The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our unaudited consolidated financial statements and related notes included in this Quarterly Report on Form 10-Q and the audited financial statements and notes thereto as of and for the year ended December 31, 2025 and the related Management’s Discussion and Analysis of Financial Condition and Results of Operations, both of which are contained in our Annual Report on Form 10-K for the year ended December 31, 2025, filed with the Securities and Exchange Commission ("SEC") on February 19, 2026. Past operating results are not necessarily indicative of results that may occur in future periods. In addition, see the discussion under the heading “Forward-Looking Statements” immediately preceding the consolidated financial statements included under Part I of this Quarterly Report on Form 10-Q. Overview We are a biopharmaceutical company headquartered in San Diego, California, focused on identifying, developing and delivering life-changing therapies to people living with rare kidney and metabolic diseases. Our approach centers on advancing our innovative pipeline with multiple late-stage clinical programs targeting rare diseases with significant unmet medical needs. Upon approval of any of our late-stage programs, we intend to leverage the skills of our talented commercial organization which has successfully identified, supported and treated patients prescribed our approved products for over ten years. Our Pipeline and Approved Products We have a diversified pipeline designed to address areas of high unmet need in rare kidney and metabolic diseases. We invest revenues from our commercial portfolio into our pipeline with the goal of delivering new treatments for diseases with limited or no approved therapies. The following table summarizes the status of our clinical programs, preclinical programs and approved products, each of which is described in further detail below. 1 On September 5, 2024, the FDA granted full approval of FILSPARI® (sparsentan) to slow kidney function decline in adults with primary Immunoglobulin A nephropathy ("IgAN”) who are at risk of disease progression. FILSPARI had previously been granted accelerated approval in February 2023. 2 On April 13, 2026, the FDA granted full (traditional) approval of FILSPARI to reduce proteinuria in adult and pediatric patients aged 8 years and older with focal segmental glomerulosclerosis (“FSGS”) without nephrotic syndrome. 3 Following a voluntarily pause in enrollment, we restarted enrollment activities for the pivotal Phase 3 HARMONY Study in the first quarter of 2026. 4 Current Everest Medicines studies. 5 As part of the ongoing basket study conducted by Everest Medicines. FILSPARI® (sparsentan) for the treatment of IgAN On September 5, 2024, the FDA granted full approval of FILSPARI® (sparsentan) to slow kidney function decline in adults with primary IgAN who are at risk of disease progression. FILSPARI had previously been granted accelerated approval in February 2023 based on the surrogate marker of proteinuria. Full approval was based on positive long-term confirmatory results from the PROTECT Study demonstrating that FILSPARI significantly slowed kidney function decline over two years compared to irbesartan. FILSPARI is the only oral, once-daily, non-immunosuppressive medication that directly targets glomerular injury in the kidney by blocking two critical pathways of IgAN disease progression (endothelin-1 and angiotensin II). 27 Table of Contents The two-year efficacy data contained in the FDA-approved label is a modified intention to treat ("ITT") analysis and evaluates data from all patients regardless of treatment discontinuation. In the final analysis of the 404 randomized patients, FILSPARI significantly reduced the rate of decline in kidney function from baseline to Week 110 compared to irbesartan. In the ITT analysis included in the label, the mean eGFR slope from baseline to Week 110 was -3.0 mL/min/1.73 m2/year for FILSPARI and -4.2 mL/min/1.73 m2/year for irbesartan, corresponding to a statistically significant treatment effect of 1.2 mL/ min/1.73 m2/year (p=0.0168). The positive treatment effects on proteinuria compared to the active control irbesartan that were observed at Week 36 were durable out to the two-year measurement period. Additional results from the PROTECT Study demonstrated the benefit of FILSPARI on absolute eGFR accrued over time and by Week 110 resulted in a 3.8 mL/min/1.73 m2 difference in the mean change from baseline between FILSPARI and irbesartan. Results from the PROTECT Study showed that FILSPARI was well tolerated with a clearly defined safety profile that has been consistent across all clinical trials conducted to date. FILSPARI is a dual endothelin angiotensin receptor antagonist. Pre-clinical data have shown that blockade of both endothelin type A and angiotensin II type 1 pathways in forms of rare chronic kidney disease, reduces proteinuria, protects podocytes and prevents glomerulosclerosis and mesangial cell proliferation. FILSPARI has been granted seven years of Orphan Drug Exclusivity in the U.S. (running from the date of accelerated approval) for the reduction of proteinuria in adults with primary IgAN at risk of rapid disease progression, and has been granted a separate seven years of Orphan Drug Exclusivity in the U.S. (running from the date of full approval) to slow kidney function decline in adults with primary IgAN who are at risk for disease progression, excluding the use provided for in the aforementioned Orphan Drug Exclusivity granted in connection with the accelerated approval. IgAN is characterized by hematuria, proteinuria, and variable rates of progressive renal failure. With an estimated prevalence of up to 150,000 people in the United States and greater numbers in Europe and Asia, IgAN is the most common primary glomerular disease. Most patients are diagnosed between the ages of 16 and 35, with up to 40% progressing to kidney failure within 15 years. FILSPARI is the first non-immunosuppressive therapy approved for IgAN and is the only oral, once-daily, non-immunosuppressive therapy approved for this condition that directly targets glomerular injury in the kidney by blocking two critical pathways of IgAN disease progression (endothelin-1 and angiotensin II). We estimate more than 70,000 patients in the United States to be addressable under FILSPARI's full approval indication. Data to support the approval of FILSPARI was generated from the Phase 3 PROTECT Study, the largest head-to-head interventional study to date in IgAN. It is a global, randomized, multicenter, double-blind, parallel-arm, active-controlled clinical trial that evaluated the safety and efficacy of 400mg of sparsentan, compared to 300mg of irbesartan, in 404 patients ages 18 years and up with IgAN and persistent proteinuria despite available angiotensin converting enzyme ("ACE") inhibitor or angiotensin