Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

MANAGEMENT’S DISCUSSION AND ANALYSIS OF

FINANCIAL CONDITION AND RESULTS OF OPERATIONS

You should read the following discussion and analysis of our financial condition and results of operations together with our Consolidated Financial Statements and related notes included elsewhere in this Annual Report.

This discussion and analysis generally covers our financial condition and results of operations for the year ended December 31, 2023, including year-over-year comparisons versus the year ended December 31, 2022. Our Annual Report on Form 10-K for the year ended December 31, 2022 includes a discussion and analysis of our financial condition and results of operations for the year ended December 31, 2021 in "Part II, Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations.”

Overview

Ultragenyx Pharmaceutical Inc., we or the Company, are a biopharmaceutical company committed to bringing novel products to patients for the treatment of serious rare and ultrarare genetic diseases. We have built a diverse portfolio of approved therapies and product candidates aimed at addressing diseases with high unmet medical need and clear biology for treatment, for which there are typically no approved therapies treating the underlying disease. Our strategy is predicated upon time- and cost-efficient drug development, with the goal of delivering safe and effective therapies to patients with the utmost urgency.

Approved Therapies and Clinical Product Candidates

Our current approved therapies and clinical-stage pipeline consist of four product categories: biologics, small molecules, AAV gene therapy, and nucleic acid product candidates. We have four commercially approved products, consisting of Crysvita® (burosumab) for the treatment of X-linked hypophosphatemia, or XLH, and tumor-induced osteomalacia, or TIO, Mepsevii® (vestronidase alfa) for the treatment of mucopolysaccharidosis VII, or MPSVII or Sly Syndrome, Dojolvi® (triheptanoin) for the treatment of long-chain fatty acid oxidation disorders, or LC-FAOD, and Evkeeza® (evinacumab) for the treatment of homozygous familial hypercholesterolemia, or HoFH. Please see “Item 1. Business” above for a description of our approved products and our clinical stage pipeline products.

Financial Operations Overview

We are a biopharmaceutical company with a limited operating history. To date, we have invested substantially all of our efforts and financial resources in identifying, acquiring, and developing our products and product candidates, including conducting clinical studies and providing selling, general and administrative support for these operations. To date, we have funded our operations primarily from the sale of our equity securities, revenues from our commercial products, the sale of certain future royalties, and strategic collaboration arrangements.

We have incurred net losses in each year since inception. Our net losses were $606.6 million and $707.4 million for the years ended December 31, 2023 and 2022, respectively. Substantially all of our net losses have resulted from costs incurred in connection with our research and development programs and from selling, general and administrative costs associated with our operations.

For the year ended December 31, 2023, our total revenues increased to $434.2 million, compared to $363.3 million for the same period in 2022. The increase in revenue was driven by higher demand for our approved products.

As of December 31, 2023, we had $777.1 million in available cash, cash equivalents and marketable debt securities.

Critical Accounting Policies and Significant Judgments and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our Consolidated Financial Statements, which have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP. The preparation of these Consolidated Financial Statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported expenses incurred during the reporting periods. Our estimates are based on our historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions. We periodically review our estimates as a result of changes in circumstances, facts and experience. The effects of material revisions in estimates are reflected in the financial statements prospectively from the date of the change in estimate. Our significant accounting policies are more fully described in Note 2 to our financial statements included elsewhere in this Annual Report.

We define our critical accounting policies as those GAAP accounting principles that require us to make subjective estimates and judgments about matters that are uncertain and are likely to have a material impact on our financial condition and results of operations as well as the specific manner in which we apply those principles. We believe the critical accounting policies used in the preparation of our financial statements that require significant estimates and judgments are as follows:

Accrued Research and Development, and Research and Development Expenses

As part of the process of preparing consolidated financial statements, we are required to estimate and accrue expenses, the largest of which is related to accrued research and development expenses. This process involves reviewing contracts and purchase orders, identifying services that have been performed on our behalf, and estimating the level of service performed and the associated cost incurred for the service when we have not yet been invoiced or otherwise notified of the actual costs.

We record accruals for estimated costs of research, preclinical and clinical studies, and manufacturing development. These costs are a significant component of our research and development expenses. A substantial portion of our ongoing research and development activities is conducted by third-party service providers. We accrue the costs incurred under our agreements with these third parties based on actual work completed in accordance with agreements established with these third parties. We determine the actual costs through discussions with internal personnel and external service providers as to the progress or stage of completion of the services and the agreed-upon fee to be paid for such services. We make significant judgments and estimates in determining the accrual balance in each reporting period. As actual costs become known, we adjust our accruals. Although we do not expect our estimates to be materially different from amounts actually incurred, our understanding of the status and timing of services performed relative to the actual status and timing of services performed may vary and could result in us reporting amounts that are too high or too low in any particular period. Our accrual is dependent, in part, upon the receipt of timely and accurate reporting from clinical research organizations and other third-party vendors.

Research and development costs are expensed as incurred and consist of salaries and benefits, stock-based compensation, lab supplies, materials and facility costs, as well as fees paid to other nonemployees and entities that conduct certain research and development activities on our behalf. Amounts incurred in connection with collaboration and license agreements are also included in research and development expense. Payments made prior to the receipt of goods or services to be used in research and development are capitalized until the goods or services are received.

To date, there have been no material differences from our accrued estimated expenses to the actual clinical trial expenses; however, due to the nature of estimates, we cannot assure you that we will not make changes to our estimates in the future as we become aware of additional information about the status or conduct of our clinical studies and other research activities.

Revenue Recognition

Product Sales

We sell our approved products through a limited number of distributors. Under ASC 606, revenue from product sales is recognized at the point in time when control is transferred to these distributors. We also recognize revenue from sales of certain products on a “named patient” basis, which are allowed in certain countries prior to the commercial approval of the product. Prior to recognizing revenue, we make estimates of the transaction price, including any variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. Product sales are recorded net of estimated government-mandated rebates and chargebacks, estimated product returns, and other deductions.

Provisions for returns and other adjustments are provided for in the period the related revenue is recorded, as estimated by management. These reserves are based on estimates of the amounts earned or to be claimed on the related sales and are reviewed periodically and adjusted as necessary. Our estimates of government mandated rebates, chargebacks, estimated product returns, and other deductions depends on the identification of key customer contract terms and conditions, negotiated pricing, as well as estimates of sales volumes to different classes of payors. If actual results vary, we may need to adjust these estimates, which could have a material effect on earnings in the period of the adjustment.

Collaboration, License and Royalty Revenue

We have certain license and collaboration agreements that are within the scope of Accounting Standards Codification, or ASC, 808, Collaborative Agreements, which provides guidance on the presentation and disclosure of collaborative arrangements. Generally, the classification of the transactions under the collaborative arrangements is determined based on the nature of contractual terms of the arrangement, along with the nature of the operations of the participants. We record our share of collaboration revenue, net of transfer pricing related to net sales in the period in which such sales occur, if we are considered as an

agent in the arrangement. We are considered an agent when the collaboration partner controls the product before transfer to the customers and has the ability to direct the use of and obtain substantially all of the remaining benefits from the product. Funding received related to research and development services and commercialization costs is generally classified as a reduction of research and development expenses and selling, general and administrative expenses, respectively, in the Consolidated Statement of Operations, because the provision of such services for collaborative partners are not considered to be part of our ongoing major or central operations.

We also record royalty revenues under certain of our license or collaboration agreements in exchange for license of intellectual property.

We utilize certain information from our collaboration partners to record collaboration revenue, including revenue from the sale of the product, associated reserves on revenue, and costs incurred for development and sales activities. For the periods covered in the financial statements presented, there have been no material changes to prior period estimates of revenues and expenses.

We sold the right to receive certain royalty payments from net sales of Crysvita in certain territories to RPI Finance Trust, or RPI, an affiliate of Royalty Pharma, and to OCM LS23 Holdings LP, an investment vehicle for Ontario Municipal Employees Retirement System, or OMERS, as further described in “Liabilities for Sales of Future Royalties” below. We record the royalty revenue from the net sales of Crysvita in the applicable territories on a prospective basis as non-cash royalty revenue in the Consolidated Statements of Operations over the term of the applicable arrangement.

The terms of our collaboration and license agreements may contain multiple performance obligations, which may include licenses and research and development activities. We evaluate these agreements under ASC 606, Revenue from Contracts with Customers, or ASC 606, to determine the distinct performance obligations. We analogize to ASC 606 for the accounting for distinct performance obligations for which there is a customer relationship. Prior to recognizing revenue, we make estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. Total consideration may include nonrefundable upfront license fees, payments for research and development activities, reimbursement of certain third-party costs, payments based upon the achievement of specified milestones, and royalty payments based on product sales derived from the collaboration.

If there are multiple distinct performance obligations, we allocate the transaction price to each distinct performance obligation based on our relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost-plus margin. We estimate the efforts needed to complete the performance obligations and recognize revenue by measuring the progress towards complete satisfaction of the performance obligations using input measures.

Inventory

We expense costs associated with the manufacture of our products prior to regulatory approval. Typically, capitalization of such costs begins when we have received the regulatory approval of the product. Prior to the approval of our products by the U.S. Food and Drug Administration, or FDA, manufacturing and related costs are expensed. As of December 31, 2023, we do not hold a material amount of previously expensed inventory for our approved products.

Inventory that is manufactured after regulatory approval is valued at the lower of cost and net realizable value and cost is determined using the average-cost method.

We periodically review our inventories for excess amounts or obsolescence and write down obsolete or otherwise unmarketable inventory to the estimated net realizable value.

Liabilities for Sales of Future Royalties

In December 2019, we entered into a Royalty Purchase Agreement with RPI. Pursuant to the agreement, RPI paid us $320.0 million in consideration for our right to receive royalty payments on the net sales of Crysvita in the European Union, or the EU, the United Kingdom, and Switzerland, effective January 1, 2020, under the terms of our Collaboration and License Agreement with Kyowa Kirin Co., Ltd., or KKC. The agreement with RPI will automatically terminate, and the payment of royalties to RPI will cease, in the event aggregate royalty payments received by RPI are equal to or greater than the capped amount of $608.0 million prior to December 31, 2030, or in the event aggregate royalty payments received by RPI are less than $608.0 million prior to December 31, 2030, when aggregate royalty payments received by RPI are equal to $800.0 million.

