FOR-46

Total consideration for the sale of FibroGen China to AstraZeneca now expected to be approximately $185 million, a $25 million increase from initial guidance Net cash held in China at closing now estimated to be approximately $100 million Transaction expected to close in 3Q 2025 Net cash held in China at closing now estimated to be approximately $100 million Transaction expected to close in 3Q 2025 Upon close of sale of FibroGen China, cash runway extended into 2H 2027 Initiation of the Phase 2 monotherapy trial of FG-3246, a potential first-in-class antibody-drug conjugate (ADC) targeting CD46 in metastatic castration-resistant prostate cancer (mCRPC), expected in 3Q 2025 Topline results from Phase 2 portion of the investigator-sponsored study of FG-3246 in combination with enzalutamide in patients with mCRPC expected in 4Q 2025 Filed Type-C meeting request with FDA for roxadustat in anemia associated with lower-risk myelodysplastic syndromes (LR-MDS) Expect feedback on potential path forward in 3Q 2025 Expect feedback on potential path forward in 3Q 2025 SAN FRANCISCO, May 12, 2025 (GLOBE NEWSWIRE) -- FibroGen, Inc. (NASDAQ: FGEN) today reported financial results for the first quarter 2025 and provided an update on the company’s recent developments. “We continue to focus on our most important strategic priority of advancing our lead asset, FG-3246, with the initiation of the Phase 2 monotherapy dose optimization study in mCRPC, expected to start in the third quarter of 2025,” said Thane Wettig, Chief Executive Officer, FibroGen. “In addition, we have filed a Type C meeting request with the FDA to discuss the potential Phase 3 development program for roxadustat in the treatment of anemia associated with LR-MDS, an indication with significant unmet medical need. As we look to finalize the sale of FibroGen China in the third quarter of 2025, we remain highly focused on driving significant shareholder value by supporting our US development initiatives with our strong balance sheet and extended cash runway into the second half of 2027.” Recent Developments and Key Highlights of First Quarter 2025: Sale of FibroGen China to AstraZeneca now expected to be for a total consideration of approximately $185 million, representing an enterprise value of $85 million plus estimated net cash held in China at closing of approximately $100 million. The transaction is expected to close in the third quarter of 2025. Upon closing, FibroGen will repay its term loan to Morgan Stanley Tactical Value, further simplifying the Company’s capital structure. FibroGen maintains its rights to roxadustat in the U.S. and in all markets outside of China, South Korea, and those licensed to Astellas. Publication of results from Phase 1 Monotherapy Study of FG-3246 titled, “A Phase 1, First-in-Human Study of FOR46 (FG-3246), an Immune-Modulating Antibody-Drug Conjugate Targeting CD46, in Patients with Metastatic Castration Resistant Prostate Cancer", in the peer-reviewed Journal of Clinical Oncology (JCO). The trial results provide key insights into the clinical impact of targeting CD46 and its potential to become the next generation target in the prostate cancer treatment paradigm. Upon closing, FibroGen will repay its term loan to Morgan Stanley Tactical Value, further simplifying the Company’s capital structure. FibroGen maintains its rights to roxadustat in the U.S. and in all markets outside of China, South Korea, and those licensed to Astellas. Upcoming Milestones: FG-3246 (CD46 Targeting ADC) and FG-3180 (CD46 Targeting PET Imaging Agent) Anticipate initiation of Phase 2 monotherapy dose optimization study of FG-3246 in mCRPC in the third quarter of 2025. Phase 2 trial will include FG-3180 to enable assessment of its diagnostic performance and the potential correlation between CD46 expression and response to FG-3246. Topline results from the Phase 2 portion of the investigator-sponsored Phase 1b/2 study conducted by UCSF of FG-3246 in combination with enzalutamide in patients with mCRPC expected in the fourth quarter of 2025. Phase 2 portion of the study will include data on FG-3180. Phase 2 trial will include FG-3180 to enable assessment of its diagnostic performance and the potential correlation between CD46 expression and response to FG-3246. Phase 2 portion of the study will include data on FG-3180. Roxadustat Filed a Type-C