receptor blockers ("ARB") therapy, and is currently ongoing in the open label extension phase of the study. FILSPARI is available only through a risk evaluation and mitigation strategy ("REMS") approved by the FDA for liver monitoring regarding potential risk of hepatotoxicity, as has been required for certain other approved endothelin antagonists. Initially, as part of the liver monitoring REMS, monthly monitoring of each patient was required for the first year a patient was on treatment, and quarterly thereafter. In August 2025, the FDA approved updated REMS labeling, reducing the frequency of liver monitoring to every three months from the onset of treatment and also removing the embryo-fetal toxicity monitoring requirement from the REMS. In April 2024, we and our partner CSL Vifor announced that the European Commission had granted conditional marketing authorization (“CMA”) for FILSPARI (sparsentan) for the treatment of adults with primary IgAN with a urine protein excretion ≥1.0 g/day (or urine protein-to-creatinine ratio ≥0.75 g/g), and in April 2025, we and CSL Vifor announced that the European Commission had converted the CMA into a standard marketing authorization (“MA”) for FILSPARI for the treatment of adults with primary IgAN with a urine protein excretion ≥1.0 g/day (or urine protein-to-creatinine ratio ≥0.75 g/g). The MA was granted for all member states of the European Union, as well as in Iceland, Liechtenstein and Norway. As a result of the standard MA approval, we received a regulatory milestone payment of $17.5 million in May 2025 under the terms of the License Agreement. FILSPARI became commercially available in Europe under the CMA in August 2024, with an initial launch in Germany and Austria. In October 2024, we and CSL Vifor announced that Swissmedic has granted temporary marketing authorization for FILSPARI for the treatment of adults with primary IgAN with a urine protein excretion ≥1.0 g/day (or urine protein-to-creatinine ratio ≥0.75 g/g). In April 2025, the Medicines and Healthcare products Regulatory Agency ("MHRA") in the UK converted its conditional approval of FILSPARI in IgAN to standard approval. In the fourth quarter of 2025, we received a $40.0 million market access milestone payment from CSL Vifor. In January 2024, we announced our entry into an exclusive licensing agreement with Renalys Pharma, Inc. ("Renalys"), to bring sparsentan for the treatment of IgAN to patients in Japan and other countries in Asia. In December 2024, Renalys announced that sparsentan received Orphan Drug Designation from the Japanese Ministry of Health, Labour and Welfare for the indication of primary IgA nephropathy as of November 27, 2024. In the fourth quarter of 2025, Renalys announced positive topline results from its Phase 3 study of sparsentan in Japanese patients with IgAN. Renalys has also announced that it has reached an agreement with the Pharmaceuticals and Medical Devices Agency ("PMDA") regarding development plans for two other Phase 3 clinical trials of sparsentan, one investigating the use of sparsentan in FSGS and the other in Alport syndrome, in Japan. In the fourth quarter of 2025, Renalys was acquired by and merged into Chugai Pharmaceutical Co., Ltd. (“Chugai”). Through the acquisition, Chugai gained exclusive rights to develop and commercialize sparsentan in Japan, South Korea, and Taiwan. As a minority shareholder in Renalys, we received $10.2 million at the closing of the transaction and we are also eligible to receive multiple milestones according to the progress of sparsentan regulatory approval, and consideration linked to sparsentan's net sales in the applicable territory. Under the terms of the licensing agreement, Chugai is responsible for development, regulatory matters, and commercialization in the licensed territories. FILSPARI (sparsentan) for the treatment of FSGS On April 13, 2026, the FDA granted full (traditional) approval of FILSPARI (sparsentan) to reduce proteinuria in adult and pediatric patients aged 8 years and older with FSGS without nephrotic syndrome. FILSPARI is the first and only medicine approved by the FDA for the treatment of FSGS. FSGS is a leading cause of kidney failure and nephrotic syndrome. Prior to the approval of FILSPARI in April 2026, there were no FDA-approved pharmacologic treatments for FSGS, and there remains a high unmet need for patients living with FSGS as off-label treatments such as ACE/ARBs, steroids, and immunosuppressant agents are effective in only a subset of patients and use of some of these off-label treatments may be further inhibited by their safety profiles. 28 Table of Contents People with FSGS who do not have nephrotic syndrome span across types of FSGS and represent a population aligned with the KDIGO guidelines for treating glomerular diseases. Nephrotic syndrome is commonly defined as the presence of three concurrent criteria: proteinuria greater than 3.5 g/24h, edema, and albumin less than 3.0 g/dL. We estimate that the addressable population in the U.S. is more than 30,000 individuals with FSGS who do not have nephrotic syndrome. In the Phase 3 DUPLEX Study, the largest head-to-head interventional study in FSGS to date, patients treated with FILSPARI in the overall study population experienced a statistically significant 46% reduction in proteinuria from baseline to Week 108 compared to 30% for those treated with maximum labeled dose irbesartan (nominal p-value, 0.0299). In patients without nephrotic syndrome, FILSPARI demonstrated even greater improvements compared to maximum labeled dose irbesartan across proteinuria and eGFR. Those without nephrotic syndrome who were treated with FILSPARI experienced a 48% reduction in proteinuria from baseline to Week 108 compared to 27% for those treated with irbesartan, which was statistically significant (nominal p-value, 0.0075). FILSPARI-treated patients without nephrotic syndrome also demonstrated a benefit in eGFR with a treatment difference of 1.1 mL/min/1.73 m2 based on mean change from baseline to Week 108 (-11.3 mL/min/1.73 m2 for FILSPARI compared to -12.4 mL/min/1.73 m2 for maximum labeled dose irbesartan). Across both adult and pediatric patients, FILSPARI was generally well tolerated, with a safety profile comparable to irbesartan and consistent across clinical programs. The Phase 3 DUPLEX Study was a global, randomized, multicenter, double-blind, parallel-arm, active-controlled Phase 3 clinical trial that assessed the efficacy and safety of FILSPARI in 371 patients ages 8 to 75 years with biopsy-proven or genetic FSGS. After a two-week washout period, patients were randomized 1:1 to receive either FILSPARI or irbesartan, the active control, and subsequently dose titrated to the maximum dose of 800 mg of sparsentan or 300 mg of irbesartan, as tolerated. In the study, nephrotic syndrome was defined as (a) documentation of nephrotic syndrome in the medical history, or (b) the