KYNTRA BIO, INC.

Previous wording

FibroGen, Inc. (“FibroGen” or the “Company”) is a biopharmaceutical company focused on development of novel therapies at the frontiers of cancer biology and anemia.

Current wording

Kyntra Bio, Inc. (“Kyntra Bio” or “we”) is a biopharmaceutical company focused on development of novel therapies at the frontiers of cancer biology and anemia.

Previous wording

We are developing FG-3246, a potential first-in-class antibody-drug conjugate targeting CD46, for the treatment of metastatic castration-resistant prostate cancer and potentially other cancers. This program also includes the development of FG-3180, an associated CD46-targeted positron emission tomography (“PET”) biomarker and imaging agent.

Current wording

We are developing FG-3246, a potential first-in-class antibody-drug conjugate (“ADC”) targeting CD46, for the treatment of metastatic castration-resistant prostate cancer (“mCRPC”) and potentially other cancers. This program also includes the development of FG-3180, an associated CD46-targeted positron emission tomography (“PET”) biomarker and imaging agent. We initiated a Phase 2 monotherapy dose optimization study of FG-3246 for the treatment of mCRPC, along with the exploratory sub-study of FG-3180, in the third quarter of 2025.

Previous wording

We and our collaboration partners have developed roxadustat (爱瑞卓®, EVRENZOTM), which is currently approved in the People’s Republic of China (“China”), Europe, Japan, and numerous other countries for the treatment of anemia in chronic kidney disease (“CKD”) patients on dialysis and not on dialysis.

Current wording

We and our collaboration partners developed roxadustat (爱瑞卓®, EVRENZOTM), which is currently approved in Europe, Japan, the People’s Republic of China (“China”), and numerous other countries for the treatment of anemia in chronic kidney disease (“CKD”) patients on dialysis and not on dialysis.

Previous wording

In February 2025, we entered into a share purchase agreement (the “Share Purchase Agreement”) with AstraZeneca Treasury Limited pursuant to which we and our subsidiary FibroGen China Anemia Holdings, Ltd. agreed to sell all of the issued and outstanding equity interests of FibroGen International (Hong Kong) Ltd. (“FibroGen International”) to AstraZeneca Treasury Limited. AstraZeneca AB (“AstraZeneca”) is our long-time commercialization partner for roxadustat in greater China and South Korea. This sale includes all of our roxadustat assets in China, including FibroGen International’s subsidiary FibroGen (China) Medical Technology Development Co., Ltd and its 51.1% interest in Beijing Falikang Pharmaceutical Co. Ltd. (“Falikang”). The transaction is expected to close by mid-2025, and is subject to customary closing conditions and closing deliverables, including receipt of regulatory approval from the China State Administration for Market Regulation.

Current wording

On August 29, 2025, we closed the sale of our China operations through FibroGen International (Hong Kong) Ltd. (“FibroGen International”) to AstraZeneca Treasury Limited pursuant to the share purchase agreement entered into with AstraZeneca Treasury Limited on February 20, 2025, as amended (the “Share Purchase Agreement”) for a total consideration of $220.4 million comprised of $85.0 million in enterprise value and $135.4 million in net cash held in China. AstraZeneca AB (“AstraZeneca”) was our long-time commercialization partner for roxadustat in greater China. This sale included all of our roxadustat assets in China, including FibroGen International’s subsidiary FibroGen (China) Medical Technology Development Co., Ltd. (“FibroGen Beijing”) and its 51.1% interest in Beijing Falikang Pharmaceutical Co. Ltd. (“Falikang”).

Previous wording

We will retain the rights to roxadustat in the United States of America (“U.S.”), Canada, Mexico, and in all markets not held by AstraZeneca or licensed to Astellas Pharma Inc. (“Astellas”). Astellas is commercializing roxadustat (EVRENZOTM) in Europe and Japan to treat anemia under two development and commercialization license agreements: one for Japan, and one for Europe, the Commonwealth of Independent States, the Middle East and South Africa.

Current wording

Kyntra Bio has retained the rights to roxadustat in the United States of America (“U.S.”), Canada, Mexico, and in all markets not held by AstraZeneca or licensed to Astellas Pharma Inc. (“Astellas”). Astellas is commercializing roxadustat (EVRENZOTM) in Europe and Japan to treat anemia under two development and commercialization license agreements: one for Japan, and one for Europe, the Commonwealth of Independent States, the Middle East and South Africa.

