ARDELYX, INC. (ARDX) Business

ITEM 1. BUSINESS

Overview

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, a sodium/hydrogen exchanger (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 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 chronic idiopathic constipation (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 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.

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.

Strategy

We are committed to our mission of developing and commercializing innovative medicines that address unmet patient needs. Our principal strategy is to continue our commercial momentum with our current products while advancing and expanding a portfolio of important medicines for patients with unmet medical needs.

Our priorities include (i) driving significant IBSRELA growth, (ii) maintaining XPHOZAH commercial momentum, (iii) further advancing our pipeline and portfolio and (iv) maintaining a solid financial foundation to support our future growth.

We have incurred losses in each year since our inception in October 2007. We continue to incur commercialization, development and additional expenses related to our ongoing operations and pursuit of future business opportunities. We have historically funded our operations primarily from product sales, sales of our common stock, funds from our loan agreements with SLR, funds from our collaboration partnerships, as well as the sale of future royalties and commercialization milestones to HCR. We expect that we will increasingly rely on cash generated from our commercial operations to fund our operating plan while maintaining financial flexibility to source cash from future equity sales and debt financing.

Our Commercial Products

IBSRELA for IBS-C

IBSRELA is a first-in-class NHE3 inhibitor approved by the FDA for the treatment of IBS-C in adults. IBSRELA acts locally in the gut and is minimally absorbed. IBS-C is a gastrointestinal disorder characterized by both constipation and abdominal pain. IBS-C is associated with significantly impaired quality of life, reduced productivity and substantial economic burden. We recognized our first sales of IBSRELA in the U.S. in March 2022.

We deploy a market-responsive commercial strategy for IBSRELA and have a commercial organization highly experienced in commercializing novel therapies in specialty areas. The dynamics of the IBS-C market reflect an established patient base, limited number of competitors all confined to a single mechanism of action (secretagogues), concentrated number of prescribers who see a large number of IBS-C patients, and recognized unmet need. These dynamics enable a targeted promotional focus on IBS-C patients currently being managed by high-writing healthcare providers. Central to our commercial strategy for IBSRELA has been our highly experienced specialty sales force, many with existing relationships across their gastrointestinal target base,

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omnichannel digital initiatives and our patient services programs, including ArdelyxAssist, that support patient access to our therapies.

We believe competition for IBSRELA comes largely from prescription products indicated for IBS-C: branded products, Linzess (linaclotide) and Trulance (plecanatide), as well as generic lubiprostone.

In January 2026, we initiated ACCEL (ten-03-301), a Phase 3 clinical trial designed to assess the safety and efficacy of tenapanor for the treatment of CIC. Enrollment in ACCEL is expected throughout 2026, with topline data read out in the second half of 2027. CIC is characterized by difficult, infrequent or incomplete bowel movements, and is associated with significantly impaired quality of life, disrupted productivity and high healthcare-related costs and is estimated to affect more than 34 million Americans.

XPHOZAH for Hyperphosphatemia in CKD Patients on Dialysis

XPHOZAH was approved by the FDA in October 2023. XPHOZAH is a first-in-class phosphate absorption inhibitor 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. XPHOZAH has a differentiated mechanism of action and acts locally in the gut to inhibit NHE3. This results in the tightening of the epithelial cell junctions, thereby significantly reducing paracellular uptake of phosphate, the primary pathway of phosphate absorption. It is estimated that there are more than 550,000 adult patients with CKD on dialysis in the U.S. and approximately 80% of those patients are being treated with phosphate lowering therapies. In addition, approximately 70% of patients treated with phosphate binders to treat hyperphosphatemia were unable to consistently maintain phosphorous levels =5.5 mg/dL over a six-month period. XPHOZAH is the first therapy for phosphate management that blocks phosphate absorption at the primary site of uptake. We recognized our first sales of XPHOZAH in the U.S. in December 2023.

We have a commercial organization highly experienced and knowledgeable of the nephrology market. The dynamics of the hyperphosphatemia market reflect an established patient base, limited number of competitors all confined to a single mechanism of action (phosphate binders), concentrated number of prescribers and significant unmet need. Central to our commercial strategy is our highly experienced specialty sales force, many with existing relationships across the nephrology target base, innovative omnichannel digital initiatives and our patient services programs, including ArdelyxAssist, that support patient access to our therapies.

On January 1, 2025, XPHOZAH, along with other oral drugs for ESRD patients on dialysis without injectable or intravenous equivalents, became part of the ESRD Prospective Payment System and coverage for XPHOZAH and these other oral drugs under Medicare Part D was eliminated. We made the decision to preserve access to XPHOZAH for all appropriate patients. Although more patients had access to XPHOZAH and we increased the number of patients on treatment compared to 2024, the change in Medicare reimbursement coverage had a negative and material impact on our XPHOZAH revenue in 2025. Our strategy for XPHOZAH remains a targeted promotional focus on nephrology healthcare providers to preserve access for patients, regardless of insurance coverage, determined to be appropriate candidates for XPHOZAH by their healthcare provider.

XPHOZAH is indicated 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. The various types of phosphate binders commercialized in the U.S. include the following: Calcium acetate (several prescription brands, including PhosLo and Phoslyra); Lanthanum carbonate (Fosrenol); Sevelamer hydrochloride (Renagel); Sevelamer carbonate (Renvela); Sucroferric oxyhydroxide (Velphoro) and Ferric citrate (Auryxia). All of the listed phosphate binders are available as generics in the U.S., with the exception of Velphoro. Additionally, over-the-counter calcium carbonate, such as Tums and Caltrate, is also used to bind phosphorus.

In addition to the currently available phosphate binders, we are aware of at least four phosphate binders in development, including AP-301, developed by Alebund Pharmaceutical (Hong Kong) Limited; VS-505, developed by Vidasym; TS-172, developed by Taisho Pharmaceutical; and OLC, developed by Unicycive Therapeutics. Additionally, Alebund is developing AP-306, an inhibitor of phosphate transporters NaPi-2b, PiT-1, and PiT-2.

Our Commercial Strategy

We have established a high-quality commercial organization, with capabilities, including marketing, market access, patient services and sales designed to support our commercialization of IBSRELA and XPHOZAH. We have executed collaborations with established industry leaders to efficiently bring XPHOZAH and IBSRELA to patients in specific territories outside of the U.S. We continue to evaluate our strategy for the commercialization of IBSRELA and XPHOZAH in ex-U.S. territories.