concurrent presence of proteinuria >3.5 g/24 hours (adults) or UPCR >2.0 g/g (pediatric patients <18 years of age), serum albumin <3.0 g/dL, and edema at baseline. The primary efficacy endpoint at the final analysis was the rate of change in eGFR from baseline to Week 108. The two-year results from the study were published in the New England Journal of Medicine. Patients who completed the DUPLEX double-blind portion of the study on treatment were eligible to participate in the open-label extension of the trial. Sparsentan has been granted Orphan Drug Designation for the treatment of FSGS in the U.S. and the EEA. As noted above in more detail, FILSPARI is available only through a REMS approved by the FDA for liver monitoring regarding potential risk of hepatotoxicity, as has been required for certain other approved endothelin antagonists. Together with CSL Vifor and Chugai, we continue to evaluate the potential for a regulatory pathway forward for sparsentan in FSGS in Europe and Japan. Under the terms of our exclusive license to CSL Vifor, CSL Vifor is responsible for all commercialization activities in its licensed territories. We remain responsible for the clinical development of sparsentan in the applicable territories. If sparsentan receives marketing authorization in any of the territories covered by the exclusive license to Chugai, Chugai will be responsible for all development, regulatory matters, and commercialization activities in such licensed territories. We will retain all rights to sparsentan in the United States and rest of world outside of the territories licensed to CSL Vifor and Chugai, provided that CSL Vifor has a right of negotiation to expand the licensed territories into Canada and/or Mexico. Clinical-Stage Programs: Pegtibatinase Pegtibatinase is a novel investigational human enzyme replacement candidate being evaluated for the treatment of classical homocystinuria ("HCU"). Classical HCU is a rare metabolic disorder characterized by elevated levels of plasma homocysteine that can lead to vision, skeletal, circulatory and central nervous system complications. We estimate that there are approximately 7,000 to 10,000 addressable HCU patients globally. Pegtibatinase has been granted Rare Pediatric Disease, Fast Track and Breakthrough Therapy designations by the FDA, as well as orphan drug designation in the United States and European Union. In December 2021, we announced positive topline results from the Phase 1/2 COMPOSE Study, a double blind, randomized, placebo-controlled dose escalation study to assess its safety, tolerability, pharmacokinetics, pharmacodynamics and clinical effects in patients with classical HCU. Pegtibatinase demonstrated dose-dependent reductions in total homocysteine ("tHcy") during the 12 weeks of treatment, and in the highest dose cohort to date evaluating 1.5 mg/kg of pegtibatinase twice weekly ("BIW"), treatment with pegtibatinase resulted in rapid and sustained reductions in tHcy through 12 weeks of treatment, including a 55.1% mean relative reduction in tHcy from baseline as well as maintenance of tHcy below a clinically meaningful threshold of 100 μmol. Additionally, in a dose-dependent manner in the study to date, methionine levels were substantially reduced and cystathionine levels were substantially elevated following treatment with pegtibatinase, suggesting that pegtibatinase acts in a manner similar to the native CBS enzyme. In May 2023, we announced positive topline results from the sixth cohort of the Phase 1/2 COMPOSE Study, which was initiated to inform and refine formulation work for future development and commercial purposes and to further evaluate the dose response curve for pegtibatinase, and to further inform our pivotal development program to ultimately support potential approval of pegtibatinase for the treatment of HCU. In this cohort, five patients were randomized in a blinded fashion to receive 2.5 mg/kg of lyophilized pegtibatinase or placebo BIW, with four patients assigned to the treatment group. In this highest dose cohort to date, treatment with pegtibatinase resulted in rapid and sustained reductions in tHcy, with a 67.1% mean relative reduction in tHcy from baseline, as well as maintenance of mean tHcy below the clinically meaningful threshold of 100 μmol, over weeks 6 to 12. In the double-blind period, pegtibatinase was generally well-tolerated, with no discontinuations due to treatment-related adverse events. In December 2023, we initiated the pivotal Phase 3 HARMONY Study to support the potential approval of pegtibatinase for the treatment of classical HCU. The HARMONY Study is a global, randomized, multi-center, double-blind, placebo-controlled Phase 3 clinical trial designed to evaluate the efficacy and safety of pegtibatinase as a novel treatment to reduce tHcy levels. In the beginning of 2024, the first patients were dosed in the HARMONY Study. In September 2024, we announced a voluntary pause of enrollment in the Phase 3 HARMONY Study. The voluntary enrollment pause was enacted following our determination that the desired drug substance profile was not achieved in the initial scale-up process, and it enabled us to address necessary process improvements in manufacturing scale-up to support initial commercial scale manufacturing as well as full enrollment in the HARMONY Study. Following 29 Table of Contents successful process improvements, the Company restarted enrollment activities in the first quarter of 2026 and dosed the first new patient following study restart in April 2026, with topline data anticipated in the second half of 2027. We acquired pegtibatinase as part of the November 2020 acquisition of Orphan Technologies Limited. Civorebrutinib Civorebrutinib is an investigational oral, covalent reversible Bruton’s tyrosine kinase (“BTK”) inhibitor designed to provide differentiated efficacy, safety and convenience for patients with rare, immune-mediated kidney diseases, including primary membranous nephropathy (“PMN”), with planned evaluation in FSGS, minimal change disease (“MCD”) and potentially additional indications. BTK is a key mediator of B-cell receptor signaling and plays an important role in B-cell activation, maturation, proliferation, and differentiation into antibody-producing cells. In immune-mediated kidney diseases, B-cell activation and autoantibody production are believed to contribute directly to kidney injury. Civorebrutinib has demonstrated proof of concept in a Phase 1/2 clinical trial of patients with PMN. The previously reported Phase 1/2 data demonstrated rapid and sustained reductions in anti-PLA2R autoantibodies and proteinuria, with high rates of immunologic and clinical remission and stable kidney function through 52 weeks of follow-up. Civorebrutinib has been generally well tolerated throughout the development program to date. In June 2026, we entered into a license and collaboration agreement (the “Everest