Submission (Etebrios): For expansion to children ages 6–<12 with FOP.
  • sNDA Submission (Livmarly): Based on EXPAND study data for new indications.
• Clinical Readouts:
  • Gorlovotug (Brilovotug) - HDV: "Azure 4" Phase 3 readout expected this quarter (Q4 2026) to support BLA.
  • Blitzabat (Velixibat) - PBC: "Vantage" study readout expected Q1 2027.

Market and Competitive Outlook:

• HDV Market:
  • Current diagnostic rates are extremely low (single-digit percentages of Hepatitis B patients tested for Delta).
  • Management anticipates increased testing rates driven by the availability of effective therapies and disease state education efforts.
  • Market size potential: 15,000 diagnosed patients in the US currently under management; significant international expansion opportunities for Brilovotug.
• PSC/PBC Market:
  • PSC: Addressable US population estimated at 20,000 patients with pruritus; management notes no current competition in this specific niche.
  • PBC: Addressable US population estimated at 50,000 patients; acknowledges some competition but emphasizes the lack of oral options for pruritus compared to IV alternatives.
• Exclusivity:
  • Liz Marly (Livmarly): Colesevelam has passed orphan exclusivity, but the tax (likely referring to the active ingredient or a specific formulation) retains orphan protection.
  • No evidence of generic or biosimilar entry expected in the near term for the bile acid franchise.
  • Takeda royalties are minimal with no new orders expected in Q4 2026.

Macro / Industry Outlook:

• Regulatory Environment:
  • Management expresses strong confidence in the ability to submit five regulatory applications in H1 2027, citing robust team staffing and prior organizational preparation.
  • Confident in FDA's understanding of rare disease trial designs (specifically contrasting recent PSC interactions from 2019/2020 with current dialogues for EXPAND and Vantage studies).
  • No material changes expected in regulatory guidance regarding the H1 2027 submission timeline.
• Capital Structure:
  • Financing activities completed in 2026 (issuance of $690M zero-coupon convertible notes due 2032; repurchase of $20M 2029 convertible notes) have reduced outstanding 2029 debt balance by over 80%.
  • Objective to reduce future dilution and interest expense while preserving financial flexibility.

Strategic Initiatives:

• Business Development (BD):
  • Maintaining an opportunistic lens for M&A; no specific "breather" planned despite the busy submission schedule in H1 2027.
  • Willing to pursue both early-stage clinical assets and commercial-stage assets, specifically focusing on "underappreciated rare disease assets" where they can add value.
• Capacity & Manufacturing:
  • Planned manufacturing expenses for the HDV program (Brilovotug) are included in current R&D spend levels.
• Organizational Bandwidth:
  • Teams are fully staffed and organized to manage the wave of regulatory submissions without disruption to BD or other operations.

Risks and Headwinds to Outlook:

• Regulatory Uncertainty: Potential for delays or feedback from the FDA during the NDA/BLA review process for the five pending submissions.
• Clinical Trial Outcomes: Outcomes of the "Azure 4" (HDV) and "Vantage" (PBC) trials remain critical; mixed results could impact the BLA filing or approval timing.
• Diagnosis Rates: Success of the commercial pipeline relies heavily on improving diagnostic rates for HDV and PFIC, which are historically under-diagnosed.
• Competitive Landscape: While currently noting no direct competition for PSC pruritus, the PBC market has existing competitors.
• Execution Risk: Managing the simultaneous execution of five major regulatory submissions in H1 2027.

Management Tone on the Future:

• Highly Confident: Management describes the company as being at a "strong inflection point" and entering a "unique period of commercial growth."
• Optimistic: Emphasis on "strong confidence" regarding the strength of clinical data (e.g., EXPAND, ASR01, Azure 1) and the ability to achieve cash flow positivity in 2027.
• Strategic Maturity: Management highlights the company's transition from a pure R&D focus to a mature commercial entity with a balanced portfolio of approved medicines and late-stage assets.
• No Hedges: Guidance is raised without significant caveats regarding macro headwinds; focus is on internal execution and clinical validation.

Miscellaneous:

• Data Presentations: Full data package for Brilovotug (HDV) to be presented at AASLD, including 24-week Phase 3 ASR01 results, 48-week Phase 2b data, and long-term safety/efficacy data (up to 2 years) in cirrhotic patients.
• Financial Performance: Q3 2026 net product sales were $186 million (up from $133 million in Q3 2025); YTD sales of $522 million already equal full-year 2025 revenue.
• Stock Repurchases: $20M repurchase of 2029 convertible notes completed in September 2026 to reduce dilution and interest costs.
• Company Milestone: Approaching the 8th anniversary of the company's founding.