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Product Pipeline

Label Extension for IBSRELA to Treat Patients with CIC

In September 2025, we submitted an IND application to the FDA for IBSRELA to expand the IBSRELA eligible patient population to include patients with CIC. In January 2026, we initiated ACCEL (ten-03-301), a Phase 3 clinical trial designed to assess the safety and efficacy of tenapanor for the treatment of CIC. Enrollment in ACCEL is expected throughout 2026, with topline data read out in the second half of 2027. CIC is characterized by difficult, infrequent or incomplete bowel movements, and is associated with significantly impaired quality of life, disrupted productivity and high healthcare-related costs. CIC is estimated to affect more than 34 million Americans. Pending the outcome of the Phase 3 clinical trial, if successful, we intend to submit a supplemental NDA to the FDA for tenapanor for the CIC indication.

Discovery and Development Asset

In October 2025, we announced a development program for RDX10531. We believe RDX10531 is a next-generation NHE3 inhibitor with potential application across multiple therapeutic areas. We are currently conducting activities to support an IND submission to the FDA for RDX10531 in the second half of 2026.

Collaboration Partners

We have entered into collaboration agreements with third parties for the development and commercialization of tenapanor for certain indications in their respective territories. In exchange for granting the respective licenses, we receive upfront payments upon contract execution, are eligible to receive development and regulatory milestones upon achievement of respective events and are eligible to receive sales-based royalties and commercialization milestones. We also enter into supply agreements with our partners to supply drug substance or finished product for a fee.

We have an exclusive license agreement with Knight for the development, commercialization and distribution of tenapanor in Canada for hyperphosphatemia and IBS-C. IBSRELA was launched in Canada in March 2021. We supply IBSRELA drug product packaged for the Canadian market to Knight to satisfy Knight’s commercial needs.

We have an exclusive license agreement with Kyowa Kirin for the development, commercialization and distribution of tenapanor in Japan for cardiorenal indications. We supply tenapanor drug substance to satisfy Kyowa Kirin’s commercial needs. In February 2024, Kyowa Kirin announced the launch of tenapanor, marketed as PHOZEVEL®, for CKD patients with hyperphosphatemia in Japan. As discussed in Note 8. Deferred Royalty Obligation Related to the Sale of Future Royalties, the future royalties and commercialization milestone payments we may receive under the license, as amended, will be remitted to HCR pursuant to the HCR Agreement.

We have an exclusive license agreement with Fosun Pharma for the development and commercialization of tenapanor in China for both hyperphosphatemia and IBS-C. In February 2025, we announced the approval of an NDA for tenapanor for the control of hyperphosphatemia in adult patients with CKD undergoing hemodialysis by China’s Center for Drug Evaluation of the NMPA.

We have an exclusive license agreement with METiS for the development and commercialization of a portfolio of TGR5 agonist compounds that we discovered and developed for all therapeutic areas.

Corporate Financings

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, 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

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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.

We have a loan and security agreement (as amended, the 2022 Loan Agreement) with SLR. The 2022 Loan Agreement provides a total of $300.0 million, of which $200.0 million has been drawn and is outstanding as of December 31, 2025, including $50.0 million of the Term E Loan drawn during the 2025 second quarter.

As of December 31, 2025, we had cash, cash equivalents and short-term investments totaling $264.7 million, an increase of $14.6 million, or 5.8%, from our cash position as of December 31, 2024.

Intellectual Property

Our commercial success depends in part on our ability to obtain and maintain proprietary protection for our products, drug candidates, manufacturing and process discoveries and other know-how, to operate without infringing the proprietary rights of others and to prevent others from infringing our proprietary rights. Our policy is to seek to protect our intellectual property by, among other methods, filing U.S. and foreign patent applications related to our proprietary technology and inventions that are important to the development and operation of our business. We also rely on trade secrets and careful monitoring of our proprietary information to protect aspects of our business that are not amenable to, or that we do not consider appropriate for, patent protection.

The patent positions of biopharmaceutical companies like us are generally uncertain and involve complex legal, scientific and factual questions. In addition, the coverage claimed in a patent application can be significantly reduced before the patent is issued and its scope can be reinterpreted after issuance. Consequently, we do not know whether any of our products or drug candidates will be protectable or remain protected by enforceable patents. We cannot predict whether the patent applications we are currently pursuing will issue as patents in any particular jurisdiction or whether the claims of our issued patents will provide sufficient proprietary protection from competitors. Any patents that we hold may be challenged, circumvented or invalidated by third parties. If third parties prepare and file patent applications in the U.S. that also claim technology or therapeutics to which we have rights, we may have to participate in interference proceedings in the USPTO to determine priority of invention, which would result in substantial costs to us even if the eventual outcome is favorable to us.

The term of individual patents depends upon the legal term of the patents in countries in which they are obtained. In most countries, including the U.S., the patent term is generally 20 years from the earliest date of filing a non-provisional patent application in the applicable country. In the U.S., a patent’s term may, in certain cases, be lengthened by patent term adjustment, which compensates a patentee for administrative delays by the USPTO in examining and granting a patent, or may be shortened if a patent is terminally disclaimed over a commonly owned patent or a patent naming a common inventor and having an earlier expiration date.

In addition, in the U.S., the Hatch-Waxman Act permits a patent term extension of up to five years beyond the expiration of a U.S. patent as partial compensation for the patent term lost during the FDA regulatory review process occurring while the patent is in force. A patent extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval, and only one patent applicable to each regulatory review period may be extended and only those claims covering the approved drug, a method for using it or a method for manufacturing it may be extended. Similar provisions are available in the European Union and certain other foreign jurisdictions to extend the term of a patent that covers an approved drug.

We may rely, in some circumstances, on trade secrets to protect our technology. Although we take steps to protect our proprietary information and trade secrets, including through contractual means with our employees and consultants, third parties may independently develop substantially equivalent proprietary information and techniques or otherwise gain access to our trade secrets or disclose our technology. Thus, we may not be able to meaningfully protect our trade secrets. It is our policy to require our employees, consultants, outside scientific collaboration partners, sponsored researchers and other advisors to execute confidentiality agreements upon the commencement of employment or consulting relationships with us. These agreements provide that all confidential information concerning the business or financial affairs developed or made known to the individual during the course of the individual’s relationship with us is to be kept confidential and not disclosed to third parties except in specific circumstances. In the case of employees, the agreements provide that all inventions conceived by the individual, and which are related to our current or planned business or research and development or made during the normal working hours, on our premises or using our equipment or proprietary information, are our exclusive property.

Tenapanor Patents

Our tenapanor patent portfolio includes seven issued U.S. patents, three issued patents in each of Israel and Mexico, two issued patents in each of the European Patent Organization, Japan, Korea and Hong Kong and one issued patent in each of the

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following territories: Australia, Brazil, China and India. These issued patents cover the composition and certain methods of using tenapanor, are wholly owned by us, and are predicted, without extension or adjustment, to expire in December 2029. The term of U.S. patent no. 8,541,448, which claims the composition of matter of tenapanor, was extended under the Hatch-Waxman Act to August 1, 2033. The portfolio further includes patents covering the use of tenapanor for controlling serum phosphorus that are wholly owned by us and have been issued in the U.S., Europe, Japan, China, Australia, Gulf Co-op countries, Hong Kong, Israel, Korea, Macao, Mexico, New Zealand, Russia, South Africa and Taiwan and are pending in other countries. These patents are predicted, without extension or adjustment, to expire in April 2034. On January 22, 2026, we received an Issue Notification from the USPTO indicating the issuance of U.S. Patent No. 12,539,299. The patent relates to the formulation of tenapanor and covers the commercial formulations of IBSRELA and XPHOZAH and has an expiration date of November 26, 2042.