Agreement”) with Everest Medicines (Singapore) Pte. Ltd. (“Everest”), pursuant to which we obtained an exclusive license to develop, manufacture and commercialize civorebrutinib in the United States and global markets excluding Greater China and certain countries in East and Southeast Asia (the “Territory”). The Everest Agreement became effective in July 2026 following the satisfaction of customary closing conditions. We and Everest will collaborate on global clinical development, including sharing development costs for global clinical trials. Except for certain global development activities, we are responsible for development and commercialization of civorebrutinib in the Territory, while Everest retains responsibility for its territory. Under the Everest Agreement, we paid Everest an upfront payment of $112.5 million in July 2026 and Everest is eligible to receive up to approximately $1.03 billion in additional development, regulatory and commercial milestone payments, as well as tiered royalties on net sales of civorebrutinib products in the Territory. Other Commercial Products: Thiola and Thiola EC (tiopronin) Thiola and Thiola EC are approved by the FDA for the treatment of cystinuria, a rare genetic cystine transport disorder that causes high cystine levels in the urine and the formation of recurring kidney stones. Due to the larger stone size, cystine stones may be more difficult to pass, often requiring surgical procedures to remove. More than 80 percent of people with cystinuria develop their first stone by the age of 20. More than 25 percent will develop cystine stones by the age of 10. Recurring stone formation can cause loss of kidney function in addition to substantial pain and loss of productivity associated with renal colic and stone passage. While a portion of people living with the disease are able to manage symptoms through diet and fluid intake, the prevalence of cystinuria in the U.S. is estimated to be 10,000 to 12,000, indicating that there may be as many as 4,000 to 5,000 affected individuals with cystinuria in the U.S. that would be candidates for Thiola or Thiola EC. In June 2019 we announced that the FDA approved 100mg and 300mg tablets of Thiola EC, an enteric-coated formulation of Thiola, to be used for the treatment of cystinuria. Thiola EC offers the potential for administration with or without food, and the ability to reduce the number of tablets necessary to manage cystinuria. Thiola EC became available to patients in July 2019. In May 2021, a generic option for the 100mg version of the original formulation of Thiola (tiopronin tablets) became available and in June 2022, a second option for the 100mg version of the original formulation of Thiola (tiopronin tablets) was approved. These generic versions of the original formulation of Thiola have impacted our sales, and these or additional generic versions of either formulation could have a material adverse impact on sales. To date, several generic options for the 100mg and 300mg versions of Thiola EC have been approved by the FDA and become available. Accordingly, Thiola EC is subject to generic competition. 30 Table of Contents Results of Operations Results of operations for the three and six months ended June 30, 2026 compared to the three and six months ended June 30, 2025 Revenue The following table provides information regarding revenue, including net product sales and license and collaboration revenue (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2026 2025 Change 2026 2025 Change FILSPARI $ 141,078 $ 71,887 $ 69,191 $ 246,230 $ 127,768 $ 118,462 Tiopronin products 20,274 22,955 (2,681) 39,614 42,934 (3,320) Total net product sales 161,352 94,842 66,510 285,844 170,702 115,142 License and collaboration revenue 8,232 19,607 (11,375) 10,938 25,478 (14,540) Total revenue $ 169,584 $ 114,449 $ 55,135 $ 296,782 $ 196,180 $ 100,602 Net product sales The increase in total net product sales for the three and six months ended June 30, 2026 compared to the three and six months ended June 30, 2025 was primarily due to growth in sales of FILSPARI. License and collaboration revenue The decrease in license and collaboration revenue for the three months ended June 30, 2026 compared to the three months ended June 30, 2025 was primarily due to recognition of a $17.5 million regulatory milestone associated with the CSL Vifor License Agreement during the three months ended June 30, 2025, offset by recognition of a $5.0 million regulatory milestone associated with the Chugai License Agreement during the three months ended June 30, 2026. The decrease in license and collaboration revenue for the six months ended June 30, 2026 compared to the six months ended June 30, 2025 was primarily due to recognition of a $17.5 million regulatory milestone associated with the CSL Vifor License Agreement and the sale of $3.8 million in active pharmaceutical ingredients ("API") during the three months ended June 30, 2025, offset by recognition of a $5.0 million regulatory milestone associated with the Chugai License Agreement during the six months ended June 30, 2026. Operating Expenses We revised the presentation of amortization expense of certain royalty and milestone payments associated with license agreements. Historically, these royalties were included within selling, general and administrative expenses in the consolidated statements of operations. Beginning in the current year, we present these amounts separately as royalty expense to better reflect the nature of these costs as consideration payable to licensors based on sales of licensed products and regulatory milestone payments. The following table provides information regarding operating expenses (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2026 2025 Change 2026 2025 Change Cost of goods sold - product sales $ 2,174 $ 1,521 $ 653 $ 4,123 $ 2,775 $ 1,348 Cost of goods sold - license and collaboration — — — — 3,426 (3,426) Total cost of goods sold 2,174 1,521 653 4,123 6,201 (2,078) Research and development 60,283 49,362 10,921 117,377 96,251 21,126 Selling, general and administrative 96,112 62,581 33,531 176,366 122,995 53,371 Royalty expense 7,061 13,635 (6,574) 31,877 26,060 5,817 Total operating expenses $ 165,630 $ 127,099 $ 38,531 $ 329,743 $ 251,507 $ 78,236 Cost of goods sold Cost of goods sold includes the cost of inventory sold, third party manufacturing and supply chain costs, product shipping and handling costs, and provisions for excess and obsolete inventory. Cost of goods sold also includes the cost of goods sold under our license and collaboration agreements, which currently consists of the sale of APIs to our collaboration partners, at cost or at cost plus a margin. Prior to the February 2023 FDA accelerated approval of FILSPARI (sparsentan) in IgAN, we expensed the production of APIs purchased to support the commercial launch of FILSPARI, in research and development expenses. For the three and six months ended June 30, 2025 sales of FILSPARI primarily consisted of zero-cost inventories, and therefore cost of goods sold did not increase proportionally to the increase in product sales. We began capitalizing inventory costs associated with FILSPARI following the February 2023 accelerated approval. For the six months ended June 30, 2026 compared to the six months ended June 30, 2025, our cost of goods sold - license and collaboration decreased by $3.4 million, due to the sale of API in 2025. 