Previous wording

We continue to evaluate a development plan for roxadustat in anemia associated with lower-risk myelodysplastic syndrome, a high-value indication with significant unmet medical need.

Current wording

We continue to advance our development plan for roxadustat in anemia associated with lower-risk myelodysplastic syndromes (“MDS”), a high-value indication with significant unmet medical need. We had a positive Type-C meeting with the U.S. Food and Drug Administration (“FDA”) in July 2025 and reached alignment on several elements of our proposed Phase 3 study design for roxadustat in anemia associated with lower-risk MDS, including the starting dose and the patient inclusion criteria. We are starting preparations for the Phase 3 trial, while evaluating internal development and potential partnership opportunities for this late-stage program. We submitted the Phase 3 trial protocol for roxadustat for the treatment of anemia in patients with lower-risk MDS and high transfusion burden to the FDA in December 2025.

Previous wording

$25.7 million cumulative catch-up net adjustment in the drug product revenue, as a result of terminating the AstraZeneca U.S./RoW Agreement (as defined below), effective as of February 25, 2024 (“AstraZeneca Termination and Transition Agreement”), with the exception of South Korea.

Current wording

$25.7 million cumulative catch-up net adjustment in the drug product revenue, as a result of terminating the AstraZeneca U.S./RoW Agreement (as defined below), effective as of February 25, 2024 as amended and restated on August 29, 2025 (“AstraZeneca Termination and Transition Agreement”), with the exception of South Korea.

Previous wording

$2.0 million of drug product revenue related to active pharmaceutical ingredient (“API”) deliveries to Astellas; and

Current wording

$2.0 million of drug product revenue related to API deliveries to Astellas; and

Previous wording

Total operating costs and expenses decreased $189.5 million for the year ended December 31, 2024 compared to the prior year as a result of the net effect of the following:

Current wording

Total operating costs and expenses decreased $127.7 million for the year ended December 31, 2025 compared to the prior year as a result of the net effect of the following:

Previous wording

$51.5 million lower employee-related expenses primarily due to the impact from reduction in force actions in August 2024 and July 2023, and cost control efforts;

Current wording

$25.8 million lower employee-related expenses primarily due to the impact from reduction in force actions in August 2024 and July 2023, and cost control efforts;

Previous wording

$16.7 million lower facilities-related expenses due to cost control efforts and lower depreciation expense as certain property and equipment reached their useful lives in prior year period, offset by the loss on disposal of property and equipment associated with efforts to streamline operations;

Current wording

$23.8 million lower facilities-related expenses due to cost control efforts and lower depreciation expense as certain property and equipment reached their useful lives in prior year period, offset by the loss on disposal of property and equipment associated with efforts to streamline operations;

Previous wording

$6.8 million higher restructuring charge recorded related to the reduction in force plan in August 2024 with larger scale as compared to the reduction in force plan in July 2023.

Current wording

$18.9 million restructuring charge related to the reduction in force plan in August 2024 recorded in prior year, which did not recur in 2025;

Previous wording

$24.9 million lower stock-based compensation primarily resulting from significantly lower stock price and cancellations of stock options and restricted stock units due to reduced headcount;

Current wording

$17.1 million lower stock-based compensation primarily resulting from significantly lower stock price and cancellations of stock options and restricted stock units due to reduced headcount;

Previous wording

$61.4 million lower clinical trial expenses primarily associated with the termination of pamrevlumab programs during the second half of 2024 responding to the topline clinical data results we reported in July 2024;

Current wording

$16.9 million lower clinical trial expenses primarily associated with the termination of pamrevlumab programs during the second half of 2024 responding to the topline clinical data results we reported in July 2024;

Previous wording

$10.0 million lower drug development expenses associated with drug substance activities and logistic expenses related to pamrevlumab programs which were completed and terminated;

Current wording

$8.0 million lower drug development expenses associated with drug substance activities and logistic expenses related to pamrevlumab programs which were completed and terminated.