Additional U.S. and international patent applications are pending covering additional methods of treatment with tenapanor, and composition of matter and methods of using compounds that we believe may be follow on compounds to tenapanor.

Manufacturing

To date, we have relied upon third-party CMOs to manufacture both the API and final drug product dosage forms of our commercial products, as well as our clinical trial material, and we expect that we will continue to rely upon CMOs for the manufacture of commercial product for IBSRELA, commercial product for XPHOZAH and clinical trial materials. Our license agreements with Knight and Fosun Pharma currently require us to supply final drug product dosage forms of tenapanor for their use in the development and commercialization of tenapanor in each of their respective territories. We are further obligated to supply API to Kyowa Kirin to support their development and commercialization of tenapanor in Japan. We expect that we will continue to use CMOs to satisfy our supply obligations to our collaboration partners.

Government Regulation

The FDA and comparable regulatory authorities in state and local jurisdictions and in other countries impose substantial and burdensome requirements upon companies involved in the clinical development, manufacture, marketing and distribution of drugs. These agencies and other federal, state and local entities regulate research and development activities and the testing, manufacture, quality control, safety, effectiveness, labeling, storage, record keeping, approval, advertising and promotion, distribution, post-approval monitoring and reporting, sampling and export and import of our products and product candidates.

In the U.S., the FDA regulates drug products under the FFDCA and the FDA’s implementing regulations. If we fail to comply with applicable FDA or other requirements at any time during the drug development process, the approval process or after approval, we may become subject to administrative or judicial sanctions. These sanctions could include the FDA’s refusal to approve pending applications, license suspension or revocation, withdrawal of an approval, warning or untitled letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, civil penalties or criminal prosecution. Any FDA enforcement action could have a material adverse effect on us. FDA approval is required before any new unapproved drug or dosage form, including a new use of a previously approved drug, can be marketed in the U.S.

The process required by the FDA before a drug may be marketed in the U.S. generally involves:

•completion of extensive preclinical laboratory tests, preclinical animal studies and formulation studies, some performed in accordance with the FDA’s current GLP regulations;

•submission to the FDA of an IND application which must become effective before human clinical trials in the U.S. may begin;

•approval by an independent IRB or ethics committee at each clinical trial site before each trial may be initiated;

•performance of adequate and well-controlled human clinical trials in accordance with GCP regulations to establish the safety and efficacy of the drug candidate for each proposed indication;

•submission to the FDA of an NDA for marketing approval of the new drug;

•determination by the FDA within 60 days of its receipt of an NDA to accept and file the NDA for review;

•satisfactory completion of an FDA inspection of the manufacturing facility or facilities at which the drug is produced to assess compliance with cGMP regulations;

•satisfactory completion of a potential FDA audit of the non-clinical and/or clinical trial sites that generated the data in support of the NDA;

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•satisfactory completion of a potential review by an FDA advisory committee, if applicable; and

•payment of applicable user fees and FDA review and approval of the NDA prior to any commercial marketing, sale or commercial shipment of the drug.

The preclinical and clinical testing and approval process requires substantial time, effort and financial resources, and we cannot be certain that any approvals for any product candidates that we may seek to advance, or any approvals for label expansions for existing marketed products that we may seek to obtain, will be granted on a timely basis, if at all. Nonclinical tests include laboratory evaluation of product chemistry, formulation, stability and toxicity, as well as animal studies to assess the characteristics and potential safety and efficacy of the product. The results of preclinical tests, together with manufacturing information, analytical data and a proposed clinical trial protocol and other information, are submitted as part of an IND to the FDA. Additional preclinical testing may continue even after the IND is submitted. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day period, raises concerns or questions relating to the IND and places the clinical trial on a clinical hold, including concerns that human research subjects will be exposed to unreasonable health risks. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before the clinical trial can begin. A separate submission to an existing IND must also be made for each successive clinical trial conducted during product development.

Clinical trials involve the administration of the investigational drug to human subjects under the supervision of qualified investigators. Clinical trials are conducted under protocols detailing, among other things, the objectives of the clinical trial, the parameters to be used in monitoring safety and the effectiveness criteria to be used. Each protocol must be submitted to the FDA as part of the IND.

An independent IRB or ethics committee for each medical center proposing to conduct a clinical trial must also review and approve a plan for any clinical trial before it can begin at that center and the IRB must monitor the clinical trial until it is completed. The FDA, the IRB or the sponsor may suspend or discontinue a clinical trial at any time on various grounds, including a finding that the subjects are being exposed to an unacceptable health risk. Clinical testing also must satisfy extensive GCP requirements, including the requirements for informed consent.

All clinical research to be performed in the U.S. in support of an NDA must be reviewed in advance by the FDA under the IND regulations and procedures described above. However, a sponsor who wishes to conduct a clinical trial outside the U.S. may, but need not, obtain FDA authorization to conduct the clinical trial under an IND. If a foreign clinical trial is not conducted under an IND, the sponsor may still submit data from the clinical trial in support of an NDA as long as the clinical trial is conducted in compliance with GCP and if the FDA is able to validate the data from the study through an onsite inspection, if necessary. GCP includes, among other things, review and approval by an independent ethics committee, such as an IRB, and obtaining and documenting the freely given informed consent of each subject before study initiation. If the applicant seeks approval of an NDA solely on the basis of foreign data, the FDA will only accept such data if they are applicable to the U.S. population and U.S. medical practice, the studies have been performed by clinical investigators of recognized competence, and the data may be considered valid without the need for an on-site inspection by the FDA, or if the FDA considers such an inspection to be necessary, the FDA is able to validate the data through an on-site inspection or through other appropriate means.

Clinical Trials

The clinical investigation of a new drug is typically conducted in three or four phases, which may overlap or be combined, and generally proceed as follows.

•Phase 1: Clinical trials are initially conducted in a limited population of subjects to test the drug candidate for safety, dose tolerance, absorption, metabolism, distribution and excretion in healthy humans or, on occasion, in patients with severe problems or life-threatening diseases to gain an early indication of its effectiveness.

•Phase 2: Clinical trials are generally conducted in a limited patient population to evaluate dosage tolerance and appropriate dosage, identify possible adverse effects and safety risks and evaluate preliminarily the efficacy of the drug for specific targeted indications in patients with the disease or condition under study.