In July 2022, we entered into a Royalty Purchase Agreement with OMERS. Pursuant to the agreement, OMERS paid $500.0 million to us in consideration for the right to receive 30% of the future royalty payments due to us from KKC based on net sales of Crysvita in the U.S. and Canada under the terms of the KKC Collaboration Agreement. The calculation of royalty payments to OMERS

is based on net sales of Crysvita beginning in April 2023 and continuing until expiration, which is the earlier of the date on which aggregate payments received by OMERS equals $725.0 million or the date the final royalty payment is made to us under the KKC Collaboration Agreement.

Proceeds from these transactions were recorded as liabilities (specifically, liabilities for sales of future royalties on the Consolidated Balance Sheets). We are amortizing $320.0 million and $500.0 million, net of transaction costs of $5.8 million and $9.1 million for RPI and OMERS, respectively, using the effective interest method over the estimated life of the applicable arrangement. In order to determine the amortization of the liabilities, we are required to estimate the total amount of future royalty payments to be received by us and paid to RPI and OMERS, subject to the capped amount, over the life of the arrangements. The excess of future estimated royalty payments (subject to the capped amount) to RPI and OMERS, in excess of the net proceeds received of $314.2 million and $491.0 million, respectively, is recorded as non-cash interest expense over the life of the arrangements. Consequently, we estimate an imputed interest on the unamortized portion of the liabilities and record interest expense relating to the transactions. We record the royalty revenue arising from the net sales of Crysvita in the applicable territories as non-cash royalty revenue in the Consolidated Statements of Operations over the term of the arrangements.

We periodically assess the expected royalty payments using a combination of historical results, internal projections and forecasts from external sources. To the extent such payments are greater or less than our initial estimates or the timing of such payments is materially different than its original estimates, we will prospectively adjust the amortization of the liabilities and the effective interest rate. Our effective annual interest rates were 6.2% and 7.8%, for RPI and OMERS, respectively, as of December 31, 2023.

There are a number of factors that could materially affect the amount and timing of royalty payments from KKC in the applicable territories, most of which are not within our control. Such factors include, but are not limited to, the success of KKC’s sales and promotion of Crysvita, changing standards of care, macroeconomic and inflationary pressures, the introduction of competing products, pricing for reimbursement in various territories, manufacturing or other delays, intellectual property matters, adverse events that result in governmental health authority imposed restrictions on the use of Crysvita, significant changes in foreign exchange rates as the royalty payments are made in U.S. dollars, or USD, while significant portions of the underlying sales of Crysvita are made in currencies other than USD, and other events or circumstances that could result in reduced royalty payments from sales of Crysvita, all of which would result in a reduction of non-cash royalty revenue and the non-cash interest expense over the life of the arrangement. Conversely, if sales of Crysvita in the relevant territories are more than expected, the non-cash royalty revenue and the non-cash interest expense recorded by us would be greater over the term of the arrangements.

Stock-Based Compensation

Stock-based compensation costs related to equity awards granted to employees are measured at the date of grant based on the estimated fair value of the award, net of estimated forfeitures. We estimate the grant date fair value of options, and the resulting stock-based compensation expense, using the Black-Scholes option-pricing model. The grant date fair value of the stock-based awards is recognized on a straight-line basis over the requisite service period, which is generally the vesting period of the respective awards. We expect to continue to grant equity awards in the future, and to the extent that we do, our actual stock-based compensation expense will likely increase. The Black-Scholes option-pricing model requires the use of certain subjective assumptions which determine the estimated fair value of stock-based awards.

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Expected Term — The expected term represents the period that the stock-based awards are expected to be outstanding and is determined using the simplified method (based on the midpoint between the vesting date and the end of the contractual term).

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Expected Volatility— The expected volatility is based on historical volatility over the look-back period corresponding to the expected term.

Strike price for options, including performance stock options, or PSOs, is equal to the closing market value of our common stock on the date of grant.

In addition to the assumptions used in the Black-Scholes option-pricing model, we also estimate a forfeiture rate to calculate the stock-based compensation for our awards. We will continue to use judgment in evaluating the expected volatility, expected terms, and forfeiture rates utilized for our stock-based compensation calculations on a prospective basis and will revise in subsequent periods, if actual forfeitures differ from those estimates.

For restricted stock units, or RSUs, and performance stock units, or PSUs, the fair value is based on the market value of our common stock on the date of grant, except for certain PSUs with a market vesting condition, for which fair value is estimated using a Monte Carlo simulation model. Stock-based compensation expense for RSUs is recognized on a straight-line basis over the requisite service period. PSUs are subject to vest only if certain specified criteria are achieved and the employees’ continued service with the Company. For certain PSUs, the number of PSUs that may vest are also subject to the achievement of certain specified criteria, including both performance conditions and market conditions. Compensation expense for PSUs is recognized only after the achievement of the specified criteria is considered probable and recognized on a straight-line basis between the grant date and the expected vest date, with a catch-up for previously unrecognized expense, if any, recognized in the period the achievement criteria is deemed probable.

For the years ended December 31, 2023, 2022, and 2021 stock-based compensation expense was $135.2 million, $130.4 million, and $105.0 million, respectively. As of December 31, 2023, we had $219.8 million of total unrecognized stock-based compensation costs, net of estimated forfeitures, which we expect to recognize over a weighted-average period of 2.2 years.

Income Taxes

We use the liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. We assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized.

In conjunction with the acquisition of Dimension Therapeutics, or Dimension, in 2017, we recorded a deferred tax liability reflecting the tax impact of the difference between the book basis and tax basis of acquired IPR&D. Such deferred income tax liability was not used to offset deferred tax assets when analyzing our valuation allowance as the acquired IPR&D is considered to have an indefinite life until we complete or abandon development of the acquired IPR&D.

We recognize benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. Our policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits.

As of December 31, 2023, our total gross deferred tax assets were $1,041.8 million. Due to our lack of earnings history and uncertainties surrounding our ability to generate future taxable income, the net deferred tax assets have been fully offset by a valuation allowance. The deferred tax assets were primarily comprised of federal and state tax net operating losses and tax credit carryforwards. Utilization of the net operating loss and tax credit carryforwards may be subject to an annual limitation due to historical or future ownership percentage change rules provided by the Internal Revenue Code of 1986, and similar state provisions. The annual limitation may result in the expiration of certain net operating loss and tax credit carryforwards before their utilization.

Results of Operations

Comparison of Years Ended December 31, 2023 and 2022

Revenues (dollars in thousands)

Year Ended December 31, Dollar Percent

Product sales:

Collaboration and license revenue:

* not meaningful

Our product sales increased $61.5 million for the year ended December 31, 2023, compared to the same period in 2022. The increase was primarily due to an increase in demand for Crysvita in Latin America resulting from an increase in the number of patients on therapy, continued increase in demand for our other approved products, and increases in revenue under our named patient programs.

Our Crysvita collaboration revenue in the Profit-Share Territory and royalty revenue increased by a net $15.6 million for the year ended December 31, 2023, compared to the same period in 2022; this increase in Crysvita revenue is primarily due to an increase in the number of patients on therapy. We transitioned commercial responsibilities to KKC in the Profit-Share Territory in April 2023. Post transition, we recognize our revenue share for Crysvita sales in the Profit-Share Territory as royalty revenue, which was recorded as collaboration revenue prior to the transition.

Our revenue from the Daiichi Sankyo arrangement decreased by $6.2 million for the year ended December 31, 2023, compared to the same period in 2022. The decrease was due to the completion of the technology transfer and the technology transfer period as of March 31, 2023.

Cost of Sales (dollars in thousands)

Year Ended December 31, Dollar Percent

Cost of sales increased by $16.9 million for the year ended December 31, 2023, compared to the same period in 2022. The increase in cost of sales was due to increased demand for our approved products, partially offset by a decrease in the Crysvita transfer price on sales of the product in Latin America from 35% prior to December 31, 2022, to 30% in 2023.

Research and Development Expenses (dollars in thousands)

Research and development expenses include internal and external costs incurred for research and development of our programs and program candidates and expenses related to certain technology that we acquire or license through business development transactions. These expenses consist primarily of clinical studies performed by contract research organizations, manufacturing of drug substance and drug product performed by contract manufacturing organizations and at our gene therapy manufacturing facility, materials and supplies, fees from collaborative and other arrangements including milestones, licenses and other fees, personnel costs including salaries, benefits and stock-based compensation, and overhead allocations consisting of various support and infrastructure costs.

Clinical programs include study conduct and manufacturing costs related to clinical program candidates. Translational research includes costs for preclinical study work and costs related to preclinical programs prior to IND filing. Upfront license, acquisition, and milestone fees include any significant expenses related to strategic licensing agreements. Approved products include costs for disease monitoring programs for post-marketing clinical studies, medical affairs activities to support scientific discovery efforts on

existing programs, and regulatory costs for unapproved regions. Infrastructure costs include direct costs related to laboratory, IT, and equipment depreciation costs, and overhead allocations for human resources, IT, and other allocable costs.

