Kyntra Bio, Inc. (formerly FibroGen, Inc.) is a biopharmaceutical company headquartered in San Francisco, California. Once regarded as a promising developer of innovative therapies for anemia and fibrotic diseases, with a market capitalization of roughly $4 billion in 2018–19, the company's value collapsed following late-stage trial failures, regulatory setbacks, and a data manipulation scandal. By 2026, Kyntra was mainly reduced to a single early-stage oncology drug candidate.
On January 8, 2026, FibroGen changed its name to Kyntra Bio and ticker symbol to KYNB.
History FibroGen was founded in 1993 by investment banker Thomas B. Neff and Finnish biochemist Kari Kivirikko, a professor at the University of Oulu. The company’s early ambition was to commercialize synthetic collagen for use in plastic surgery. Over time, FibroGen redirected its main focus toward a broader goal: developing medicines that could stimulate red blood cell production for patients suffering from anemia. FibroGen established a Finnish subsidiary, FibroGen Europe Oy, in Oulu in 1996 to develop recombinant collagen technologies, and the subsidiary was briefly considered as a potential IPO candidate in 2000, but it never materialized and the operation eventually became dormant. (The company's early work in recombinant collagen biomaterials would later inform development of corneal regeneration in China in the 2010s and 2020s.)
By the 2000s, FibroGen had gathered momentum around a promising compound that boosted red blood cell production, a drug that would eventually be known as roxadustat. The company signed partnership agreements with Astellas in 2004 and 2006, granting rights in Japan, Europe, and other regions. The 2006 agreement was viewed within the industry as highly favorable to FibroGen.
In the following decade, FibroGen established a partnership with AstraZeneca, which was seeking to rebuild its development pipeline. The 2013 collaboration granted AstraZeneca rights to roxadustat in the United States, China, and other territories not covered by Astellas, setting the stage for the company’s 2014 Nasdaq IPO. By then, FibroGen faced a tightening race, as GlaxoSmithKline (Daprodustat) and the Ohio-based startup Akebia Therapeutics (Vadadustat) advanced rival HIF-PH inhibitors. But FibroGen retained a crucial lead. In what Fierce Pharma called "a rare event, if not a singular one in the biopharma world," 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" when Chinese regulators gave their approval at the end of 2018, followed by its commercial rollout the next year.
That milestone marked the peak of FibroGen’s ascent. By 2018–19, its market capitalization had reached roughly US$4 billion. Founder Thomas Neff, who had served as CEO and chairman since the company’s inception, lived to see his vision realized with roxadustat’s approval and at the cusp of launch in China before his unexpected death on August 25, 2019. In the years following his passing, the company faced growing management turmoil, fraudulent clinical data, failed trials, and a sharp decline in its fortunes.
In 2021, FibroGen 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. Over the next few years, multiple late-stage clinical trials across its pipeline failed, leading the company to significantly reduce its workforce in 2023 and 2024. In July 2024, FibroGen discontinued pamrevlumab following failed trials in pancreatic cancer, triggering further layoffs and a broader restructuring that eliminated most of its US-based staff. In October 2024, the company paid $10 million to terminate its lease for its longtime Mission Bay headquarters, citing the reduced need for office space. Meanwhile, rival Akebia Therapeutics won FDA approval for its competing anemia drug in March 2024, capturing the US market for anemia in dialysis patients with chronic kidney disease.
In August 2025, FibroGen sold its Chinese subsidiary, FibroGen China, to AstraZeneca for approximately US$220 million, including enterprise value and cash held in the country. The total consideration was initially set at around US$160 million when first announced in February 2025 and was revised upward twice (first to US$185 million and then finally to US$220 million) reflecting stronger than expected roxadustat sales in China. The proceeds from the sale was necessary to pay off a loan of approximately US$81 million with Morgan Stanley Tactical Value and to provide the company with a longer financial runway into 2028.
Following the sale of its Chinese subsidiary, FibroGen is now left primarily with FG-3246, an asset it acquired from Fortis Therapeutics, a defunct biotech company, at no upfront cost with a large milestone due only if the drug advances into Phase 3. FibroGen's future largely depends on the development of this unpromising drug.
