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 ...

Corporate Presentation May 2025 Confidential and Proprietary Forward looking statements Cautionary note regarding forward-looking statements: This presentation contains forward-looking statements, including, but not limited to, statements regarding our expectations, estimates, assumptions, and projections regarding our future operating results and financial performance, including our expectations for profitability in 2027, anticipated cost or expense management, plans with respect to commercializing our pro ...

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 Sanfilippo syndrome, biologics license application (BLA) on track for PDUFA action date of August 18, 2025 NOVATO, Calif., May 06, 2025 (GLOBE NEWSWIRE) -- Ultragenyx Pha ...

NOVATO, Calif., April 30, 2025 (GLOBE NEWSWIRE) -- Ultragenyx Pharmaceutical Inc. (NASDAQ: RARE), a biopharmaceutical company focused on the development and commercialization of novel products for serious rare and ultra-rare genetic diseases, today announced that it will host a conference call at 5:00 p.m. ET on Tuesday, May 6, 2025, to discuss its financial results and corporate update for the quarter ending March 31, 2025. The live and replayed webcast of the call will be available through the company’s w ...

Group 1 - Ultragenyx Pharmaceutical is transitioning from a development-stage biotech to a commercial entity with a promising pipeline for significant expansion in the rare disease sector [1] - The company is positioned in a high-growth industry, focusing on disruptive technologies and innovative solutions [1] Group 2 - The article emphasizes the importance of fundamental analysis and future trend prediction in evaluating investment opportunities within the biotech sector [1]

Company Overview - Ultragenyx shares increased by 9.2% to $33.91, following a significant trading volume, contrasting with a 19% decline over the past four weeks [1] - The company is expected to report a quarterly loss of $1.58 per share, reflecting a year-over-year increase of 22.2%, with revenues projected at $142.49 million, a 30.9% rise from the previous year [2] - The consensus EPS estimate for Ultragenyx has remained stable over the last 30 days, indicating that stock price movements may not sustain without earnings estimate revisions [3] Industry Insights - Ultragenyx operates within the Zacks Medical - Biomedical and Genetics industry, where Entrada Therapeutics also resides, having seen a 9.5% increase in its stock price to $8.27, despite a 29.1% decline over the past month [3] - Entrada Therapeutics has experienced a -2.9% change in its EPS estimate over the past month, now projected at -$0.78, which is a significant decline of 214.7% compared to the previous year [4] - Both Ultragenyx and Entrada Therapeutics currently hold a Zacks Rank of 3 (Hold), indicating a neutral outlook for investors [3][4]

Core Insights - Ultragenyx Pharmaceutical Inc. is focused on developing and commercializing novel therapies for serious rare and ultrarare genetic diseases [1] - The company will participate in three upcoming investor conferences, showcasing its commitment to engaging with the investment community [1][2][3][4] Conference Participation - At the 45th Annual Cowen Healthcare Conference in Boston, MA on March 3, 2025, Eric Crombez, M.D., Chief Medical Officer, will participate in a fireside chat and host one-on-one meetings [2] - At the Barclays 27th Annual Global Healthcare Conference in Miami, FL on March 11, 2025, Eric Crombez will again participate in a fireside chat and host one-on-one meetings [3] - At the Leerink Partners Global Biopharma Conference in Miami, FL on March 12, 2025, Eric Crombez will participate in a fireside chat and host one-on-one meetings, with a live and archived webcast available on the company's website [4] Company Overview - Ultragenyx is committed to bringing novel products to patients for the treatment of serious rare and ultrarare genetic diseases, with a diverse portfolio of approved therapies and product candidates [5] - The management team has extensive experience in the development and commercialization of rare disease therapeutics, focusing on time- and cost-efficient drug development [6]