The following table provides a breakout of our research and development expenses by major program type and business activities:

Year Ended December 31, Dollar Percent

Clinical programs:

Total research and development expenses decreased $57.3 million for the year ended December 31, 2023 compared to the same period in 2022. The change in research and development expenses was due to:

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for gene therapy programs, an increase of $15.0 million, primarily related to the addition of the development costs for the UX111 program acquired from Abeona Therapeutics in May 2022, and an increase in production materials purchases for internal manufacturing, partially offset by decreases in external clinical manufacturing expenses for DTX401;

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for biologic and nucleic acid programs, an increase of $11.6 million, primarily related to the continued clinical progress of the UX143 and GTX102 programs and associated clinical development and manufacturing expenses, partially offset by a reduction in development expense on UX053 for the treatment of Glycogen Storage Disease Type III;

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for translational research, a decrease of $9.6 million, primarily related to decreases in manufacturing and headcount expense for IND-stage projects;

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for upfront license, acquisition, and milestone fees, a decrease of $66.0 million, due to $9.0 million related to payment for achievement of a clinical enrollment milestone for the UX143 program recognized during the year ended December 31, 2023, as compared to $75.0 million recognized from the GeneTx acquisition for the year ended December 31, 2022;

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for approved products, a decrease of $22.2 million, primarily due to transition of Crysvita commercialization responsibilities in North America to KKC and realized cost efficiencies for Dojolvi, partially offset by reimbursement of Regeneron collaboration expenses and increased personnel and launch costs for Evkeeza;

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for infrastructure, an increase of $7.3 million, primarily related to increased expenses for support of our clinical and research program pipeline, expansion of laboratory space, depreciation of laboratory-related leasehold improvements and equipment, and IT-related expenses; and

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for other research and development expenses, an increase of $6.6 million, primarily related to increased staffing and material costs to support internal manufacturing and increased administrative and general support.

We expect our annual research and development expenses to continue to moderate in the future as we advance our product candidates through clinical development. The timing and amount of expenses incurred will depend largely upon the outcomes of current or future clinical studies for our product candidates as well as the related regulatory requirements, manufacturing costs, and any costs associated with the advancement of our preclinical programs.

Selling, General and Administrative Expenses (dollars in thousands)

Year Ended December 31, Dollar Percent

Selling, general and administrative expenses increased $31.7 million for the year ended December 31, 2023, compared to the same period in 2022. The increases in selling, general and administrative expenses were primarily due to increases in commercialization costs, and professional services costs, as well as a one-time legal settlement of $6.2 million for the year ended December 31, 2023.

We expect selling, general and administrative expenses to continue to moderate in the future as we continue to support our approved products and multiple clinical-stage product candidates, with expected decreases in commercial activities due to transition of Crysvita commercial responsibilities to our partner in the Profit-Share Territory.

Interest Income (dollars in thousands)

Year Ended December 31, Dollar Percent

Interest income increased $15.6 million for the year ended December 31, 2023 compared to the same period in 2022, primarily due to increases in interest rates.

Change in Fair Value of Equity Investments (dollars in thousands)

Year Ended December 31, Dollar Percent

For the year ended December 31, 2023, we recorded a net increase in the fair value of our equity investments of $0.4 million due to an increase in the fair value of our investments in Solid Biosciences Inc., or Solid, common stock for the period.

For the year ended December 31, 2022, we recorded a net decrease in the fair value of our equity investments of $19.3 million. The fair value of our investments in Arcturus Therapeutics Holdings Inc., or Arcturus, and Solid common stock decreased by $8.4 million and $10.9 million, respectively, for the period. The change in fair value of Arcturus included a realized gain on the sale of all our remaining shares of common stock for net proceeds of $10.1 million. As of December 31, 2022, we had sold all our remaining equity investments in Arcturus.

Non-cash Interest Expense on Liabilities for Sales of Future Royalties (dollars in thousands)

Year Ended December 31, Dollar Percent

Our non-cash interest expense on liabilities for sales of future royalties increased by $23.0 million for the year ended December 31, 2023, compared to the same period in 2022. This was primarily due to the partial sale of North American Crysvita royalties to OMERS in July 2022, with a full year of interest expense in 2023. To the extent the royalty payments are greater or less than our initial estimates or the timing of such payments is materially different than our original estimates, we prospectively adjust the effective interest rate.

Other Expense (dollars in thousands)

Year Ended December 31, Dollar Percent

Other expense decreased $1.2 million for the year ended December 31, 2023, compared to the same period in 2022. These changes were primarily due to fluctuations in foreign exchange rates.

Benefit from (provision for) income taxes

Year Ended December 31, Dollar Percent

For the year ended December 31, 2023, we recognized an income tax benefit of $4.8 million attributable to modifications in our state apportionment methodology. We realized no benefit for current year losses due to a full valuation allowance against the U.S. net deferred tax assets. The benefit was offset by an income tax expense of $3.0 million from foreign jurisdictions.

Beginning in 2022, the Tax Cuts and Jobs Act of 2017 eliminated the right to deduct research and development expenditures for tax purposes in the period the expenses were incurred and instead requires all U.S. and foreign research and development expenditures to be amortized over five and fifteen tax years, respectively. Due to this required capitalization of research and

development expenditures and the significant taxable income generated as a result of our sale of royalties in July 2022, we recorded a one-time discrete tax expense of $6.1 million for the year ended December 31, 2022. The discrete tax expense is for state taxes we anticipate paying as a result of statutory limitations on our ability to offset expected taxable income with net operating loss carry forwards in certain states. We realized no benefit for current year losses due to a full valuation allowance against the U.S. net deferred tax assets.

Liquidity and Capital Resources

To date, we have funded our operations primarily from the sale of our equity securities, revenue from our commercial products, the sale of certain future royalties, and strategic collaboration arrangements.

As of December 31, 2023, we had $777.1 million in available cash, cash equivalents, and marketable debt securities. We believe that our existing capital resources will be sufficient to fund our projected operating requirements for at least the next twelve months. Our cash, cash equivalents, and marketable debt securities are held in a variety of deposit accounts, interest-bearing accounts, corporate bond securities, commercial paper, U.S government securities, asset-backed securities, and money market funds. Cash in excess of immediate requirements is invested with a view toward liquidity and capital preservation, and we seek to minimize the potential effects of concentration and credit risk.

In October 2023, we completed an underwritten public offering in which 9,833,334 shares of common stock were sold, including the exercise in full by the underwriters of their option to purchase an additional 1,500,000 shares, at a public offering price of $30.00 per share. In connection with the offering, we sold to certain investors pre-funded warrants, in lieu of common stock, to purchase 1,666,722 shares of common stock at a purchase price of $29.999 per pre-funded warrant, which equals the public offering price per share of common stock less the $0.001 exercise price per share of each pre-funded warrant. The total proceeds that we received from the offering were $326.5 million, net of underwriting discounts and commissions.

In May 2021, we entered into an Open Market Sale Agreement with Jefferies LLC, or Jefferies, pursuant to which we may offer and sell shares of our common stock having an aggregate offering proceeds up to $350.0 million, from time to time, in at-the-market, or ATM, offerings through Jefferies. There were 1,175,584 shares sold under this arrangement for the year ended December 31, 2023, for net proceeds of $53.3 million. No shares were sold under this arrangement for the year ended December 31, 2022. As of December 31, 2023, net proceeds from shares sold under the arrangement were $132.2 million.

The following table summarizes our cash flows for the periods indicated (in thousands):

Year Ended December 31,

Cash provided by (used in) investing activities 168,000 (291,652 )

Effect of exchange rate changes on cash 462 (1,075 )

Cash Used in Operating Activities

Our primary use of cash is to fund operating expenses, which consist primarily of research and development and commercial expenditures. Due to our significant research and development expenditures, we have generated significant operating losses since our inception. Cash used to fund operating expenses is affected by the timing of when we pay these expenses, as reflected in the change in our outstanding accounts payable and accrued expenses.

Cash used in operating activities for the year ended December 31, 2023 was $474.8 million and primarily reflected a net loss of $606.6 million, partially offset by non-cash items of $146.9 million, net, which consisted primarily of non-cash collaboration royalty revenues, interest expense related to the sale of future royalties to RPI and OMERS, net of amounts capitalized, stock-based compensation, amortization of discounts on marketable debt securities, and depreciation and amortization. The change in operating assets and liabilities also reflected a net use of cash of $15.1 million, primarily due to an increase in accounts receivable primarily related to an increase in sales of our approved products, partially offset by a net decrease in other assets primarily in prepaid manufacturing.

Cash used in operating activities for the year ended December 31, 2022 was $380.5 million and reflected a net loss of $707.4 million partially offset by non-cash items of $266.7 million, net, which consisted primarily of non-cash collaboration royalty revenues, interest expense related to the sale of future royalties to RPI and OMERS, net of amounts capitalized, stock-based compensation, acquired in-process research and development relating to our acquisition of GeneTx, the change in fair value of equity investments, primarily for the net change in fair value of equity investments from Arcturus and Solid, and depreciation and amortization. The change in operating assets and liabilities also reflected net cash provided of $60.2 million, primarily due to an increase in accounts payable, accrued, and other liabilities, primarily due to timing of payments and receipt of invoices, as well as an increase in manufacturing accruals related to manufacturing and clinical expenses, an increase in accrued bonus due to an increase in headcount, and an increase in accrued development costs owed to a collaboration partner, partially offset by an increase in accounts receivable primarily related to an increase in sales of our approved products.

Cash Provided by (Used in) Investing Activities

Cash provided by investing activities for the year ended December 31, 2023 was $168.0 million and was primarily related to $219.8 million from net activities in marketable debt securities, offset by purchases of property, plant, and equipment of $44.3 million, primarily related to the fit-out of our gene therapy manufacturing facility.

Cash used in investing activities for the year ended December 31, 2022 was $291.7 million and was primarily related to purchases of property, plant, and equipment of $116.1 million, primarily related to the construction of our gene therapy manufacturing facility, the acquisition of GeneTx for $75.0 million, net of cash acquired, $79.8 million from net activities in marketable debt securities, and the payment to Regeneron for intangible assets of $30.0 million, offset by proceeds from the sale of Arcturus common stock of $10.1 million.

Cash Provided by Financing Activities

Cash provided by financing activities for the year ended December 31, 2023 was $388.1 million and was primarily comprised of $326.5 million in net proceeds from the sale of common stock in our October 2023 underwritten public offering and $53.3 million in net proceeds from the issuance of common stock from our ATM.

Cash provided by financing activities for the year ended December 31, 2022 was $501.2 million and was primarily comprised of $491.0 million in net proceeds from the partial sale of future North America Crysvita royalties to OMERS and $10.8 million in net proceeds from the issuance of common stock upon the exercise of stock options, net of taxes withheld from the vesting of restricted stock units.