Products and research + Phase 3 Trials for FDA-Submitted Programs Drug / Program Indication Phase 3 Trial(s) Outcome Notes Roxadustat Anemia in Chronic Kidney Disease (CKD) ANDES, OLYMPUS, ALPS, ROCKIES, SIERRAS, HIMALAYAS, PYRENEES FDA rejected August 2021 Company changed prespecified statistical criteria for cardiovascular safety analysis and FDA raised concerns about data integrity Roxadustat Anemia in Myelodysplastic Syndromes (MDS) MATTERHORN Failed May 2023 Did not meet primary endpoint Pamrevlumab Idiopathic Pulmonary Fibrosis (IPF) ZEPHYRUS-1, ZEPHYRUS-2 Failed June 2023 ZEPHYRUS-1 missed primary endpoint; ZEPHYRUS-2 terminated after interim review Pamrevlumab Duchenne Muscular Dystrophy (DMD) LELANTOS-1, LELANTOS-2 Failed June–August 2023 Both trials failed to meet primary endpoints on motor function Pamrevlumab Pancreatic Cancer (Locally Advanced, unresectable) LAPIS Failed July 2024 Did not meet primary or key secondary endpoints Pamrevlumab Pancreatic Cancer (Precision Promise platform trial) Precision Promise arm Failed July 2024 Program discontinued
FibroGen has focused on therapies for anemia, fibrotic diseases, and cancer. Its former flagship product, roxadustat, was developed for anemia associated with chronic kidney disease for multiple global markets, though it only achieved commercial success in China, where it became the company’s golden goose. All of its US Phase 3 trials for both roxadustat and pamrevlumab including indications for anemia, Duchenne muscular dystrophy, idiopathic pulmonary fibrosis, and pancreatic cancer ultimately failed or were rejected. In 2025, the only significant remaining asset is FG-3246.
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.
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.
Preclinical and partnerships FibroGen began developing the compound in the early 2000s as part of its anti-fibrosis research program. Early preclinical studies indicated that roxadustat (then referred to as FG-4592) could stimulate red blood cell production, prompting the company to shift its focus toward anemia and select FG-4592 as its lead candidate. By the mid-2000s, FibroGen was considered a potential challenger to Amgen’s dominance in the anemia drug market, with its oral therapy viewed as more convenient for patients and potentially more cost-effective than the injectable treatments that defined the standard of care.
To support global development, FibroGen entered into major licensing agreements with Astellas in 2004 and 2006. The 2004 agreement granted Astellas rights in Japan, while the 2006 agreement extended exclusive rights to develop and commercialize FG-4592 and related compounds in Europe, the Commonwealth of Independent States, the Middle East, and South Africa, with FibroGen retaining rights elsewhere. The companies also agreed to share the costs of the US development program and patent support. Despite the significant payments, FibroGen retained the US and China rights. In 2013, FibroGen partnered with AstraZeneca to develop and commercialize roxadustat. Under the US agreement, AstraZeneca gained rights to commercialize the drug in the United States and all countries outside China and territories licensed to Astellas, while under a separate China agreement, FibroGen and AstraZeneca shared profits and losses 50/50.
In February 2024, following the debacles with US clinical trials, AstraZeneca returned US commercial rights for roxadustat to FibroGen. In contrast, the China collaboration with AstraZeneca remained successful. In July 2020, FibroGen China and AstraZeneca entered into an amendment to their China agreement to address the commercialization of roxadustat in China.
Clinical trials In 2011, FibroGen established FibroGen (China) to run Phase III trials and seek approval of roxadustat as a Class 1 innovative drug. The National Medical Products Administration approved roxadustat in December 2018 for anaemia in patients with chronic kidney disease not on dialysis. In August 2019, approval was extended to include patients on dialysis.
Roxadustat was approved in Japan in September 2019 for the treatment of anemia associated with chronic kidney disease in dialysis-dependent patients, based on the results of four Phase III clinical trials conducted in the country. In the European Union, roxadustat received approval in August 2021 for the treatment of symptomatic anemia in adults with chronic kidney disease. This approval was supported by a large-scale global Phase III program, consisting of eight multicenter, randomized studies that enrolled over 9,000 patients across multiple countries.
In the US, 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. The 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. FibroGen’s Phase 3 MATTERHORN trial evaluating roxadustat in lower-risk myelodysplastic syndrome also failed in 2023.
Following the last clinical setback in 2023 and the return of US rights by AstraZeneca in 2024, the company continues to pursue development of roxadustat in the US for anemia in lower-risk myelodysplastic syndromes with a high transfusion burden, a narrower clinical sub-set of the 2023 trial population. In July 2025, FibroGen held a Type C meeting, a catch-all meeting for clarifications, with the Food and Drug Administration to take a step forward. At the end of 2025, roxadustat was also granted Orphan Drug Designation by the FDA for the treatment of myelodysplastic syndromes.
Sales