meeting request with the FDA for roxadustat in anemia associated with LR-MDS. The Company expects feedback on a potential path forward in the third quarter of 2025. Financial: Total revenue from continuing operations for the first quarter of 2025 was $2.7 million, as compared to $25.4 million for the first quarter of 2024. Net loss from continuing operations for the first quarter of 2025 was $16.8 million, or $0.16 net loss per basic and diluted share, compared to a net loss of $49.0 million, or $0.49 net loss per basic and diluted share, one year ago. At March 31, 2025, FibroGen reported $33.8 million in cash, cash equivalents and accounts receivable in the U.S. and $128.4 million in total consolidated cash, cash equivalents and accounts receivable. Upon closing of the announced sale of FibroGen China, the Company expects its cash, cash equivalents and accounts receivable to be sufficient to fund our operating plans into the second half of 2027. Conference Call and Webcast Presentation The FibroGen management team will host a conference call and webcast presentation to discuss the financial results and provide a business update. A live Q&A session will follow the brief presentation. Interested parties may access a live audio webcast of the conference call here. To access the call by phone, please register here, and you will be provided with dial in details. A replay of the webcast will also be available for a limited time on the Events & Presentations page on FibroGen’s website. About FG-3246 FG-3246 (FOR46) is a potential first-in-class fully human antibody-drug conjugate (ADC), exclusively in-licensed from Fortis Therapeutics, and is being developed by FibroGen for metastatic castration-resistant prostate cancer and potentially other tumor types. FG-3246 binds to an epitope of CD46, a cell receptor target, that induces internalization upon antibody binding, is present at high levels in prostate cancer and other tumor types and demonstrates very limited expression in most normal tissues. FG-3246 is comprised of an anti-CD46 antibody, YS5, linked to the anti-mitotic agent, MMAE, which is a clinically and commercially validated ADC payload. FG-3246 has demonstrated anti-tumor activity in both preclinical and clinical studies. FG-3246 is currently in an ongoing Phase 1b/2 study being conducted at UCSF as an investigator-sponsored trial to evaluate FG-3246 in combination with enzalutamide. An additional investigator-sponsored radiopharmaceutical marker trial using a zirconium-89 positron emission tomography (PET) tracer for CD46 that utilizes the YS5 antibody is also underway at UCSF. The initiation of the Phase 2 monotherapy dose optimization trial for FG-3246 in metastatic castration-resistant prostate cancer is anticipated in the third quarter of 2025. FG-3246 is an investigational drug and not approved for marketing by any regulatory authority. About Roxadustat Roxadustat, an oral medication, is the first in a new class of medicines comprising HIF-PH inhibitors that promote erythropoiesis, or red blood cell production, through increased endogenous production of erythropoietin, improved iron absorption and mobilization, and downregulation of hepcidin. Roxadustat is in clinical development for chemotherapy-induced anemia (CIA) and a Supplemental New Drug Application (sNDA) has been accepted by the China Health Authority. Roxadustat is approved in China, Europe, Japan, and numerous other countries for the treatment of anemia of CKD in adult patients on dialysis (DD) and not on dialysis (NDD). FibroGen has the sole rights to roxadustat in the United States, Canada, Mexico, and in all markets not held by AstraZeneca or licensed to Astellas. Astellas and FibroGen are collaborating on the commercialization of roxadustat for the treatment of anemia in territories including Japan, Europe, Turkey, Russia, and the Commonwealth of Independent States, the Middle East, and South Africa. About FibroGen FibroGen, Inc. is a biopharmaceutical company focused on development of novel therapies at the frontiers of cancer biology and anemia. Roxadustat (爱瑞卓®, EVRENZOTM) is currently approved in China, Europe, Japan, and numerous other countries for the treatment of anemia in chronic kidney disease (CKD) patients on dialysis and not on dialysis. The Company continues to evaluate a development plan for roxadustat in anemia associated