Funding Requirements

We anticipate that, excluding non-recurring items, we will continue to generate annual losses for the foreseeable future as we continue the development of, and seek regulatory approvals for, our product candidates, and continue with commercialization of approved products. We may require additional capital to fund our operations, to complete our ongoing and planned clinical studies, to commercialize our products, to continue investing in early-stage research capabilities to promote our pipeline growth, to continue to acquire or invest in businesses or products that complement or expand our business, including future milestone payments thereunder, and to further develop our general infrastructure and such funding may not be available to us on acceptable terms or at all.

If we are unable to raise additional capital in sufficient amounts or on terms acceptable to us, we may be required to delay, limit, reduce the scope of, or terminate one or more of our clinical studies, research and development programs, future commercialization efforts, or grant rights to develop and market product candidates that we would otherwise prefer to develop and market ourselves.

Our future funding requirements will depend on many factors, including the following:

•

the scope, rate of progress, results and cost of our clinical studies, nonclinical testing, and other related activities;

•

the cost of manufacturing clinical supplies, and establishing commercial supplies, of our product candidates, products that we have begun to commercialize, and any products that we may develop in the future;

•

the cost of operating our GMP gene therapy manufacturing facility;

•

the number and characteristics of product candidates that we pursue;

•

the cost, timing, and outcomes of regulatory interactions and approvals;

•

the cost and timing of establishing our commercial infrastructure, and distribution capabilities;

•

the impact of macroeconomic conditions, including the general economic slowdown, inflationary pressure, high interest rates, a potential U.S. federal government shutdown, and potential recessionary environment on our business operations and operating results, as described in “Part I, Item IA. Risk Factors " and

•

the terms and timing of any collaborative, licensing, marketing, distribution, acquisition and other arrangements that we may establish, including any required upfront milestone, royalty, reimbursements or other payments thereunder.

We expect to satisfy future cash needs through existing capital balances, revenue from our commercial products, and a combination of public or private equity offerings, debt financings, collaborations, strategic alliances, licensing arrangements, and other marketing and distribution arrangements. Please see “Risk Factors—Risks Related to Our Financial Condition and Capital Requirements.”

Contractual Obligations and Commitments

Material contractual obligations arising in the normal course of business primarily consist of operating and finance leases and manufacturing and service contract obligations. See Note 9 to the Consolidated Financial Statements for amounts outstanding for operating and finance leases on December 31, 2023.

Manufacturing and service contract obligations primarily relate to manufacturing of inventory for our approved products, the majority of which are due in the next 12 months. See Note 15 to the Consolidated Financial Statements for these contractual obligations.

The terms of certain of our licenses, royalties, development and collaboration agreements, as well as other research and development activities, require us to pay potential future milestone payments based on product development success. The amount and timing of such obligations are unknown or uncertain. These potential obligations are further described in Note 8 to the Consolidated Financial Statements.

Recent Accounting Pronouncements

None.

Item 7A. Quantitative and Qualitative Disclosures about Market Risk

Interest Rate Risk

Our exposure to market risk for changes in interest rates relates primarily to interest earned on our cash equivalents and marketable debt securities. The primary objective of our investment activities is to preserve our capital to fund operations. A secondary objective is to maximize income from our investments without assuming significant risk. Our investment policy provides for investments in low-risk, investment-grade debt instruments. As of December 31, 2023, we had cash, cash equivalents, and marketable debt securities totaling $777.1 million, which included bank deposits, money market funds, U.S. government treasury and agency securities, and investment-grade corporate bond securities which are subject to default, changes in credit rating, and changes in market value. The securities in our investment portfolio are classified as available for sale and are subject to interest rate risk and will decrease in value if market interest rates increase. A hypothetical 100 basis point change in interest rates during any of the periods presented would not have had a material impact on the fair market value of our cash equivalents and marketable debt securities as of December 31, 2023. To date, we have not experienced a loss of principal on any of our investments and as of December 31, 2023, we did not record any allowance for credit loss from our investments.

Foreign Currency Risk

We face foreign exchange risk as a result of entering into transactions denominated in currencies other than U.S. dollars. Due to the uncertain timing of expected payments in foreign currencies, we do not utilize any forward exchange contracts. All foreign transactions settle on the applicable spot exchange basis at the time such payments are made. Volatile market conditions arising from the macroeconomic environment (including financial conditions affecting the banking system and financial institutions), inflation, or global political instability may result in significant changes in exchange rates, and in particular a weakening of foreign currencies relative to the U.S. dollar may negatively affect our revenue and operating income as expressed in U.S. dollars. An adverse movement in foreign exchange rates could have a material effect on payments made to foreign suppliers and payments related to license agreements. For the year ended December 31, 2023, a majority of our revenue, expenses, and capital expenditures were denominated in U.S. dollars. A hypothetical 10% change in foreign exchange rates during any of the periods presented would not have had a material impact on our Consolidated Financial Statements.

Item 8. Financial Statements and Supplementary Data

Our financial statements are annexed to this Annual Report beginning on page F-1 and are incorporated by reference into this Item 8.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

Evaluation of Disclosure Controls and Procedures

Management carried out an evaluation, under the supervision and with the participation of our Principal Executive Officer and our Principal Financial Officer, of the effectiveness of our “disclosure controls and procedures” as of the end of the period covered by this Annual Report, pursuant to Rules 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, or the Exchange Act. In connection with that evaluation, our Principal Executive Officer and our Principal Financial Officer concluded that our disclosure controls and procedures were effective and designed to provide reasonable assurance that the information required to be disclosed is recorded, processed, summarized, and reported within the time periods specified in the SEC rules and forms as of December 31, 2023. For the purpose of this review, disclosure controls and procedures means controls and procedures designed to ensure that information required to be disclosed by us in the reports that we file or submit is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms. These disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by us in the reports that we file or submit is accumulated and communicated to management, including our Principal Executive Officer and our Principal Financial Officer, as appropriate to allow timely decisions regarding required disclosure. In designing and evaluating the disclosure controls and procedures, our management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives, and our management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures.

Management’s Annual Report on Internal Control Over Financial Reporting

Management is responsible for establishing and maintaining adequate internal control over financial reporting as defined in Rules 13a-15(f) and 15d-15(f) of the Exchange Act. Our management used the Committee of Sponsoring Organizations of the Treadway Commission Internal Control - Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework), or the COSO framework, to evaluate the effectiveness of internal control over financial reporting. Management believes that the COSO framework is a suitable framework for its evaluation of financial reporting because it is free from bias, permits reasonably consistent qualitative and quantitative measurements of our internal control over financial reporting, is sufficiently complete so that those relevant factors that would alter a conclusion about the effectiveness of our internal control over financial reporting are not omitted and is relevant to an evaluation of internal control over financial reporting.

Management has assessed the effectiveness of our internal control over financial reporting as of December 31, 2023, and has concluded that as of such date, our internal control over financial reporting was effective.

Our independent registered public accounting firm, Ernst & Young LLP, has audited the financial statements included in this Annual Report and has issued a report on the effectiveness of our internal control over financial reporting. The report of Ernst & Young LLP is included below.

Changes in Internal Control over Financial Reporting

There have been no changes in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) during our fourth quarter ended December 31, 2023, that have materially affected, or are reasonably likely to materially affect our internal control over financial reporting.

Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of Ultragenyx Pharmaceutical Inc.

Opinion on Internal Control Over Financial Reporting

We have audited Ultragenyx Pharmaceutical Inc.’s internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the

Treadway Commission (2013 framework) (the COSO criteria). In our opinion, Ultragenyx Pharmaceutical Inc. (the Company) maintained, in all material respects, effective internal control over financial reporting as of December 31, 2023, based on the COSO criteria.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the consolidated balance sheets of the Company as of December 31, 2023 and 2022, the related consolidated statements of operations, comprehensive loss, stockholders’ equity and cash flows for each of the three years in the period ended December 31, 2023, and the related notes and our report dated February 21, 2024 expressed an unqualified opinion thereon.

Basis for Opinion

The Company’s management is responsible for maintaining effective internal control over financial reporting and for its assessment of the effectiveness of internal control over financial reporting included in the accompanying Management’s Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company’s internal control over financial reporting based on our audit. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects.

Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

Definition and Limitations of Internal Control Over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

/s/ Ernst & Young LLP

San Mateo, California

February 21, 2024

Item 9B. Other Information

On November 10, 2023, Corsee Sanders, Ph.D., a member of the Company’s Board of Directors, adopted a trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c), to sell up to 2,322 shares of the Company’s common stock through July 12, 2024, subject to certain conditions.

On December 7, 2023, Matthew Fust, a member of the Company’s Board of Directors, adopted a trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c), to sell up to 12,195 shares of the Company’s common stock through December 6, 2024, subject to certain conditions.

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Not applicable.

PART III

Item 10. Directors, Executive Officers and Corporate Governance

Except as set forth below, the information required by this Item is incorporated herein by reference to information in the proxy statement for our 2024 Annual Meeting of Stockholders, which we will file with the SEC within 120 days of the end of the fiscal year to which this Annual Report relates, or the “2024 Proxy Statement”, including under the headings “Nominees and Incumbent Directors,” “Executive Officers,” ““Board of Directors and Committees,” and, as applicable, “Delinquent Section 16(a) Beneficial Ownership Reports.” We have adopted a code of ethics that applies to all of our directors, officers and employees, including our principal executive, principal financial and principal accounting officers, or persons performing similar functions, or Code of Ethics. Our Code of Ethics is posted on our website located at https://ir.ultragenyx.com/ under “Corporate Governance”. We intend to disclose future amendments to certain provisions of the Code of Ethics, and waivers of the Code of Ethics granted to executive officers and directors, on the website within four business days following the date of the amendment or waiver.

Item 11. Executive Compensation

The information required by this Item is incorporated herein by reference to information in the 2024 Proxy Statement, including under the headings “Executive Compensation,” “Director Compensation,” and “Board of Directors and Committees.”