•Phase 3: Clinical trials are typically conducted when Phase 2 clinical trials demonstrate that a dose range of the product candidate is effective and has an acceptable safety profile. Phase 3 clinical trials are commonly referred to as “pivotal” studies, which typically denotes a study which presents the data that the FDA or other relevant regulatory agency will use to determine whether or not to approve a drug. Phase 3 clinical trials are generally undertaken with large numbers of patients, such as groups of several hundred to several thousand, to further evaluate dosage, to provide

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substantial evidence of clinical efficacy and to further test for safety in an expanded and diverse patient population at multiple, geographically dispersed clinical trial sites.

•Phase 4: In some cases, the FDA may condition approval of an NDA for a product candidate on the sponsor’s agreement to conduct additional clinical trials after NDA approval. In other cases, a sponsor may voluntarily conduct additional clinical trials post approval to gain more information about the drug. Such post approval trials are typically referred to as Phase 4 clinical trials.

Concurrent with clinical trials, companies usually complete additional nonclinical studies and must also develop additional information about the chemistry and physical characteristics of the drug and finalize a process for manufacturing the drug in commercial quantities in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the drug candidate and, among other things, the manufacturer must develop methods for testing the identity, strength, quality and purity of the final drug product. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the drug candidate does not undergo unacceptable deterioration over its shelf life.

The FDA, the IRB or the clinical trial sponsor may suspend or terminate a clinical trial at any time on various grounds, including a finding that the research subjects are being exposed to an unacceptable health risk.

Additionally, some clinical trials are overseen by an independent group of qualified experts organized by the clinical trial sponsor, known as a data safety monitoring board or committee. This group provides authorization for whether or not a trial may move forward at designated check points based on access to certain data from the study.

We may also suspend or terminate a clinical trial based on evolving business objectives and/or competitive climate.

New Drug Applications

The results of preclinical studies and of the clinical trials, together with other detailed information, including extensive manufacturing information and information on the composition of the drug, are submitted to the FDA in the form of an NDA requesting approval to market the drug for one or more specified indications. The FDA reviews an NDA to determine, among other things, whether a drug is safe and effective for its intended use.

Under the Prescription Drug User Fee Act, the FDA has a goal of responding to standard review NDAs for new molecular entities within ten months after the 60-day filing review period, or six months after the 60-day filing review period for priority review NDAs. For non-new molecular entities, the FDA has a goal of responding within ten months of receipt of standard review NDAs and six months of receipt for priority review NDAs. These timeframes are often extended by FDA requests for additional information or clarification. The FDA may refer the application to an advisory committee for review, evaluation and recommendation as to whether the application should be approved. The FDA is not bound by the recommendation of an advisory committee, but it generally follows such recommendations.

After the FDA evaluates the NDA and conducts inspections of manufacturing facilities where the drug product and/or its API will be produced, if deemed necessary, it may issue an approval letter or a Complete Response Letter. An approval letter authorizes commercial marketing of the drug with specific prescribing information for specific indications. A Complete Response Letter indicates that the review cycle of the application is complete, and the application is not ready for approval. A Complete Response Letter may require additional clinical data and/or an additional Phase 3 clinical trial(s), and/or other significant, expensive and time-consuming requirements related to clinical trials, preclinical studies or manufacturing. Even if such additional information is submitted, the FDA may ultimately decide that the NDA does not satisfy the criteria for approval. The FDA could also approve the NDA with a REMS if it determines that a REMS is necessary to ensure that the drug’s benefits outweigh its risks, which could include medication guides, physician communication plans or elements to assure safe use, such as restricted distribution methods, patient registries and other risk minimization tools. The FDA also may condition approval on, among other things, changes to proposed labeling, development of adequate controls and specifications, or a commitment to conduct one or more post-market studies or clinical trials. Such post-market testing may include Phase 4 clinical trials and surveillance to further assess and monitor the product’s safety and effectiveness after commercialization. The FDA has the authority to prevent or limit further marketing of a drug based on the results of these post-market programs. Once the FDA approves an NDA, or any supplement thereto, the FDA may withdraw the approval if ongoing regulatory requirements are not met or if safety problems are identified after the drug reaches the market.

Drugs may be marketed only for the FDA-approved indications and in accordance with the provisions of the approved labeling. Further, if there are any modifications to the drug, including changes in indications, labeling, or manufacturing processes or facilities, the applicant may be required to submit and obtain FDA approval of a new NDA or NDA supplement, which may require the applicant to develop additional data or conduct additional preclinical studies and clinical trials. There can

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be no assurances that the FDA will approve any requested changes in indications, labeling or manufacturing processes or facilities.

The testing and approval processes require substantial time, effort and financial resources, and each may take several years to complete. The FDA may not grant approval on a timely basis, or at all. Even if we believe a clinical trial has demonstrated safety and efficacy of one of our drug candidates for the proposed indication, the results may not be satisfactory to the FDA. Nonclinical and clinical data may be interpreted by the FDA in different ways, which could delay, limit or prevent regulatory approval. We may encounter difficulties or unanticipated costs in our efforts to secure necessary governmental approvals which could delay or preclude us from marketing drugs. The FDA may limit the indications for use or place other conditions on any approvals that could restrict the commercial application of the drugs.

Ongoing Regulatory Requirements

Any drugs manufactured or distributed by us or our collaboration partners pursuant to FDA approvals would be subject to continuing regulation by the FDA, including recordkeeping requirements and reporting of adverse experiences associated with the drug. Drug manufacturers and their subcontractors are required to register their establishments with the FDA and certain state agencies and are subject to periodic announced and unannounced inspections by the FDA and certain state agencies for compliance with ongoing regulatory requirements, including cGMP, which impose certain procedural and documentation requirements upon us and our third-party manufacturers. Failure to comply with the statutory and regulatory requirements can subject a manufacturer to possible legal or regulatory action, such as warning or untitled letters, suspension of manufacturing, seizure of product, injunctive action or possible civil penalties. We cannot be certain that we or our present or future third-party manufacturers or suppliers will be able to comply with the cGMP regulations and other ongoing FDA regulatory requirements. If we or our present or future third-party manufacturers or suppliers are not able to comply with these requirements, the FDA may, among other things, halt our clinical trials, require us to recall a drug from distribution or withdraw approval of the NDA for that drug.

The FDA closely regulates the post-approval marketing and promotion of drugs, including standards and regulations for direct-to-consumer advertising, off-label promotion, industry-sponsored scientific and educational activities and promotional activities involving the Internet. A company can make only those claims relating to safety and efficacy that are in the final label or consistent with the final label. Failure to comply with these requirements can result in, among other things, adverse publicity, warning or untitled letters, corrective advertising and potential civil and criminal penalties. Physicians may prescribe legally available drugs for uses that are not described in the product’s labeling and that differ from those tested by us and approved by the FDA. Such off-label uses are common across medical specialties. Physicians may believe that such off-label uses are the best treatment for many patients in varied circumstances. The FDA does not regulate the behavior of physicians in their choice of treatments. The FDA does, however, impose stringent restrictions on manufacturers’ communications regarding off-label use.

