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Item 8. Financial Statements and Supplementary Data

2026-02-19 compared with 2025-02-20 · 406 added, 420 removed, 642 unchanged (56% of the section changed)

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Notes to Financial Statements

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Report of Independent Registered Public Accounting Firm

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(the “Company”) as of December 31, 2025 and 2024, the related statements of operations and comprehensive loss, stockholders’ equity, and cash flows for each of the three years in the period ended December 31, 2025, and the related notes (collectively referred to as the “financial statements”).

In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2024 and 2023, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2024, in conformity with U.S.

In our opinion, the financial statements present fairly, in all material respects, the financial position of the Company at December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025, in conformity with U.S.

generally accepted accounting principles.

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The communication of the critical audit matter does not alter in any way our opinion on the 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.

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Description of the Matter

Estimates of Reserves for Variable Consideration Impacted by Estimated Payor Mix

As described in Notes 2 and 6 to the financial statements, the transaction price for product sales, net is reduced for estimates of variable consideration related to gross-to-net (“GTN”) adjustments for discounts and chargebacks, rebates, wholesaler and group purchasing organization (“GPO”) fees, copay assistance and returns.

As described in Note 2 and 6 to the financial statements, the transaction price for product sales, net is reduced for estimates of variable consideration related to gross-to-net (“GTN”) adjustments for discounts and chargebacks, rebates, wholesaler and group purchasing organization (“GPO”) fees, copay assistance and returns.

Except for certain wholesaler and GPO fees and discounts, which are based on contracts, these adjustments involve estimation and judgment.

The GTN adjustments for rebates, copay assistance and chargebacks are impacted by our estimate of payor mix, which requires significant judgment.

The GTN adjustments for rebates, copay assistance and chargebacks are impacted by the Company’s estimate of payor mix, which requires significant judgment.

The Company’s total estimate of reserves for variable consideration was $45.4 million as of December 31, 2025.

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We have served as the Company’s auditor since 2009.

Boston, Massachusetts

February 19, 2026

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ARDELYX, INC.

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Inventory, non-current 105,372 70,011

Prepaid commercial manufacturing, non-current — 4,235

Right-of-use assets 4,795 2,380

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Stockholders’ equity

Common stock, $ 0.0001 par value;

Common stock, $ 0.0001 par value per share;

500,000,000 shares authorized;

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The accompanying notes are an integral part of these financial statements.

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ARDELYX, INC.

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Total revenues 407,320 333,615 124,456

Cost of goods sold

Cost of product sales 6,851 2,323 566

Other cost of revenue 43,705 15,472 3,551

Total cost of goods sold 50,556 17,795 4,117

Operating expenses

Costs and operating expenses

Cost of sales 39,537 50,556 17,795

Research and development 71,527 52,317 35,536

Selling, general and administrative 337,233 258,692 134,401

Total operating expenses 311,009 169,937 111,800

Total costs and operating expenses 448,297 361,565 187,732

Loss from operations ( 40,977 ) ( 27,950 ) ( 63,276 )

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Net loss $ ( 61,599 ) $ ( 39,136 ) $ ( 66,067 )

Unrealized (losses) gains on available-for-sale securities ( 167 ) 278 ( 48 )

Unrealized gains (losses) on available-for-sale securities 141 ( 167 ) 278

Comprehensive loss $ ( 61,458 ) $ ( 39,303 ) $ ( 65,789 )

The accompanying notes are an integral part of these financial statements.

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ARDELYX, INC.

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Stock-based compensation — — 13,530 — — 13,530

Unrealized losses on available-for-sale securities — — — — ( 48 ) ( 48 )

Unrealized gains on available-for-sale securities — — — — 278 278

Net loss — — — ( 66,067 ) — ( 66,067 )

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Issuance of common stock upon vesting of restricted stock units 2,388,107 — — — — —

Issuance of common stock in at-the-market offering 32,274,741 3 119,233 — — 119,236

Stock-based compensation — — 37,381 — — 37,381

Unrealized gains on available-for-sale securities — — — — 278 278

Unrealized losses on available-for-sale securities — — — — ( 167 ) ( 167 )

Net loss — — — ( 39,136 ) — ( 39,136 )

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Stock-based compensation — — 48,962 — — 48,962

Unrealized losses on available-for-sale securities — — — — ( 167 ) ( 167 )

Unrealized gains on available-for-sale securities — — — — 141 141

Net loss — — — ( 61,599 ) — ( 61,599 )

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The accompanying notes are an integral part of these financial statements.

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ARDELYX, INC.

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Non-cash royalty revenue related to the sale of future royalties ( 8,545 ) ( 2,692 ) —

Gain on sale of equipment — — ( 1,260 )

Other, net ( 3,913 ) ( 4,664 ) ( 2,930 )

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Purchases of investments ( 218,923 ) ( 195,161 ) ( 215,225 )

Proceeds from sale of property and equipment — — 1,798

Purchases of property and equipment ( 1,492 ) ( 1,011 ) ( 344 )

Net cash (used in) provided by investing activities ( 18,318 ) ( 131,248 ) 18,415

Net cash used in investing activities ( 8,959 ) ( 18,318 ) ( 131,248 )

Financing activities

Proceeds from issuance of common stock in at the market offering, net of issuance costs — — 119,236

Proceeds from 2022 Loan Agreement, net of issuance costs 99,451 22,386 26,971

Proceeds from 2022 Loan Agreement, net of costs 48,668 99,451 22,386

Proceeds from the sale of future royalties, net of issuance costs — — 5,000

Proceeds from issuance of common stock under equity incentive and stock purchase plans 8,138 1,173 202

Payment of the exit fees ( 1,000 ) ( 1,500 ) —

Payments for the 2018 Loan, net of costs — — ( 33,038 )

Proceeds from issuance of common stock under equity incentive plans 5,841 8,138 1,173

Payments of the previously outstanding exit fees — ( 1,000 ) ( 1,500 )

Net cash provided by financing activities 54,509 106,589 146,295

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Issuance of common stock for services $ 315 $ 257 $ 337

Issuance of derivative in connection with issuance of loan payable $ — $ — $ 375

The accompanying notes are an integral part of these financial statements.

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ARDELYX, INC.

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NATURE OF OPERATIONS

We are a biopharmaceutical company founded with a mission to discover, develop and commercialize innovative, first-in-class medicines that meet significant unmet medical needs.

We developed a unique and innovative platform that enabled the discovery of new biological mechanisms and pathways to develop potent and efficacious therapies that minimize the side effects and drug-drug interactions frequently encountered with traditional, systemically absorbed medicines.

The first molecule we discovered and developed was tenapanor, a minimally absorbed, first-in-class, oral, small molecule therapy.

We are a commercial-stage biopharmaceutical company focused on the development and commercialization of innovative medicines that meet significant unmet medical needs.

We currently market two therapies from the active ingredient tenapanor, an NHE3 inhibitor that was discovered and developed by Ardelyx.

NHE3 is an antiporter expressed on the apical surface of the small and large intestines.

Tenapanor is a minimally absorbed, first-in-class, oral, small molecule therapy.

Tenapanor, branded as IBSRELA ® , is approved in the U.S.

for the treatment of adults with IBS-C.

for the treatment of adults with irritable bowel syndrome with constipation.

We believe that IBSRELA can bring meaningful benefit to the approximately 13 million Americans who suffer from the symptoms of IBS-C, many of whom continue to experience symptoms despite intervention with other therapies.

We are seeking to further expand the IBSRELA eligible patient population to include patients with CIC, and have initiated a Phase 3 clinical trial evaluating tenapanor in adult CIC patients.

Tenapanor, branded as XPHOZAH ® , is approved in the U.S.

to reduce serum phosphorus in adults with CKD on dialysis as add-on therapy in patients who have an inadequate response to phosphate binders or who are intolerant of any dose of phosphate binder therapy.

to reduce serum phosphorus in adults with chronic kidney disease on dialysis as add-on therapy in patients who have an inadequate response to phosphate binders or who are intolerant of any dose of phosphate binder therapy.

We believe XPHOZAH can bring meaningful relief to adult chronic kidney disease patients on dialysis, the vast majority of whom have elevated levels of serum phosphorus and are unable to achieve target serum phosphorus levels with phosphate binders alone.

Continually elevated levels of serum phosphorus can result in severe cardiovascular health complications.

In addition to commercializing IBSRELA and XPHOZAH, we are also developing a next-generation NHE3 inhibitor that we believe can have application across multiple therapeutic areas.

We operate in one business segment, which is the development and commercialization of biopharmaceutical products.

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Basis of Presentation

The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (U.S.

Certain prior year amounts have been reclassified to conform to the current year presentation.

The accompanying financial statements have been prepared in accordance with U.S.

Certain prior year amounts have been reclassified to conform to the current year presentation on the statements of operations and comprehensive loss to include the “cost of product sales” and the “other cost of revenue” captions within the “cost of sales” caption.

This reclassification had no effect on the previously reported results of operations.

Prior to the end of the 2025 second quarter, the “other cost of revenue” caption was primarily comprised of royalty expenses recognized under the AstraZeneca Termination Agreement.

As of the end of the 2025 second quarter, the maximum $ 75.0 million royalty obligation under this agreement had been fully recognized.

Refer to the Summary of Abbreviated Terms at the end of this Annual Report on Form 10-K for definitions of terms used throughout the document.

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The preparation of financial statements requires management to make estimates, judgments and assumptions.

The most significant assumptions are estimates used in our revenue gross-to-net accruals and other assumptions.

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.

Significant estimates include those used in our revenue gross-to-net adjustments and other estimates.

Management bases its estimates on historical experience and on various relevant assumptions that management believes to be reasonable under the circumstances.

Actual results could materially differ from those estimates.

Cash and Cash Equivalents

Cash and cash equivalents consist of highly liquid investments purchased with an original maturity date of 90 days or less and are recognized at cost, which approximates fair value.

Cash Equivalents

Cash equivalents consist of highly liquid investments purchased with an original maturity date of 90 days or less and are recognized at cost, which approximates fair value.

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Short-Term Investments

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Short-term investments are carried at fair value based upon quoted market prices or other observable market data.

Unrealized (losses) gains on available-for-sale securities are included in accumulated other comprehensive income on our balance sheets.

Unrealized gains (losses) on available-for-sale securities are included in accumulated other comprehensive income on our balance sheets.

The cost of available-for-sale securities sold is based on the specific-identification method.

Marketable debt securities are reviewed for impairment by determining whether the decline in their market value below carrying value is other-than-temporary.

This assessment considers the intent and ability to retain the investment for a period of time sufficient for an anticipated recovery in market value, the duration and extent that the market value has been below cost, and the investee’s financial condition.

This assessment considers the intent and ability to retain the investment for a period of time sufficient for an anticipated recovery in market value;

the duration and extent that the market value has been below cost;

and the investee’s financial condition.

Other-than-temporary impairments and credit losses are recorded in the statements of operations and comprehensive loss.

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Cash, cash equivalents and short-term investments are invested through banks and other financial institutions in the U.S.

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Foreign Currency

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At the end of each reporting period, monetary assets and liabilities that are denominated in foreign currencies are translated at the rates prevailing at that date.

All gains and losses on these foreign currency transactions are recorded in other income, net in our statements of operations and comprehensive loss.

All gains and losses on these foreign currency transactions are recorded as other income, net on our statements of operations and comprehensive loss.

Property and Equipment

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The carrying values of long-lived assets, including property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate that the asset may not be recoverable.

An impairment loss is recognized when the total of estimated future undiscounted cash flows, expected to result from the use of the asset and its eventual disposition, are less than the asset’s carrying amount.

An impairment loss is recognized when the total of estimated future undiscounted cash flows, expected to result from the use of the asset and its eventual disposition, is less than the asset’s carrying amount.

Impairment, if any, would be assessed using discounted cash flows or other appropriate measures of fair value.

The asset and liability method of accounting is used for income taxes.

Deferred tax assets and liabilities are determined based on the differences between the financial reporting and the tax basis 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.

A valuation allowance is provided when it is more likely than not that a portion or all of a deferred tax asset will not be realized.

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Accounts receivable are stated at amortized cost less allowance for credit losses.

The allowance for credit losses reflects our best estimate of future losses over the contractual life of outstanding accounts receivable and is determined on the basis of historical experience, specific allowances for known troubled accounts, other currently available information including customer financial condition and both current and forecasted economic conditions.

An allowance for credit losses reflects our best estimate of future credit losses over the contractual life of outstanding accounts receivable under the assumption that the current conditions as of the balance sheet date do not change for the remaining life of the asset.

An allowance for credit losses is determined based on various factors, such as historical experience, specific allowances for known troubled accounts, customers’ financial condition and both current and forecasted economic conditions.

To date, we have determined that an allowance for doubtful accounts is not required.

As of December 31, 2025, our accounts receivable balance was comprised of $ 66.4 million from commercial customers and $ 5.4 million from our collaboration partners.

As of December 31, 2023, our accounts receivable balance was comprised of $ 17.1 million from commercial customers and $ 4.9 million from our collaboration partners.

As of December 31, 2024, our accounts

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receivable balance was comprised of $ 56.7 million from commercial customers and $ 1.0 million from our collaboration partners.

Inventory costs incurred are capitalized after regulatory approval, or if based on management’s judgment, future commercialization is considered probable and future economic benefit is expected to be realized.