Item 12.Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

The information required by this Item is incorporated herein by reference to information in the 2024 Proxy Statement, including under the headings “Security Ownership of Certain Beneficial Owners and Management” and “Equity Compensation Plan Information.”

Item 13. Certain Relationships and Related Transactions, and Director Independence

The information required by this Item is incorporated herein by reference to information in the 2024 Proxy Statement, including under the headings “Certain Relationships and Related-Person Transactions,” “Corporate Governance,” and “Board of Directors and Committees.”

Item 14. Principal Accountant Fees and Services

The information required by this Item is incorporated herein by reference to information in the 2024 Proxy Statement, including under the heading “Proposal No. 3—Ratification of the Selection of Independent Registered Public Accounting Firm.”

PART IV

Item 15. Exhibits and Financial Statement Schedules

(a) The following documents are filed as part of this Annual Report.

(1) Consolidated Financial Statements

Consolidated Financial Statements—See Index to Consolidated Financial Statements at page F-1 of this Annual Report.

(2) Consolidated Financial Statement Schedules

Consolidated Financial Statement schedules have been omitted in this Annual Report because they are not applicable, not required under the instructions, or the information requested is set forth in the Consolidated Financial Statements or related notes thereto.

(b) Exhibits

Exhibit Incorporated by Reference Filed

Number Exhibit Description Form Date Number Herewith

3.1 Amended and Restated Certificate of Incorporation 8-K 2/5/2014 3.1

10.30# Form of Incentive Stock Option Agreement (2023 Plan) X

10.31# Form of Non Statutory Stock Option Agreement (Employees)(2023 Plan) X

10.32# Form of Restricted Stock Unit Agreement (Employees)(2023 Plan) X

10.42# First Amendment to Employment Inducement Plan S-8 6/8/2023 4.7

21.1 Subsidiaries of Ultragenyx Pharmaceutical Inc. X

23.1 Consent of Independent Registered Public Accounting Firm X

24.1 Power of Attorney (included on the signature page of this report)

97.1 Ultragenyx Pharmaceutical Inc. Clawback Policy X

101.INS XBRL Instance Document, formatted in Inline XBRL X

101.SCH Inline XBRL Taxonomy Extension Schema Document X

* Certain identified information has been omitted by means of marking such information with asterisks in reliance on Item 601(b)(10)(iv) of Regulation S-K because it is both (i) not material and (ii) the type that the registrant treats as private or confidential.

# Indicates management contract or compensatory plan.

§ The certification attached as Exhibit 32.1 that accompanies this Annual Report is not deemed filed with the SEC and is not to be incorporated by reference into any filing of Ultragenyx Pharmaceutical Inc. under the Securities Act or the Exchange Act, whether made before or after the date of this Annual Report, irrespective of any general incorporation language contained in such filing.

Item 16. Form 10-K Summary

None.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

ULTRAGENYX PHARMACEUTICAL Inc.

By: /s/ Emil D. Kakkis

Emil D. Kakkis, M.D., Ph.D.

President and Chief Executive Officer(Principal Executive Officer)

Date: February 21, 2024

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Emil D. Kakkis, M.D., Ph.D. and Howard Horn, and each of them, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution for him or her, and in his or her name in any and all capacities, to sign any and all amendments to this Annual Report, and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done therewith, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, and any of them, his or her substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

Signature Title Date

/s/ Daniel G. Welch Daniel G. Welch Chairman of the Board February 21, 2024

/s/ Deborah DunsireDeborah Dunsire, M.D. Director February 21, 2024

/s/ Matthew K. Fust Matthew K. Fust Director February 21, 2024

/s/ Michael Narachi Michael Narachi Director February 21, 2024

/s/ Amrit Ray Director February 21, 2024

Amrit Ray, M.D.

/s/ Corsee D. Sanders Director February 21, 2024

Corsee D. Sanders, Ph.D.

/s/ Shehnaaz Suliman Director February 21, 2024

Shehnaaz Suliman, M.D.

Ultragenyx Pharmaceutical Inc.

INDEX TO FINANCIAL STATEMENTS

Page

Report of Independent Registered Public Accounting Firm (PCAOB ID: 42) F-2

Consolidated Financial Statements:

Consolidated Balance Sheets F-4

Consolidated Statements of Operations F-5

Consolidated Statements of Comprehensive Loss F-5

Consolidated Statements of Stockholders’ Equity F-6

Consolidated Statements of Cash Flows F-7

Notes to Consolidated Financial Statements F-9

F-1

Report of Independent Registered Public Accounting Firm

To the Stockholders and the Board of Directors of Ultragenyx Pharmaceutical Inc.

Opinion on the Financial Statements

We have audited the accompanying consolidated balance sheets of Ultragenyx Pharmaceutical Inc. (the Company) as of December 31, 2023 and 2022, the related consolidated statements of operations, comprehensive loss, stockholders' equity and cash flows for each of the three years in the period ended December 31, 2023, and the related notes (collectively referred to as the “consolidated financial statements”). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2023, in conformity with U.S. generally accepted accounting principles.

We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the Company's internal control over financial reporting as of December 31, 2023, based on criteria established in Internal Control—Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (2013 framework), and our report dated February 21, 2024 expressed an unqualified opinion thereon.

Basis for Opinion

These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on the Company’s financial statements based on our audits. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. Our audits included performing procedures to assess the risks of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the financial statements and (2) involved our especially challenging, subjective or complex judgments. The communication of the critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Liabilities for sales of future royalties

F-2

/s/ Ernst & Young LLP

We have served as the Company’s auditor since 2012.

San Mateo, California

February 21, 2024

F-3

ULTRAGENYX PHARMACEUTICAL INC.

CONSOLIDATED BALANCE SHEETS

(In thousands, except share and per share amounts)

December 31,

ASSETS

Current assets:

LIABILITIES AND STOCKHOLDERS' EQUITY

Current liabilities:

Contract liabilities — 1,479

Liabilities for sales of future royalties 29,242 —

Commitments and contingencies (Notes 9 and 15)

Stockholders’ equity:

Deferred compensation obligation 432 —

Accumulated other comprehensive income (loss) 647 (6,573 )

See accompanying notes.

F-4

ULTRAGENYX PHARMACEUTICAL INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except share and per share amounts)

Year Ended December 31,

Revenues:

Operating expenses:

Change in fair value of equity investments 397 (19,299 ) (42,063 )

Benefit from (provision for) income taxes 1,825 (5,696 ) (1,044 )

Net loss per share, basic and diluted $ (8.25 ) $ (10.12 ) $ (6.70 )

See accompanying notes.

ULTRAGENYX PHARMACEUTICAL INC.

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

(In thousands)

Year Ended December 31,

Other comprehensive income (loss):

Foreign currency translation adjustments 239 (724 ) (550 )

Unrealized gain (loss) on available-for-sale securities 6,981 (4,445 ) (1,543 )

See accompanying notes.

F-5

ULTRAGENYX PHARMACEUTICAL INC.

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

(In thousands, except share amounts)

Shares Amount Capital Income (Loss) Deficit Stock Obligation Equity

Other comprehensive loss — — — (2,093 ) — — — (2,093 )

Other comprehensive loss — — — (5,169 ) — — — (5,169 )

Deferred compensation — — — — — (432 ) 432 —

Other comprehensive income — — — 7,220 — — — 7,220

See accompanying notes.

F-6

ULTRAGENYX PHARMACEUTICAL INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

Year Ended December 31,

Operating activities:

Adjustments to reconcile net loss to net cash used in operating activities:

Acquired in-process research and development — 75,033 —

Changes in operating assets and liabilities:

Deferred tax liabilities (1,619 ) (1,639 ) —

Investing activities:

Acquisition, net of cash acquired — (75,025 ) —

Proceeds from sale of equity investments — 10,094 79,843

Payment for intangible asset (2,500 ) (30,000 ) —

Financing activities:

Proceeds from the sale of future royalties, net — 490,950 —

Effect of exchange rate changes on cash 462 (1,075 ) (1,194 )

F-7

See accompanying notes.

ULTRAGENYX PHARMACEUTICAL INC.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

Year Ended December 31,

Supplemental disclosures of non-cash investing and financing information:

See accompanying notes.

F-8

ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements

Organization and Basis of Presentation

Ultragenyx Pharmaceutical Inc., or the Company, is a biopharmaceutical company incorporated in Delaware.

The Company is focused on the identification, acquisition, development, and commercialization of novel products for the treatment of serious rare and ultrarare genetic diseases. The Company operates as one reportable segment and has four commercially approved products.

Crysvita® (burosumab) is approved in the United States, or U.S., the European Union, or EU, and certain other regions for the treatment of X-linked hypophosphatemia, or XLH, in adult and pediatric patients one year of age and older. Crysvita is also approved in the U.S. and certain other regions for the treatment of fibroblast growth factor 23, or FGF23-related hypophosphatemia in tumor-induced osteomalacia, or TIO, associated with phosphaturic mesenchymal tumors that cannot be curatively resected or localized in adults and pediatric patients 2 years of age and older.

Mepsevii® (vestronidase alfa) is approved in the U.S., the EU and certain other regions, as the first medicine for the treatment of children and adults with mucopolysaccharidosis VII, or MPS VII, also known as Sly syndrome.

Dojolvi® (triheptanoin) is approved in the U.S. and certain other regions for the treatment of pediatric and adult patients severely affected by long-chain fatty acid oxidation disorders, or LC-FAOD.

Evkeeza® (evinacumab) is approved in the U.S. and the European Economic Area, or EEA, for the treatment of homozygous familial hypercholesterolemia, or HoFH. The Company has exclusive rights to commercialize Evkeeza® (evinacumab) outside of the U.S.