Previous wording

Our research and development expenses were $95.7 million and $266.5 million for the years ended December 31, 2024 and 2023, respectively. Since inception and through December 31, 2024, we have incurred a total of approximately $3.3 billion in research and development expenses, a majority of which relates to the development of roxadustat, pamrevlumab, FG-3246 and other HIF-PH inhibitors. We expect to continue to incur significant expenses and operating losses over at least the next few years as we continue to make investments in research and development to advance our product candidate portfolio. We consider the active management and development of our clinical pipeline to be particularly crucial to our long-term success. The process of conducting the necessary clinical research to obtain regulatory approval is costly and time consuming. We implemented cost reduction efforts in 2023 and 2024 in connection with our efforts to streamline operations to align with our business goals. As a result, operating expenses have decreased and may continue to decrease in certain areas over time.

Current wording

Our research and development expenses were $23.5 million and $95.7 million for the years ended December 31, 2025 and 2024, respectively. Since inception and through December 31, 2025, we have incurred a total of approximately $3.3 billion in research and development expenses, a majority of which relates to the development of roxadustat, pamrevlumab, FG-3246 and other hypoxia-inducible factor prolyl hydroxylase inhibitors. We expect to incur significant expenses and operating losses over at least the next few years as we continue to make investments in research and development to advance our current product candidate portfolio. We consider the active management and development of our clinical pipeline to be particularly crucial to our long-term success. The process of conducting the necessary clinical research to obtain regulatory approval is costly and time consuming. We implemented cost reduction efforts in 2024 in connection with our efforts to streamline operations to align with our business goals. As a result, operating expenses have decreased and may continue to decrease in certain areas over time.

Previous wording

During the year ended December 31, 2024, we had a loss from continuing operations of $153.1 million or loss from continuing operations per basic and diluted share of $(1.53), as compared to a loss from continuing operations of $323.0 million, or loss from continuing operations per basic and diluted share of $(3.32) for the prior year, primarily due to a decrease in operating costs and expenses, offset by a decrease in revenues.

Current wording

During the year ended December 31, 2025, we had a loss from continuing operations of $58.2 million or loss from continuing operations per basic and diluted share of $14.40, as compared to a loss from continuing operations of $153.1 million, or loss from continuing operations per basic and diluted share of $38.26 for the prior year, primarily due to a decrease in operating costs and expenses, offset by a decrease in revenues.

Previous wording

In 2018, we and Astellas entered into an amendment to the Astellas Japan Agreement that allows Astellas to manufacture roxadustat drug product for commercialization in Japan (the “Astellas Japan Amendment”). The related drug product revenue was ($2.9) million and $15.7 million for the years ended December 31, 2024 and 2023, respectively.

Current wording

In 2018, we and Astellas entered into an amendment to the Astellas Japan Agreement that allows Astellas to manufacture roxadustat drug product for commercialization in Japan (the “Astellas Japan Amendment”). The related drug product revenue was $0.8 million and $(2.9) million for the years ended December 31, 2025 and 2024, respectively.

Previous wording

During the first quarter of 2021, we entered into an EU Supply Agreement with Astellas under the Astellas Europe Agreement to define general forecast, order, supply and payment terms for Astellas to purchase roxadustat bulk drug product from FibroGen in support of commercial supplies (the “Astellas EU Supply Agreement”). The related drug product revenue was $4.9 million and $3.1 million for the years ended December 31, 2024 and 2023, respectively.

Current wording

During the first quarter of 2021, we entered into an EU Supply Agreement with Astellas under the Astellas Europe Agreement to define general forecast, order, supply and payment terms for Astellas to purchase roxadustat bulk drug product from us in support of commercial supplies (the “Astellas EU Supply Agreement”). The related drug product revenue was $5.1 million and $4.9 million for the years ended December 31, 2025 and 2024, respectively.

Previous wording

In July 2013, we entered into a collaboration agreement with AstraZeneca for roxadustat for the treatment of anemia in the U.S. and all territories except for China and those territories previously licensed to Astellas (the “AstraZeneca U.S./RoW Agreement”). In 2020, we entered into a Master Supply Agreement with AstraZeneca under the AstraZeneca U.S./RoW Agreement (the “AstraZeneca Master Supply Agreement”) to define general forecast, order, supply and payment terms for AstraZeneca to purchase roxadustat bulk drug product from FibroGen in support of commercial supplies.