We began to capitalize inventory costs associated with IBSRELA during the fourth quarter of 2021, when our intent to commercialize IBSRELA was established and we commenced preparation for the launch of IBSRELA.

We began to capitalize inventory costs associated with XPHOZAH during the fourth quarter of 2023, following approval by the U.S.

FDA to market XPHOZAH in the U.S.

We began to capitalize inventory costs associated with IBSRELA during the 2021 fourth quarter, when our intent to commercialize IBSRELA was established and we commenced preparation for the launch of IBSRELA.

We began to capitalize inventory costs associated with XPHOZAH during the 2023 fourth quarter, following approval by the FDA to market XPHOZAH in the U.S.

Inventory costs incurred prior to regulatory approval were expensed as research and development.

Inventories are stated at the lower of cost or estimated net realizable value with cost determined under the specific identification method.

A portion of inventory that represents product that is not expected to be sold or used within the next 12 months is classified as non-current assets on our balance sheets.

A portion of inventory that represents product that is not expected to be sold or used within the next 12 months is classified as non-current assets in our balance sheets.

Revenue Recognition

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Total revenues are recognized following a five-step model:

(i) identify the customer contract;

(ii) identify the contract’s performance obligations;

(iii) determine the transaction price;

(iv) allocate the transaction price to the performance obligations;

and (v) recognize revenue when or as a performance obligation is satisfied.

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Product Sales, Net Recognition

The transaction price for product sales, net is reduced for estimates of variable consideration related to GTN adjustments for discounts and chargebacks, rebates, wholesaler and GPO fees, copay assistance and returns.

Except for certain wholesaler and GPO fees and discounts, which are based on contracts, these adjustments involve estimation and judgment.

The GTN adjustments for rebates, copay assistance and chargebacks are impacted by our estimate of payor mix, which requires significant judgment.

We consider legal interpretations of applicable laws and regulations, historical experience, current contract prices under applicable programs, unbilled claims, processing time lags and inventory levels in the distribution channel in determining our estimates.

(i) identify the customer contract, (ii) identify the contract’s performance obligations, (iii) determine the transaction price, (iv) allocate the transaction price to the performance obligations and (v) recognize revenue when or as a performance obligation is satisfied.

Product Sales, Net

We apply the ASC 606 five-step process above to the contracts with our Customers.

Product revenue is recognized when Customers take control of the product, which typically occurs upon delivery to the Customers.

The transaction price for product sales is reduced for estimates of variable consideration related to (i) discounts and chargebacks, (ii) rebates, wholesaler and GPO fees, and (iii) copay assistance and returns (collectively, gross-to-net adjustments or GTN adjustments).

Except for certain wholesaler and GPO fees and discounts, which are based on contracts, our estimates of GTN adjustments involve assumptions and judgments.

Our estimates of GTN adjustments for rebates, copay assistance and chargebacks require significant assumptions and judgments, considering factors such as legal interpretations of applicable laws and regulations, historical experience, payor mix (e.g., Medicare or Medicaid), current contract prices under applicable programs, unbilled claims, processing time lags and inventory levels in the distribution channel.

Estimates are assessed each period and adjusted as required to revise information or actual experience.

Changes in estimates recorded through December 31, 2024 have not been material.

Licensing Revenue Recognition

Licensing revenue and product supply revenue result from our collaboration and licensing agreements as discussed in Note 7.

Collaboration And Licensing Agreements.

Goods and services in these agreements may include the grant of licenses for use of our intellectual property and manufacturing services.

Significant judgment is required to determine whether promised goods and services represent distinct performance obligations, which are identified and separated when the other party can benefit from the rights, goods or services either on their own or together with other readily available resources and when the rights, goods or services are not highly interdependent or interrelated.

Transaction prices for these arrangements may include non-refundable, up-front license fees;

research, development, regulatory and commercial milestone payments;

Collaboration and Licensing Revenue

Our collaboration and licensing arrangements may include the grant of licenses for use of our intellectual property and manufacturing supply services.

Considerations for such arrangements may include non-refundable upfront license fees;

payments based upon the achievement of development, regulatory, or commercialization milestones;

payments for manufacturing supply services;

and future royalties on net sales of licensed products.

Variable consideration is included in the transaction price only to the extent significant reversal of cumulative revenue recognized is not probable of occurring when the uncertainty associated with the variable consideration is subsequently resolved.

Significant judgment is required in estimating variable consideration for each performance obligation identified in the contract.

This judgment involves assessing factors outside of our influence, including market conditions, development timelines, likelihood of regulatory success, reimbursement rates for personnel costs, forecasted revenues, potential limitations on the selling price of the product, discount rates, lack of relevant past experience and a large number and broad range of possible amounts.

The most likely amount method is used to estimate contingent development, regulatory and sales-based milestones because the ultimate outcomes are binary in nature.

The expected value method is used to estimate royalties because a broad range of potential outcomes exists, except in instances where the royalties relate to a license.

For arrangements with multiple separable performance obligations, the transaction price assigned to each distinct performance obligation is reflective on the relative stand-along selling price and recognized at a point in time upon the transfer of control.

Collaboration agreements typically include:

(i) licensing intellectual property to a third party with no further performance obligations and (ii) arrangements that include both a license and an additional performance obligation to supply product upon the request of the third party.

Out-licensing arrangements that contain a single performance obligation are satisfied upon execution of the agreement, when development and commercialization rights are transferred to a third party.

Upfront fees are immediately recognized as licensing revenue.

Contingent development and regulatory milestones are assessed each period for likelihood of achievement, however, they are typically constrained and recognized when uncertainty is subsequently resolved for the full amount of the milestone and included in licensing revenue.

Licensing revenue also includes sales-based milestones and royalties, which are recognized when the milestone is achieved or when the subsequent sales occur.

Certain collaboration agreements also include contingent performance obligations to supply commercial product to the third party upon its request.

The license and supply obligations are accounted for as separate distinct performance obligations as the third party can benefit from the license either on its own or together with the other supply resources readily available to it and the other obligations in the contract.

Consideration for the supply obligation is based upon stipulated cost-plus margin contractual terms which represent a standalone selling price.

The supply consideration is recognized as product supply revenue at a point in time upon transfer of control of the product to the third party.

After considering the stand-alone selling price of these supply arrangements, the upfront fees, contingent development, regulatory and sales-based milestones and royalties are allocated to the license.

When two or more contracts are entered into with the same customer at or near the same time, we evaluate the contracts to determine whether the contracts should be accounted for as a single arrangement.

Contract modifications due to the addition of distinct promised goods or services with price increases consistent with stand-alone selling prices are accounted for as a separate contract.

Contract modifications that are not considered a separate contract and containing remaining goods or services distinct from the goods or services transferred on or before the date of the contract modification are accounted for as a termination of the existing contract and the subsequent creation of a new contract.

Contract modifications not considered a

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separate contract and containing remaining goods or services not distinct are accounted for as an add-on to the existing contract and as an adjustment to revenue on a cumulative catch-up basis.

We perform the ASC 606 five-step process above to determine the appropriate amount of revenue to be recognized under our collaboration and licensing arrangements.

For performance obligations that are satisfied over time, we recognize revenue using an input or output measure of progress that best depicts the satisfaction of the relevant performance obligation.

We evaluate performance obligations by assessing whether promised goods or services are both (i) capable of being distinct and (ii) distinct in the context of the arrangement.

Goods or services that meet these criteria are considered distinct performance obligations.

Judgment is required to determine whether promised goods or services represent distinct performance obligations.

We estimate the transaction price based on expected consideration, which may include fixed or variable consideration.

At the inception of each arrangement that includes variable consideration, we evaluate the amount of potential transaction price and the likelihood that the transaction price will be received.

The amount of variable consideration that is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period.

After contract inception, the transaction price is reassessed at every period end and updated for changes such as resolution of uncertain events.

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Licensing Revenue :

• Non-refundable upfront license fees:

For arrangements that include a license of intellectual property, and it is determined to be distinct from the other performance obligations identified in the arrangement, we recognize the transaction price allocated to the license as licensing revenue upon transfer of control of the license.

• Milestone payments:

Contingent milestones at contract inception are estimated at the amount which is not probable of a material reversal and included in the transaction price using the most likely amount method.

Milestone payments that are not within our control, such as regulatory approvals, are not considered probable of being achieved until those approvals are received and therefore, the variable consideration is constrained.

At the end of each subsequent reporting period, we re-evaluate the probability of achievement of such contingent milestones and any related constraints, and if necessary, adjust our estimate of the overall transaction price.

Any such adjustments are recorded on a cumulative catch-up basis, which would affect earnings in the period of adjustment.

For arrangements that include sales-based royalties and a license of intellectual property that is deemed to be the predominant item to which the royalties relate, revenue is recognized at the later of when the related sales occur or when the performance obligation to which some or all of the royalties have been allocated has been satisfied (or partially satisfied).

To date, royalty revenue resulting from licensing arrangements has not been material.

Product Supply Revenue :

For arrangements that include a promise for the future supply of drug substance or drug product for either clinical development or commercial supply at the customer’s discretion (manufacturing supply services), and it is determined to be distinct from the other performance obligations identified in the arrangement, we recognize the transaction price allocated to the manufacturing supply services as product supply revenue upon transfer of control of the product to the customer, which is upon delivery.

Advanced payments from customers for the manufacturing of drug substance are recognized as deferred revenue until delivery.

Non-Cash Royalty Revenue Related to the Sale of Future Royalties:

Royalties and commercialization milestones earned from Kyowa Kirin are recorded as non-cash royalty revenue.

As discussed in Note 8.

Deferred Royalty Obligation Related to the Sale of Future Royalties , future royalties and commercialization milestone payments we may receive under the Kyowa Kirin Agreement will be remitted to HCR pursuant to the HCR Agreement.

Accrued Expenses

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The majority of our service providers invoice us monthly in arrears for services performed or when contractual milestones are met.

We make estimates of our accrued expenses as of each balance sheet date based on facts and circumstances known to us at that time.

We estimate our accrued expenses as of each balance sheet date based on facts and circumstances known to us at that time.

We periodically confirm the accuracy of our estimates with our service providers and make adjustments if necessary.

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If the actual timing of the performance of services or the level of effort varies from our estimate, we adjust the accrued or prepaid expense balance accordingly.

Although we do not expect our estimates to be materially different from amounts actually incurred, if our estimates of the status and timing differ from the actual status and timing of services performed, we may report amounts that are too high or too low in any particular period.

Although we do not expect our estimates to be materially different from amounts actually incurred, our estimates of the status and timing may differ from the actual status and timing of services performed.

Retirement Savings Plan

We offer retirement saving plans through our 401(k) plan, which is available to all full-time employees.

In June 2023, we expanded the benefit with the inclusion of a company matching contribution.We contribute to tax-qualified retirement plans for the benefit of employees who meet certain eligibility requirements and choose to participate in the plans.

In June 2023, we expanded the benefit with the inclusion of a company matching contribution.

We contribute to tax-qualified retirement plans for the benefit of employees who meet certain eligibility requirements and choose to participate in the plans.

Participating employees specify the percentage of salary they wish to contribute from their compensation, and we make matching contributions.

We recognized compensation costs from our contributions of $ 1.1 million and $ 0.2 million in 2024 and 2023, respectively.

We recognized compensation costs from our contributions of $ 1.4 million, $ 1.1 million and $ 0.2 million in 2025, 2024 and 2023, respectively.

Stock-Based Compensation

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The grant date fair value of the awards is determined using the Black-Scholes option-pricing model.

Stock-based compensation expense is recognized on a straight-line basis over the requisite service period and is reduced for estimated forfeitures at the date of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

Stock-based compensation expense is recognized on a straight-line basis over the requisite service period

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and is reduced for estimated forfeitures at the date of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates.

Non-Cash Interest Expense on Deferred Royalty Obligation

Non-cash interest expense related to the sale of future royalties represents imputed interest expense on our deferred royalty obligation related to the sale of future royalties using the effective interest method.

In connection with the HCR Agreement, as discussed further in Note 8.

Deferred Royalty Obligation Related to the Sale of Future Royalties, we recorded a liability related to the sale of future royalties and commercialization milestones that is amortized using the effective interest method over the estimated life of the HCR Agreement.

As a result, we impute interest on proceeds received from HCR and record non-cash interest expense at the effective interest rate derived from estimated amounts and timing of future royalties and commercialization payments expected to be received by HCR.

Operating leases are included in right-of-use assets, current portion of operating lease liability and operating lease liability, net of current portion on our balance sheets.

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Our lease terms may include options to extend or terminate a lease when it is reasonably certain that we will exercise any such option.

Leases with an initial term of 12 months or less are not recorded on the balance sheets.

Lease expense is recognized on a straight-line basis over the expected lease term.

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Basic net loss per common share is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding during the period, without consideration of potential shares of common stock.

Diluted net loss per common share in the periods presented is the same as basic net loss per common share because the effects of potentially dilutive securities are antidilutive due to net loses recognized for each period presented.

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Recent Accounting Pronouncements

New Accounting Pronouncements Recently Adopted

In November 2023, the FASB issued ASU No.

2023-07, Segment Reporting (Topic 280) - Improvements to Reportable Segment Disclosures .

This Update requires publicly traded entities to provide enhanced disclosures about significant segment expenses regularly reviewed by the chief operating decision maker, including publicly traded entities with a single reportable segment.

