Financial Data and Key Metrics Changes - In Q1 2025, the company reported revenue of $139 million, representing a 28% increase compared to Q1 2024 [15] - The net loss for the quarter was $151 million, or $1.57 per share, with total operating expenses of $282 million [18] - Cash, cash equivalents, and marketable securities stood at $563 million as of March 31, 2025 [18] - The company reaffirmed its 2025 revenue guidance of $640 million to $670 million, indicating a growth of 14% to 20% over 2024 [19] Business Line Data and Key Metrics Changes - Crysvita generated $103 million in revenue, with significant contributions from North America ($41 million), Latin America and Turkey ($55 million), and Europe ($7 million), marking a 25% growth over 2024 [16] - DeJolvi contributed $17 million, while EVKYSA and Mepsevii contributed $11 million and $8 million, respectively [17] - In Latin America and Turkey, Crysvita saw a remarkable 52% growth over 2024 [16] Market Data and Key Metrics Changes - The commercial team in Latin America reported approximately 775 patients on reimbursed therapy for Crysvita, with expectations for continued growth following successful reimbursement negotiations [8] - In the U.S., the adult patient population for Crysvita has exceeded initial expectations, contributing to revenue growth [9] - The EMEA region showed strong demand for DERJOVY, with over 260 patients treated under named patient sales [11] Company Strategy and Development Direction - The company is focused on expanding its commercial operations outside the U.S. and preparing for new product launches [3] - The development pipeline includes multiple late-stage programs, with significant progress in Phase III studies for various treatments [5] - The company is working on two separate Biologics License Applications (BLAs), with one under review and another expected to be submitted mid-2025 [6] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in 2025 being a transformational year, with expectations for substantial revenue growth and successful clinical data readouts [29] - The company is actively monitoring regulatory changes and does not anticipate material exposure from tariffs affecting its products [21] - Management highlighted the importance of continued demand for products in Latin America and the U.S. pediatric and adult markets [19] Other Important Information - The company is on track for a PDUFA action date of August 18 for the UX-111 BLA under review by the FDA [7] - The company expects net cash used in operations to decrease in the remaining quarters of 2025, aiming for full-year GAAP profitability by 2027 [19] Q&A Session Summary Question: Discussion on setrusumab and fracture reduction - Management explained the concept of variation in fracture rates among patients and its impact on study outcomes, emphasizing confidence in achieving significant results [34][36] Question: Likelihood of success in the third interim read for OI - Management expressed optimism about meeting the p-value threshold based on the study's design and patient data [44][46] Question: Impact of recent FDA appointments on the rare disease space - Management indicated that while there are concerns, they remain confident in their clinical data supporting their programs [50][52] Question: Growth drivers for Crysvita in Latin America - Management noted that patient experiences and physician engagement are key factors driving growth in the region [116]

Exhibit 99.1 Contacts Ultragenyx Pharmaceutical Inc. Investors Joshua Higa ir@ultragenyx.com Ultragenyx Reports First Quarter 2025 Financial Results and Corporate Update First quarter total revenue of $139 million, Crysvita® revenue of $103 million and Dojolvi® revenue of $17 million Reaffirm 2025 Financial Guidance: Total revenue between $640 million to $670 million, Crysvita revenue of $460 million to $480 million, and Dojolvi revenue of $90 million to $100 million UX111, an investigational treatment for ...

Pipeline & Approvals - Ultragenyx expects a PDUFA date of August 18, 2025, for UX111 in Sanfilippo syndrome (MPS IIIA) and a potential commercial launch in the second half of 2025[67, 98] - The company anticipates BLA submission for DTX401 in Glycogen Storage Disease Type Ia (GSDIa) in mid-2025, with a potential launch in 2026[78, 80, 98] - Phase 3 enrollment for GTX-102 in Angelman Syndrome (AS) is expected to be completed in the second half of 2025, with a Phase 2/3 Aurora study initiation planned for 2025[46, 49, 61, 98] - Ultragenyx plans to complete Stage 1, Cohort 4 enrollment for UX701 in Wilson Disease (WD) in the second half of 2025[88, 90, 98] - Phase 3 data readout for UX143 in Osteogenesis Imperfecta (OI) is expected in 2025[21, 28, 32] Financial Performance & Projections - Ultragenyx projects total revenue between $640 million and $670 million in 2025, representing a 14-20% annual revenue growth[94, 95] - Crysvita revenue is projected to be between $460 million and $480 million in 2025, a 12-17% increase[95] - Dojolvi revenue is expected to be between $90 million and $100 million in 2025, a 2-13% increase[95] - The company aims to achieve full-year GAAP profitability in 2027, driven by revenue growth, expense management, and monetization of Priority Review Vouchers (PRVs)[2, 96, 97, 99] - Ultragenyx reported $563 million in cash, cash equivalents, and marketable debt securities as of March 31, 2025[97]

Core Insights - Ultragenyx Pharmaceutical Inc. reported total revenue of $139 million for Q1 2025, reflecting a 28% increase compared to Q1 2024, with Crysvita revenue at $103 million, a 25% increase year-over-year [4][8] - The company reaffirmed its 2025 financial guidance, projecting total revenue between $640 million to $670 million, with Crysvita revenue expected to be between $460 million to $480 million, and Dojolvi revenue between $90 million to $100 million [10][12] - The investigational treatment UX111 for Sanfilippo syndrome is on track for a Biologics License Application (BLA) action date set for August 18, 2025 [14] Financial Performance - Total revenues for Q1 2025 were $139 million, up from $108.8 million in Q1 2024, with significant contributions from Crysvita and Dojolvi [3][4] - Crysvita's product sales in Latin America and Türkiye reached $55 million, marking a 52% increase compared to the previous year [4][5] - Operating expenses totaled $282 million in Q1 2025, with research and development costs at $165.8 million [6][7] Net Loss and Cash Position - The net loss for Q1 2025 was $151 million, or $1.57 per share, an improvement from a net loss of $171 million, or $2.03 per share, in Q1 2024 [8][9] - As of March 31, 2025, the company had cash, cash equivalents, and marketable securities totaling $563 million, down from $745 million at the end of 2024 [9][29] Clinical Developments - The company is progressing with multiple clinical trials, including UX143 for osteogenesis imperfecta and GTX-102 for Angelman syndrome, with key interim analyses expected in mid-2025 [10][11] - The Phase 3 study for DTX401 is anticipated to submit a BLA in mid-2025, following positive results from the GlucoGene study [15][16] Strategic Focus - Ultragenyx aims to manage expenses while prioritizing investments in upcoming commercial launches and advancing multiple Phase 3 programs, which is expected to reduce net cash used in operations in 2025 compared to 2024 [10][12]

Core Viewpoint - Ultragenyx Pharmaceutical Inc. will host a conference call on May 6, 2025, to discuss its financial results and corporate updates for Q1 2025 [1]. Group 1: Company Overview - Ultragenyx is a biopharmaceutical company focused on developing and commercializing novel products for serious rare and ultra-rare genetic diseases [3]. - The company has established a diverse portfolio of approved therapies and product candidates aimed at addressing diseases with high unmet medical needs [3]. - Ultragenyx's management team has extensive experience in the development and commercialization of therapeutics for rare diseases [4]. Group 2: Strategic Focus - The company's strategy emphasizes time- and cost-efficient drug development to deliver safe and effective therapies to patients urgently [4].