Hatch-Waxman Act

Under the Price Competition and Patent Term Restoration Act, or Hatch-Waxman Act, Section 505 of the FFDCA describes three types of marketing applications that may be submitted to the FDA to request marketing authorization for a new drug. A Section 505(b)(1) NDA is an application that contains full reports of investigations of safety and efficacy. A Section 505(b)(2) NDA is an application that contains full reports of investigations of safety and efficacy but where at least some of the information required for approval comes from investigations that were not conducted by or for the applicant and for which the applicant has not obtained a right of reference or use from the person by or for whom the investigations were conducted. This regulatory pathway enables the applicant to rely, in part, on the FDA’s prior findings of safety and efficacy for an existing product, or on published literature, in support of its application. Section 505(j) establishes an abbreviated approval process for a generic version of approved drug products through the submission of an ANDA. An ANDA provides for marketing of a generic drug product that has the same active ingredients, dosage form, strength, route of administration, labeling, performance characteristics and intended use, among other things, to a previously approved product. ANDAs are termed “abbreviated” because they are generally not required to include nonclinical (animal) and clinical (human) data to establish safety and efficacy. Instead, generic applicants must scientifically demonstrate that their product is bioequivalent to, or performs in the same manner as, the innovator drug through in vitro, in vivo, or other testing. The generic version can often be substituted by pharmacists under prescriptions written for the reference listed drug. In seeking approval for a drug through an NDA, applicants are required to list with the FDA each patent that claims the applicant’s drug or a method of using the drug. Upon approval of a drug, each of the patents listed in the application for the drug is then published in the FDA’s publication Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. Additional patents issued after NDA approval may be added to the Orange Book.

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Once a product and any applicable patents are listed in the Orange Book, it can be referenced by potential competitors seeking approval of a follow-on version of the drug in either an ANDA or 505(b)(2) NDA. Upon submission of an ANDA or a 505(b)(2) NDA, the applicant must certify to the FDA, with respect to each patent listed in the Orange Book for the reference drug, that (1) no patent information has been submitted to the FDA; (2) such patent has expired; (3) the date on which such patent expires; or (4) such patent is invalid or will not be infringed upon by the manufacture, use or sale of the drug product for which the application is submitted. Generally, the ANDA or 505(b)(2) NDA cannot be approved until all listed patents have expired, except where the ANDA or 505(b)(2) NDA applicant challenges a listed patent through the last type of certification, known as a Paragraph IV certification. If the applicant does not challenge the listed patents or indicates that it is not seeking approval of a patented method of use, the ANDA or 505(b)(2) NDA application will not be approved until all of the applicable listed patents claiming the referenced product have expired.

If the ANDA or 505(b)(2) NDA applicant has provided a Paragraph IV certification to the FDA, the applicant must send notice of the Paragraph IV certification to the NDA holder and patent owners once the application has been accepted for filing by the FDA. The NDA and patent holders may then initiate a patent infringement lawsuit in response to the notice of the Paragraph IV certification. If the NDA holder or the patent owner(s) bring such patent infringement lawsuit within 45 days of the ANDA or 505(b)(2) NDA applicant’s Paragraph IV certification notice, the FDA may not approve that application until 30 months from the receipt of the notice of the Paragraph IV certification or such shorter or longer period as may be ordered by a court, or if applicable, the date the infringement case concerning each such patent is favorably decided or settled in the applicant’s favor. This prohibition is generally referred to as the 30-month stay. In instances where an ANDA or 505(b)(2) NDA applicant files a Paragraph IV certification, the NDA holder or patent owner(s) regularly take action to trigger the 30-month stay, recognizing that the related patent litigation may take many months or years to resolve. Thus, approval of an ANDA or 505(b)(2) NDA could be delayed for a significant period of time depending on the patent certification the applicant makes and the reference drug sponsor’s decision to initiate patent litigation.

The Hatch-Waxman Act establishes periods of regulatory exclusivity for certain approved drug products, during which the FDA cannot approve (or in some cases accept) an ANDA or 505(b)(2) NDA that relies on the reference drug. For example, the holder of an NDA, including a 505(b)(2) NDA, may obtain five years of exclusivity upon approval of a new drug containing an NCE that has not been previously approved by the FDA. A drug is an NCE if the FDA has not previously approved any other drug containing the same active moiety, which is the molecule or ion responsible for the therapeutic activity of the drug substance. During the exclusivity period, the FDA may not accept for review an ANDA or a 505(b)(2) NDA submitted by another company that contains the NCE active moiety. However, an ANDA or 505(b)(2) NDA may be submitted after four years if it contains a Paragraph IV certification of patent invalidity or non-infringement.

The Hatch-Waxman Act also provides three years of marketing exclusivity to the holder of an NDA (including a 505(b)(2) NDA) for a particular condition of approval, or change to a marketed product, such as a new formulation for a previously approved product, if one or more new clinical investigations (other than bioavailability or bioequivalence studies) was essential to the approval of the application and was conducted/sponsored by the applicant. This three-year exclusivity period protects against FDA approval of ANDAs and 505(b)(2) NDAs for the specific condition of the new drug’s approval. As a general matter, the three-year exclusivity does not prohibit the FDA from approving ANDAs or NDAs for generic versions of the original, unmodified drug product. Five-year and three-year exclusivity will not delay the submission or approval of a full 505(b)(1) NDA; however, an applicant submitting a full NDA would be required to conduct or obtain a right of reference to all of the preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and efficacy.

Fraud and Abuse Laws

In the U.S. the research, manufacturing, distribution, sale and promotion of drug products and medical devices are subject to regulation by various federal, state and local authorities in addition to the FDA, including CMS and other divisions of the U.S. Department of Health and Human Services (e.g., the Office of Inspector General), the U.S. Department of Justice, state Attorneys General, and other state and local government agencies. These laws include, but are not limited to, the Anti-Kickback Statute, the federal False Claims Act, the federal Physician Payments Sunshine Act and other state and federal laws and regulations.

The Anti-Kickback Statute makes it illegal for any person, including a prescription drug manufacturer (or a party acting on its behalf), to knowingly and willfully solicit, receive, offer or pay any remuneration that is intended to induce the referral of business, including the purchase, order or prescription of a particular drug, for which payment may be made under a federal healthcare program, such as Medicare or Medicaid. The term remuneration has been interpreted broadly to include anything of value. There are a number of statutory exceptions and regulatory safe harbors protecting some common activities from prosecution. The exceptions and safe harbors are drawn narrowly and practices that involve remuneration that may be alleged to be intended to induce prescribing, purchasing or recommending may be subject to scrutiny if they do not qualify for an exception or safe harbor. Failure to meet all of the requirements of a particular applicable statutory exception or regulatory safe

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harbor does not make the conduct per se illegal under the federal Anti-Kickback Statute. Instead, the legality of the arrangement will be evaluated on a case-by-case basis based on a cumulative review of all of its facts and circumstances. Additionally, a person or entity does not need to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation.

