FibroGen

FibroGen, Inc. is a biopharmaceutical company headquartered in San Francisco, California. Once regarded as a promising developer of innovative anemia and fibrosis therapies, the company’s reputation and market value declined sharply after 2020 following a series of late-stage trial failures, regulatory setbacks, and a data manipulation scandal involving its former chief medical officer.

FibroGen, Inc.

Company type	Public
Traded as	Nasdaq: FGEN
Industry	Biotechnology
Founded	1993
Founder	Thomas B. Neff
Headquarters	Virtual office address: 350 Bay Street, Suite 100 #6009, San Francisco, California
Key people	Thane Wettig (CEO) David DeLucia (CFO) John Alden (General Counsel)
Number of employees	52 (United States, December 2024)[1]
Website	fibrogen.com

Products and research

FibroGen's most prominent product had long been roxadustat, which stimulates the body’s production of red blood cells.^[2] However, following the 2025 sale of its Chinese subsidiary and all related commercial rights to AstraZeneca, the drug is no longer a central part of FibroGen’s business. The company has since shifted its focus toward oncology drug development, primarily pursuing the long-shot candidate FG-3246.^[3][4]

Roxadustat

Roxadustat is a first-in-class oral drug for the treatment of anemia associated with chronic kidney disease. Developed by FibroGen, it stimulates the body’s natural production of red blood cells by inhibiting hypoxia-inducible factor prolyl hydroxylase, thereby activating the body’s response to low oxygen levels. This mechanism, which was later recognized by the 2019 Nobel Prize in Physiology or Medicine, represented a departure from traditional injectable therapies that relied on synthetic erythropoietin. William Kaelin, one of the Nobel laureates honored for this discovery, has also served as chairman of FibroGen’s Scientific Advisory Board in the United States.^[5]

FibroGen began developing the compound in the early 2000s as part of its anti-fibrosis research program. Early preclinical studies showed that the molecule could stimulate red blood cell production, prompting the company to redirect its focus toward anemia and select FG-4592 as the lead candidate. By the mid-2000s, FibroGen was seen as a potential challenger to Amgen’s dominance in the anemia drug market, with its oral approach considered more convenient for patients and potentially more cost-effective than the injectable treatments that defined the standard of care.^[6] To support global development, FibroGen entered into major licensing agreements, including a 2006 deal with Astellas valued at $300 million upfront plus milestones and equity, and a 2013 strategic partnership with AstraZeneca that provided a $350 million upfront payment and up to 20% royalties on sales.^[5]

In 2011, FibroGen established FibroGen (China) to conduct Phase III clinical trials and to pursue regulatory approval as a Class 1 innovative drug. In what Fierce Pharma described as "a rare event, if not a singular one in the biopharma world,"^[7] roxadustat became the first first-in-class drug developed by multinational pharmaceutical companies to be approved in China before the United States, European Union, or Japan. The drug received approval from China's National Medical Products Administration in December 2018 and was commercially launched in July 2019. Within one year of launch, roxadustat established itself as the leading therapy for anemia in patients with chronic kidney disease in China, aided by inclusion in the national medical insurance catalog. Sales grew from about 500 million yuan in 2020 to over 1 billion yuan in 2021, and surpassed 2 billion yuan in 2023. By 2024, the drug held approximately 46% market share in its therapeutic category. Chinese pharmaceutical analysts characterized this trajectory as "unprecedented" for a non-oncology chemical drug, calling roxadustat a "miraculous medicine."^[5]

Outside China, roxadustat’s development was derailed after FibroGen admitted in April 2021 that it had altered heart safety analyses to make the anemia drug appear safer than it was, prompting investor lawsuits and damaging credibility.^[8] The U.S. Food and Drug Administration later rejected FibroGen’s application for roxadustat to treat anemia in chronic kidney disease by issuing a Complete Response Letter in August 2021, citing concerns about the drug’s safety data.^[9] FibroGen’s Phase 3 Matterhorn trial in lower-risk myelodysplastic syndrome also failed in 2023,^[10] and in February 2024 AstraZeneca returned commercial rights for the U.S. and other regions to FibroGen.^[11]

In Japan and Europe, sales were disappointing: Astellas, which commercializes roxadustat under the brand Evrenzo in those regions, recorded a ¥47 billion ($348 million) impairment charge in 2023 due to lower-than-expected sales. In Japan, roxadustat faces stiff competition from four other approved HIF prolyl hydroxylase inhibitors, limiting its market share despite being the first HIF-PH inhibitor to be clinically used worldwide.^[12] In Europe, the drug struggled to differentiate itself from existing erythropoiesis-stimulating agents.^[10]

Roxadustat also attracted attention outside clinical development. In 2015, while still undergoing trials, the compound was linked to professional cycling doping cases when Italian rider Fabio Taborre and Chilean rider Carlos Oyarzun tested positive for the substance; the World Anti-Doping Agency had already classified roxadustat as a banned substance despite its not yet being commercially available at the time.^[13]

Pamrevlumab

Pamrevlumab is a monoclonal antibody targeting connective tissue growth factor, developed by FibroGen for the treatment of fibrotic and oncologic diseases.