31 Table of Contents Research and development expenses Research and development costs include expenses related to sparsentan, pegtibatinase and our other pipeline programs. We expense all research and development costs as they are incurred. Our research and development costs are comprised of salaries and bonuses, benefits, non-cash share-based compensation, license fees, milestones under license agreements, costs paid to third-party contractors to perform research, conduct clinical trials, and develop drug materials and delivery methods, costs to manufacture drug product supplies to support clinical development, and associated overhead expenses and facilities costs. We charge direct internal and external program costs to the respective development programs. We also incur indirect costs that are not allocated to specific programs because such costs benefit multiple development programs and allow us to increase our pharmaceutical development capabilities. These consist of internal shared resources related to the development and maintenance of systems and processes applicable to all of our programs. We currently have three Phase 3 clinical trials in process that are in various stages of activity, with ongoing non-clinical support trials. As such, clinical trial expenses will vary depending on all the factors set forth above and may fluctuate significantly from quarter to quarter and year to year. We routinely engage vendors and service providers for scientific research, clinical trial, regulatory compliance, manufacturing and other consulting services. We also make grants to research and non-profit organizations to conduct research which may lead to new intellectual properties that we may subsequently license under separately negotiated license agreements. Such grants may be funded in lump sums or installments. The following table provides information regarding research and development expenses (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2026 2025 Change 2026 2025 Change External service provider costs: Sparsentan $ 6,971 $ 13,737 $ (6,766) $ 16,470 $ 25,056 $ (8,586) Pegtibatinase 24,244 13,283 10,961 42,473 24,319 18,154 General and other product candidates 5,106 4,127 979 9,947 8,559 1,388 Total external service provider costs 36,321 31,147 5,174 68,890 57,934 10,956 Internal personnel costs 23,962 18,215 5,747 48,487 38,317 10,170 Total research and development $ 60,283 $ 49,362 $ 10,921 $ 117,377 $ 96,251 $ 21,126 For the three and six months ended June 30, 2026 compared to 2025, our research and development expenses increased by $10.9 million and $21.1 million, respectively. External service provider costs increased by $5.2 million and $11.0 million, respectively, for the three and six months ended June 30, 2026 compared to 2025, largely driven by an increase in costs associated with pegtibatinase due to restarting enrollment activities for the HARMONY Study in 2026, as well as additional manufacturing costs, offset by a decrease in costs associated with the development of sparsentan as our Phase 3 programs advanced towards completion. The increase in internal personnel costs of $5.7 million and $10.2 million, respectively, for the three and six months ended June 30, 2026 compared to 2025, is due to an increase in headcount. Selling, general and administrative expenses Selling, general and administrative expenses consist of salaries and bonuses, benefits, non-cash share-based compensation, legal and other professional fees, rent, depreciation and amortization, travel, insurance, business development, sales and marketing programs, and other operating expenses. For the three and six months ended June 30, 2026 compared to 2025, our selling, general and administrative expenses increased by $33.5 million and $53.4 million, respectively, primarily as a result of an increase in commercial investments to support FILSPARI in IgAN and commercial investments for the launch of FSGS, including an expansion of our field force to support both indications. Royalty expense Royalty expense includes amortization of royalties and milestones paid that are capitalized to the intangible asset under the asset accumulation model as well as royalties expensed after the estimated useful life of the license agreement has been reached. For the three months ended June 30, 2026 compared to 2025, our royalty expense decreased by $6.6 million due to the Thiola intangible asset reaching the end of its useful life on March 31, 2026. For the six months ended June 30, 2026 compared to 2025, royalty expense increased by $5.8 million, primarily due to elevated amortization of the Thiola intangible asset in the first quarter of 2026 as it reached the end of its useful life on March 31, 2026. Other Income/Expenses The following table provides information regarding other (expense) income, net (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2026 2025 Change 2026 2025 Change Interest income $ 3,356 $ 3,287 $ 69 $ 5,939 $ 7,083 $ (1,144) Interest expense (2,134) (2,846) 712 (4,434) (5,702) 1,268 Other (expense) income, net (169) (526) 357 (259) 24 (283) Inducement expense (40,008) — (40,008) (40,008) — (40,008) Total other (expense) income, net $ (38,955) $ (85) $ (38,870) $ (38,762) $ 1,405 $ (40,167) 32 Table of Contents The change in our total other (expense) income, net for the three and six months ended June 30, 2026 as compared to the three and six months ended June 30, 2025 is primarily due to the $40.0 million inducement expense related to the partial repurchase of the 2.25% Convertible Senior Notes due 2029 (“2029 Notes”). Liquidity and Capital Resources We have financed our operations through a combination of borrowings, sales of our equity securities, and revenues generated from our commercialized products, along with proceeds from license and collaboration agreements and the divestiture of our bile acid business. We experienced significant growth in recent years in the number of our employees and the scope of our operations. We also expanded our sales and marketing, compliance and legal functions in addition to expansion of all functions to support a commercial organization, including by adding additional members to our sales force in connection with the commercial launch of FILSPARI in the United States for IgAN and for the commercial launch of FILSPARI in the United States for FSGS. We believe that our available cash and short-term investments as of