The federal False Claims Act prohibits anyone from knowingly presenting, or causing to be presented, for payment to federal programs (including Medicare and Medicaid) claims for items or services, including drugs, that are false or fraudulent, claims for items or services not provided as claimed, or claims for medically unnecessary items or services. Although we do not submit claims directly to payors, manufacturers can be held liable under these laws if they are deemed to “cause” the submission of false or fraudulent claims by, for example, providing inaccurate billing or coding information to customers or promoting a product off-label. In addition, our activities relating to the reporting of wholesaler or estimated retail prices for our products, the reporting of prices used to calculate Medicaid rebate information and other information affecting federal, state, and third-party reimbursement for our products, and the sale and marketing of our products, are subject to scrutiny under this law. Moreover, the government may assert that a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the False Claims Act. If the government were to allege that we were, or convict us of, violating these false claims laws, we could be subject to a substantial fine and may suffer a decline in our stock price. In addition, private individuals have the ability to bring actions under the federal False Claims Act.

The civil monetary penalties statute imposes penalties against any person or entity who, among other things, is determined to have presented or caused to be presented a claim to a federal health program that the person knows or should know is for an item or service that was not provided as claimed or is false or fraudulent.

The federal HIPAA created additional federal criminal statutes that prohibit knowingly and willfully executing, or attempting to execute, a scheme to defraud any healthcare benefit program or obtain, by means of false or fraudulent pretenses, representations or promises, any of the money or property owned by, or under the custody or control of, any healthcare benefit program, regardless of whether the payor is public or private, knowingly and willfully embezzling or stealing from a health care benefit program, willfully obstructing a criminal investigation of a health care offense and knowingly and willfully falsifying, concealing or covering up by any trick or device a material fact or making any materially false statements in connection with the delivery of, or payment for, healthcare benefits, items or services relating to healthcare matters. Similar to the federal Anti-Kickback Statute, a person or entity does not need to have actual knowledge of the statute, or the specific intent to violate it, to have committed a violation.

In addition to the laws described above, the Physician Payments Sunshine Act requires certain drug manufacturers to report payments and other transfer of value made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors) certain non-physician practitioners (physician assistants, nurse practitioners, clinical nurse specialists, certified nurse anesthetists, anesthesiologist assistants and certified nurse midwives) and teaching hospitals, as well as ownership and investment interests held by physicians and their immediate family members. Failure to submit required information may result in significant civil monetary penalties, and additional penalties for knowing failures, for all payments, transfers of value or ownership or investment interests that are not timely, accurately and completely reported in an annual submission. Manufacturers must submit reports by the 90th day of each subsequent calendar year.

Many states have also adopted laws similar to the federal laws discussed above. Some of these state prohibitions apply to the referral of patients for healthcare services reimbursed by any insurer, not just federal healthcare programs such as Medicare and Medicaid. There has also been a recent trend of increased regulation of payments made to physicians and other healthcare providers. Certain states mandate implementation of compliance programs, impose restrictions on drug manufacturers’ marketing practices and/or require the tracking and reporting of pricing and marketing information as well as gifts, compensation and other remuneration to physicians. Many of these laws contain ambiguities as to what is required to comply with such laws, which may affect our sales, marketing, and other promotional activities by imposing administrative and compliance burdens on us. In addition, given the lack of clarity with respect to these laws and their implementation, our reporting actions could be subject to the penalty provisions of the pertinent state and perhaps federal authorities.

Violations of any of such laws or any other governmental regulations that apply may result in penalties, including, without limitation, administrative, civil and criminal penalties, damages, fines, disgorgement, the curtailment or restructuring of operations, reporting obligations and integrity oversight, exclusion from participation in federal and state healthcare programs and imprisonment.

Third-Party Coverage and Reimbursement

Sales of pharmaceutical products depend in significant part on the availability of coverage and adequate reimbursement by third-party payors, such as state and federal governments, including Medicare and Medicaid, and commercial managed care providers. In the U.S., no uniform policy of coverage and reimbursement for drug products exists among third-party payors.

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Accordingly, decisions regarding the extent of coverage and amount of reimbursement to be provided for our product candidates are made on a payor by payor basis. As a result, the coverage determination process is often a time-consuming and costly process that will require us to provide scientific and clinical support for the use of our product candidates to each payor separately, with no assurance that coverage and adequate reimbursement will be obtained. Third-party payors may limit coverage to specific drug products on an approved list, or formulary, which might not include all of the FDA-approved drugs for a particular indication. A decision by a third-party payor not to cover our product candidates could reduce physician utilization of our products once approved and have a material adverse effect on our future sales, results of operations and financial condition. Moreover, a payor’s decision to provide coverage for a drug product does not imply that an adequate reimbursement rate will be approved. Adequate third-party reimbursement may not be available to enable us to maintain price levels sufficient to realize an appropriate return on our investment in product development.

Additionally, under the ESRD PPS, CMS generally makes a single bundled payment to the dialysis facility for each dialysis treatment that is intended to cover all items and services CMS has determined are routinely required for dialysis treatments furnished to Medicare beneficiaries in Medicare-certified ESRD facilities or at their home, including the cost of certain drugs required for treatment of ESRD patients on dialysis. On January 1, 2025, XPHOZAH, along with other oral drugs for ESRD patients on dialysis without injectable or intravenous equivalents, became part of the ESRD PPS and coverage for XPHOZAH and these other oral drugs under Medicare Part D was eliminated. We made the decision to preserve access to XPHOZAH for all appropriate patients. Although more patients had access to XPHOZAH and we increased the number of patients on treatment compared to 2024, the change in Medicare reimbursement coverage had a negative and material impact on our XPHOZAH revenue in 2025. Our strategy for XPHOZAH remains a targeted promotional focus on nephrology healthcare providers to preserve access for patients, regardless of insurance coverage, determined to be appropriate candidates for XPHOZAH by their healthcare provider.

Healthcare Reform

In the U.S. and some foreign jurisdictions, there have been and continue to be ongoing efforts to implement legislative and regulatory changes regarding the healthcare system at the federal and state level, including with respect to the containment of healthcare costs. The significant interest by federal and state legislatures, as well as by foreign governments, in the adoption of drug price controls and other cost-containment measures, in addition to adoption of more restrictive policies in jurisdictions with existing controls and measures, could place additional downward pressure on the prices we or our collaborators may receive for our products and future product candidates, if approved, and may adversely affect our ability to achieve or maintain profitability.