with lower-risk myelodysplastic syndrome (LR-MDS) in the U.S. FG-3246 (also known as FOR46), a first-in-class antibody-drug conjugate (ADC) targeting CD46 is in development for the treatment of metastatic castration-resistant prostate cancer. This program also includes the development of FG-3180, an associated CD46-targeted PET biomarker. For more information, please visit www.fibrogen.com. Forward-Looking Statements This release contains forward-looking statements regarding FibroGen’s strategy, future plans and prospects, including statements regarding its commercial products and clinical programs and those of its collaboration partners Fortis and UCSF. These forward-looking statements include, but are not limited to, statements regarding the efficacy, safety, and potential clinical or commercial success of FibroGen products and product candidates, statements under the caption “Upcoming Milestones”, statements about regulatory interactions, the net cash portion of the purchase price and closing of the sale of FibroGen China as well as the payoff of the Morgan Stanley Tactical Value term loan, statements regarding cash, such as the expectation that cash, cash equivalents and accounts receivable will be sufficient to fund FibroGen’s operating plans into the second half of 2027, and statements about FibroGen’s plans and objectives. These forward-looking statements are typically identified by use of terms such as “may,” “will”, “should,” “on track,” “could,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “continue” and similar words, although some forward-looking statements are expressed differently. FibroGen’s actual results may differ materially from those indicated in these forward-looking statements due to risks and uncertainties related to the continued progress and timing of its various programs, including the enrollment and results from ongoing and potential future clinical trials, and other matters that are described in FibroGen’s most recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q, each as filed with the Securities and Exchange Commission (SEC), including the risk factors set forth therein. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release, and FibroGen undertakes no obligation to update any forward-looking statement in this press release, except as required by law. (1) The condensed consolidated balance sheet amounts at December 31, 2024 are derived from audited financial statements. For Investor Inquiries: David DeLucia, CFA Senior Vice President and Chief Financial Officer ir@fibrogen.com Source: FibroGen, Inc.

FG-3246 showed encouraging anti-cancer activity with an acceptable safety profile in patients with metastatic castration-resistant prostate cancer Initiation of Phase 2 monotherapy dose optimization study of FG-3246 in mCRPC expected by mid-2025 SAN FRANCISCO, March 28, 2025 (GLOBE NEWSWIRE) -- FibroGen, Inc. (NASDAQ: FGEN) today announced the peer-reviewed publication titled “A Phase 1, First-in-Human Study of FOR46 (FG-3246), an Immune-Modulating Antibody-Drug Conjugate Targeting CD46, in Patients with Metastatic Castration Resistant Prostate Cancer” in the Journal of Clinical Oncology. The manuscript includes the complete results from the Fortis Therapeutics-sponsored Phase 1 study of FOR46 (now known as FG-3246), a potential first-in-class anti-CD46 antibody drug conjugate (ADC) with an MMAE-containing payload, in patients with metastatic castration-resistant prostate cancer (mCRPC). “I am excited to see the results from the Phase 1 monotherapy study of FOR46 (FG-3246) published in the Journal of Clinical Oncology. This is the first clinical trial targeting CD46 in patients with prostate cancer, and the totality of the data highlights the promising potential of FG-3246 anti-cancer activity, especially when considering the unselected, heavily pre-treated patient population in the trial. The trial results provide key insights into the potential clinical impact of targeting CD46 in the treatment of mCRPC and support its further development in this disease space with high unmet need,” said Dr. Rahul Aggarwal, Professor of Medicine at the University of California San Francisco, and Principal Investigator of the study. “We are looking forward to advancing FG-3246 in the clinic and remain on track for initiating the Phase 2 monotherapy study by mid-2025 as well as disclosing