Current wording

In July 2013, we entered into a collaboration agreement with AstraZeneca for roxadustat for the treatment of anemia in the U.S. and all territories except for China and those territories previously licensed to Astellas (the “AstraZeneca U.S./RoW Agreement”). In 2020, we entered into a Master Supply Agreement with AstraZeneca under the AstraZeneca U.S./RoW Agreement (the “AstraZeneca Master Supply Agreement”) to define general forecast, order, supply and payment terms for AstraZeneca to purchase roxadustat bulk drug product from Kyntra Bio in support of commercial supplies.

Previous wording

On February 23, 2024, we entered into an agreement to terminate the AstraZeneca U.S./RoW Agreement with AstraZeneca, effective as of February 25, 2024. Pursuant to the AstraZeneca Termination and Transition Agreement, AstraZeneca returns all of their non-China roxadustat rights to us, with the exception of South Korea, and provides certain assistance during a transition period. In addition, as a part of this AstraZeneca Termination and Transition Agreement, AstraZeneca will receive tiered mid-single digit royalties on FibroGen’s sales of roxadustat in the terminated territories, or thirty-five percent of all revenue FibroGen receives if it licenses or sells such rights to a third-party. Neither party incurred any early termination penalties. The aggregate amount of consideration for milestone and upfront payments received under the AstraZeneca U.S./RoW Agreement through the termination totaled $439.0 million. In addition, resulting from the AstraZeneca Termination and Transition Agreement, FibroGen and AstraZeneca settled the outstanding balances relating to past transactions under the AstraZeneca Master Supply Agreement. Accordingly, during the first quarter of 2024, we recorded a cumulative catch-up net adjustment of $25.7 million to the drug product revenue.

Current wording

In February 2024, we entered into an agreement to terminate the AstraZeneca U.S./RoW Agreement with AstraZeneca, as amended and restated on August 29, 2025. Pursuant to the AstraZeneca Termination and Transition Agreement, AstraZeneca returns all of their non-China roxadustat rights to us, with the exception of South Korea, and provides certain assistance during a transition period. In addition, as a part of this AstraZeneca Termination and Transition Agreement, AstraZeneca will receive tiered mid-single digit royalties on Kyntra Bio’s sales of roxadustat in the terminated territories, or thirty-five percent of all revenue Kyntra Bio receives if it licenses or sells such rights to a third-party. Neither party incurred any early termination penalties. The aggregate amount of consideration for milestone and upfront payments received under the AstraZeneca U.S./RoW Agreement through the termination totaled $439.0 million. In addition, resulting from the AstraZeneca Termination and Transition Agreement, Kyntra Bio and AstraZeneca settled the outstanding balances relating to past transactions under the AstraZeneca Master Supply Agreement. Accordingly, during the first quarter of 2024, we recorded a cumulative catch-up net adjustment of $25.7 million to the drug product revenue.

Previous wording

We account for our investment in Falikang under the equity method, and Falikang is not consolidated into our consolidated financial statements. Our proportionate share of the reported profits or losses of Falikang, is included in the discontinued operations in the consolidated statement of operations, and the investment in unconsolidated subsidiary is included the held for sale assets in the consolidated balance sheet. See Note 3, Discontinued Operations, to the consolidated financial statements for details.

Current wording

We accounted for our investment in Falikang under the equity method, and Falikang was not consolidated into our consolidated financial statements. Our proportionate share of the reported profits or losses of Falikang, was included in the discontinued operations in the consolidated statement of operations, and the investment in unconsolidated subsidiary is included the held for sale assets in the consolidated balance sheet as of December 31, 2024. See Note 3, Discontinued Operations and Divestiture, to the consolidated financial statements for details.

Previous wording

Product revenue, net, which is included in the discontinued operations, consists primarily of revenues from sales of roxadustat commercial product to Falikang. Falikang is jointly owned by AstraZeneca and FibroGen Beijing.

Current wording

Product revenue, net, which was included in the discontinued operations, consisted primarily of revenues from sales of roxadustat commercial product to Falikang.