The amendments in this update were effective for fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024.

We adopted the ASU in the fourth quarter of 2024 and determined that its adoption did not have a material impact on our financial statements.

Refer to Note 17.

Segment Reporting for additional information.

Recent Accounting Pronouncements Not Yet Adopted

In December 2023, the FASB issued ASU No.

2023-09, Income Taxes (Topic 740) - Improvements to Income Tax Disclosures , an amendment which modifies the measurement and recognition of credit losses for most financial assets and certain other instruments.

The amendments in this Update provide more transparency about income tax information through improvements to income tax disclosures primarily related to the rate reconciliation and income taxes paid information.

For public business entities, the amendments in this Update are effective for annual periods beginning after December 15, 2024.

Early adoption is permitted on a prospective basis for annual financial statements that have not yet been issued or made available for issuance.

Management is currently assessing the impact of this standard on our financial statements.

2023-09, Income Taxes (Topic 740) - Improvements to Income Tax Disclosures .

The ASU provides additional transparency within the income tax disclosures, primarily related to the rate reconciliation and income taxes paid information.

We adopted ASU 2023-09 retrospectively in the 2025 fourth quarter and determined that the adoption did not have a material impact on our financial statements.

Refer to the related disclosures presented in Note 16.

Income Taxes .

Recent Accounting Pronouncements Not Yet Adopted

In November 2024, the FASB issued ASU No.

2024-03, Income Statement (Topic 220) - Reporting Comprehensive Income - Expense Disaggregation Disclosures, Disaggregation of Income Statement Expenses , which requires public companies to disclose, in interim and reporting periods, additional information about certain expenses in the financial statements.

2024-03 is effective for annual periods beginning after December 15, 2026, and interim reporting periods beginning after December 15, 2027.

Early adoption is permitted and is effective on either a prospective basis or retrospective basis.

Management is currently assessing the impact of this standard on our financial statements.

2024-03, Income Statement (Topic 220) - Reporting Comprehensive Income - Expense Disaggregation Disclosures, Disaggregation of Income Statement Expenses , which requires public companies to disclose, in interim and annual reporting periods, additional information about certain expenses in the financial statements.

The new disclosure requirements are effective for our annual periods beginning January 1, 2027, and interim periods beginning January 1, 2028, with early adoption permitted, and may be applied either prospectively or retrospectively.

We are in the process of evaluating the impact of this new guidance on our disclosures.

Table of Co n t e n t s

CASH, CASH EQUIVALENTS AND SHORT-TERM INVESTMENTS

Securities classified as cash, cash equivalents and short-term investments as of December 31, 2024 and 2023 were as follows:

December 31, 2024

Gross Unrealized

(in thousands) Amortized Cost Gains Losses Fair Value

The following table summarizes our cash, cash equivalents and short-term investments:

December 31, 2025 December 31, 2024

Gross Unrealized Gross Unrealized

(in thousands) Amortized Cost Gains Losses Fair Value Amortized Cost Gains Losses Fair Value

Cash and cash equivalents

4 unchanged sentences

treasury securities $ 95,052 $ 105 $ — $ 95,157 $ 79,720 $ 58 $ ( 5 ) $ 79,773

government-sponsored agency bonds 45,960 29 ( 27 ) 45,962

Commercial paper 46,421 32 ( 3 ) 46,450 37,061 19 ( 15 ) 37,065

government-sponsored agency bonds 27,330 36 — 27,366 45,960 29 ( 27 ) 45,962

Corporate bonds 22,557 25 — 22,582 17,415 4 ( 6 ) 17,413

Asset-backed securities 2,983 2 — 2,985

Yankee bonds 5,132 3 — 5,135 1,972 — ( 2 ) 1,970

Total short-term investments 185,111 112 ( 55 ) 185,168

Total cash, cash equivalents and investments $ 250,043 $ 112 $ ( 55 ) $ 250,100

Table of Conten t s

December 31, 2023

Gross Unrealized

(in thousands) Amortized Cost Gains Losses Fair Value

Cash and cash equivalents

Cash $ 2,829 $ — $ — $ 2,829

Money market funds 18,641 — — 18,641

Total cash and cash equivalents 21,470 — — 21,470

Short-term investments

government-sponsored agency bonds $ 101,892 $ 235 $ ( 34 ) $ 102,093

Commercial paper 49,630 41 ( 17 ) 49,654

Asset-backed securities — — — — 2,983 2 — 2,985

treasury securities 2,455 2 — 2,457

Total short-term investments 196,492 201 ( 3 ) 196,690 185,111 112 ( 55 ) 185,168

Total cash, cash equivalents and investments $ 264,491 $ 201 $ ( 3 ) $ 264,689 $ 250,043 $ 112 $ ( 55 ) $ 250,100

Realized gains or losses have not been significant and are included in other income, net, in our statements of operations and comprehensive loss.

Realized gains or losses have not been significant and are included in other income, net on our statements of operations and comprehensive loss.

Unrealized losses in 2025 and 2024 were not material.

All of the short-term available-for-sale securities held as of December 31, 2025 and 2024 had contractual maturities of less than one year.

We determined that none of our available-for-sale securities were other-than-temporarily impaired as of December 31, 2025 and 2024, and no investment was in a continuous unrealized loss position for more than one year.

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Level 3 – Valuations based on unobservable inputs for which there is little or no market data, which require us to develop our own assumptions.

Table of Conten t s

The following table sets forth the fair value of our financial assets and liabilities that are measured or disclosed on a recurring basis by level within the fair value hierarchy:

Table of Co n t e n t s

The following table sets forth the fair value of our financial assets that are measured or disclosed on a recurring basis by level within the fair value hierarchy:

December 31, 2025 December 31, 2024

(in thousands) Total Fair Value Level 1 Level 2 Level 3 Total Fair Value Level 1 Level 2 Level 3

(in thousands) Total

Level 1 Level 2 Level 3 Total

Fair Value Level 1 Level 2 Level 3

Money market funds $ 49,430 $ 49,430 $ — $ — $ 48,650 $ 48,650 $ — $ —

government-sponsored agency bonds 45,962 — 45,962 — 102,093 — 102,093 —

treasury securities 95,157 — 95,157 — 79,773 — 79,773 —

Commercial paper 46,450 — 46,450 — 37,065 — 37,065 —

government-sponsored agency bonds 27,366 — 27,366 — 45,962 — 45,962 —

Corporate bonds 22,582 — 22,582 — 17,413 — 17,413 —

Asset-backed securities 2,985 — 2,985 — 8,625 — 8,625 —

Yankee bonds 5,135 — 5,135 — 1,970 — 1,970 —

Total $ 233,818 $ 48,650 $ 185,168 $ — $ 181,470 $ 18,641 $ 162,829 $ —

Derivative liabilities for exit fee $ — $ — $ — $ — $ 675 $ — $ — $ 675

Asset-backed securities — — — — 2,985 — 2,985 —

Total $ 246,120 $ 49,430 $ 196,690 $ — $ 233,818 $ 48,650 $ 185,168 $ —

The 2022 Exit Fee valuation as of December 31, 2023 as defined and discussed in Note 10.

Derivative Liabilities , was classified as Level 3.

During 2024, the conditions for payment of the 2022 Exit Fee were met and the $ 1.0 million contract amount was fully valued and settled accordingly.

Fair Value of Debt

The principal outstanding under our term loan is subject to a variable interest rate and therefore, we believe the carrying amount of the term loan approximates fair value.

The principal outstanding under our 2022 Loan Agreement is subject to a variable interest rate and therefore, we believe the carrying amount of the term loan approximates fair value as of December 31, 2025 and 2024.

Borrowing for a description of the Level 2 inputs used to estimate the fair value of the liability.

The carrying value of the deferred royalty obligation related to the sale of future royalties approximates its fair value as of December 31, 2024 and is based on our current estimate of future royalties and commercialization milestones expected to be paid to us by Kyowa Kirin over the life of the agreement.

The carrying value of the deferred royalty obligation related to the sale of future royalties approximates its fair value as of December 31, 2025 and 2024 and is based on our current estimate of future royalties and commercialization milestones expected to be received by HCR over the life of the HCR Agreement.

Deferred Royalty Obligation Related to the Sale of Future Royalties for a description of the Level 3 inputs used to estimate the fair value of the liability.

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Total $ 123,107 $ 91,184

Prepaid commercial manufacturing with third-party CMOs not included in inventory was $ 16.4 million and $ 23.2 million at December 31, 2024 and 2023, respectively.

There were no prepayments expected to be converted into inventory after 12 months at December 31, 2024, compared to $ 4.2 million at December 31, 2023.

Table of Conten t s

Prepaid commercial manufacturing with third-party CMOs not included in inventory was $ 14.5 million and $ 16.4 million as of December 31, 2025 and 2024, respectively.

There were no prepayments expected to be converted into inventory after 12 months as of December 31, 2025 and 2024.

Table of Co n t e n t s

Disaggregation of total revenues by nature is as follows:

2 unchanged sentences

Product sales, net $ 377,808 $ 319,196 $ 82,526

$ 319,196 $ 82,526 $ 15,600

Product supply revenue 15,879 11,649 6,121

3 unchanged sentences

Product Sales, Net

Products are primarily sold to wholesalers, GPOs and specialty pharmacies, and to a lesser extent, directly to retailers, hospitals, clinics and government agencies.

Customer orders are generally fulfilled within a few days from receipt.

Contractual performance obligations are fulfilled once our Customers receive the product and obtain legal title, at which point, they are able to direct the use of and obtain substantially all of the remaining benefits of the product.

Total product sales, net was as follows:

5 unchanged sentences

Total product sales, net $ 377,808 $ 319,196 $ 82,526

Product sales, net approximated 95.7 %, 66.3 % and 29.9 % of total revenues in 2024, 2023 and 2022, respectively.

Products are primarily sold to wholesalers, GPOs and specialty pharmacies, and to a lesser extent, directly to retailers, hospitals, clinics and government agencies.

Customer orders are generally fulfilled within a few days from receipt.

Contractual performance obligations are fulfilled once control of product is transferred to our customer, which occurs when our customer receives the product and obtains legal title.

At this point, our customers are able to direct the use of and obtain substantially all of the remaining benefits of the product.

Product sales, net as a percentage of total revenues

92.8 % 95.7 % 66.3 %

GTN Adjustments

Wholesalers, GPOs and specialty pharmacies are initially invoiced at contract list prices.

Wholesalers and GPOs may also receive prompt pay discounts for payment within a specified period, generally approximating two percent of the invoiced sales price.

We recognize revenue from product sales at the net sales price which includes estimates of variable consideration related to the following GTN adjustments:

• Discounts and chargebacks:

We offer prompt pay discounts to our Customers for payment within a specified period, generally approximating two percent of the invoiced sales price.

Our payment terms are generally 30 to 60 days.

At the time of recognition, revenue is reduced from contract list price for estimates of variable consideration related to GTN adjustments for chargebacks and cash discounts, rebates, wholesaler and GPO fees, and copay assistance and returns.

These GTN adjustments are attributed to governmental programs such as Medicare, Medicaid and the 340B program, which involve various pricing implications, including mandatory discounts and discounts when Medicare Part D beneficiaries are in the coverage gap.

Chargebacks and specialty pharmacies fees are reflected as reductions to receivables and are typically settled within contractual terms through credits to our customers.

All other GTN adjustments are reflected as a liability and settled through cash payments to our customer or government payor program, typically over various time periods that may span for multiple quarters.

Significant judgment is required to estimate certain of our GTN adjustments, considering factors such as legal interpretations of applicable laws and regulations, historical experience, payor mix (e.g., Medicare or Medicaid), current contract prices under applicable programs, unbilled claims, processing time lags and inventory levels in the distribution channel.

Table of Conten t s

Chargebacks represent the estimated liability to wholesalers resulting from the difference between the wholesale acquisition cost and the lower program price offered to qualified government healthcare providers.

• Rebates, wholesaler and GPO fees:

We are subject to discount obligations under governmental programs, such as Medicare and Medicaid.

For the Medicaid program, we estimate the portion of sales attributed to Medicaid patients as rebates to be paid to the respective state.

For the Medicare Part D program, beginning in 2025, we estimate the percentage of products sold to patients in the initial coverage and catastrophic coverage phases and adjust the transaction price for such discount at the time of sale.

Prior to 2025, we paid a 70% discount to CMS when the Medicare Part D beneficiaries were in the coverage gap.

Wholesaler and GPO fees are based on contracts and therefore require less estimation.

• Copay assistance and returns:

We estimate the expected cost under the copay assistance program for qualified commercially-insured patients based on the terms of the program and redemption information provided by third-party claims processing organizations.

We estimate products’ returns based on products’ actual returns history and other factors, including levels of our inventory in the distribution channel, estimated shelf life and historical sales returns of similar products.

Discounts, chargebacks, returns and wholesaler and GPO fees are reflected as reductions to receivables and are typically settled within contractual terms through credits to our Customers.

All other GTN adjustments are reflected as a liability and settled through cash payments to our Customers or governmental payor programs, typically over various time periods that may span for multiple quarters.