In addition to the approved products, the Company has the following ongoing clinical development programs:

•

UX111 (formerly ABO-102) is an AAV9 gene therapy product candidate for the treatment of patients with Sanfilippo syndrome type A, or MPS IIIA, a rare lysosomal storage disease;

•

DTX401 is an adeno-associated virus 8, or AAV8, gene therapy product candidate for the treatment of patients with glycogen storage disease type Ia, or GSDIa;

•

DTX301 is an AAV8 gene therapy product candidate in development for the treatment of patients with ornithine transcarbamylase, or OTC deficiency, the most common urea cycle disorder;

•

UX143 (setrusumab), which is subject to the Company’s collaboration agreement with Mereo BioPharma 3, or Mereo, is a fully human monoclonal antibody that inhibits sclerostin, a protein that acts on a key bone-signaling pathway and inhibits the activity of bone-forming cells for the treatment of patients with osteogenesis imperfect, or OI;

•

GTX-102 is an antisense oligonucleotide, or ASO for the treatment of Angelman syndrome, a debilitating and rare neurogenetic disorder caused by loss-of-function of the maternally inherited allele of the UBE3A gene.; and

•

UX701 is an adeno-associated virus 9, or AAV9, gene therapy designed to deliver stable expression of a truncated version of the ATP7B copper transporter following a single intravenous infusion to improve copper distribution and excretion from the body and reverse pathological findings of Wilson liver disease;

The Company has sustained operating losses and expects such annual losses to continue over the next several years. The Company’s ultimate success depends on the outcome of its research and development and commercialization activities. Through December 31, 2023, the Company has relied primarily on its sale of equity securities, its revenues from commercial products, its sale of future royalties, and strategic collaboration arrangements to finance its operations. The Company may need to raise additional capital to fully implement its business plans through the issuance of equity, borrowings, or strategic alliances with partner companies. However, if such financing is not available at adequate levels, the Company would need to reevaluate its operating plans.

Summary of Significant Accounting Policies

Basis of Consolidation

The Consolidated Financial Statements include the accounts of Ultragenyx Pharmaceutical Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated.

ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Use of Estimates

The accompanying Consolidated Financial Statements have been prepared in accordance with U.S. generally accepted accounting principles, or GAAP. The preparation of the Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent liabilities and the reported amounts of expenses in the Consolidated Financial Statements and the accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to clinical trial accruals, fair value of assets and liabilities, income taxes, stock-based compensation, revenue recognition, and the liabilities for sales of future royalties. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could differ from those estimates.

Cash, Cash Equivalents, and Restricted Cash

The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash equivalents consist primarily of amounts invested in money market accounts.

Restricted cash primarily consists of money market accounts used as collateral for the Company’s obligations under its facility leases and the gene therapy building construction project.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows (in thousands):

December 31,

Restricted cash included in other current assets 2,008 862 —

Restricted cash included in other non-current assets 3,807 3,795 2,001

Marketable Debt Securities

All marketable debt securities have been classified as “available-for-sale” and are carried at estimated fair value as determined based upon quoted market prices or pricing models for similar securities. Management determines the appropriate classification of its investments at the time of purchase and reevaluates such designation as of each balance sheet date. Investments with a maturity of one year or less from the balance sheet date are reported as current marketable debt securities and investments with a maturity of greater than one year from the balance sheet date are reported as non-current marketable debt securities. Unrealized gains and losses are excluded from earnings and are reported as a component of comprehensive loss. Realized gains and losses and declines in fair value judged to be other than temporary, if any, on available-for-sale securities are included in other income (expense). The cost of securities sold is based on the specific-identification method. Interest on investments is included in interest income.

Equity Investments

The Company records investments in equity securities, other than equity method investments, at fair market value, if the fair value is readily determinable. Equity securities with no readily determinable fair values are recorded using the measurement alternative of cost adjusted for observable price changes in orderly transactions for identical or similar investments of the same issuer less impairment, if any. Investments in equity securities are recorded in Equity investments on the Company's Consolidated Balance Sheets. Unrealized gains and losses are reported in Change in fair value of equity investments on the Company’s Consolidated Statements of Operations. The Company regularly reviews its non-marketable equity securities for indicators of impairment.

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Concentration of Credit Risk, Credit Losses, and Other Risks and Uncertainties

Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash, cash equivalents, and investments. The Company’s cash, cash equivalents, and investments are held by financial institutions that management believes are of high credit quality. The Company’s investment policy limits investments to fixed income securities denominated and payable in U.S. dollars such as U.S. government obligations, money market instruments and funds, corporate bonds, commercial paper, and asset-backed securities and places restrictions on maturities and concentrations by type and issuer. Such deposits may, at times, exceed federally insured limits. The Company has not experienced any losses on its deposits of cash and cash equivalents and its accounts are monitored by management to mitigate risk. The Company is exposed to credit risk in the event of default by the financial institutions holding its cash and cash equivalents, corporate issuers, and other financial instruments, to the extent recorded in the Consolidated Balance Sheets.

The Company is exposed to credit losses primarily through receivables from customers and collaborators and through its available-for-sale debt securities. For trade receivables and other instruments, the Company uses a forward-looking expected loss model that generally results in the earlier recognition of allowances for losses. For available-for-sale debt securities with unrealized losses, the losses are recognized as allowances rather than as reductions in the amortized cost of the securities.

The Company’s expected loss allowance methodology for the receivables is developed using historical collection experience, current and future economic market conditions, a review of the current aging status and financial condition of the entities. Specific allowance amounts are established to record the appropriate allowance for customers that have a higher probability of default. Balances are written off when determined to be uncollectible. The Company’s expected loss allowance methodology for the debt securities is developed by reviewing the extent of the unrealized loss, the size, term, geographical location, and industry of the issuer, the issuers’ credit ratings and any changes in those ratings, as well as reviewing current and future economic market conditions and the issuers’ current status and financial condition. There was no allowance for losses on available-for-sale debt securities which were attributable to credit risk for the years ended December 31, 2023 and 2022.

The Company is dependent on third-party manufacturers to supply products for research and development activities in its programs. In particular, the Company relies and expects to continue to rely on a small number of manufacturers to supply it with its requirements for the active pharmaceutical ingredients and formulated drugs related to these programs. These programs could be adversely affected by a significant interruption in the supply of active pharmaceutical ingredients and formulated drugs.

Inventory

The Company values inventory at the lower of cost and net realizable value and determines the cost of inventory using the average-cost method. The Company expenses costs associated with the manufacture of product candidates prior to regulatory approval. Inventories consist of currently approved products. The Company periodically reviews its inventories for excess amounts or obsolescence and writes down obsolete or otherwise unmarketable inventory to its estimated net realizable value. Management determines excess inventory based on expected future demand. Estimates related to future demand are sensitive to significant inputs and assumptions such as acceptance by patients and physicians and the availability of formulary coverage and adequate reimbursement from private third-party payers for the product.

Property, Plant, and Equipment

Property, plant, and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization is computed using the straight-line method over the estimated useful lives of the respective assets. Depreciation and amortization begins when the asset is placed in service. Interest costs incurred during the construction of major capital projects are capitalized until the underlying asset is ready to be placed in service. Maintenance and repairs are charged to operations as incurred. Upon sale or retirement of assets, the cost and related accumulated depreciation or amortization are removed from the balance sheet and the resulting gain or loss, if any, is reflected in operations. See “Note 4. Balance Sheet Components” for further disclosure on the useful lives of property, plant, and equipment.

Intangible Assets

Finite-lived intangibles consist of contractual payments made for certain milestones achieved with collaboration partners. The contractual payments are recorded as intangible assets and are amortized over their estimated useful lives. The Company reviews its definite-lived intangible assets when events or circumstances may indicate that the carrying value of these assets is not recoverable and exceeds their fair value. The Company measures fair value based on the estimated future undiscounted cash flows associated with these assets in addition to other assumptions and projections that the Company deems to be reasonable and supportable.

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Indefinite-lived intangibles consist of acquired in-process research and development, or IPR&D. IPR&D assets represent capitalized incomplete research projects that the Company acquired through business combinations. Such assets are initially measured at their acquisition date fair values and are tested for impairment annually and whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. When development of the project is complete, which generally occurs when regulatory approval to market a product is obtained, the associated assets will be deemed finite-lived and will be amortized over a period that best reflects the economic benefits provided by these assets.

If it is determined that an intangible asset becomes impaired, the carrying value is written down to its fair value with the related impairment charge recognized in Consolidated Statements of Operations in the period in which the impairment occurs. The Company has not recorded any impairments of intangible assets to date.

Goodwill

Goodwill represents the excess of purchase price over fair value of net assets acquired in a business combination and is not amortized. Goodwill is subject to impairment testing at least annually during the fourth quarter or when a triggering event occurs that could indicate a potential impairment. If it is determined that the goodwill becomes impaired, the carrying value is written down to its fair value with the related impairment charge recognized in Consolidated Statements of Operations in the period in which the impairment occurs. The Company has not recorded any impairments of goodwill.

Impairment of Long-Lived Assets

The Company evaluates its long-lived assets, including property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable. Recoverability of these assets is measured by comparison of the carrying amount of each asset to the future undiscounted cash flows expected to result from the use of the asset and its eventual disposition. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. The Company has not recorded material impairment of any long-lived assets.

Accruals of Research and Development Costs

The Company records accruals for estimated costs of research, preclinical and clinical studies and manufacturing development. These costs are a significant component of the Company’s research and development expenses. A substantial portion of the Company’s ongoing research and development activities are conducted by third-party service providers, including contract research organizations. The Company accrues the costs incurred under its agreements with these third parties based on actual work completed in accordance with agreements established with these third parties. The Company determines the actual costs through obtaining information from external service providers as to the progress or stage of completion of the services and the agreed-upon fee to be paid for such services.

Revenue Recognition

Product Sales

The Company sells its approved products through a limited number of distributors. Under ASC 606, revenue from product sales is recognized at the point in time when control is transferred to these distributors. The Company also recognizes revenue from sales of certain products on a “named patient” basis, which are allowed in certain countries prior to the commercial approval of the product. Prior to recognizing revenue, the Company makes estimates of the transaction price, including any variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. Product sales are recorded net of estimated government-mandated rebates and chargebacks, estimated product returns, and other deductions.