topline results from the combination trial of FG-3246 and enzalutamide in the second half of 2025,” added Thane Wettig, Chief Executive Officer of FibroGen. “FG-3246 represents a potential first-in-class, non-PSMA approach to treating mCRPC and we, along with the medical community, are excited about the potential for CD46 to become a next generation target in the prostate cancer treatment paradigm.” This Phase 1 study was a multi-center, first-in-human, open label dose escalation and expansion study evaluating the safety, tolerability, and anti-tumor activity as measured by the decline of prostate-specific antigen (PSA) from baseline, objective tumor response rate in patients with measurable disease, and radiographic progression free survival (rPFS). The completed Phase 1 trial includes a total of 56 patients from the dose-escalation and dose-expansion cohorts. Notably, patients were biomarker unselected and heavily pre-treated, having received a median of 5 lines of therapy prior to receiving FG-3246. Key highlights from the publication include: The maximally tolerated dose of FG-3246 was 2.7 mg/kg by adjusted body weight (AjBW) every 3 weeks The most frequent adverse events were consistent with other MMAE-based ADCs and included infusion related reactions (48.2%), neutropenia (41.1%), and peripheral neuropathy (32.1%). Ocular adverse events were infrequent, which may be a distinguishing feature compared with other MMAE-based ADCs Efficacy observed in the RECIST-evaluable set of 25 patients: Confirmed objective response rate was 20% with median duration of response of 7.5 months All objective responses observed at a starting dose of 2.7 mg/kg or higher Disease control rate was 80% with duration of treatment exceeding 24 weeks in 12 patients (48%) PSA50 response rate of 36% in 39 evaluable patients Of eight evaluable patients who received docetaxel in the castration-sensitive setting, four (50%) achieved a confirmed PSA50 response Median radiographic progression-free survival of 8.7 months in all 40 subjects in the efficacy analysis set Of 15 evaluable baseline tumors, 12 (80%) were positive for CD46 expression by immunohistochemistry FG-3246 responders were found to have a significantly higher frequency of effector T cells and lower frequency of immunosuppressive myeloid cells Ocular adverse events were infrequent, which may be a distinguishing feature compared with other MMAE-based ADCs Confirmed objective response rate was 20% with median duration of response of 7.5 months All objective responses observed at a starting dose of 2.7 mg/kg or higher Disease control rate was 80% with duration of treatment exceeding 24 weeks in 12 patients (48%) All objective responses observed at a starting dose of 2.7 mg/kg or higher Of eight evaluable patients who received docetaxel in the castration-sensitive setting, four (50%) achieved a confirmed PSA50 response The Company anticipates initiating the Phase 2 monotherapy dose optimization study of FG-3246 in patients with mCRPC by mid-2025. FG-3246 is also being evaluated in combination with enzalutamide in an investigator-sponsored study with topline results from the Phase 2 portion of the study anticipated in 2H 2025. About the Phase 1 Study FOR46-001 (NCT03575819) is a Phase 1, dose-escalation study sponsored by Fortis Therapeutics to evaluate multiple doses of IV-administered FG-3246 (also known as FOR46) in patients with mCRPC who have progressive disease on at least one ARSI, followed by a dose-expansion cohort, to evaluate the safety, tolerability, PK, biological activity, and preliminary evidence of anti-tumor activity of FG-3246 in this patient population. Thirty-three (33) patients were enrolled in the dose-escalation phase of the study at doses between 0.1 mg/kg and 3.0 mg/kg every three weeks (Q3W), with adjusted body weight dosing (AjBW) used at most dose levels above 2.1 mg/kg. Safety and tolerability of FG-3246 were evaluated in the dose-escalation period of the study. Twenty-three (23) patients were enrolled in the dose-expansion period of the study; 18 patients with adenocarcinoma mCRPC (Cohort 1) and five patients with neuroendocrine prostate cancer (Cohort 2). All patients in the expansion cohorts were treated at 2.7 mg/kg AjBW to a maximum of 270 mg every three weeks. The safety profile of FG-3246 was characterized, and anti-tumor activity of FG-3246 