the date of this filing, together with anticipated cash generated from operations, will be sufficient to fund our anticipated level of operations beyond the next 12 months from the date of this filing. We expect that our operating results will vary from quarter-to-quarter and year-to-year depending upon various factors including revenues, selling, general and administrative expenses, and research and development expenses, particularly with respect to our clinical and preclinical development activities. Our ability to fund our operations in subsequent years will depend upon certain factors which are beyond our control and may require us to obtain additional debt or equity capital or refinance all or a portion of our debt, including the 2029 Notes and 0.50% Convertible Senior Notes due 2032 (“2032 Notes”), on or before maturity. Though we generate revenues from product sales, we may incur significant operating losses over the next several years. Our ability to achieve profitable operations in the future will depend in large part upon completing development of products in our pipeline, obtaining regulatory approvals for these products and bringing these products to market, along with potential in-licensing of additional products approved by the FDA and manufacturing and selling these products. We had the following balances and financial performance at June 30, 2026 and December 31, 2025 (in thousands): June 30, 2026 December 31, 2025 Cash and cash equivalents $ 117,735 $ 93,035 Marketable debt securities, at fair value $ 371,442 $ 229,761 Convertible debt $ 602,781 $ 311,724 Accumulated deficit $ (1,544,612) $ (1,472,713) Stockholders' equity $ 24,522 $ 114,828 Net working capital* $ 463,116 $ 277,661 Net working capital ratio** 4.05 2.74 * Current assets less current liabilities. **Current assets divided by current liabilities. As of June 30, 2026, we had cash and cash equivalents of $117.7 million and available-for-sale marketable debt securities of $371.4 million. In July 2026, we paid Everest an upfront payment of $112.5 million pursuant to the terms of the Everest Agreement. Substantial sources of funds over the past year, as summarized further below, include net proceeds of $158.4 million from the issuance of 2032 Notes after giving effect to the partial repurchase of 2029 Notes, milestone payments from CSL Vifor totaling $40.0 million, a milestone payment of $25.0 million from Mirum and $10.2 million from the sale of Renalys stock to Chugai. Over the next 12 months, our expected financial obligations include, but are not limited to, funding our operations, operating lease payments, interest payments on our outstanding debt, anticipated milestone payments, royalties on sales of our existing commercialized products, research and development expenses pertaining to clinical and preclinical development activities across our pipeline, expenses associated with the ongoing commercialization of FILSPARI in IgAN and expenses associated with the commercial launch of FILSPARI in FSGS. Sources of cash over this period include net revenues from sales of our products, the sale or maturity of investments in our portfolio of marketable debt securities, FILSPARI royalties and certain earned and potential milestone payments. Beyond the next 12 months and over the foreseeable future, our known commitments and potential financial obligations will likely include ongoing operations funding, operating lease payments, interest payments on our outstanding debt, royalties on sales of our existing commercialized products, research and development expenses pertaining to clinical and preclinical development activities across our pipeline, milestone and royalty payments associated with FILSPARI, pegtibatinase, and other developmental programs based upon the achievement of certain agreement-specific criteria, along with sales-based royalties and the repayment of principal on the outstanding 2029 Notes, which mature on March 1, 2029, and 2032 Notes, which mature on May 15, 2032. Potential sources of cash over this time horizon may include net revenues from sales of our existing products and, if commercialized, our pipeline products, licensing revenue, the sale or maturity of marketable debt securities in our investment portfolio, the refinancing of all or a portion of our debt, on or before maturity, or the issuance of additional debt or equity. In addition, depending on prevailing market conditions, our liquidity requirements, contractual restrictions, and other factors, we may also from time to time seek to retire or purchase our outstanding debt through cash purchases and/or exchanges for equity securities, in open market purchases, privately negotiated transactions or otherwise, and the amounts involved in such purchases and/or exchanges, individually or in the aggregate, may be material. We may not be able to successfully conduct financing or refinancing activity on favorable terms or at all. 33 Table of Contents Purchase Agreement Proceeds Sale of Bile Acid Product Portfolio In July 2023, we entered into the Purchase Agreement with Mirum, pursuant to which Mirum agreed to purchase substantially all of the assets primarily related to our business of development, manufacture and commercialization of the Products, which comprised our bile acid business. Upon the Closing of the transaction in August 2023, we received an upfront cash payment of $210.0 million. Pursuant to the Purchase Agreement, we are eligible to receive up to $235.0 million upon the achievement of certain milestones based on specified amounts of annual net sales (tiered from $125.0 million to $500.0 million) of the Products. Mirum achieved the first such milestone based on its annual net sales in 2025, and we received a milestone payment of $25.0 million in April 2026, as a result of such achievement. Collaboration and License Proceeds License and Collaboration Agreement with CSL Vifor In September 2021, we entered into a license agreement with CSL Vifor, pursuant to which we granted an exclusive license to CSL Vifor for the commercialization of FILSPARI in the licensed territories. Under the terms of the license agreement, we will be eligible for up to $135.0 million in aggregate regulatory and market access related milestone payments and up to $655.0 million in aggregate sales-based milestone payments for a total potential value of up to $845.0 million. Through June 30, 2026, we have received milestone payments totaling $57.5 million associated with the license agreement. We are also entitled to receive tiered double-digit royalties of up to 40 percent of annual net sales of sparsentan in the licensed territories. See Note 4 to our unaudited Consolidated Financial Statements for further discussion. Licensing Agreement with Chugai In January 2024, our license agreement with Renalys Pharma, Inc. came into effect. Under the terms of the agreement, we granted an exclusive license to Renalys