Previous wording

Product revenue, net, which is included in the discontinued operations, consists primarily of revenues from sales of roxadustat commercial product to Falikang. Substantially all direct roxadustat product sales to distributors in China are made by Falikang, while FibroGen Beijing continues to sell roxadustat product directly in one province in China. FibroGen Beijing manufactures and supplies commercial product to Falikang. The net transaction price for FibroGen Beijing’s product sales to Falikang is based on a gross transaction price, adjusted for the estimated profit share.

Current wording

Substantially all direct roxadustat product sales to distributors in China were made by Falikang, while FibroGen Beijing continues to sell roxadustat product directly in limited areas in China. FibroGen Beijing manufactures and supplies commercial product to Falikang, based on a gross transaction price, adjusted for the estimated profit share.

Previous wording

We recognize revenue upon the transfer of control of commercial products to Falikang in an amount that reflects the allocation of transaction price of the China manufacturing and supply obligation (“China performance obligation”) to the performance obligation satisfied during the reporting period. For our direct sales of commercial drug product, we recognize revenue when control of the promised good is transferred to the customer in an amount that reflects the consideration that we expect to be entitled to in exchange for the product. During the years ended December 31, 2024 and 2023, included in the discontinued operations, we recognized $159.0 million and $89.1 million of net product revenue from the sales to Falikang, and $14.7 million and $11.9 million of net product revenue from sales directly to distributors in one province in China, respectively.

Current wording

We recognized revenue upon the transfer of control of commercial products to Falikang in an amount that reflected the allocation of transaction price of the China manufacturing and supply obligation (“China Performance Obligation”) to the performance obligation satisfied during the reporting period. For our direct sales of commercial drug product, we recognized revenue when control of the promised good was transferred to the customer in an amount that reflected the consideration that we expected to be entitled to in exchange for the product. As discussed in Note 3, Discontinued Operations and Divestiture, to the consolidated financial statements, the divestiture of FibroGen International was completed on August 29, 2025 and accordingly, the performance obligation to AstraZeneca was completely satisfied upon the closing of the divestiture. As a result, all the previously deferred revenues were recognized as revenue during the third quarter of 2025. During the years ended December 31, 2025 and 2024, included in the discontinued operations, we recognized $218.6 million and $159.0 million of net product revenue from the sales to Falikang, and $8.1 million and $14.7 million of net product revenue from sales directly to distributors in one province in China, respectively.

Previous wording

In April 2023, FibroGen and Eluminex entered into an Amended and Restated Exclusive License Agreement (“A&R Eluminex Agreement”) in order to add to the license rights to recombinant human collagen Type I (in addition to the rights to collagen Type III that were already licensed).

Current wording

In April 2023, we entered into an Amended and Restated Exclusive License Agreement with Eluminex (“A&R Eluminex Agreement”) in order to add to the license rights to recombinant human collagen Type I (in addition to the rights to collagen Type III that were already licensed).

Previous wording

Development revenue includes co-development and other development related services. We recognize development services as revenue in the period in which they are billed to our partners, excluding China. As of December 31, 2024, we do not expect to incur significant future co-development services. For China co-development services, we defer revenue until we begin to transfer control of the manufactured commercial product to AstraZeneca, which commenced in the first quarter of 2021 and we expect to continue through 2033, which reflects our best estimates. Other revenues consist of contract manufacturing revenue, patent transfer and sales of research and development material, which have not been material for any of the periods presented. Development and other revenues represented 7% and 39% of total revenues for the years ended December 31, 2024 and 2023, respectively.

Current wording

Under our revenue recognition policy, development revenue includes co-development and other development related services. We recognize development services as revenue in the period in which they are billed to our partners, excluding China. As of December 31, 2025, we do not expect to incur significant future co-development services. Other revenues consist of contract manufacturing revenue, patent transfer and sales of research and development material, which have not been material for any of the periods presented. Development and other revenues represented 9% and 7% of total revenues for the years ended December 31, 2025 and 2024, respectively.