Table of Co n t e n t s

The activities and ending reserve balances for each significant category of GTN adjustments on product sales, net, which constitute variable consideration, were as follows:

7 unchanged sentences

Provisions (1)

23,356 108,547 31,667 163,570

Credits/payments ( 23,306 ) ( 88,566 ) ( 33,563 ) ( 145,435 )

Balance as of December 31, 2025 $ 1,693 $ 34,456 $ 9,274 $ 45,423

Adjustments to prior period provisions recorded in the current period were not material.

(1) Provisions included approximately $ 4.4 million of net favorable adjustment resulting from changes in prior periods’ estimates.

Geographic Information and Concentrations

10 unchanged sentences

Total revenues $ 407,320 $ 333,615 $ 124,456

(1) Revenues from the United States are primarily comprised of amounts earned from sales of IBSRELA and XPHOZAH, as well as the upfront license fee from the METiS Agreement.

(2) Revenues from Asia Pacific are primarily comprised of amounts earned in accordance with the Kyowa Kirin Agreement and the Fosun Agreement.

(3) Revenues from North America are comprised of amounts earned from Canada in accordance with the Knight Agreement.

(1) Revenues from the United States were comprised of amounts earned from sales of IBSRELA and XPHOZAH.

(2) Revenues from Asia Pacific were comprised of amounts earned in accordance with the Kyowa Kirin Agreement and the Fosun Agreement.

(3) Revenues from North America were comprised of amounts earned from Canada in accordance with the Knight Agreement.

Gross product sales from Customers and revenues from collaboration partners, each accounting for more than 10% of total revenues, were as follows:

1 unchanged sentence

2025 2024 2023

Customers (1)

BioRidge Pharma, LLC 65.9 % 75.4 % 24.0 %

16.4 % 19.1 % 11.1 %

Cardinal Health 21.4 % 14.5 % 19.8 %

McKesson Corporation 17.9 % 14.1 % 15.7 %

Cencora (formerly AmerisourceBergen Drug Corporation)

17.3 % 16.4 % 19.1 %

Collaboration partners

Kyowa Kirin 5.9 % 4.3 % 29.0 %

(1) The total of the above percentages exceeds 100% as the numerators used in the calculations represent gross product sales for each Customer, as opposed to product sales, net as presented on our statements of operations and comprehensive loss.

COLLABORATION AND LICENSING AGREEMENTS

We out-licensed to external partners the development of tenapanor and commercialization of tenapanor through agreements with Kyowa Kirin in Japan, Fosun Pharma in China and Knight in Canada for the development and commercialization of tenapanor for certain indications in their respective territories.

We recognize revenue from such arrangements as licensing revenue, product supply revenue or non-cash royalty revenue related to the sale of future royalties.

Our significant accounting policies for such revenue streams are as follows:

Table of Conten t s

Licensing revenue includes:

• upfront license fees, as well as developmental, regulatory and commercialization milestone payments.

We assess upfront and milestone payments using the most likely amount method, including variable payments only when it is probable that no significant revenue reversal will occur.

Upfront license fees are recognized upon receipt.

Milestones tied to external factors, such as regulatory approvals, are considered probable when those accomplishments are achieved.

• sales-based royalties, other than non-cash royalty revenue related to the sale of future royalties as discussed below, are recognized when sales occur or when related performance obligations are met.

Product supply revenue includes drug substance or drug supply revenue received from our out-licensing agreements.

Product supply revenue is recognized when control of goods is transferred upon delivery.

Advanced payments from partners for drug substance are recognized as deferred revenue until delivery.

Non-cash royalty revenue related to the sale of future royalties includes royalties earned and received under the Kyowa Kirin Agreement, which are remitted to HCR upon receipt, pursuant to the HCR Agreement as discussed in Note 8.

Deferred Royalty Obligation Related To The Sale Of Future Royalties .

The following table summarizes total revenue by collaboration partner:

We have out-licensed to external partners for the development and commercialization of tenapanor outside of the U.S.

We recognize revenue from our agreements with Kyowa Kirin, Fosun Pharma and Knight as licensing revenue, product supply revenue or non-cash royalty revenue related to the sale of future royalties.

Refer to Note 2.

Summary of Significant Accounting Policies for more information about our significant accounting policies for such revenue streams.

Table of Co n t e n t s

The following table summarizes total revenues by collaboration partner:

Year Ended December 31,

2 unchanged sentences

$ — $ — $ 30,000

5,000 — 5,000

Total licensing revenue

6 unchanged sentences

$ 8,545 $ 2,692 $ —

We granted Kyowa Kirin an exclusive license (Kyowa Kirin Agreement) to develop and commercialize certain NHE3 inhibitors including tenapanor in Japan for the treatment of cardiorenal diseases and conditions, excluding cancer, in exchange for future royalties defined below, an upfront license fee of $ 30.0 million, and potential future development and regulatory milestones up to $ 55.0 million, of which $ 35.0 million has been received and recognized as revenue to date, as well as approximately ¥ 8.5 billion for commercialization milestones, or approximately $ 54.0 million at the currency exchange rate on December 31, 2024.

In addition, we are eligible to receive royalties on net sales of tenapanor in Japan throughout the term of the agreement.

Under a Commercial Supply Agreement, we supply tenapanor drug substance that will be used to satisfy Kyowa Kirin’s commercial needs which includes advanced payments for reimbursement of costs plus a reasonable overhead for the supply of product.

In February 2024, Kyowa Kirin announced the launch of tenapanor, marketed as PHOZEVEL ® , for patients with CKD with hyperphosphatemia in Japan.

The Kyowa Kirin Agreement was amended to reduce the royalty rate Kyowa Kirin would pay on tenapanor sales in Japan from high teens to low double digits for a two-year period of time following the first commercial sale in Japan, and then to mid-single digits for the remainder of the royalty term (2022 Amendment).

As consideration for reduction in the royalty rate, Kyowa Kirin agreed to pay us up to an additional $ 40.0 million payable in two tranches, with the first payment due following Kyowa Kirin’s filing with the Japanese MHLW of its application for marketing approval for tenapanor and the second payment due following Kyowa Kirin’s receipt of regulatory approval to market tenapanor for hyperphosphatemia in Japan, both of which occurred as of September 30, 2023.

As discussed in Note 8.

Deferred Royalty Obligation Related To The Sale Of Future Royalties , future royalties and commercial milestone payments we may receive under the license, as amended, will be remitted to HCR pursuant to the HCR Agreement.

Table of Conten t s

The following table presents changes in our current and non-current deferred revenue balances, which are all attributable to Kyowa Kirin:

The following table presents changes in our current and non-current deferred revenue balances, which are primarily attributable to Kyowa Kirin:

(in thousands) Current Non-Current Current Non-Current

Balance at January 1,

Deferred revenue balance as of January 1,

$ 10,686 $ 7,232 $ 7,182 $ 8,644

2 unchanged sentences

Reclassify amounts to be recognized in the next twelve months — — 9,624 ( 9,624 )

Balance at December 31, $ 10,686 $ 7,232 $ 7,182 $ 8,644

Deferred revenue balance as of December 31, $ 1,206 $ 13,699 $ 10,686 $ 7,232

(ii) an upfront license fee of $ 30.0 million, recognized upon execution of the agreement;

(iii) potential future development and regulatory milestones of up to $ 55.0 million, of which $ 35.0 million has been recognized as revenue to date;

and (iv) commercialization milestones of up to ¥ 8.5 billion (or approximately $ 54.5 million at the currency exchange rate as of December 31, 2025), of which $ 3.4 million has been recognized as revenue to date.

In addition, we are eligible to receive royalties on net sales of tenapanor in Japan throughout the term of the agreement.

As consideration for the reduced royalty rate, Kyowa Kirin agreed to pay us up to an additional $ 40.0 million payable in two tranches:

(i) the first payment due following Kyowa Kirin’s filing with the Japanese MHLW of its application for marketing approval for tenapanor, recognized as revenue in 2022;

and (ii) the second payment due following Kyowa Kirin’s receipt of regulatory approval to market tenapanor for hyperphosphatemia in Japan, recognized as revenue in 2023.

As discussed in Note 8.

Deferred Royalty Obligation Related to the Sale of Future Royalties , future royalties and commercialization milestone payments we may receive under the license, as amended, will be remitted to HCR pursuant to the HCR Agreement.

Table of Co n t e n t s

In February 2024, Kyowa Kirin announced the launch of tenapanor, marketed as PHOZEVEL ® , for patients with CKD with hyperphosphatemia in Japan.

Following the launch, we began to recognize earned royalties and commercialization milestones from sales of tenapanor in Japan, which are remitted to HCR in accordance with the HCR Agreement.

The first commercialization milestone was achieved in the 2025 third quarter, triggering a ¥ 500.0 million payment to us, or approximately $ 3.4 million at the currency exchange rate as of September 30, 2025.

This milestone was recorded as non-cash royalty revenue related to the sale of future royalties on our statements of operations and comprehensive loss and was remitted to HCR upon receipt.

We have an exclusive license agreement with Fosun Pharma (Fosun Agreement) for the development, commercialization and distribution of tenapanor in China for both hyperphosphatemia and IBS-C.

The Fosun Agreement granted exclusive license rights to Fosun Pharma in exchange for an upfront license fee of $ 12.0 million, recognized upon execution of the agreement, and potential regulatory milestone payments up to $ 113.0 million, of which $ 8.0 million has been received and recognized to date.

The Fosun Agreement granted exclusive license rights to Fosun Pharma in exchange for (i) an upfront license fee of $ 12.0 million, recognized upon execution of the agreement;

and (ii) potential future development and commercialization milestones of up to $ 113.0 million, of which $ 13.0 million has been recognized as revenue to date.

In addition, we are eligible to receive reimbursement of cost plus a reasonable overhead for the supply of product and tiered royalties on net sales ranging from the mid-teens to 20 %.

In February 2025, we announced the NDA approval by China’s Center for Drug Evaluation of the NMPA for tenapanor in the control of serum phosphorus in adult patients with CKD on hemodialysis.

This approval triggered a $ 5.0 million milestone to us, which was recorded as licensing revenue on our statements of operations and comprehensive loss when earned during the 2025 first quarter and was received in April 2025.

We have an exclusive license agreement with Knight (Knight Agreement) for the development, commercialization and distribution of tenapanor in Canada for hyperphosphatemia and IBS-C.

The Knight Agreement granted exclusive license rights to Knight in exchange for an upfront license fee of $ 2.3 million, recognized upon execution, and potential regulatory and commercialization milestones up to CAD 22.2 million, or approximately $ 15.4 million at the currency exchange rate on December 31, 2024, of which $ 0.7 million has been received and recognized to date.

The Knight Agreement granted exclusive license rights to Knight in exchange for (i) an upfront license fee of $ 2.3 million, recognized upon execution of the agreement;

and (ii) potential future development and commercialization milestones of up to CAD 22.2 million (or approximately $ 16.2 million at the currency exchange rate as of December 31, 2025), of which $ 0.7 million has been recognized as revenue to date.

In addition, we are eligible to receive royalties ranging from the mid-single digits to the low twenties throughout the term of the agreement and a transfer price for manufacturing supply services.

We have an exclusive license agreement with METiS Therapeutics Inc., (METiS Agreement) for the development and commercialization of a portfolio of TGR5 agonist compounds that we discovered and developed for all therapeutic areas in exchange for an upfront license fee of $ 0.8 million, recognized upon execution in 2023.

In addition, we may be eligible to receive development and commercialization milestone payments worth up to $ 243.0 million.

We are also eligible to receive royalties ranging within the mid-single digits throughout the term of the agreement.

In June 2015, we entered into a termination agreement with AstraZeneca (AstraZeneca Termination Agreement) pursuant to which we have agreed to pay AstraZeneca (i) future royalties at a royalty rate of 10 % of net sales of tenapanor or other NHE3 products by us or our licensees, and (ii) 20 % of non-royalty revenue received from a new collaboration partner should we elect to license, or otherwise provide rights to develop and commercialize tenapanor or other NHE3 products, up to a maximum of $ 75.0 million in aggregate for (i) and (ii).

Royalty expense recognized under this agreement as other cost of revenue on our statements of operations and comprehensive loss was $ 34.7 million, $ 12.4 million and $ 3.6 million in 2024, 2023 and 2022, respectively.

As of December 31, 2024, we have recognized $ 62.3 million of the total $ 75.0 million outstanding royalty obligation.

We have an exclusive license agreement with METiS Therapeutics Inc., (METiS Agreement) for the development and commercialization of a portfolio of TGR5 agonist compounds that we discovered and developed for all therapeutic areas in exchange for (i) an upfront license fee of $ 0.8 million, recognized upon execution of the agreement in 2023;

and (ii) potential future development and commercialization milestones of up to $ 243.0 million.

In addition, we are also eligible to receive royalties ranging within the mid-single digits throughout the term of the agreement.

We had a termination agreement with AstraZeneca (AstraZeneca Termination Agreement), pursuant to which we agreed to pay AstraZeneca (i) future royalties at a royalty rate of 10 % of net sales of tenapanor or other NHE3 products by us or our licensees;

and (ii) 20 % of non-royalty revenue received from a new collaboration partner should we elect to license, or otherwise provide rights to develop and commercialize tenapanor or other NHE3 products, up to a maximum of $ 75.0 million in aggregate for (i) and (ii).

Royalty expense recognized under this agreement as cost of sales on our statements of operations and comprehensive loss was $ 12.7 million, $ 34.7 million and $ 12.4 million in 2025, 2024 and 2023, respectively.