for the development and commercialization of sparsentan in Japan and other specified countries in Asia. Pursuant to the terms of the agreement, we are eligible to receive up to $120.0 million in aggregate regulatory, development and sales-based milestone payments. We are also entitled to receive tiered double-digit to mid-20 percent royalties of annual net sales of sparsentan in the licensed territories. In addition, we received an option to purchase shares of common stock of Renalys, which we exercised in January 2024. In the fourth quarter of 2025, Renalys was acquired by and merged into Chugai. Through the acquisition, Chugai gained exclusive rights to develop and commercialize sparsentan in Japan, South Korea, and Taiwan. As a minority shareholder in Renalys, we received $10.2 million at the closing of the transaction and we are also eligible to receive multiple milestones according to the progress of sparsentan regulatory approval, and consideration linked to sparsentan's net sales in the applicable territory. Under the terms of the licensing agreement, Chugai is responsible for development, regulatory matters, and commercialization in the licensed territories. See Note 4 to our unaudited Consolidated Financial Statements for further discussion. Equity Offerings At-the-Market Equity Offering In October 2024, we filed a prospectus supplement to the prospectus included in our registration statement on Form S-3 (File No. 333-281194), pursuant to which we may offer and sell, from time to time through Jefferies LLC, as agent (“Jefferies”), up to $100.0 million of our common stock pursuant to an Amended and Restated Open Market Sale Agreement ("ATM Agreement") with Jefferies. We have not sold any shares under the ATM Agreement. Operating Leases Future Minimum Rental Commitments As of June 30, 2026, we have future minimum rental commitments totaling $15.2 million arising from our operating lease and sublease income totaling $2.8 million. These commitments represent the aggregate base rent through August 2028. See Note 7 to our unaudited Consolidated Financial Statements for further discussion. Purchase Commitments Manufactured Product Certain of our contractual arrangements with contract manufacturing organizations ("CMOs") require binding forecasts or commitments to purchase minimum amounts for the manufacture of drug product supply, which may be material to our financial statements. Royalties and Contingent Cash Payments Ligand License Agreement In 2012, we entered into an agreement with Ligand Pharmaceuticals, Inc. ("Ligand") for a worldwide sublicense to develop, manufacture and commercialize FILSPARI (the “Ligand License Agreement”). As consideration for the license, we are required to make substantial payments upon the achievement of certain milestones, totaling up to $114.1 million. Through June 30, 2026, we have paid $48.7 million for contractual milestones achieved under the Ligand License Agreement. Pursuant to the terms of the Ligand License Agreement, we are obligated to pay to Ligand an escalating royalty between 15% and 17% of net sales of FILSPARI and any other products containing FILSPARI or related compounds, with payments due quarterly. We began incurring costs associated with such royalties following the February 2023 approval of FILSPARI. 34 Table of Contents The Ligand License Agreement will continue until neither party has any further payment obligations under the agreement and is expected to continue for up to 20 years from the effective date. Ligand may terminate the Ligand License Agreement due to (i) our insolvency, (ii) our material uncured breach of the agreement, (iii) our failure to use commercially reasonable efforts to develop and commercialize FILSPARI as described above or (iv) certain other conditions. We may terminate the Ligand License Agreement due to a material uncured breach of the agreement by Ligand. See Note 9 to our unaudited Consolidated Financial Statements for further discussion. Mission License Agreement In 2014, we entered into a license agreement with Mission Pharmacal ("Mission"), pursuant to which we obtained an exclusive, royalty-bearing license to market, sell and commercialize Thiola (tiopronin) in the United States and Canada, and a non-exclusive license to use know-how relating to Thiola to the extent necessary to market Thiola ("Mission License Agreement"). Under the terms of the Mission License Agreement, as subsequently amended, which runs through May 2029, we are obligated to pay to Mission the greater of $2.1 million, representing the guaranteed minimum royalty, or 20% of our Thiola net sales generated globally during each calendar year. See Note 9 to our unaudited Consolidated Financial Statements for further discussion. Acquisition of Orphan Technologies Limited In November 2020, we completed the acquisition of Orphan Technologies Limited (“Orphan”), including Orphan’s rare metabolic disorder drug pegtibatinase. We acquired Orphan by purchasing all of its outstanding shares. Under the Stock Purchase Agreement (the "Agreement"), we agreed to make contingent cash payments up to an aggregate of $427.0 million based on the achievement of certain development, regulatory and commercialization events as set forth in the Agreement, as well as additional tiered mid-single digit royalty payments based upon future net sales of any pegtibatinase products in the U.S. and Europe, subject to certain reductions as set forth in the Agreement, and a contingent payment in the event a pediatric rare disease voucher for any pegtibatinase product is granted. Through June 30, 2026, we have paid $65.2 million for contractual milestones achieved under the stock purchase agreement. See Note 13 to our unaudited Consolidated Financial Statements for further discussion. French Rebate Accrual In October 2021, our distributor in France for our previously marketed product Kolbam informed us that they had received a notice that the price previously paid for Kolbam during its period on the market in France had been recalculated by the agency responsible for pharmaceutical pricing in France. In October 2024, we received an invoice from the government authority in the amount of approximately $6.2 million for reimbursement of amounts previously paid for Kolbam, which we paid in November 2024. We have appealed the pricing decision and will pursue an appeal of the amount owed with the Competent Administrative Court. Borrowings Convertible Senior Notes Due 2032 On May 11, 2026, we completed a registered underwritten public offering of $525.0 million aggregate principal amount of our 2032 Notes. We issued the 2032 Notes under an indenture dated as of May 11, 2026, as supplemented by the first supplemental indenture, dated as of May 11, 2026 (collectively, the “2032 Indenture”). The 2032 Notes will mature on May 15, 2032, unless earlier repurchased, redeemed, or converted. The 2032 Notes are senior unsecured