Previous wording

Drug product revenue includes commercial-grade API or bulk drug product sales to AstraZeneca, under the AstraZeneca U.S./RoW Agreement, and Astellas in support of pre-commercial preparation prior to the New Drug Application or marketing authorization application approval, and to Astellas for ongoing commercial activities in Japan and Europe. We recognize drug product revenue when we fulfill the inventory transfer obligations. The amount of variable consideration that is included in the transaction price may be constrained, and is included in the drug product revenue only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period when the uncertainty associated with the variable consideration is subsequently resolved. Actual amounts of consideration ultimately received in the future may differ from our estimates, for which we will adjust these estimates and affect the drug product revenue in the period such variances become known. Drug product revenues represented 93% and 40% of total revenues for the years ended December 31, 2024 and 2023, respectively.

Current wording

Drug product revenue includes commercial-grade API or bulk drug product sales to AstraZeneca, under the AstraZeneca U.S./RoW Agreement, and Astellas in support of pre-commercial preparation prior to the new drug application or marketing authorization application approval, and to Astellas for ongoing commercial activities in Japan and Europe. We recognize drug product revenue when we fulfill the inventory transfer obligations. The amount of variable consideration that is included in the transaction price may be constrained, and is included in the drug product revenue only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period when the uncertainty associated with the variable consideration is subsequently resolved. Actual amounts of consideration ultimately received in the future may differ from our estimates, for which we will adjust these estimates and affect the drug product revenue in the period such variances become known. Drug product revenues represented 91% and 93% of total revenues for the years ended December 31, 2025 and 2024, respectively.

Previous wording

The AstraZeneca U.S./RoW Agreement was terminated on February 23, 2024 (except for South Korea), while the AstraZeneca China Agreement and relationship continue unaffected. In the future, we will continue generating revenue from collaboration agreements in the form of milestone payments and royalties on drug product sales. We expect that any revenues we generate will fluctuate from quarter to quarter due to the uncertain timing and amount of such payments and sales.

Current wording

The AstraZeneca U.S./RoW Agreement was terminated on February 25, 2024 (except for South Korea). On August 29, 2025, we closed the sale of our China operations through FibroGen International to AstraZeneca Treasury Limited pursuant to the Share Purchase Agreement. For additional details, refer to Note 3, Discontinued Operations and Divestiture, to the consolidated financial statements. In the future, we will continue generating revenue from collaboration agreements in the form of milestone payments and royalties on drug product sales. We expect that any revenues we generate will fluctuate from quarter to quarter due to the uncertain timing and amount of such payments and sales.

Previous wording

Total revenue decreased $17.2 million or 37% for the year ended December 31, 2024 compared to the year ended December 31, 2023 for the reasons discussed in the sections below.

Current wording

Total revenue decreased $23.2 million or 78% for the year ended December 31, 2025 compared to the year ended December 31, 2024 for the reasons discussed in the sections below.

Previous wording

Development revenue recognized under our collaboration agreements with Astellas for the year ended December 31, 2024 was impacted by the decrease in co-development billings due to the closeout activities under our collaboration agreements with Astellas for roxadustat.

Current wording

Development and other revenue decreased $1.4 million, or 70% for the year ended December 31, 2025 compared to the year ended December 31, 2024, mainly due to the decrease in co-development billings resulting from the closeout activities under our collaboration agreements with Astellas for roxadustat.

Previous wording

During the second quarter of 2023, we fulfilled two shipment obligations under the terms of Astellas Japan Amendment, and recognized related drug product revenue of $14.4 million in the same period. In addition, we updated our estimate of variable consideration related to the API shipments fulfilled under the terms of Astellas Japan Amendment and accordingly recorded an adjustment to the drug product revenue of $1.3 million for the year ended December 31, 2023. Specifically, the change in estimated variable consideration was based on the API held by Astellas at period end, adjusted to reflect the changes in the estimated bulk product strength mix intended to be manufactured by Astellas, foreign exchange impacts and estimated yield from the manufacture of bulk product tablets, among others.

Current wording

We updated our estimate of variable consideration related to the API shipments fulfilled under the terms of Astellas Japan Amendment and accordingly recorded an adjustment to the drug product revenue of $0.8 million for the year ended December 31, 2025. Specifically, the change in estimated variable consideration was based on the API held by Astellas at period end, adjusted to reflect the changes in the estimated bulk product strength mix intended to be manufactured by Astellas and foreign exchange impacts, among others.