Provisions for returns and other adjustments are provided for in the period the related revenue is recorded, as estimated by management. These reserves are based on estimates of the amounts earned or to be claimed on the related sales and are reviewed periodically and adjusted as necessary. The Company’s estimates of government mandated rebates, chargebacks, estimated product returns, and other deductions depends on the identification of key customer contract terms and conditions, as well as estimates of sales volumes to different classes of payors. If actual results vary, the Company may need to adjust these estimates, which could have a material effect on earnings in the period of the adjustment.

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Collaboration, License, and Royalty Revenue

The Company has certain license and collaboration agreements that are within the scope of Accounting Standards Codification, or ASC, 808, Collaborative Agreements, which provides guidance on the presentation and disclosure of collaborative arrangements. Generally, the classification of the transactions under the collaborative arrangements is determined based on the nature of contractual terms of the arrangement, along with the nature of the operations of the participants. The Company records its share of collaboration revenue, net of transfer pricing related to net sales in the period in which such sales occur, if the Company is considered as an agent in the arrangement. The Company is considered an agent when the collaboration partner controls the product before transfer to the customers and has the ability to direct the use of and obtain substantially all of the remaining benefits from the product. Funding received related to research and development services and commercialization costs is generally classified as a reduction of research and development expenses and selling, general and administrative expenses, respectively, in the Consolidated Statements of Operations, because the provision of such services for collaborative partners are not considered to be part of the Company’s ongoing major or central operations.

The Company utilizes certain information from its collaboration partners to record collaboration revenue, including revenue from the sale of the product, associated reserves on revenue, and costs incurred for development and sales activities. For the periods covered in the financial statements presented, there have been no material changes to prior period estimates of revenues and expenses. The Company also records royalty revenues under certain of the Company’s license or collaboration agreements in exchange for license of intellectual property.

The Company sold the right to receive certain royalty payments from net sales of Crysvita in certain territories to RPI Finance Trust, or RPI, an affiliate of Royalty Pharma, and to OCM LS23 Holdings LP, an investment vehicle for Ontario Municipal Employees Retirement System, or OMERS, as further described in “Note 10. Liabilities for Sales of Future Royalties.” The Company records the royalty revenue from the net sales of Crysvita in the applicable territories on a prospective basis as non-cash royalty revenue in the Consolidated Statements of Operations over the term of the applicable arrangement.

The terms of the Company’s collaboration and license agreements may contain multiple performance obligations, which may include licenses and research and development activities. The Company evaluates these agreements under ASC 606, Revenue from Contracts with Customers, or ASC 606, to determine the distinct performance obligations. The Company analogizes to ASC 606 for the accounting for distinct performance obligations for which there is a customer relationship. Prior to recognizing revenue, the Company makes estimates of the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. Total consideration may include nonrefundable upfront license fees, payments for research and development activities, reimbursement of certain third-party costs, payments based upon the achievement of specified milestones, and royalty payments based on product sales derived from the collaboration.

If there are multiple distinct performance obligations, the Company allocates the transaction price to each distinct performance obligation based on its relative standalone selling price. The standalone selling price is generally determined based on the prices charged to customers or using expected cost-plus margin. The Company estimates the efforts needed to complete the performance obligations and recognizes revenue by measuring the progress towards complete satisfaction of the performance obligations using input measures.

Deferred Compensation Plan

The Company maintains a nonqualified deferred compensation plan whereby certain employees and members of the board of directors are able to defer certain equity awards and other compensation. Amounts deferred are invested into shares of the Company's common stock, mutual funds, and other investment options. The plan complies with the provisions of Section 409A of the Internal Revenue Code. All of the various mutual funds held in the plan are classified as trading securities and recorded at fair value in other non-current assets in the Consolidated Balance Sheets with changes in fair value recognized as earnings in the period they occur. The short-term portion of the corresponding liability for the plan is included in accrued expenses. The long-term portion of the liability is included in other non-current liabilities in the Consolidated Balance Sheets. Certain equity awards deferred under the plan are required to be settled through the issuance of Company stock. These awards are recorded as treasury stock and deferred compensation obligation within stockholders’ equity.

Leases

Lease agreements are evaluated to determine whether an arrangement is or contains a lease in accordance with ASC 842, Leases. The Company determines if an arrangement includes a lease at inception. Right-of-use lease assets and lease liabilities are

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. The right-of-use lease asset includes any lease payments made and excludes lease incentives. Incremental borrowing rate is used in determining the present value of future payments. The Company applies a portfolio approach to the property leases to apply an incremental borrowing rate to leases with similar lease terms. The lease terms may include options to extend or terminate the lease. The Company recognizes the options to extend the lease as part of the right-of-use lease assets and lease liabilities only if it is reasonably certain that the option would be exercised. Lease expense for minimum lease payments is recognized on a straight-line basis over the non-cancelable lease term. The Company has elected to not separate lease and non-lease components. See “Note 9. Leases” for further disclosure.

Comprehensive Loss

Comprehensive loss is the change in stockholders’ equity from transactions and other events and circumstances other than those resulting from investments by stockholders and distributions to stockholders. The Company’s other comprehensive loss is comprised of unrealized gains and losses on investments in available-for-sale securities and foreign currency translation adjustments.

Research and Development

Research and development costs are expensed as incurred and consist of salaries and benefits, stock-based compensation expense, lab supplies and facility costs, as well as fees paid to other nonemployees and entities that conduct certain research and development activities on the Company’s behalf. Amounts incurred in connection with license agreements are also included in research and development expense. Nonrefundable advance payments for goods or services to be received in the future for use in research and development activities are deferred. The deferred amounts are expensed as the related goods are delivered or the services are performed.

Stock-Based Compensation

Stock-based awards issued to employees, including stock options, performance stock options, or PSOs, restricted stock units, or RSUs, and performance stock units, or PSUs are recorded at fair value as of the grant date and recognized as expense on a straight-line basis over the employee’s requisite service period (generally the vesting period). PSOs and PSUs vest only if certain specified criteria are achieved and the employees’ continued service requirements are met; therefore, the expense recognition occurs when the likelihood of the PSOs and PSUs being earned is deemed probable. Stock compensation expense on awards expected to vest is recognized net of estimated forfeitures.

Income Taxes

The Company uses the liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The Company must then assess the likelihood that the resulting deferred tax assets will be realized. A valuation allowance is provided when it is more likely than not that some portion or all of a deferred tax asset will not be realized. Due to the Company’s lack of earnings history, the net deferred tax assets have been fully offset by a valuation allowance.

In conjunction with the acquisition of Dimension Therapeutics, Inc., or Dimension, a deferred tax liability was recorded reflecting the tax impact of the difference between the book basis and tax basis of acquired IPR&D. Such deferred income tax liability is not used to offset deferred tax assets when analyzing the Company’s valuation allowance as the acquired IPR&D is considered to have an indefinite life until the Company completes or abandons development of the acquired IPR&D.

The Company recognizes benefits of uncertain tax positions if it is more likely than not that such positions will be sustained upon examination based solely on their technical merits, as the largest amount of benefit that is more likely than not to be realized upon the ultimate settlement. The Company’s policy is to recognize interest and penalties related to the underpayment of income taxes as a component of income tax expense or benefit. To date, there have been no interest or penalties charged in relation to the unrecognized tax benefits.

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Foreign Currency

Assets and liabilities of non-U.S. subsidiaries that operate in a local currency environment, where the local currency is the functional currency, are translated to U.S. dollars at exchange rates in effect at the balance sheet date, with the resulting translation adjustments directly recorded to a separate component of accumulated other comprehensive loss. Income and expense accounts are translated at average exchange rates for the period. Transactions which are not in the functional currency of the entity are remeasured into the functional currency and gains or losses resulting from the remeasurement recorded in other income (expense).

Net Loss per Share

Basic net loss per share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration for common stock equivalents. Shares of common stock into which pre-funded warrants may be exercised are considered outstanding for the purposes of computing basic net loss per share because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date. Diluted net loss per share is the same as basic net loss per share, since the effects of potentially dilutive securities are antidilutive. In periods when we have incurred a net loss, options and warrants to purchase common stock are considered common stock equivalents, but have been excluded from the calculation of diluted net loss per share, as their effect is antidilutive.

Fair Value Measurements

Financial assets and liabilities are recorded at fair value. The carrying amount of certain financial instruments, including cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows:

Level 1—Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date;

Level 2—Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and

Level 3—Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data.

The Company’s financial instruments consist of Level 1, Level 2, and Level 3 assets. Where quoted prices are available in an active market, securities are classified as Level 1. Money market funds and U.S. Government treasury bills are classified as Level 1. Level 2 assets consist primarily of corporate bonds, asset backed securities, commercial paper, U.S. Government Treasury and agency securities, and debt securities in government-sponsored entities based upon quoted market prices for similar movements in active markets, quoted prices for identical or similar instruments in markets that are not active and model-based valuation techniques for which all significant inputs are observable in the market or can be corroborated by observable market data for substantially the full term of the assets. Where applicable these models project future cash flows and discount the future amounts to a present value using market-based observable inputs obtained from various third-party data providers, including but not limited to, benchmark yields, interest rate curves, reported trades, broker/dealer quotes and reference data.

The Company determines the fair value of its equity investments in Solid Biosciences, Inc., or Solid, by using the quoted market prices, which are Level 1 fair value measurements.

F-15

ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

The following tables set forth the fair value of the Company’s financial assets remeasured on a recurring basis based on the three-tier fair value hierarchy (in thousands):

Level 1 Level 2 Level 3 Total

Financial Assets:

Certificates of deposit and time deposits — 17,986 — 17,986

Investment in Solid common stock 3,204 — — 3,204

Financial Liabilities:

Deferred compensation liabilities $ — $ 10,365 $ — $ 10,365

Level 1 Level 2 Level 3 Total

Financial Assets:

Certificates of deposit and time deposits — 25,972 — 25,972

Debt securities in government-sponsored entities — 15,855 — 15,855

Investment in Solid common stock 2,807 — — 2,807

Deferred compensation assets — 4,575 — 4,575

Financial Liabilities:

Deferred compensation liabilities $ — $ 4,657 $ — $ 4,657

Deferred compensation assets are recorded at fair value in other non-current assets in the Consolidated Balance Sheets. There have been no significant gains or losses on deferred compensation assets for the periods presented.