As of the end of the 2025 second quarter, we had fully recognized the maximum $ 75.0 million royalty obligation, which had been fully remitted as of the end of the 2025 third quarter.

DEFERRED ROYALTY OBLIGATION RELATED TO THE SALE OF FUTURE ROYALTIES

In June 2022, we and HCR entered into the HCR Agreement in which HCR agreed to pay up to $ 20.0 million in exchange for royalty payments and commercial milestone payments that we may receive under our Kyowa Kirin License Agreement.

Collaboration And Licensing Agreements for further detail.

The $ 20.0 million is payable as follows:

• $ 10.0 million upfront upon agreement execution, received in June 2022;

• $ 5.0 million upon Kyowa Kirin’s receipt of regulatory approval to market tenapanor for hyperphosphatemia in Japan, received in October 2023;

Table of Conten t s

• $ 5.0 million in the event net sales by Kyowa Kirin in Japan exceed a certain annual target level by the end of 2025.

We and HCR have an agreement in which HCR agreed to pay up to $ 20.0 million in exchange for future royalties and commercialization milestone payments that we may receive under our Kyowa Kirin Agreement, as discussed further in Note 7.

Collaboration and Licensing Agreements .

The $ 20.0 million was payable as follows:

(i) $ 10.0 million upfront upon agreement execution, received in June 2022;

(ii) $ 5.0 million upon Kyowa Kirin’s receipt of regulatory approval to market tenapanor for hyperphosphatemia in Japan, received in October 2023;

and (iii) $ 5.0 million in the event net sales of tenapanor in Japan by Kyowa Kirin exceeded a defined annual target level by the end of 2025, which was not achieved as of December 31, 2025.

The HCR Agreement is effective until terminated by the mutual agreement of the parties and contains customary representations and warranties and customary affirmative and negative covenants.

Table of Co n t e n t s

Payments received from HCR are recorded as a deferred royalty obligation on our balance sheets.

Due to our ongoing manufacturing obligations under the Kyowa Kirin Agreement, we account for the proceeds as imputed debt and therefore recognize royalties earned under the Kyowa Kirin Agreement as non-cash royalty revenue.

In conjunction with the HCR Agreement, we incurred approximately $ 0.4 million in transaction costs, which, along with the deferred royalty obligation, are being amortized as non-cash interest expense over the estimated life of the HCR Agreement using the effective interest method, which is based on the imputed interest rate derived from estimated amounts and timing of future royalty payments to be received from Kyowa Kirin.

The deferred royalty obligation will be effectively repaid over the life of the HCR Agreement as we remit royalties paid to us from Kyowa Kirin, recorded as non-cash royalty revenue related to the sale of future royalties, to HCR.

We periodically assess the estimated royalty payments from Kyowa Kirin and, to the extent that the amount or timing of such payments is materially different than our original estimates, we prospectively adjust the imputed interest rate and the related amortization of the deferred royalty obligation.

Due to our ongoing manufacturing obligations under the Kyowa Kirin Agreement, we account for the proceeds as imputed debt and therefore recognize royalties and commercialization milestones earned under the Kyowa Kirin Agreement as non-cash royalty revenue.

Non-cash interest expense is recorded at the imputed interest rate derived from estimated amounts and timing of future royalties and commercialization milestone payments expected to be received by HCR.

The deferred royalty obligation will be effectively repaid over the life of the HCR Agreement as we remit to HCR royalties and commercialization milestones paid to us by Kyowa Kirin.

We periodically assess the estimated amounts and timing of future royalties and commercialization milestone payments from Kyowa Kirin and, to the extent that the amount or timing of such payments is materially different than our original estimates, we prospectively adjust the imputed interest rate and the related amortization of the deferred royalty obligation.

A summary of financial information related to the HCR Agreement is as follows:

1 unchanged sentence

($ in thousands) 2025 2024 2023

2024 2023 2022

Non-cash interest expense related to the sale of future royalties $ ( 8,296 ) $ ( 7,088 ) $ ( 3,924 )

1 unchanged sentence

(in thousands) 2025 2024 2023

Beginning deferred royalty obligation

$ 20,179 $ 11,254 $ —

Upfront payment, net of transaction costs

Regulatory approval milestone

Non-cash interest expense related to sale of future royalties

7,088 3,924 1,673

Royalty distributed to HCR

( 1,740 ) — —

Ending deferred royalty obligation

Deferred royalty obligation balance as of January 1,

$ 25,527 $ 20,179 $ 11,254

Proceeds received from HCR — — 5,000

Non-cash interest expense related to the sale of future royalties 8,296 7,088 3,924

Royalty and commercialization milestone payments remitted to HCR ( 7,947 ) ( 1,740 ) —

Deferred royalty obligation balance as of December 31, $ 25,876 $ 25,527 $ 20,179

Long-term borrowing was as follows:

(in thousands) 2025 2024 Interest rate

$ 27,500 $ 27,500 7.95 % + 0.022 % + SOFR (subject to a floor of 1.0 %)

22,500 22,500 7.95 % + 0.022 % + SOFR (subject to a floor of 1.0 %)

50,000 — 4.25 % + 0.022 % + SOFR (subject to a floor of 4.7 %)

Term A Loan $ 27,500 $ 27,500 7.95 % + 0.022 % + SOFR (subject to a floor of 1.0 %)

Term B Loan 22,500 22,500 7.95 % + 0.022 % + SOFR (subject to a floor of 1.0 %)

Term C Loan 50,000 50,000 4.25 % + 0.022 % + SOFR (subject to a floor of 4.7 %)

Term D Loan 50,000 50,000 4.00 % + 0.022 % + SOFR (subject to a floor of 4.7 %)

50,000 — 4.00 % + 0.022 % + SOFR (subject to a floor of 4.7 %)

Total principal 200,000 150,000

$ 150,000 $ 50,000

Adjustments to principal value

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Long-term debt, net of current portion $ 202,834 $ 150,853

On February 23, 2022 (Closing Date), we entered into a loan and security agreement with SLR (2022 Loan Agreement) as collateral agent (Agent) and the lenders listed in the 2022 Loan Agreement (collectively, the 2022 Lenders), which was subsequently amended in August 2022 (the First Amendment) and February 2023 (the Second Amendment).

The 2022 Loan Agreement, as amended, provided for a senior secured loan facility (the Term A Loan) funded on the Closing Date and Term B Loan borrowable on or prior to December 20, 2023;

provided that (i) we received approval by the U.S.

FDA for our NDA for

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XPHOZAH by November 30, 2023, and (ii) we achieved certain product revenue milestone targets described in the 2022 Loan Agreement.

We met the requirements to borrow Term B Loan and subsequently drew it in October 2023.

In October 2023, we entered into a Third Amendment (the Third Amendment) with the 2022 Lenders.

The Third Amendment provided us with the option to draw the Term C Loan by March 15, 2024, contingent upon having drawn the Term B Loan;

and provided us with the option to draw the Term D Loan of uncommitted capital by December 31, 2026, subject to approval by the Agent’s investment committee.

We provided the Agent with notice of our decision to draw the Term C Loan in February 2024 and received the proceeds in March 2024.

In October 2024, we entered into a Fourth Amendment (the Fourth Amendment) with the 2022 Lenders.

The Fourth Amendment, among other things, provided for the immediate draw of the Term D Loan on the closing date of the Fourth Amendment and provides us with the option to draw an additional $ 50.0 million of committed capital by June 30, 2025 (the Term E Loan and together with the Term A, B, C and D Loans, the Five Loans).

The interest rate for the Term E Loan will be 4.00 % plus a SOFR value equal to 0.022 % plus the 1-month CME Term SOFR reference rate as published by the CME Term SOFR Administrator on the CME Term SOFR Administrator’s Website, subject to a SOFR floor of 4.7 %.

We drew the Term D Loan in October 2024.

Under the Fourth Amendment, the maturity date for the Five Loans was extended to July 1, 2028 (the Maturity Date) and the period under which we are permitted to make interest-only payments on the Five Loans was extended to the Maturity Date.

We paid fees of $ 0.2 million, $ 0.1 million, $ 0.3 million and $ 0.3 million on each funding date of the Term A, Term B, Term C and Term D Loans, respectively.

In addition, we will be obligated to pay 0.5 % of the aggregate original principal amount of the Term E Loan commitment, which shall be due on the earliest of (1) the funding of the Term E Loan, (2) June 30, 2025, or (3) the prepayment, refinancing, substitution or replacement of any of the Five Loans on or prior to the date immediately preceding June 30, 2025.

We are obligated to pay a final fee equal to 4.95 % of the aggregate original principal amount of the Five Loans, to the extent such loans are funded, upon the earliest to occur of the maturity date, the acceleration of the Five Loans, and the prepayment, refinancing, substitution, or replacement of the Five Loans.

The total unaccreted final fee was $ 5.4 million and $ 1.7 million at December 31, 2024 and December 31, 2023, respectively.

We may voluntarily prepay all amounts outstanding under the Five Loans, subject to a prepayment premium of 2 % of the outstanding principal amount of the Five Loans if prepaid through and including October 17, 2025 or 1 % of the outstanding principal amount of the Five Loans if prepaid after October 17, 2025 and prior to the maturity date.

The Five Loans are secured by substantially all of our assets, except for our intellectual property and certain other customary exclusions.

Additionally, as discussed in Note 10.

Derivative Liabilities , in connection with the Term A and Term B Loans (Original Loans), we paid an exit fee in the amount of $ 1.0 million in October 2024.

The 2022 Loan Agreement, as amended, contains customary representations and warranties that place restrictions on disposition of assets, granting liens, occurring additional debt and other matters, as well as customary events of default.

We have agreed to not allow our cash, cash equivalents and available-for-sale investments to be less than the eighty percent ( 80 %) of the outstanding balance of the Five Loans for any period in which our net revenue from the sale of any products, calculated on a trailing six ( 6 ) month basis and tested monthly, is less than sixty percent ( 60 %) of the outstanding balance of the Five Loans.

We have concluded that the provisions that could cause acceleration of the principal repayment are remote as of December 31, 2024.

As of December 31, 2024, our total future payment obligation related to the outstanding balance of the Five Loans, excluding interest payments, was $ 157.4 million, which is due on July 1, 2028.

We have a loan and security agreement (as amended, 2022 Loan Agreement) with SLR, as collateral agent, and the lenders listed in the 2022 Loan Agreement (collectively, the 2022 Lenders).

On June 30, 2025, we entered into an amendment to our 2022 Loan Agreement (the Fifth Amendment), by and between us and the 2022 Lenders.

The Fifth Amendment, among other things, (i) provided for the immediate draw of the principal amount of $ 50.0 million (the Term E Loan and together with the Term A, B, C and D Loans, the Five Loans) on the closing date of the Fifth Amendment;

and (ii) provides us with the option to draw an additional $ 100.0 million of committed senior secured term loans, consisting of two separate term loans, each in a principal amount of $ 50.0 million:

(a) the first of which is available at our election through June 30, 2026 (the Term F Loan) and (b) the second of which is available at our election through

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December 20, 2026 (the Term G Loan and, together with the Term F Loan, the Incremental Term Loans).

We concluded that the Fifth Amendment was a modification to the 2022 Loan Agreement and is accounted for accordingly.

The interest rate for each of the Incremental Term Loans, if drawn, will be 4.95 % plus the 1-month CME Term SOFR reference rate as published by the CME Term SOFR Administrator on the CME Term SOFR Administrator’s Website, subject to a SOFR floor of 3.50 %.

Under the Fifth Amendment, the maturity date for the Term E Loan (and the other outstanding term loans) remains July 1, 2028.

We are permitted to make interest-only payments on the Term E Loan (and the other outstanding term loans) through July 1, 2028.

The maturity date for each of the Incremental Term Loans will be July 1, 2030.

We will be permitted to make interest-only payments on the Incremental Term Loans from the date each of the Incremental Term Loans is drawn through July 1, 2030.

We paid fees of $ 0.2 million, $ 0.1 million, $ 0.3 million, $ 0.3 million and $ 0.3 million on each funding date of the Term A, Term B, Term C, Term D and Term E Loans, respectively.

In addition, we paid a facility fee of $ 1.0 million with respect to the Incremental Term Loans on the closing date of the Fifth Amendment.

We are obligated to pay a final fee equal to 4.95 % of the aggregate original principal amount of the Five Loans, upon the earliest to occur of July 1, 2028, the acceleration of the Five Loans, and the prepayment, refinancing, substitution, or replacement of the Five Loans.

We will be obligated to pay a final fee equal to 3.45 % of the aggregate original principal amount of the Incremental Term Loans, to the extent such loans are funded, upon the earliest of any final termination, acceleration, prepayment or July 1, 2030.

We may voluntarily prepay all amounts outstanding under the Five Loans, subject to a prepayment premium of one percent of the outstanding principal amount of the Five Loans if prepaid prior to July 1, 2028.

We may voluntarily prepay all amounts outstanding under the Incremental Term Loans, if drawn, subject to a prepayment premium of two percent of the outstanding principal amount of the Incremental Term Loans if prepaid prior to June 30, 2026 and one percent of the outstanding principal amount of the Incremental Term Loans if prepaid after June 30, 2026 and prior to July 1, 2030.