in adenocarcinoma patients dosed at ≥ 1.2 mg/kg was evaluated. About Metastatic Castration-Resistant Prostate Cancer Prostate cancer is the second most common malignancy in men, contributing significantly to male mortality rates. Approximately 13% of men will be diagnosed with prostate cancer at some point during their lifetime. There are about 65,000 drug treatable mCRPC cases in the U.S. annually and 5-year survival in mCRPC is approximately 30%1. About FG-3246 FG-3246 (also known as FOR46) is a potential first-in-class, fully human antibody-drug conjugate (ADC), exclusively in-licensed from Fortis Therapeutics, and is being developed by FibroGen for metastatic castration-resistant prostate cancer and other tumor types. FG-3246 binds to an epitope of CD46, a cell receptor target, that induces internalization upon antibody binding, is present at high levels in prostate cancer and other tumor types and demonstrates very limited expression in most normal tissues. FG-3246 is comprised of an anti-CD46 antibody, YS5, linked to the anti-mitotic agent, MMAE, which is a clinically and commercially validated ADC payload. FG-3246 has demonstrated anti-tumor activity in both preclinical and clinical studies. FG-3246 is currently in an ongoing Phase 1/2 study being conducted at UCSF to evaluate it in combination with enzalutamide with topline data from the Phase 2 portion of the study expected in the second half of 2025, and a biomarker trial using a PET biomarker for CD46 using the same antibody backbone. We anticipate the initiation of the Phase 2 monotherapy dose optimization trial in metastatic castration-resistant prostate cancer by mid-2025. FG-3246 is an investigational drug and not approved for marketing by any regulatory authority. About FibroGen FibroGen, Inc. is a biopharmaceutical company focused on development of novel therapies at the frontiers of cancer biology and anemia. Roxadustat (爱瑞卓®, EVRENZOTM) is currently approved in China, Europe, Japan, and numerous other countries for the treatment of anemia in chronic kidney disease (CKD) patients on dialysis and not on dialysis. The Company continues to evaluate a development plan for roxadustat in anemia associated with lower-risk myelodysplastic syndrome (LR-MDS) in the U.S. FG-3246 (also known as FOR46), a first-in-class antibody-drug conjugate (ADC) targeting CD46 is in development for the treatment of metastatic castration-resistant prostate cancer. This program also includes the development of FG-3180, an associated CD46-targeted PET biomarker. For more information, please visit www.fibrogen.com. Forward-Looking Statements This release contains forward-looking statements regarding FibroGen’s strategy, future plans and prospects, including statements regarding its commercial products and clinical programs and those of its collaboration partners Fortis and UCSF. These forward-looking statements include, but are not limited to, statements regarding the efficacy, safety, and potential clinical or commercial success of FibroGen products and product candidates, and statements about FibroGen’s plans and objectives. These forward-looking statements are typically identified by use of terms such as “may,” “will”, “should,” “on track,” “could,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “potential,” “continue” and similar words, although some forward-looking statements are expressed differently. FibroGen’s actual results may differ materially from those indicated in these forward-looking statements due to risks and uncertainties related to the continued progress and timing of its various programs, including the enrollment and results from ongoing and potential future clinical trials, and other matters that are described in FibroGen’s Annual Report on Form 10-K for the most recent fiscal year, and any more recent Quarterly Reports on Form 10-Q, each as filed with the Securities and Exchange Commission (SEC), including the risk factors set forth therein. Investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this release, and FibroGen undertakes no obligation to update any forward-looking statement in this press release, except as required by law. References: 1. Seer.cancer.gov https://seer.cancer.gov/statfacts/html/prost.html For Investor Inquiries: David DeLucia, CFA Senior Vice President and Chief Financial Officer ir@fibrogen.com Source: FibroGen, Inc.