For example, the ACA, enacted in 2010, substantially changed the way healthcare is financed by both governmental and private insurers and contains a number of provisions that may affect our business, including those governing enrollment in federal healthcare programs, reimbursement changes, rules regarding prescription drug benefits under the health insurance exchanges, changes to the Medicaid Drug Rebate Program, expansion of the Public Health Service Act’s 340B drug pricing program, or 340B program, and fraud and abuse measures. These changes have impacted existing government healthcare programs and have resulted in the development of new programs, including Medicare payment for performance initiatives and improvements to the physician quality reporting system and feedback program. There have been ongoing changes to the implementation of the ACA since its adoption. For example, the availability of enhanced premium tax credits and other subsidies under the ACA expired as of December 31, 2025, and absent legislative action to reinstate or replace them, many individuals may experience higher out-of-pocket premium costs. These changes could result in an increase in uninsured or underinsured patients, which could negatively affect patients’ ability or willingness to start or continue treatment with our products or future product candidates, if successfully developed and approved, or may otherwise increase prescription abandonment rates or place greater pressure on drug pricing generally.

Other legislative changes have been proposed and adopted in the U.S. since the ACA was enacted. These laws, among other things, included aggregate reductions of Medicare payments to providers that will remain in effect through 2032, unless additional Congressional action is taken, additional specific reductions in Medicare payments to several providers, including hospitals, imaging centers and cancer treatment centers, and increased the statute of limitations period for the government to recover overpayments to providers from three to five years. The American Rescue Plan Act of 2021 eliminated the statutory Medicaid drug rebate cap beginning January 1, 2024. The rebate was previously capped at 100% of a drug’s AMP.

There has also been heightened governmental scrutiny over the manner in which drug manufacturers set prices for their marketed products, which has resulted in several Congressional inquiries and proposed bills designed to, among other things, bring more transparency to product pricing, review the relationship between pricing and manufacturer patient programs, and reform government program reimbursement methodologies for drug products. In 2022, the IRA was signed into law. This statute marks the most significant action by Congress with respect to the pharmaceutical industry since adoption of the ACA in 2010. Among other things, the IRA requires manufacturers of certain drugs to engage in price negotiations with Medicare, with

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prices that can be negotiated subject to a cap; imposes rebates under Medicare Part B and Medicare Part D to penalize price increases that outpace inflation (first due in 2023); redesigns the Medicare Part D benefit (beginning in 2024); and replaces the Part D coverage gap discount program with a new manufacturer discount program (beginning in 2025). CMS has published the negotiated prices for the initial ten drugs, which went into effect in January 2026, and the subsequent 15 drugs, which will first be effective in 2027. The IRA permits the Secretary of HHS to implement many of these provisions through guidance, as opposed to regulation, for the initial years. HHS has and will continue to issue and update guidance as these programs are implemented, although the Medicare drug price negotiation program is currently subject to legal challenges. While the impact of the IRA on the pharmaceutical industry cannot yet be fully determined, it is likely to be significant.

The One Big Beautiful Bill Act, which was enacted in July 2025, imposes significant reductions in the funding of the Medicaid program, and imposes requirements for recipients to work and/or participate in qualifying activities in order to receive Medicaid benefits. Such reductions and requirements are expected to decrease the number of persons enrolled in Medicaid and reduce the services covered by Medicaid, which could adversely affect sales of our products.

The current administration is pursuing a two-fold strategy to reduce drug costs in the U.S. While it is unclear whether and how these proposals will be implemented, the current administration’s policies are likely to have a negative impact on the pharmaceutical industry and on our ability to receive adequate revenues for our products. On the one hand, President Trump has threatened to impose significant tariffs on pharmaceutical manufacturers that do not adopt pricing policies such as most favored nation pricing, which would tie the price for drugs in the U.S. to the lowest price in a group of other countries. In response, multiple manufacturers have entered into confidential pricing agreements with the federal government. On the other hand, the current administration is pursuing traditional regulatory pathways to impose drug pricing policies and published two proposed regulations in December 2025, referred to as GLOBE and GUARD. If finalized, these regulations would implement mandatory payment models under which manufacturers of eligible drugs would be required to pay rebates to the federal government on a portion of the units of their drugs that are reimbursed by Medicare, with the rebate amount based on most favored nation pricing. Imposing a rebate in the U.S. that is based on drug prices outside the U.S. would mark a drastic and unprecedented shift in the U.S. pharmaceutical market, and while the impact of the GLOBE and GUARD proposed regulations, if finalized, cannot yet be determined, it is likely to be significant. Even regulatory proposals or executive actions that are ultimately deemed unlawful could negatively impact the U.S. pharmaceutical sector and our business.

Additionally, individual states have become increasingly active in passing legislation and implementing regulations designed to control pharmaceutical product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access, and to encourage importation from other countries and bulk purchasing. Some states have enacted legislation creating so-called prescription drug affordability boards, which ultimately may attempt to impose price limits on certain drugs in these states, and at least one state board is imposing an upper payment limit. States are also seeking to implement general, across the board price caps for pharmaceuticals, or are seeking to regulate drug distribution.

These new laws and the regulations and policies implementing them, as well as other healthcare reform measures that may be adopted in the future, may have a material adverse effect on our industry generally and on our ability to successfully develop and commercialize our products.

Government Price Reporting

Medicaid is a joint federal and state program for low-income and disabled beneficiaries. Medicare is a federal program covering individuals age 65 and over as well as those with certain disabilities. As a condition of having federal funds being made available for our covered outpatient drugs under Medicaid, we have enrolled in the MDRP, which requires us to pay a rebate to state Medicaid programs for each unit of our covered outpatient drugs dispensed to a Medicaid beneficiary and paid for by a state Medicaid program. Medicaid drug rebates are based on pricing data that we must report on a monthly and quarterly basis to the U.S. CMS, the federal agency that administers the MDRP and Medicare programs. For the MDRP, these data include the AMP and the best price for each drug. If we become aware that our MDRP price reporting submission for a prior period was incorrect or has changed as a result of recalculation of the pricing data, we must resubmit the corrected data for up to three years after those data originally were due. Manufacturers who fail to provide information timely or are found to have knowingly submitted false information to the government may be subject to civil monetary penalties and other sanctions, including termination from the MDRP.