The 2022 Loan Agreement contains certain covenants, including a single financial covenant that the sum of our net product revenue, calculated on a trailing six-month basis, plus unrestricted cash and cash equivalents that are subject to a first-priority perfected lien in favor of SLR, shall be greater than or equal to 100 % of the principal amount outstanding under the 2022 Loan Agreement.

In addition, the 2022 Loan Agreement contains subjective acceleration clauses to accelerate the maturity of outstanding principal amount in the event that a material adverse change has occurred within the business, operations or financial condition of the Company.

As of December 31, 2025, we believe that the likelihood of the acceleration of the maturity due to subjective acceleration clauses is remote.

The total unaccreted final fee was $ 5.9 million and $ 5.4 million as of December 31, 2025 and 2024, respectively.

As of December 31, 2025, our total future payment obligation related to the outstanding balance of the term loans, excluding interest payments, was $ 209.9 million, which is due on July 1, 2028.

DERIVATIVE LIABILITIES

2018 Exit Fee

In October 2023, we received approval from the U.S.

FDA for XPHOZAH to reduce serum phosphorus in adults with CKD on dialysis as add-on therapy in patients who have an inadequate response to phosphate binders or who are intolerant of any dose of phosphate binder therapy.

In connection with a previous loan agreement (2018 Loan), we became obligated to pay an exit fee of $ 1.5 million, which was paid in 2023.

2022 Exit Fee

The 2022 Loan Agreement obligated us to pay an exit fee in the amount of 2 % of the Original Loans funded (2022 Exit Fee) upon (i) any change of control transaction or (ii) our achievement of net revenue from the sale of any products equal to or

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greater than $ 100.0 million, measured on a six (6) months basis (Revenue Milestone), tested monthly at the end of each month.

The 2022 Exit Fee was accounted for as a freestanding derivative and recorded at fair value.

The estimated fair value of the 2022 Exit Fee of $ 0.7 million was recorded as a derivative liability and included in accrued expenses and other current liabilities at December 31, 2023.

The Revenue Milestone was achieved in the second quarter of 2024, resulting in a $ 1.0 million payment in October 2024 to settle the obligation.

The Term C and Term D Loans do not contain an exit fee obligation.

The fair value of the derivative liability was determined using a discounted cash flow analysis and was classified as a Level 3 measurement within the fair value hierarchy since our valuation utilized significant unobservable inputs prior to June 30, 2024.

Specifically, the key assumptions included in the calculation of the estimated fair value of the 2022 Exit Fee derivative liability included:

(i) our estimates of both the probability and timing of achieving the Revenue Milestone and (ii) the probability and timing of funding the Term B Loan, which was dependent upon (a) approval by the U.S.

FDA for our NDA for the control of serum phosphorus in adult patients with CKD on dialysis by November 30, 2023, and (b) achievement of certain product revenue milestone targets.

As of December 31, 2023, uncertainty around all of the noted valuation estimates had been removed, as the Term B Loan had been funded, the U.S.

FDA had approved our NDA for the control of serum phosphorus in adult patients with CKD on dialysis prior to November 30, 2023, and we had achieved the Revenue Milestone.

Changes in the fair value of recurring measurements are presented as other income, net in our statements of operations and comprehensive loss and were as follows:

(in thousands) 2024 2023

January 1, $ 675 $ 1,656

Changes in estimated fair value

2018 Exit Fee — 292

In October 2023, we received approval from the FDA for XPHOZAH to reduce serum phosphorus in adults with CKD on dialysis as add-on therapy in patients who have an inadequate response to phosphate binders or who are intolerant of any dose of phosphate binder therapy.

In connection with a previous loan agreement (2018 Loan Agreement), we became obligated to pay an exit fee of $ 1.5 million, which was paid in October 2023.

2022 Exit Fee

2018 Exit Fee payment — ( 1,500 )

2022 Exit Fee payment

Fair value of exit fee derivative liabilities at December 31, $ — $ 675

Our lease obligation is comprised of operating leases for our offices and research facilities with remaining lease terms ranging from two months to four years and each containing customary rent escalation clauses.

Our leases contain one renewal, at our option, which is generally for a five-year period.

We have not included these renewal periods in the calculation of the right-of-use asset and lease liability since it is uncertain whether we will exercise the renewal option.

Our leased offices and research facilities in Fremont, California expired on February 10, 2025 and our sub-lease agreement for office space at that facility, entered into with Chronus Health in 2023 expired on February 1, 2025.

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The 2022 Loan Agreement obligated us to pay an exit fee in the amount of two percent of the Original Loans funded upon (i) any change of control transaction or (ii) our achievement of net revenue from the sale of any products equal to or greater than $ 100.0 million, measured on a six-month basis (Revenue Milestone), tested monthly at the end of each month.

The Revenue Milestone was achieved in the 2024 second quarter, resulting in a $ 1.0 million payment that was settled in October 2024.

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Our lease obligation is comprised of operating leases for our offices with remaining lease terms ranging from approximately two years to four years and each containing customary rent escalation clauses.

Each of our leases contains one renewal, at our option, for a five-year period.

We have not included these renewal periods in the calculation of the right-of-use assets and lease liabilities since it is uncertain whether we will exercise the renewal options.

The following table provides additional details of our facility leases presented in our balance sheets:

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Weighted-average discount rate 5.6 % 6.5 %

The lease costs, which are included in operating expenses in our statements of operations and comprehensive loss, were as follows:

The lease costs, which are included in our statements of operations and comprehensive loss, and the supplemental cash flow information related to the leases were as follows:

Year Ended December 31,

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(in thousands) Operating Leases

Thereafter 21

Total undiscounted operating lease payments 5,597

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STOCKHOLDERS’ EQUITY

Under a registration statement filed in 2020, we had the ability to sell up to $ 150.0 million of our common stock through Jefferies, as our sales agent.

As of March 2023, we had received the maximum gross proceeds of $ 150.0 million at a weighted average share price of approximately $ 1.57 .

In January 2023, we filed a registration statement on Form S-3, which became effective in January 2023, containing (i) a base prospectus for the offering, issuance and sale by us of up to a maximum aggregate offering price of $ 250.0 million of our common stock, preferred stock, debt securities, warrants and/or units, from time to time in one or more offerings;

and (ii) a prospectus supplement for the offering, issuance and sale by us of up to a maximum aggregate offering price of $ 150.0 million of our common stock that may be issued and sold, from time to time, under a sales agreement with Jefferies, deemed to be “at-the-market offerings” (2023 Open Market Sales Agreement).

Pursuant to the 2023 Open Market Sales Agreement, Jefferies, as sales agent, may receive a commission of up to 3.0 % of the gross sales price for shares of common stock sold under the 2023 Open Market Sales Agreement.

As of December 31, 2024, we have completed sales pursuant to the 2023 Open Market Sales Agreement resulting in the issuance of 16.8 million shares of our common stock and receipt of gross proceeds of $ 70.0 million at a weighted average sales price of approximately $ 4.17 .

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In January 2023, we entered into the 2023 Open Market Sales Agreement with Jefferies with respect to an “at-the-market offering” program, which was established under the Company’s shelf registration statement on Form S-3 and expired in January 2026.

Under the 2023 Open Market Sales Agreement, we sold a total of 16.8 million shares of our common stock and received gross proceeds of $ 70.0 million at a weighted average sales price of approximately $ 4.17 .

During the year ended December 31, 2025, we did not sell any shares under the 2023 Open Market Sales Agreement.

In November 2025, we filed an automatic shelf registration statement on Form S-3ASR, which became effective upon filing, containing (i) a base prospectus, which covers the offering, issuance and sale from time to time in one or more offerings of our common stock, preferred stock, debt securities, warrants and/or units;

and (ii) a prospectus supplement for the offering,

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issuance and sale of up to a maximum aggregate offering price of $ 100.0 million of our common stock that may be issued and sold from time to time, under the 2025 Open Market Sales Agreement, deemed to be “at-the-market offerings.” Pursuant to the 2025 Open Market Sales Agreement, Jefferies, as sales agent, may receive a commission of up to three percent of the gross sales price for shares of our common stock sold under the 2025 Open Market Sales Agreement.

As of December 31, 2025, there have been no sales of our common stock under the 2025 Open Market Sales Agreement.

EQUITY INCENTIVE PLANS

The 2008 Stock Incentive Plan (2008 Plan), which governed the granting of stock options, stock purchase rights and other equity awards, was terminated in June 2014 for future awards.

When the 2014 Equity Incentive Award Plan (2014 Plan) was approved by the board of directors and stockholders on June 18, 2014, all remaining shares available for future award under the 2008 Plan were transferred to the 2014 Plan, as discussed below.

The 2014 Equity Incentive Plan (2014 Plan), effective on June 18, 2014, provided for the stock-based compensation awards, including stock options, stock appreciation rights, restricted stock, service-based RSUs, performance-based RSUs, deferred stock, deferred stock units, dividend equivalents, stock payments and performance awards.

The 2014 Plan initially reserved 1.5 million shares, including the 35 thousand shares remaining for future awards under the 2008 Plan, with up to 1.2 million additional shares which could be added from forfeited or lapsed awards from the 2008 Plan.

The 2014 Plan initially reserved 1.5 million shares, including the 35 thousand shares remaining for future awards under a previous equity incentive plan (2008 Plan), with up to 1.2 million additional shares which could be added from forfeited or lapsed awards from the 2008 Plan.

The 2014 Plan allowed for an annual increase in the number of shares available for issuance on the first day of each year through 2024, equal to the lesser of four percent of our outstanding common stock on the last day of the immediately preceding year or a smaller amount determined by the board of directors (2014 Plan evergreen provision).

On June 14, 2024, stockholders approved the Amended and Restated 2014 Equity Incentive Award Plan (2014 A&R Plan).

The key provisions pursuant to the 2014 A&R Plan include:

(1) 19.0 million shares were added to the total existing share reserve;

(2) the 2014 Plan evergreen provision was removed such that any increase to the total number of shares that may be issued must be approved by our stockholders;

and (3) the limit of shares that may be issued upon exercise of incentive stock options was increased from 10.7 million to 58.5 million shares.

The key provisions pursuant to the 2014 A&R Plan included (i) an addition of 19.0 million shares to the total existing share reserve;

(ii) the removal of the 2014 Plan evergreen provision such that any increase to the total number of shares that may be issued must be approved by our stockholders;

and (iii) an increase for the limit of shares that may be issued upon exercise of incentive stock options from 10.7 million to 58.5 million shares.

In addition to increases resulting from repurchases, forfeitures, expirations and cancellations of awards under the 2008 Plan, shares reserved for issuance under the 2014 A&R Plan will be increased by the number of shares subject to awards granted under the Inducement Plan, as discussed below, that are repurchased, forfeited, expire or are cancelled on or after June 14, 2024.

As a result, no new awards will be made under the Inducement Plan after June 14, 2024.

As of December 31, 2024, approximately 18.1 million shares of our common stock were available for future issuance under the 2014 A&R Plan.

As a result, no new awards would be made under the Inducement Plan following June 14, 2024.

On June 18, 2025, stockholders approved the Equity Plan Amendment to the 2014 A&R Plan to (i) increase the number of shares reserved for issuance under the 2014 A&R Plan by 10.0 million shares;

and (ii) increase the limit of shares that may be issued upon exercise of incentive stock options from 58.5 million to 68.5 million shares.

As of December 31, 2025, approximately 16.9 million shares of our common stock were available for future issuance under the 2014 A&R Plan, as amended.

In November 2016, our board of directors approved the 2016 Employment Commencement Incentive Plan (Inducement Plan) under which 1.0 million shares were reserved.

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As of December 31, 2025, 9.0 million shares of our common stock were subject to inducement grants that were issued pursuant to the Inducement Plan.

As of December 31, 2024, approximately 3.9 million shares of our common stock were available for future issuance under the 2016 Plan.

As of December 31, 2025, no additional shares of our common stock were available for future issuance under the 2016 Plan.

Stock Options

A summary of our stock option activity and related information during the year ended December 31, 2024 is as follows:

Options Issued and Outstanding Weighted Average Remaining Contractual Term

Aggregate Intrinsic Value

(in thousands)

A summary of our stock option activity and related information for the year ended December 31, 2025 is as follows:

Number of Shares

(in thousands) Weighted-Average Exercise Price per Share Weighted-Average Remaining Contractual Term

Aggregate Intrinsic Value

(in thousands)

Weighted-Average Exercise Price per Share

Balance at December 31, 2023 22,168 $ 4.20

Balance as of December 31, 2024 28,085 $ 5.63

Options granted 9,011 $ 5.08

Options exercised ( 1,880 ) $ 2.20

Options canceled ( 1,103 ) $ 5.35

Balance at December 31, 2024 28,085 $ 5.63 7.1 $ 31,830

Vested and expected to vest at December 31, 2024 28,085 $ 5.63 7.1 $ 31,830

Exercisable at December 31, 2024 14,968 $ 5.52 5.7 $ 19,161

Options forfeited or canceled

( 6,239 ) $ 6.29

Balance as of December 31, 2025 28,977 $ 5.54 6.4 $ 37,405

Vested and expected to vest as of December 31, 2025 28,977 $ 5.54 6.4 $ 37,405

Exercisable as of December 31, 2025 18,133 $ 5.43 5.1 $ 28,181

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The aggregate intrinsic value represents the difference between the total pre-tax value (i.e., the difference between our stock price and the exercise price) of stock options outstanding as of December 31, 2025, based on our common stock closing price of $ 5.83 per share, which would have been received by the option holders if all their in-the-money options had been exercised as of that date.