Previous wording

As of December 31, 2024, the balances related to the API price true-up under the Astellas Japan Agreement were $2.5 million in accrued liabilities and $0.6 million in other long-term liabilities, representing the Company’s best estimate of the timing for these amounts to be paid. As of December 31, 2023, the related balances were $1.2 million in accrued liabilities and $0.7 million in other long-term liabilities.

Current wording

As of December 31, 2025, the balances related to the API price true-up under the Astellas Japan Agreement were $1.6 million in accrued liabilities, representing our best estimate of the timing for these amounts to be paid. As of December 31, 2024, the related balances were $2.5 million in accrued liabilities and $0.6 million in other long-term liabilities.

Previous wording

During the fourth quarter of 2024, we transferred bulk drug product for commercial purposes under the terms of the Astellas Europe Agreement and the Astellas EU Supply Agreement, and recognized the related fully-burdened manufacturing costs of $0.6 million as drug product revenue, and recorded $4.4 million as deferred revenue due to a high degree of uncertainty associated with the variable consideration for revenue recognition purposes. In addition, we updated our estimate of variable consideration related to the bulk drug product transferred in prior years. Specifically, the change in estimated variable consideration was based on the bulk drug product held by Astellas at the period end, adjusted to reflect the changes in the estimated transfer price, forecast information, shelf-life estimates and other items. As a result, for the year ended December 31, 2024, we reclassified $7.2 million from the related deferred revenue to accrued liabilities. As of December 31, 2024, the related balance in accrued liabilities was $10.5 million, representing our best estimate that this amount will be paid within the next 12 months.

Current wording

During the fourth quarter of 2025, we transferred bulk drug product for commercial purposes under the terms of the Astellas Europe Agreement and the Astellas EU Supply Agreement, and recognized the related fully-burdened manufacturing costs of $0.3 million as drug product revenue, and recorded $2.2 million as deferred revenue due to a high degree of uncertainty associated with the variable consideration for revenue recognition purposes. In addition, we updated our estimate of variable consideration related to the bulk drug product transferred in prior years. Specifically, the change in estimated variable consideration was based on the bulk drug product held by Astellas at the period end, adjusted to reflect the changes in the estimated transfer price, forecast information, shelf-life estimates and other items. As a result, for the year ended December 31, 2025, we reclassified $1.8 million from the related deferred revenue to accrued liabilities. As of December 31, 2025, the related balance in accrued liabilities was $5.4 million, representing our best estimate that this amount will be paid within the next 12 months.

Previous wording

During the fourth quarter of 2023, we transferred bulk drug product for commercial purposes under the terms of the Astellas Europe Agreement and the Astellas EU Supply Agreement, and recognized the related fully-burdened manufacturing costs of $0.8 million as drug product revenue, and recorded $17.7 million as deferred revenue due to a high degree of uncertainty associated with the variable consideration for revenue recognition purposes. In addition, we updated our estimate of variable consideration related to the bulk drug product transferred in prior years. Specifically, the change in estimated variable consideration was based on the bulk drug product held by Astellas at the period end, adjusted to reflect the changes in the estimated transfer price, forecast information, shelf-life estimates and other items. As a result, for the year ended December 31, 2023, we reclassified $38.7 million from the related deferred revenue to accrued liabilities. As of December 31, 2023, the related balance in accrued liabilities was $38.6 million, and we paid $35.3 million to Astellas during the year ended December 31, 2024.

Current wording

During the fourth quarter of 2024, we transferred bulk drug product for commercial purposes under the terms of the Astellas Europe Agreement and the Astellas EU Supply Agreement, and recognized the related fully-burdened manufacturing costs of $0.6 million as drug product revenue, and recorded $4.4 million as deferred revenue due to a high degree of uncertainty associated with the variable consideration for revenue recognition purposes. In addition, we updated our estimate of variable consideration related to the bulk drug product transferred in prior years. Specifically, the change in estimated variable consideration was based on the bulk drug product held by Astellas at the period end, adjusted to reflect the changes in the estimated transfer price, forecast information, shelf-life estimates and other items. As a result, for the year ended December 31, 2024, we reclassified $7.2 million from the related deferred revenue to accrued liabilities. As of December 31, 2024, the related balance in accrued liabilities was $10.5 million, and we paid $7.1 million to Astellas during the year ended December 31, 2025.