In July 2024, FibroGen announced it would discontinue the pamrevlumab program following the failure of two late-stage trials in pancreatic cancer. The Lapis study evaluated neoadjuvant pamrevlumab in combination with chemotherapy for unresectable locally advanced pancreatic cancer, while the investigator-sponsored Precision Promise trial assessed the same combination as first-line therapy. Neither trial met its primary endpoint of overall survival. The decision marked the end of a long development effort for pamrevlumab, which had previously shown disappointing results in idiopathic pulmonary fibrosis, Duchenne muscular dystrophy, and pancreatic cancer.^[14]

FG-3246

FG-3246 (also called FOR46) is an experimental antibody–drug conjugate developed by FibroGen to treat metastatic castration-resistant prostate cancer. It targets CD46 on cancer cells to deliver therapy directly to the tumor. FibroGen is also developing FG-3180, a PET imaging agent, to help track the cancer and predict responses to FG-3246. A Phase 2 trial of FG-3246 began in September 2025, with full completion expected in March 2028.^[4]

History

FibroGen was founded in 1993 by investment banker Thomas B. Neff and Finnish biochemist Kari Kivirikko, a professor at the University of Oulu.^[2] Early in its history, the company explored supplying synthetic collagen for plastic surgery applications, but later abandoned that strategy and shifted to developing drugs that stimulate red blood cell production to treat anemia.^[2]

FibroGen went public on the Nasdaq in 2014. In 2019, it was near the peak of its market capitalization, around US$4 billion.^[2] Neff remained CEO and chairman from founding until his death in August 2019. He lived long enough to see his vision realized with the approval and commercial rollout of roxadustat in China, before later crises overtook the company.^[15]

Starting around 2020, FibroGen’s fortunes reversed. In 2021, the company disclosed that efficacy data for roxadustat submitted to the US Food and Drug Administration had been manipulated, prompting regulatory scrutiny and a subsequent rejection of its approval application.^[16] The Lelantos Phase 3 trial in Duchenne muscular dystrophy failed in August 2022. In June 2023, the Zephyrus-1 and Zephyrus-2 Phase 3 trials for idiopathic pulmonary fibrosis did not meet endpoints. In May 2023, the Phase 3 Matterhorn trial in lower-risk myelodysplastic syndrome also failed.^[10] Following these setbacks, FibroGen announced in July 2023 that it would cut 32% of its U.S. workforce (104 employees) as part of a restructuring plan to lower operating expenses.^[17] By July 2024, FibroGen discontinued pamrevlumab following failed pancreatic cancer trials, triggering a further workforce reduction, including 127 layoffs at its San Francisco location as part of a broader plan to eliminate 75% of its US-based staff.^[18] In October 2024, FibroGen paid $10 million to terminate its lease for its longtime Mission Bay headquarters at 409 Illinois Street, years before its 2028 expiration, after unsuccessful attempts to sublease the property. The company said it no longer required such a large office footprint following the clinical failures and significant workforce reduction.^[19]

On August 29, 2025, FibroGen completed the sale of its Chinese subsidiary, FibroGen China, to AstraZeneca for about US$85 million in enterprise value plus about US$135 million in net cash held in China, totaling US$220 million.^[1] The total consideration surged significantly from initial expectations: when first announced in February 2025, the deal was valued at approximately US$160 million (US$85 million enterprise value plus US$75 million expected net cash). The guidance was adjusted upward twice: first to US$185 million during the Q1 2025 earnings call in May and finally to US$220 million at closing, representing a US$60 million increase from the original estimate due to stronger-than-expected roxadustat sales in China during the first half of 2025.^[20]

According to CEO Thane Wettig, the sale was necessary to "allow for the payoff of our term loan facility with Morgan Stanley Tactical Value" and to "provide the most efficient pathway to access the company's cash held in China." Approximately US$81 million of the proceeds were used to repay the Morgan Stanley term loan, extending the company's cash runway into 2028.^[20] FibroGen retains rights to roxadustat in the US and markets not licensed to Astellas.^[3]

Legal and regulatory issues

Securities fraud litigation

Following revelations that FibroGen's former chief medical officer manipulated clinical trial data for Roxadustat, the company faced a securities class action in 2021 in the United States District Court for the Northern District of California over allegedly false or misleading statements; the case was settled for $28.5 million. Stockholders later filed a derivative action in the Delaware Court of Chancery claiming that FibroGen directors breached their fiduciary duties under Malone and Caremark theories. The court dismissed the derivative claims, finding that the plaintiffs had not pleaded sufficient facts to show that directors knowingly approved or ignored the false statements based on the manipulated trial data.^[21]

SEC investigation

In September 2025, FibroGen agreed to pay $1.25 million to the SEC to settle allegations that its former chief medical officer manipulated clinical trial data for roxadustat. According to the SEC, between 2019 and 2021 the executive “reverse engineered” Phase III trial results to make the drug appear superior to existing treatments when it was in fact only comparable. The misleading claims were alleged to have been made in SEC filings, press releases, earnings calls, and a published article. The SEC also alleged that the company misrepresented the FDA’s position on the statistical methods used. FibroGen did not admit wrongdoing but agreed to pay the settlement over the following year.^[16]

See also

• Daprodustat, Vadadustat – other HIF-PH inhibitors, the same drug class as roxadustat