Financial Performance - For the year ended December 31, 2024, total revenues increased to $560.2 million, compared to $434.2 million for the same period in 2023, representing a growth of approximately 29% driven by higher demand for approved products [378]. - Net losses for the years ended December 31, 2024 and 2023 were $569.2 million and $606.6 million, respectively, indicating a reduction in losses of about 6.2% year-over-year [377]. - Total revenues for the year ended December 31, 2024, were $560.2 million, up 29% from $434.2 million in 2023, driven by a $105.0 million increase in product sales [410]. - Product sales for Crysvita increased by 78% to $134.7 million in 2024, while Dojolvi sales rose by 25% to $88.2 million [410]. - Selling, general and administrative expenses increased by $11.8 million, or 4%, to $321.6 million for the year ended December 31, 2024, compared to $309.8 million in 2023 [420]. - Interest income rose by $9.8 million, or 37%, to $36.5 million for the year ended December 31, 2024, primarily due to higher marketable debt securities balances [422]. - The company recognized an income tax provision of $1.6 million for the year ended December 31, 2024, compared to an income tax benefit of $4.8 million in 2023, reflecting a change of 188% [426]. Cash and Investments - As of December 31, 2024, the company had $745.0 million in available cash, cash equivalents, and marketable debt securities [378]. - Cash used in operating activities for the year ended December 31, 2024, was $414.2 million, reflecting a net loss of $569.2 million [434]. - Cash provided by financing activities for the year ended December 31, 2024, was $399.2 million, primarily from a public offering that generated $381.0 million in net proceeds [439]. - The investment portfolio is primarily composed of low-risk, investment-grade debt instruments, including U.S. government treasury and agency securities [449]. - A hypothetical 100 basis point change in interest rates would not have had a material impact on the fair market value of cash equivalents and marketable debt securities as of December 31, 2024 [449]. - The company has not experienced a loss of principal on any investments to date and did not record any allowance for credit loss as of December 31, 2024 [449]. Research and Development - The company has incurred substantial costs related to research and development, which are a significant component of its net losses [377]. - Research and development expenses rose by 8% to $697.9 million in 2024, with significant increases in gene therapy programs and biologic and nucleic acid programs [418]. - The company expects annual research and development expenses to moderate as product candidates advance through clinical development [419]. - Upfront license, acquisition, and milestone fees increased by 238% to $30.5 million in 2024, primarily due to a clinical enrollment milestone achievement for the GTX-102 program [418]. Product Portfolio - The company has four commercially approved products, including Crysvita® and Evkeeza®, targeting serious rare genetic diseases [375]. - The company has a diverse pipeline of product candidates, including biologics and gene therapies, aimed at treating serious genetic diseases [375]. - The company transitioned commercial responsibilities for Crysvita in the Profit-Share Territory to KKC in April 2023, impacting revenue recognition [411]. Royalty Agreements - In December 2019, the company entered into a Royalty Purchase Agreement with RPI for $320.0 million for future royalty payments on Crysvita, with a capped amount of $608.0 million [397]. - In July 2022, the company entered into a Royalty Purchase Agreement with OMERS for $500.0 million for 30% of future royalty payments from Crysvita, with a cap of $725.0 million [398]. - The effective annual interest rates for the royalty agreements with RPI and OMERS were 6.2% and 7.5%, respectively, as of December 31, 2024 [400]. Other Financial Metrics - Stock-based compensation expense for the year ended December 31, 2024, was $158.1 million, an increase from $135.2 million in 2023, reflecting a growth of 17.5% [406]. - Cost of sales increased by 70% to $76.7 million in 2024, primarily due to increased demand for approved products, especially Crysvita and Evkeeza [413]. - The change in fair value of equity investments recorded a net decrease of $1.1 million for the year ended December 31, 2024, compared to a net increase of $0.4 million in 2023, reflecting a change of 381% [423]. - Non-cash interest expense on liabilities for sales of future royalties decreased by $3.0 million, or 4%, to $66.0 million for the year ended December 31, 2024 [424]. - Other expenses increased by $3.6 million for the year ended December 31, 2024, primarily due to fluctuations in foreign exchange rates [425]. Future Outlook - The company anticipates continued annual losses in the near term as it develops and seeks regulatory approvals for product candidates [441]. - Total gross deferred tax assets as of December 31, 2024, were $1,213.7 million, fully offset by a valuation allowance due to uncertainties in generating future taxable income [409]. Foreign Exchange Risk - The company faces foreign exchange risk due to transactions in currencies other than U.S. dollars, with a majority of revenue, expenses, and capital expenditures denominated in U.S. dollars for the year ended December 31, 2024 [451]. - A hypothetical 10% change in foreign exchange rates would not have had a material impact on the company's Consolidated Financial Statements [451].