Previous wording

In addition, we recognized royalty revenue of $4.3 million and $2.3 million as drug product revenue from the deferred revenue under the Astellas Europe Agreement for the years ended December 31, 2024 and 2023, respectively. The remainder of the deferred revenue will be recognized as and when uncertainty is resolved, based on the performance of roxadustat product sales in the Astellas territory.

Current wording

In addition, we recognized royalty revenue of $4.8 million and $4.3 million as drug product revenue from the deferred revenue under the Astellas Europe Agreement for the years ended December 31, 2025 and 2024, respectively. The remainder of the deferred revenue will be recognized as and when uncertainty is resolved, based on the performance of roxadustat product sales in the Astellas territory.

Previous wording

As described above, pursuant to the AstraZeneca Termination and Transition Agreement related to the AstraZeneca U.S./RoW Agreement, FibroGen and AstraZeneca settled the outstanding balances relating to past transactions under the AstraZeneca Master Supply Agreement. Accordingly, during the first quarter of 2024, we accounted for the termination of the AstraZeneca U.S./RoW agreement as a contract modification under the ASC 606 and recorded a cumulative catch-up net adjustment of $25.7 million to the drug product revenue, and received the cash during the second quarter of 2024. In addition, the related accrued liabilities of $11.2 million as of December 31, 2023 was settled during the second quarter of 2024.

Current wording

As described above, pursuant to the AstraZeneca Termination and Transition Agreement related to the AstraZeneca U.S./RoW Agreement, Kyntra Bio and AstraZeneca settled the outstanding balances relating to past transactions under the AstraZeneca Master Supply Agreement. Accordingly, during the first quarter of 2024, we accounted for the termination of the AstraZeneca U.S./RoW Agreement as a contract modification under the ASC 606 and recorded a cumulative catch-up net adjustment of $25.7 million to the drug product revenue.

Previous wording

Total operating expenses decreased $189.5 million, or 51% for the year ended December 31, 2024 compared to the year ended December 31, 2023, for the reasons discussed in the sections below.

Current wording

Total operating expenses decreased $127.7 million, or 71% for the year ended December 31, 2025 compared to the year ended December 31, 2024, for the reasons discussed in the sections below.

Previous wording

Cost of goods sold associated with the roxadustat drug product revenue in the U.S. was $0.8 million and $3.1 million for the years ended December 31, 2024 and 2023, respectively, associated with the costs of API or bulk drug product delivered to Astellas and AstraZeneca in the respective periods.

Current wording

Cost of goods sold associated with the roxadustat drug product revenue in the U.S. was $0.3 million and $0.8 million for the years ended December 31, 2025 and 2024, respectively, associated with the costs of API or bulk drug product delivered to Astellas and AstraZeneca in the respective periods.

Previous wording

Research and development expenses consist of third-party research and development costs and the fully-burdened amount of costs associated with work performed under collaboration agreements. Research and development expenses include employee-related expenses for research and development functions, expenses incurred under agreements with clinical research organizations, other clinical and preclinical costs and allocated direct and indirect overhead costs, such as facilities costs, information technology costs and other overhead. We expense research and development costs as incurred. We recognize costs for certain development activities based on an evaluation of the progress to completion of specific tasks using information and data provided to us by our vendors and our clinical sites. Research and development expenses also include in-process research and development (“IPR&D”) assets that have no alternative future use other than in a particular research and development project. We have implemented a significant cost reduction plan in the U.S. in the third quarter of 2024, and efforts to streamline operations to align with our business goals in the second half of 2023. As a result, research and development expenses have overall decreased and may continue to decrease in certain areas over time.

Current wording

Research and development expenses consist of independent research and development costs and the gross amount of costs associated with work performed under collaboration agreements. Research and development expenses include employee-related expenses for research and development functions, expenses incurred under agreements with clinical research organizations, other clinical and preclinical costs and allocated direct and indirect overhead costs, such as facilities costs, information technology costs and other overhead. We expense research and development costs as incurred. We recognize costs for certain development activities based on an evaluation of the progress to completion of specific tasks using information and data provided to us by our vendors and our clinical sites. We have implemented a significant cost reduction plan in the U.S. in the third quarter of 2024. As a result, research and development expenses have overall decreased and may continue to decrease in certain areas over time.