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The intrinsic value of options exercised during the years ended December 31, 2024, 2023 and 2022 was $ 19.6 million, $ 1.1 million and $ 30 thousand, respectively.

The intrinsic value of options exercised during the years ended December 31, 2025, 2024 and 2023 was $ 9.6 million, $ 19.6 million and $ 1.1 million, respectively.

The total fair value of options vested during the years ended December 31, 2025, 2024 and 2023 was $ 68.1 million, $ 61.0 million and $ 24.9 million, respectively.

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Expected Term —We estimate the expected term of our options based upon historical exercises and post-vesting termination behavior.

Expected Volatility —We use the historic volatility of our own stock over the retrospective period corresponding to the expected remaining term of the options, or the period since our shares were first quoted on The Nasdaq Global Market, if that is shorter, to compute our expected stock price volatility.

Expected Volatility —We use the historic volatility of our own stock over the retrospective period corresponding to the expected remaining term of the options to compute our expected stock price volatility.

Risk-Free Interest Rate —The risk-free interest rate assumption is based on the zero-coupon U.S.

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Number of RSUs

(in thousands)

Weighted-Average Grant Date Fair Value Per Share

Non-vested restricted stock units at December 31, 2023 3,646 $ 3.09

(in thousands) Weighted-Average Grant Date Fair Value per Share

Non-vested restricted stock units as of December 31, 2024 8,013 $ 6.59

Granted 11,291 $ 5.15

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Forfeited ( 2,651 ) $ 5.93

Non-vested restricted stock units at December 31, 2024 8,013 $ 6.59

Non-vested restricted stock units as of December 31, 2025 12,583 $ 5.71

Restricted stock units exercisable (vested and deferred) as of December 31, 2025 21

The total estimated fair value of RSUs vested during the years ended December 31, 2025, 2024 and 2023 was $ 21.7 million, $ 16.4 million and $ 3.5 million, respectively.

Issuance of Common Stock for Services

During the years ended December 31, 2024, 2023 and 2022, we issued approximately 41 thousand, 0.1 million and 0.7 million shares, respectively, of common stock to members of the board of directors who elected to receive stock in lieu of their cash fees under our Non-Employee Director Compensation Program.

During the years ended December 31, 2025, 2024 and 2023, we issued approximately 0.1 million, 41 thousand and 0.1 million shares, respectively, of our common stock to members of the board of directors who elected to receive stock in lieu of their cash fees under our Non-Employee Director Compensation Program, as amended.

In 2025, our board of directors adopted the Fifth Amended and Restated Non-Employee Director Compensation Program, under which the board may provide each director with the opportunity to defer the settlement of restricted stock units to be granted to a future date.

The shares issued during the years ended December 31, 2025, 2024 and 2023 were valued at $ 0.3 million, $ 0.3 million and $ 0.3 million, respectively, based on the fair value of the common stock on the date of grant.

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Employee Stock Purchase Plan

The 2014 ESPP, effective on June 18, 2014, initially reserved approximately 0.2 million shares of common stock for our eligible employees to purchase shares of our common stock at a discount.

If approved by the administrator of the ESPP, on the first day of each calendar year through 2024, the number of shares in the reserve increased by an amount equal to the lesser of (i) one percent ( 1.0 %) of the shares of common stock outstanding on the last day of the immediately preceding fiscal year and

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(ii) such number of shares of common stock as determined by the board of directors (2014 ESPP evergreen provision);

The 2014 ESPP, effective on June 18, 2014, initially reserved approximately 0.2 million shares of our common stock for our eligible employees to purchase shares of our common stock at a discount.

If approved by the administrator of the ESPP, on the first day of each calendar year through 2024, the number of shares in the reserve increased by an amount equal to the lesser of (i) one percent of the shares of our common stock outstanding on the last day of the immediately preceding fiscal year;

and (ii) such number of shares of our common stock as determined by the board of directors (2014 ESPP evergreen provision);

provided, however, no more than 2.2 million shares of our common stock could be issued under the ESPP.

On June 14, 2024, stockholders approved the Amended and Restated 2014 ESPP (A&R ESPP).

The key provisions pursuant to the A&R ESPP include:

(1) 3.0 million shares were added to the total existing share reserve and (2) the 2014 ESPP evergreen provision was eliminated and no evergreen increases will be made after June 14, 2024.

The key provisions pursuant to the A&R ESPP included (i) an addition of 3.0 million shares to the total existing share reserve;

and (ii) the removal of the 2014 ESPP evergreen provision such that no evergreen increases would be made after June 14, 2024.

During the years ended December 31, 2025, 2024 and 2023, we issued approximately 0.4 million, 0.5 million and 0.4 million shares, respectively, at an average share price of $ 4.46 , $ 4.64 and $ 1.85 , respectively, pursuant to the ESPP.

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Stock-Based Compensation Expense

Stock-based compensation expense recognized for stock options, RSUs and our ESPP is recorded as operating expenses in our statements of operations and comprehensive loss, as follows:

Stock-based compensation expense for stock options, RSUs and our ESPP included in our statements of operations and comprehensive loss was as follows:

Year Ended December 31,

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A summary of our total unrecognized stock-based compensation expense, net of estimated forfeitures, as of December 31, 2025 is as follows:

December 31, 2024

Unrecognized Compensation Expense (in thousands)

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ESPP $ 107 0.17

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PROPERTY AND EQUIPMENT, NET

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(in thousands) 2025 2024

Laboratory equipment $ 46 $ 46

Office equipment and furniture $ 2,686 $ 2,923

Leasehold improvements 2,148 9,144

Laboratory equipment — 46

Property and equipment, gross 4,834 12,113

Accumulated depreciation ( 2,650 ) ( 10,618 )

( 10,618 ) ( 10,201 )

Total property and equipment, net $ 2,184 $ 1,495

Table of Conten t s

We recognized depreciation expense in the amount of $ 0.8 million, $ 0.5 million and $ 0.6 million in 2025, 2024 and 2023, respectively.

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(in thousands) 2025 2024

Accrued payments due to AstraZeneca $ 12,077 $ 3,680

Accrued gross to net revenue liabilities $ 30,272 $ 10,112

Accrued sales and marketing expenses 4,598 3,696

Accrued contract manufacturing expenses 2,821 1,402

Accrued medical affairs expenses 2,538 817

Accrued payments due to AstraZeneca — 12,077

Other 7,348 6,538

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(in thousands) 2025 2024 2023

Loss before provision for income taxes

$ ( 60,630 ) $ ( 38,870 ) $ ( 65,520 )

Provision for income taxes

State $ 469 $ 266 $ 47

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Total deferred — — —

Provision for income taxes $ 266 $ 547 $ 8

Total provision for income taxes $ 969 $ 266 $ 547

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A reconciliation of the statutory federal income tax rate to our effective tax rate is as follows:

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2025 2024 2023

($ in thousands)

Income tax at the federal statutory rate $ ( 12,732 ) 21.0 % $ ( 8,163 ) 21.0 % $ ( 13,759 ) 21.0 %

State taxes, net of federal benefit 4.0 3.4 1.9

Tax credits 0.6 1.7 1.5

State and local income taxes, net of federal effect (1)

401 ( 0.7 ) % 191 ( 0.5 ) % 13 — %

Foreign tax effects 500 ( 0.8 ) % — — % 500 ( 0.8 ) %

Research and development tax credits ( 936 ) 1.5 % — — % ( 215 ) 0.3 %

Other ( 500 ) 0.8 % — — % ( 500 ) 0.8 %

Changes in valuation allowance 9,367 ( 15.4 ) % 8,023 ( 20.6 ) % 13,601 ( 20.8 ) %

Nontaxable or nondeductible items

Section 162(m) limitation 1,322 ( 2.2 ) % 2,247 ( 5.8 ) % 1,217 ( 1.9 ) %

Stock-based compensation 3,672 ( 6.1 ) % ( 2,003 ) 5.2 % ( 65 ) 0.1 %

Foreign withholding tax — ( 0.8 ) —

Executive compensation disallowed under IRC Sec 162(m) ( 5.8 ) ( 1.9 ) ( 1.6 )

Other ( 125 ) 0.2 % ( 29 ) 0.1 % ( 245 ) 0.4 %

Change in valuation allowance ( 25.0 ) ( 24.3 ) ( 19.7 )

Effective tax rate $ 969 ( 1.7 ) % $ 266 ( 0.6 ) % $ 547 ( 0.9 ) %

Table of Conten t s

(1) State and local income taxes that made up the majority (greater than 50%) of the tax effect in this category included:

Kentucky in 2025 and 2024;

and South Carolina and Kentucky in 2023.

The following table presents our income taxes paid, net of refunds, which are all attributable to state and local:

Year Ended December 31,

(in thousands)

2025 2024 2023

Kentucky $ 391 $ 50 *

Texas 41 18 5

South Carolina * 105 18

New Jersey * * 8

New York * 40 7

Massachusetts * 20 *

Other 53 33 13

Total $ 485 $ 266 $ 51

* Jurisdiction below the threshold for the period presented.

Table of Co n t e n t s

Deferred income tax balances reflect the effects of temporary differences between the carrying amounts of assets and liabilities and their income tax bases, as well as from net operating loss and tax credit carryforwards.

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Deferred tax assets

Amortization and depreciation $ 64,237 $ 64,919

Net operating loss carryforwards $ 124,100 $ 103,643

Amortization and depreciation 44,703 64,237

Tax credits 17,109 15,529

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Due to the existence of the valuation allowance, limitations under Section 382 and 383 will not impact our effective tax rate.

Effective January 1, 2022, research and development expenses are required to be capitalized and amortized for U.S.

tax purposes.

The mandatory capitalization requirement did not have a material impact on our deferred tax assets and did not result in a cash tax liability as we have historically elected to capitalize research and development expenses for tax purposes.

Table of Conten t s

In July 2025, the One Big Beautiful Bill Act (OBBBA) was enacted into law.

The OBBBA makes permanent many of the expired and expiring tax provisions of the Tax Cuts and Jobs Act and restores certain business provisions, including the immediate expensing of domestic research and development costs.

In addition, the OBBBA allows for an accelerated deduction of the unamortized domestic research and development costs capitalized during the 2022 through 2024 tax years.

The legislation has multiple effective dates, with certain provisions effective in 2025 and others implemented through 2027.

The enactment of the OBBBA did not have a material impact on our financial statements.

Table of Co n t e n t s

A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:

(in thousands) 2025 2024 2023

Balance at beginning of year $ 23,625 $ 24,075 $ 24,426

Balance as of January 1,

$ 22,919 $ 23,625 $ 24,075

Additions based on tax positions related to current year 864 105 262

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Subtractions based on tax positions related to prior year ( 811 ) ( 811 ) ( 811 )

Balance at end of year $ 22,919 $ 23,625 $ 24,075

Balance as of December 31,

$ 22,972 $ 22,919 $ 23,625

We recognize a tax benefit from an uncertain tax position when it is more likely than not that the position will be sustained upon examination, including resolutions of any related appeals or litigation processes, based on the technical merits.

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During the years ended December 31, 2025, 2024 and 2023, we did not recognize accrued interest and penalties related to unrecognized tax benefits.

Although the timing and outcome of an income tax audit is highly uncertain, we do not anticipate that the amount of existing unrecognized tax benefits will significantly change during the next 12 months.

We file a U.S.

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SEGMENT REPORTING

We operate in a single reportable segment with a mission to discover, develop and commercialize innovative, first-in-class medicines that meet significant unmet medical needs.

A centralized research and development organization, supply chain organization and commercial organization are all responsible for the discovery, development, manufacturing, supply and sale of our products.

We operate in a single reportable segment with a mission to develop and commercialize innovative medicines that meet significant unmet medical needs.

A centralized research and development organization, supply chain organization and commercial organization are all responsible for the development, manufacturing, supply and sale of our products.

Our business is also supported by centralized corporate functions.

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and earn revenues from sales of IBSRELA and XPHOZAH, both branded products derived from tenapanor, a molecule developed from our unique and innovative platform.

Licensing agreements with international partners are utilized for development and commercialization activities outside the U.S.

Currently, we maintain such agreements for certain indications of tenapanor in Japan (Kyowa Kirin), China (Fosun Pharma) and Canada (Knight).

Refer to Note 7.

Collaboration And Licensing Agreements for further detail.

We recognize other revenue in the form of product supply revenue and licensing revenue under the Kyowa Kirin and Knight agreements.

Revenue streams associated with the Kyowa Kirin Agreement are subject to a separate agreement where such future royalties and commercial milestones were sold to a third-party.

Refer to Note 8.

Deferred Royalty Obligation Related To The Sale Of Future Royalties for further information.

Our Chief Executive Officer (CEO) is our Chief Operating Decision Maker (CODM), responsible for allocating resources and assessing Company performance using aggregated financial information.

In addition to commercializing IBSRELA and XPHOZAH, we are also developing a next-generation NHE3 inhibitor that we believe can have application across multiple therapeutic areas.

Collaboration and licensing agreements with external partners are utilized for development and commercialization activities outside the U.S.