Core Insights - The FDA has accepted Ultragenyx Pharmaceutical Inc.'s Biologics License Application (BLA) for UX111, a gene therapy for Sanfilippo syndrome type A, with a Priority Review status and a PDUFA action date of August 18, 2025 [1][2] - The acceptance of the BLA is a significant step towards providing the first-ever treatment for Sanfilippo syndrome type A, with the company prepared to launch the therapy upon successful approval [2] - UX111 is a novel in vivo gene therapy designed to address the underlying SGSH enzyme deficiency, which leads to the accumulation of heparan sulfate in the brain, causing neurodegeneration [3][4] Company Overview - Ultragenyx is a biopharmaceutical company focused on developing therapies for serious rare and ultrarare genetic diseases, with a diverse portfolio aimed at addressing high unmet medical needs [5] - The company has a management team experienced in the development and commercialization of rare disease therapeutics, emphasizing efficient drug development processes [6] Product Details - UX111 is currently in Phase 1/2/3 development and is administered as a one-time intravenous infusion using a self-complementary AAV9 vector to deliver a functional SGSH gene [3] - The therapy has received multiple designations, including Regenerative Medicine Advanced Therapy and Orphan Drug designations in the U.S., and PRIME designation in the EU [3] Disease Context - Sanfilippo syndrome type A is a rare, fatal lysosomal storage disease affecting approximately 3,000 to 5,000 patients, characterized by rapid neurodegeneration and a median life expectancy of 15 years [4] - The disease is caused by biallelic pathogenic variants in the SGSH gene, leading to a deficiency in the SGSH enzyme responsible for breaking down heparan sulfate [4]

Core Viewpoint - Ultragenyx Pharmaceutical reported a wider loss per share in Q4 2024 compared to the previous year and the consensus estimate, despite a significant increase in total revenues driven by higher product sales [1][2][8]. Financial Performance - The total revenues for Q4 2024 were $164.9 million, reflecting a 29% year-over-year increase and surpassing the Zacks Consensus Estimate of $163 million [2]. - The net loss per share for Q4 2024 was $1.39, wider than the consensus estimate of a loss of $1.24 and compared to a loss of $1.52 in the same quarter last year [1][8]. - For the full year 2024, total revenues reached $560.2 million, up 29% from $434.2 million in 2023, exceeding the Zacks Consensus Estimate of $558.6 million [8]. Product Performance - Crysvita generated $115.4 million in revenues for Q4 2024, a 23% increase year-over-year, with notable growth in Latin America and Turkey [4]. - Dojolvi's revenues were $31.1 million, up 34% due to strong new patient demand, while Mepsevii's revenues remained flat at $8 million [5]. - Evkeeza recorded sales of $10.4 million in Q4 2024 [5]. Operating Expenses - Operating expenses for Q4 2024 totaled $287.2 million, a 15% increase year-over-year, driven by investments in late-stage pipeline programs and marketing costs [6]. - Research and development expenses were $187.8 million, up 17%, while selling, general and administrative expenses were $82.5 million, up 7% [6]. Cash Position - As of December 31, 2024, cash, cash equivalents, and marketable debt securities amounted to $745 million, down from $825 million as of September 30, 2024 [7]. Future Guidance - For 2025, Ultragenyx expects total revenues between $640 million and $670 million, indicating a growth of approximately 14-20% compared to 2024 [9]. - Crysvita revenues are projected to be between $460 million and $480 million, while Dojolvi revenues are expected to range from $90 million to $100 million [9]. Pipeline Developments - Ultragenyx is developing UX143 for osteogenesis imperfecta in collaboration with Mereo BioPharma, with updates expected in mid-2025 [12]. - The company is also evaluating UX701 for Wilson disease and plans to submit a biologics license application for DTX401 in mid-2025 [13]. - In December 2024, dosing began in the pivotal phase III Aspire study for GTX-102, targeting Angelman syndrome [14]. - A biologics license application for UX111 to treat Sanfilippo syndrome type A was submitted in December 2024, with a decision expected in the second half of 2025 [15].