Federal law requires that a manufacturer that participates in the MDRP also participate in the 340B program in order for federal funds to be available for the manufacturer’s covered outpatient drugs under Medicaid and Medicare Part B. We participate in the 340B program, which is administered by HRSA, and requires us to charge statutorily defined covered entities no more than the 340B “ceiling price” for our covered outpatient drugs used in an outpatient setting. These 340B covered entities include a variety of community health clinics and other entities that receive health services grants from the Public Health Service, as well as hospitals that serve a disproportionate share of low-income patients. The 340B ceiling price is

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calculated using a statutory formula, which is based on the AMP and rebate amount for the covered outpatient drug as calculated under the MDRP. In general, products subject to Medicaid price reporting and rebate liability are also subject to the 340B ceiling price calculation and discount requirement. We must report 340B ceiling prices to HRSA on a quarterly basis, and HRSA publishes them to 340B covered entities. HRSA has finalized regulations regarding the calculation of the 340B ceiling price and the imposition of civil monetary penalties on manufacturers that knowingly and intentionally overcharge covered entities for 340B-eligible drugs. HRSA has also finalized an administrative dispute resolution process through which 340B covered entities may pursue claims against participating manufacturers for overcharges, and through which manufacturers may pursue claims against 340B covered entities for engaging in unlawful diversion or duplicate discounting of 340B drugs.

In order to be eligible to have drug products paid for with federal funds under Medicaid and purchased by certain federal agencies and grantees, manufacturers must also participate in the U.S. VA FSS pricing program. Under the VA/FSS program, manufacturers must report the Non-FAMP for their covered drugs to the VA and charge certain federal agencies no more than the Federal Ceiling Price, which is calculated based on Non-FAMP using a statutory formula. These four agencies are the VA, the U.S. Department of Defense, the U.S. Coast Guard and the U.S. Public Health Service (including the Indian Health Service). Manufacturers must also pay rebates on products purchased by military personnel and dependents through the TRICARE retail pharmacy program. Manufacturers who fail to provide timely information or are found to have knowingly submitted false information may be subject to civil monetary penalties.

Individual states continue to consider and have enacted legislation to limit the growth of healthcare costs, including the cost of prescription drugs and combination products. A number of states have either implemented or are considering implementation of drug price transparency legislation. Requirements under such laws include advance notice of planned price increases, reporting price increase amounts and factors considered in taking such increases, wholesale acquisition cost information disclosure to prescribers, purchasers, and state agencies, and new product notice and reporting. Such legislation could limit the price or payment for certain drugs, and a number of states are authorized to impose civil monetary penalties or pursue other enforcement mechanisms against manufacturers who fail to comply with drug price transparency requirements, including the untimely, inaccurate or incomplete reporting of drug pricing information.

Data Privacy and Security Laws

Numerous state, federal and foreign laws, including consumer protection laws and regulations, govern the collection, dissemination, use, access to, confidentiality and security of personal information, including health-related information. In the U.S., numerous federal and state laws and regulations, including data breach notification laws, health information privacy and security laws that govern the collection, use, disclosure, and protection of health-related and other personal information could apply to our operations or the operations of our partners. Further, certain foreign laws govern the privacy and security of personal data, including health-related data. Failure to comply with these laws, where applicable, can result in the imposition of significant civil and/or criminal penalties and private litigation. Privacy and security laws, regulations, and other obligations are constantly evolving, may conflict with each other to complicate compliance efforts, and can result in investigations, proceedings, or actions that lead to significant civil and/or criminal penalties and restrictions on data processing.

Other Regulations

We are also subject to numerous federal, state and local laws relating to such matters as safe working conditions, manufacturing practices, environmental protection, fire hazard control, and disposal of hazardous or potentially hazardous substances. We may incur significant costs to comply with such laws and regulations now or in the future.

Human Capital

The future success of our company depends on our ability to attract, retain and further develop top talent. As we continually expand our organization to support our current and future growth opportunities, we have remained steadfastly committed to our values, including our goal to develop and maintain a professional, respectful and collaborative workplace with opportunities for our employees to grow and develop in their careers, supported by strong compensation and benefits.

At December 31, 2025, we had 489 full-time employees, 93 of whom were engaged directly in research, development and manufacturing, 305 in sales and marketing and 91 in general and administrative activities. During 2025, our employee base increased by 94, or approximately 24%.

Workforce Culture and Composition

Our culture is supported by an unwavering commitment to maintaining a professional, respectful and collaborative work environment that supports engagement and performance. As of December 31, 2025, approximately 63% of our workforce was female; 38% of our executive leadership team was female and 54% of our employees in managerial roles were female. As of

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December 31, 2025, employees who self-identified as members of underrepresented groups represented 35% of our workforce and 37% of our employees in managerial roles. We strive to foster a culture where mutual respect, accountability, integrity and dignity are core to our individual expectations.

We believe that fostering an environment in which employees feel respected and supported enhances productivity, innovation and long-term organizational success.

Core Values

Fostering and maintaining a strong, healthy culture is a key strategic focus. Our core values reflect who we are and the way our employees interact with one another, our partners and our stockholders. We are committed to our core values, recognizing that they will foster an environment where we will be able to realize our vision of advancing patient care. We are Passionate, aware that with integrity and determination, we make a difference for patients. We are Fearless, aware that by challenging convention, we truly innovate. We are Dedicated, aware that working tirelessly together, we are greater than the sum of our parts. We are Inclusive, aware that with respect, grace and humor, we are family. We encourage our employees to live out our core values and believe they help our culture stay strong and unique.

Health, Safety and Well-being

The health, safety and well-being of our employees are priorities in which we have always invested and will continue to do so. We offer hybrid and remote working opportunities for our team members employed in areas within the organization where such flexible work options are possible. We will continue to adopt and align our policies to focus on the health, safety and wellness of our employees, and the needs of our business.

Compensation and Benefits

We recognize that we operate within an industry where there is significant competition for top talent, and we endeavor to provide not only a strong healthy culture, but also important compensation and benefits programs to help meet the needs of our employees. In addition to base compensation, these programs include annual bonuses, quarterly incentives for our field based teams, stock awards, an Employee Stock Purchase Plan, 401(k) with company match contribution, healthcare and insurance benefits, health savings (funded by the Company) and flexible spending accounts, family leave, family care resources, and flexible work schedules, among many others.

Ensuring fair and equitable pay is integral to our commitment to our employees. Our executive team and board of directors strongly support this commitment. We conduct pay equity reviews annually to help us understand whether our compensation structure is appropriate and to identify what improvements can be made.

Corporate Information

We were founded in October 2007 as a Delaware corporation under the name Nteryx. We changed our name to Ardelyx, Inc. in June 2008. We operate in one business segment, which is the development and commercialization of biopharmaceutical products. Our principal executive offices are located at 400 Fifth Avenue, Suite 210, Waltham, Massachusetts 02415, and our telephone number is (510) 745-1700. Our website address is www.ardelyx.com.

We file electronically with the SEC our annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K pursuant to Section 13(a) or 15(d) of the Exchange Act. We make copies of these reports available on our website, www.ardelyx.com, free of charge, as soon as reasonably practicable after we electronically file such material with, or furnish it to, the SEC. The SEC maintains a website that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC. The address of that website is www.sec.gov.