Deferred compensation liabilities consist of short-term liabilities of $0.2 million and nil as of December 31, 2023 and 2022, respectively, included in accrued liabilities on the Consolidated Balance Sheets, and long-term liabilities of $10.1 million and $4.7 million as of December 31, 2023 and 2022, respectively, included in other non-current liabilities on the Consolidated Balance Sheets.

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Balance Sheet Components

Cash Equivalents and Marketable Debt Securities

The fair values of cash equivalents and marketable debt securities classified as available-for-sale securities consisted of the following (in thousands):

Gross Unrealized

AmortizedCost Gains Losses Estimated Fair Value

Certificates of deposit and time deposits 17,986 — — 17,986

Gross Unrealized

Amortized Cost Gains Losses Estimated Fair Value

Certificates of deposit and time deposits 25,972 — — 25,972

Debt securities in government-sponsored entities 16,005 — (150 ) 15,855

At December 31, 2023, the remaining contractual maturities of available-for-sale securities were less than three years. There have been no significant realized gains or losses on available-for-sale securities for the periods presented.

Inventory

Inventory consists of the following (in thousands):

December 31,

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Property, Plant, and Equipment, net

Property, plant, and equipment, net consists of the following (in thousands):

December 31,

Construction-in-progress Not applicable 867 189,448

Other Varies by asset 183 24

Depreciation expense for the years ended December 31, 2023, 2022, and 2021 was $22.2 million, $15.0 million and $12.9 million, respectively. Amortization of leasehold improvements and software is included in depreciation expense.

Construction in progress reflects amounts incurred for construction or improvements of property or costs for equipment that has not been placed in service. The construction-in-progress balance as of December 31, 2022 is primarily the construction costs for the gene therapy manufacturing facility in Bedford, Massachusetts.

Accrued Liabilities

Accrued liabilities consists of the following (in thousands):

December 31,

Research, clinical study, and manufacturing expenses $ 65,326 $ 73,558

Intangible Assets, net

Indefinite-lived Intangibles

The Company has IPR&D assets of $129.0 million as of December 31, 2023 and 2022. IPR&D assets represent the fair value of acquired programs to develop an AAV gene therapy for OTC deficiency and to develop an AAV gene therapy for glycogen storage disease type Ia. The fair value of IPR&D assets acquired was determined based on the discounted present value of each research project’s projected cash flows using an income approach, including the application of probability factors related to the likelihood of success of the program reaching final development and commercialization. Additionally, the projections consider the relevant market sizes and growth factors, estimated future cash flows from product sales resulting from completed products and in-process projects and timing and costs to complete the in-process projects. The rates utilized to discount the net cash flows to their present value are commensurate with the stage of development of the projects and uncertainties in the economic estimates used in the projections. IPR&D assets are considered to be indefinite-life until the completion or abandonment of the associated research and development efforts.

Finite-lived Intangibles

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Subsequent to the FDA approval of Dojolvi for the treatment of LC-FAOD in 2020, the Company recorded $4.8 million for the attainment of various development and commercial milestones as finite-lived intangible assets which are amortized over a weighted-average useful life of 5.7 years.

In January 2022, the Company announced a collaboration with Regeneron to commercialize Evkeeza for HoFH outside of the U.S. Upon closing of the transaction in January 2022, the Company paid Regeneron a $30.0 million upfront payment. During the year ended December 31, 2023, a $10.0 million regulatory milestone was achieved. As both the upfront payment and the regulatory milestone are related to the Company’s use of intellectual property for Evkeeza for HoFH, these amounts were recorded as intangible assets, which are amortized over a weighted-average useful life of ten years.

The Company's intangible assets were as follows:

The Company recorded costs of sales of $3.8 million, $3.2 million and $0.3 million for the years ended December 31, 2023, 2022, and 2021, respectively, related to the amortization of the intangible assets.

The expected amortization of the intangible assets, as of December 31, 2023, for each of the next five years and thereafter is as follows:

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ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

Revenue

The following table disaggregates total revenues from external customers by product sales, royalty revenue, and collaboration and license revenue (in thousands):

Year Ended December 31,

Product sales:

Collaboration and license revenue:

Crysvita royalty revenue in European Territory — — 244

The following table disaggregates total revenues based on geographic location (in thousands):

Year Ended December 31,

The following table presents the activity and ending balances for sales-related accruals and allowances (in thousands):

Year Ended December 31,

Balance of product sales reserve at beginning of year $ 11,487 $ 7,181 $ 3,913

Balance of product sales reserve at end of year $ 17,029 $ 11,487 $ 7,181

The following table presents changes in the contract liabilities for the years ended December 31, 2023 and 2022 (in thousands):

Year Ended December 31,

Balance of contract liabilities at beginning of period $ 1,479 $ 9,076

Additions — 89

Balance of contract liabilities at end of period, net $ — $ 1,479

F-20

ULTRAGENYX PHARMACEUTICAL INC.

Notes to Consolidated Financial Statements (continued)

See Note 8 for additional details on contract liabilities activities.

The Company’s largest accounts receivable balance was from a collaboration partner and was 53% and 68% of the total accounts receivable balance as of December 31, 2023 and 2022, respectively.

GeneTx Acquisition

In August 2019, the Company entered into a Program Agreement and a Unitholder Option Agreement with GeneTx Biotherapeutics LLC, or GeneTx, to collaborate on the development of GeneTx’s GTX-102, an ASO for the treatment of Angelman syndrome. In July 2022, pursuant to the terms of the Unitholder Option Agreement, as amended, the Company exercised the option to acquire GeneTx and entered into a Unit Purchase Agreement, or the Purchase Agreement, pursuant to which the Company purchased all the outstanding units of GeneTx. In accordance with the terms of the Purchase Agreement, the Company paid the option exercise price of $75.0 million and an additional $15.6 million to acquire the outstanding cash of GeneTx, and adjustments for working capital and transaction expenses of $0.6 million, for a total purchase consideration of $91.2 million. The Company may be required to make payments of up to $190.0 million upon the achievement of certain milestones, including up to $30.0 million in milestone payments upon achievement of the earlier of initiation of a Phase 3 clinical study or product approvals in Canada and the U.K., up to $85.0 million in additional regulatory approval milestones for the achievement of U.S. and EU product approvals, and up to $75.0 million in commercial milestone payments based on annual worldwide net product sales. The Company will also pay tiered mid- to high single-digit percentage royalties based on licensed product annual net sales. If the Company receives and resells an FDA priority review voucher, or PRV, in connection with a new drug application approval, GeneTx is entitled to receive a portion of proceeds from the sale or a cash payment from the Company if the Company choses to retain the PRV. As part of the Company's acquisition of GeneTx, the Company assumed a License Agreement with Texas A&M University, or TAMU. Under this agreement, TAMU is eligible to receive from the Company up to $23.5 million upon the achievement of various future milestones, a nominal annual license fee that may increase up to a maximum of $2.0 million, as well as royalties in the mid-single-digits of net sales.

The transaction was accounted as an asset acquisition, as substantially all of the fair value of the gross assets acquired was concentrated in a single identifiable in-process research and development intangible asset. Prior to the achievement of certain development and regulatory milestones, the acquired in-process research and development intangible asset has not yet reached technological feasibility and has no alternative future use. Accordingly, the Company recorded the acquisition price of $75.0 million, net of cash and working capital acquired, as in-process research and development expense during the year ended December 31, 2022.

License and Research Agreements

Kyowa Kirin Co., Ltd.

In August 2013, the Company entered into a collaboration and license agreement with Kyowa Kirin Co., Ltd., or KKC. Under the terms of this collaboration and license agreement, as amended, the Company and KKC collaborate on the development and commercialization of Crysvita in the field of orphan diseases in the U.S. and Canada, or the Profit-Share Territory, and in the European Union, United Kingdom, and Switzerland, or the European Territory, and the Company has the right to develop and commercialize such products in the field of orphan diseases in Mexico and Central and South America, or Latin America.

Development Activities

In the field of orphan diseases, except for ongoing studies being conducted by KKC, the Company was the lead party for development activities in the Profit-Share Territory and in the European Territory until the applicable transition date. The Company shared the costs for development activities in the Profit-Share Territory and the European Territory conducted pursuant to the development plan before the applicable transition date equally with KKC. In April 2023, which was the transition date for the Profit-Share Territory, KKC became the lead party and became responsible for the costs of the subsequent development activities. However, the Company will continue to equally share in the costs of the studies with KKC that commenced prior to the applicable transition date.

The collaboration and license agreements are within the scope of ASC 808, which provides guidance on the presentation and disclosure of collaborative arrangements.

Collaboration and Royalty Revenue for Sales in the Profit-Share Territory

The Company and KKC shared commercial responsibilities and profits in the Profit-Share Territory until April 2023. Under the collaboration agreement, KKC manufactured and supplied Crysvita for commercial use in the Profit-Share Territory and charged the Company a transfer price of 30% of net sales in 2023, and 35% prior to December 31, 2022. The remaining profit or loss after supply

F-21

RARE US Equity

RARE · 10-K · period ended 2023-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7A. Quantitative and Qualitative Disclosures about Market Risk

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation

Item 12.Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence

Item 14. Principal Accountant Fees and Services

Item 15. Exhibits and Financial Statement Schedules

Item 16. Form 10-K Summary

RARE US Equity☆

RARE · 10-K · period ended 2023-12-31

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Item 7A. Quantitative and Qualitative Disclosures about Market Risk

Item 8. Financial Statements and Supplementary Data

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

Item 9A. Controls and Procedures

Item 9B. Other Information

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections

Item 10. Directors, Executive Officers and Corporate Governance

Item 11. Executive Compensation

Item 12.Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence

Item 14. Principal Accountant Fees and Services

Item 15. Exhibits and Financial Statement Schedules

Item 16. Form 10-K Summary

RARE US Equity