Currently, we maintain such agreements for certain indications of tenapanor in Japan (Kyowa Kirin), China (Fosun Pharma) and Canada (Knight), as discussed further in Note 7.

Collaboration and Licensing Agreements .

We recognize other revenues in the form of licensing revenue, product supply revenue or non-cash royalty revenue related to the sale of future royalties under such agreements.

Royalties and commercialization milestones earned under the Kyowa Kirin Agreement are subject to a separate agreement where such revenue payments are sold to HCR, as discussed further in Note 8.

Deferred Royalty Obligation Related to the Sale of Future Royalties .

Our Chief Executive Officer (CEO) is our Chief Operating Decision Maker (CODM), responsible for allocating resources and assessing the Company’s performance using aggregated financial information.

Utilizing aggregated financial information enables the CODM to determine the most appropriate resource allocation across the commercial organization, research and development projects or other initiatives consistent with our long-term corporate wide strategic goals.

The CODM primarily uses aggregated net loss as reported on the statements of operations and comprehensive loss to measure segment loss, supplemented by certain additional significant expense details reflected in the table below.

Table of Conten t s

Detailed information regarding our single operating segment’s significant revenues, expenses and operating loss are as follows:

Table of Co n t e n t s

Detailed information regarding our single operating segment’s significant revenues, expenses and operating loss is as follows:

Year Ended December 31,

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Cost of product sales (2)

11,185 6,851 2,323

Other cost of revenue (3)

Total cost of goods sold 50,556 17,795 4,117

28,352 43,705 15,472

Research and development (4)

58,429 39,480 29,231

Selling expenses (2)

226,925 162,957 80,028

General and administrative expenses (2)

General and administrative (4)

58,662 52,916 34,020

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15,782 18,275 13,128

Total operating expenses 311,009 169,937 111,800

Segment and consolidated loss from operations ( 27,950 ) ( 63,276 ) ( 63,759 )

Total costs and operating expenses 448,297 361,565 187,732

Consolidated loss from operations ( 40,977 ) ( 27,950 ) ( 63,276 )

Other reconciliation items (6)

( 20,622 ) ( 11,186 ) ( 2,791 )

Segment and consolidated net loss $ ( 39,136 ) $ ( 66,067 ) $ ( 67,207 )

(1) “Other revenues” includes revenues from our collaboration partnerships, including license fees, milestone payments, product supply revenue and non-cash royalty revenue related to the sale of future royalties.

Consolidated net loss $ ( 61,599 ) $ ( 39,136 ) $ ( 66,067 )

(1) Other revenues includes revenues from our collaboration partnerships, including licensing revenue, product supply revenue and non-cash royalty revenue related to the sale of future royalties.

(2) Cost of product sales includes the cost of commercial goods sold to our Customers, such as the cost of materials, third-party contract manufacturing, third-party packaging services, freight, labor costs for personnel involved in the manufacturing process and indirect overhead costs.

(3) Other cost of revenue includes the cost of materials sold to our collaboration partners under product supply agreements, certain costs related to capacity expansion at current and future CMOs and payments due to AstraZeneca.

As of the end of the 2025 second quarter, the maximum $ 75.0 million royalty obligation under the AstraZeneca Termination Agreement had been fully recognized.

(4) Research and development, selling and general administrative expenses herein do not include certain allocated items, such as stock-based compensation expenses.

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NET LOSS PER SHARE

Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period and excludes any dilutive effects of stock-based awards and warrants.

Diluted net loss per common share is computed giving effect to all potential dilutive common shares, including common stock issuable upon exercise of stock options, and unvested restricted common stock and stock units.

Basic net loss per share is calculated by dividing net loss by the weighted-average number of common shares outstanding during the period and excludes any dilutive effects of stock-based awards.

Diluted net loss per common share is computed giving effect to all potential dilutive common shares, including common stock issuable upon exercise of stock options, unvested restricted stock units and ESPP shares issuable pursuant to the current purchase period.

As we had net losses for the years ended December 31, 2025, 2024 and 2023, all potential common shares were determined to be anti-dilutive.

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$ ( 0.26 ) $ ( 0.17 ) $ ( 0.30 )

Table of Conten t s

Table of Co n t e n t s

The total numbers of securities that could potentially dilute net income per share in the future that were not considered in the diluted net loss per share calculations because the effect would have been anti-dilutive were as follows:

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Legal Proceedings and Claims

On July 30 and August 12, 2021, two putative securities class action lawsuits were commenced in the U.S.

District Court for the Northern District of California naming as defendants Ardelyx and two current officers captioned Strezsak v.

Ardelyx, Inc., et al.

4:21-cv-05868-HSG, and Siegel v.

Ardelyx, Inc., et al.

5:21-cv-06228-HSG (together, the Securities Class Actions).

The complaints allege that the defendants violated Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 (the Exchange Act), as amended, and Rule 10b-5 thereunder, by making false and misleading statements and omissions of material fact related to tenapanor.

The plaintiffs seek damages and interest, and an award of costs, including attorneys’ fees.

On July 19, 2022, the court consolidated the two putative class actions and appointed a lead plaintiff and lead counsel.

The lead plaintiff filed a second amended complaint under which the plaintiffs seek to represent all persons who purchased or otherwise acquired Ardelyx securities between March 6, 2020 and July 19, 2021.

Defendants filed a motion to dismiss the amended complaint on June 2, 2023.

On March 22, 2024, the court granted defendants’ motion to dismiss.

The court provided plaintiffs a third opportunity to amend and plaintiffs filed a third amended complaint on April 19, 2024.

Defendants filed a motion to dismiss the third amended complaint on June 3, 2024.

The case was dismissed with prejudice on September 12, 2024.

On October 9, 2024, plaintiff appealed the District Court’s dismissal of the case to the Ninth Circuit.

We believe the plaintiffs’ claims are without merit.

On December 7, 2021 and March 29, 2022, two verified shareholders derivative lawsuits were filed in the U.S.

On December 7, 2021 and March 29, 2022, two verified shareholder derivative lawsuits were filed in the U.S.

District Court for the Northern District of California purportedly on behalf of Ardelyx against certain of Ardelyx’s executive officers and members of our board of directors, captioned Go v.

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Raab, et al., Case No.

4:22-cv-01988-JSC.

The complaints allege that the defendants' violations of Section 14(a) of the Securities Exchange Act of 1934, as amended, breaches of fiduciary duties, unjust enrichment, abuse of control, gross mismanagement, and waste of corporate assets for personally making and/or causing Ardelyx to make materially false and misleading statements regarding the Company’s business, operations and prospects.

The complaint seeks contribution under Sections 10(b) and 21D of the Securities Exchange Act of 1934 from two executive officers.

On January 19, and April 27, 2022, the court granted the parties’ stipulation to stay the Go and Morris actions, respectively, until resolution of the anticipated motion(s) to dismiss in the Securities Class Actions.

On October 25, 2022, the parties filed a stipulation to consolidate and stay the Go and Morris actions, and on October 27, 2022, the court consolidated the Go and Morris action and stayed the consolidated action pending resolution of the anticipated motion(s) to dismiss in the Securities Class Action.

The consolidated case remains stayed pending resolution of the appeal in the Securities Class Action.

We believe the plaintiffs’ claims are without merit.

Table of Conten t s

4:22-cv-01988-JSC (together, the Go and Morris actions).

The complaints allege that the defendants’ violations of Section 14(a) of the Exchange Act, breaches of fiduciary duties, unjust enrichment, abuse of control, gross mismanagement, and waste of corporate assets for personally making and/or causing Ardelyx to make materially false and misleading statements regarding the Company’s business, operations and prospects.

The complaint seeks contribution under Sections 10(b) and 21D of the Exchange Act from two executive officers.

On January 19, 2022 and April 27, 2022, the court granted the parties’ stipulation to stay the Go and Morris actions, respectively, until resolution of the motion(s) to dismiss in the lawsuits captioned Strezsak v.

Ardelyx, Inc., et al., Case No.

4:21-cv-05868-HSG and Siegel v.

Ardelyx, Inc., et al., Case No.

5:21-cv-06228-HSG (together, the Securities Class Actions).

On October 25, 2022, the parties filed a stipulation to consolidate and stay the Go and Morris actions, and on October 27, 2022, the court consolidated the Go and Morris actions and stayed the consolidated action pending resolution of the anticipated motion(s) to dismiss in the Securities Class Action.

The Securities Class Actions were voluntarily dismissed on March 5, 2025.

The court dismissed the Go and Morris actions on April 30, 2025.

On July 17, 2024, in partnership with the AAKP and the NMQF, we filed a lawsuit in the U.S.

District Court for the District of Columbia against the CMS, claiming that CMS has violated its statutory and regulatory authority under the MIPPA, which established the ESRD PPS bundled payment system for dialysis services in 2008.

Specifically, the lawsuit claims that CMS’s plan to move XPHOZAH, along with all oral-only drugs, into the ESRD PPS is inconsistent with MIPPA’s statutory provision, and contradicts CMS’s own regulations.

XPHOZAH and other oral-only drugs, which are currently available to patients under Medicare Part D, are not administered by dialysis providers and cannot be taken during the delivery of maintenance dialysis.

The Company, AAKP and NMQF are seeking relief under the Administrative Procedure Act to enjoin CMS from proceeding with its plan to include XPHOZAH in the ESRD PPS and eliminate coverage under Medicare Part D beginning on January 1, 2025.

District Court for the District of Columbia against CMS, claiming that CMS has violated its statutory and regulatory authority under MIPPA, which established the ESRD PPS bundled payment system for dialysis services in 2008.

Specifically, the lawsuit claims that moving XPHOZAH, along with all oral-only drugs, into the ESRD PPS is inconsistent with MIPPA’s statutory provision, and contradicts CMS’s own regulations.

XPHOZAH and other oral-only drugs are not administered by dialysis providers and cannot be taken during the delivery of maintenance dialysis.

On November 8, 2024, the U.S.

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Following the District Court’s denial of plaintiffs’ Motion to Alter or Amend the Judgment, or in the Alternative, for an Injunction Pending Appeal, plaintiffs filed an Emergency Motion for an Administrative Stay and Injunction Pending Appeal, which was denied by the United States Court of Appeals for the District of Columbia Circuit.

Appellants filed a brief in the appeal on February 4, 2025, and Appellee’s brief is due March 6, 2025.

Final briefs in the appeal are currently expected to be filed on April 10, 2025.

Appellants filed an initial brief in the appeal on February 4, 2025;

Appellees filed an initial brief on March 6, 2025;

and Appellants filed a reply brief on March 27, 2025.

Both Appellees and Appellants filed a final brief on April 10, 2025.

Oral argument in the case was heard on September 25, 2025.

Table of Co n t e n t s

On August 16, 2024, a complaint was filed against us in the U.S.

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24-cv-12119 (D.

The complaint names the Company, Mike Raab, and Justin Renz as defendants and alleges violations of Sections 10(b) and 20(a) the Exchange Act and Rule 10b-5 promulgated thereunder, related to the our announcement on July 2, 2024 that it had chosen not to file an application for Transitional Drug Add-on Payment Adjustment for XPHOZAH (the “Yarborough Action”).

The complaint names the Company, Michael Raab, and Justin Renz as defendants and alleges violations of Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5 promulgated thereunder, related to our announcement on July 2, 2024 that it had chosen not to file an application for Transitional Drug Add-on Payment Adjustment for XPHOZAH (the Yarborough Action).

The plaintiffs seek damages and interest, and an award of costs, including attorneys’ fees.

Two shareholders filed motions to be appointed lead plaintiff in the Yarborough Action on October 15, 2024.

The Court appointed Tate Wood as lead plaintiff on October 30, 2024.

Lead Plaintiff filed an amended complaint on January 13, 2025, alleging violations of Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5 promulgated thereunder related to our announcement on July 2, 2024 regarding TDAPA.

Lead Plaintiff purports to bring claims on behalf of all those who acquired Ardelyx common stock between February 23, 2024 and July 1, 2024.

Defendants’ motion to dismiss the amended complaint is due March 14, 2025.

We believe the plaintiff’s claims are without merit.

The lead plaintiff filed an amended complaint on January 13, 2025, in which he added Susan Rodriguez, Laura Williams and Elizabeth Grammer as additional defendants and removed Justin Renz as a defendant.

The lead plaintiff purports to bring claims on behalf of all those who acquired Ardelyx common stock between February 22, 2024 and July 1, 2024.

Defendants filed a motion to dismiss the amended complaint on March 14, 2025.

Plaintiffs filed a response on May 13, 2025.

Defendants filed a reply in support of their motion to dismiss on June 23, 2025.

A hearing on the motion to dismiss was held on September 25, 2025, and on December 24, 2025, the Court granted defendants’ motion to dismiss and issued an order dismissing the case with prejudice.

On January 21, 2026, Plaintiffs appealed the District Court’s decisions to the United States Court of Appeals for the First Circuit.

On September 6 and 13, 2024, certain Ardelyx shareholders filed two verified derivative complaints purportedly on behalf of the Company in the United States District Court for the District of Massachusetts alleging violations of Sections 10(b) and/or 14(a) of the Exchange Act, breaches of fiduciary duty, unjust enrichment, waste, and aiding and abetting breaches of fiduciary duty against certain members of our board of directors and management based on substantially the same factual allegations in the Yarborough Action.

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Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-K

Item 8. Financial Statements and Supplementary Data