obligations of ours and bear interest at an annual rate of 0.50%, payable semi-annually in arrears on May 15 and November 15 of each year, beginning on November 15, 2026. The 2032 Notes do not contain any financial or operating covenants or any restrictions on the payment of dividends, the issuance of other indebtedness or the issuance or repurchase of securities by us. Convertible Senior Notes Due 2029 On March 11, 2022, we completed a registered underwritten public offering of $316.3 million aggregate principal amount of our 2029 Notes. We issued the 2029 Notes under an indenture, dated as of September 10, 2018, as supplemented by the second supplemental indenture, dated as of March 11, 2022 (collectively, the “2029 Indenture”). The 2029 Notes will mature on March 1, 2029, unless earlier repurchased, redeemed, or converted. The 2029 Notes are senior unsecured obligations of ours and bear interest at an annual rate of 2.25%, payable semi-annually in arrears on March 1 and September 1 of each year, beginning on September 1, 2022. On May 11, 2026, coinciding with the issuance of the 2032 Notes, we completed our repurchase of $221.4 million aggregate principal amount of 2029 Notes for cash. After giving effect to the repurchase, the total remaining principal amount outstanding under the 2029 Notes as of June 30, 2026 was $94.9 million. The 2029 Notes do not contain any financial or operating covenants or any restrictions on the payment of dividends, the issuance of other indebtedness or the issuance or repurchase of securities by us. See Note 10 to our unaudited Consolidated Financial Statements for further discussion. Funding Requirements We believe that our available cash and short-term investments as of the date of this filing will be sufficient to fund our anticipated level of operations beyond the next 12 months from the date of this filing. We expect to use cash flows from operations and, when necessary, outside financings, to meet our current and future financial obligations, including funding our operations, debt service and capital expenditures. Our ability to make these payments depends on our future performance, which will be affected by financial, business, economic, regulatory and other factors, many of which we cannot control. Factors that may affect financing requirements include, but are not limited to: •the timing, progress, cost and results of our clinical trials, preclinical studies and other discovery and research and development activities; 35 Table of Contents •the timing and outcome of, and costs involved in, seeking and obtaining marketing approvals for our products, and in maintaining quality systems standards for our products; •the timing of, and costs involved in, commercial activities, including product marketing, sales and distribution; •our ability to successfully commercialize FILSPARI for the treatment of IgAN and FSGS, and to obtain regulatory approval for, and successfully commercialize our other or future product candidates; •increases or decreases in revenue from our marketed products, including decreases in revenue resulting from generic entrants, changes in reimbursement or rebates, and/or health epidemics or pandemics; •payment obligations related to the 2029 Notes and 2032 Notes; •the number and development requirements of other product candidates that we pursue; •our ability to manufacture sufficient quantities of our products to meet expected demand; •the costs of preparing, filing, prosecuting, maintaining and enforcing any patent claims and other intellectual property rights, litigation costs and the results of litigation; •our ability to enter into collaboration, licensing or distribution arrangements and the terms and timing of these arrangements; •the potential need to expand our business, resulting in additional payroll and other overhead expenses; •the potential in-licensing of other products or technologies; •the emergence of competing technologies or other adverse market or technological developments; •the potential impacts of actions taken by the current administration, including but not limited to tariffs and changes at the FDA and other government agencies; and •the impacts of inflation and resulting cost increases. Future capital requirements will also depend on the extent to which we acquire or invest in additional complementary businesses, products and technologies. Cash Flows from Continuing Operations Cash Flows from Operating Activities Cash provided by operating activities for the six months ended June 30, 2026 was $17.7 million compared to cash used of $37.2 million for the six months ended June 30, 2025. The change was due to a $115.1 million increase in total net product sales, offset by an increase in operational expenses and the timing of payments from normal operations. Cash Flows from Investing Activities Cash used in investing activities for the six months ended June 30, 2026 was $184.7 million compared to cash provided by of $46.1 million for the six months ended June 30, 2025. The change resulted primarily from the investment of the net proceeds of the 2032 Notes and partial repurchase of the 2029 Notes, as well as timing differences in investment purchases, sales and maturities, and the fluctuation of our portfolio mix between cash equivalents and short-term investment holdings and an increase in intangible asset purchases. Cash Flows from Financing Activities Cash provided by financing activities from continuing operations for the six months ended June 30, 2026 was $191.7 million compared to cash provided by of $5.2 million for the six months ended June 30, 2025. The change was primarily due to net proceeds of $158.4 million from the issuance of the 2032 Notes and the partial repurchase of the 2029 Notes and an increase in proceeds from the exercise of stock options during the six months ended June 30, 2026. Other Matters Adoption of New Accounting Standards See Note 2 to our unaudited Consolidated Financial Statements in this report for a discussion of adoption of new accounting standards. Recently Issued Accounting Pronouncements See Note 2 to our unaudited Consolidated Financial Statements in this report for a discussion of recently issued accounting pronouncements. Critical Accounting Estimates Our consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States of America. The preparation of our consolidated financial statements and related disclosures requires us to make estimates and assumptions that affect the reported amount of assets, liabilities, revenue, costs and expenses, and related disclosures. We evaluate our estimates and assumptions on an ongoing basis. Our actual results may differ from these estimates under different assumptions and conditions. See our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 for information about critical accounting estimates as well as a description of our other significant accounting policies. 36 Table of Contents