Kyntra Bio
Kyntra Bio is a San Francisco biopharmaceutical company, formerly FibroGen, focused on medicines for anemia, fibrosis, and cancer.
Last updated August 26, 2026
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Overview
Kyntra Bio, Inc., formerly known as FibroGen, Inc., is a San Francisco-based biopharmaceutical company whose history spans recombinant collagen research, anemia therapies, anti-fibrotic medicines, and oncology. The company was established in 1993 by investment banker Thomas B. Neff and Finnish biochemist Kari Kivirikko. Its initial ambition was to commercialize synthetic collagen for applications such as plastic surgery, but its research direction gradually shifted toward therapeutics capable of stimulating the body's natural production of red blood cells and treating fibrotic disease. The company's most important development became roxadustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor. Originally identified during anti-fibrosis research and known in development as FG-4592, roxadustat activates a physiological response to low oxygen and stimulates erythropoiesis. It offered a potential oral alternative to injectable erythropoiesis-stimulating agents for anemia associated with chronic kidney disease. FibroGen licensed regional rights to Astellas in agreements signed in 2004 and 2006, and partnered with AstraZeneca in 2013 for development and commercialization in the United States, China, and other territories. Roxadustat became the company's central commercial achievement. China approved it in late 2018, first for patients with chronic-kidney-disease anemia who were not on dialysis and later for dialysis patients. Commercial launch followed in 2019, and the medicine became a leading anemia treatment in China. It was subsequently approved in Japan and the European Union, where it was marketed by Astellas as Evrenzo. Its performance outside China was considerably weaker, however, and AstraZeneca returned the United States commercial rights to FibroGen in 2024. The company's rise was followed by severe setbacks. In 2021, FibroGen disclosed that efficacy and cardiovascular-safety analyses submitted to the United States Food and Drug Administration had been altered in a way that made roxadustat appear safer and more effective than the underlying data supported. The disclosure led to regulatory scrutiny, investor litigation, reputational damage, and rejection of the United States application. Additional late-stage failures affected roxadustat and the company's other major program, pamrevlumab, an antibody directed at connective tissue growth factor. Pamrevlumab failed in Phase 3 studies involving idiopathic pulmonary fibrosis, Duchenne muscular dystrophy, and pancreatic cancer, and the company discontinued the program in 2024. The resulting contraction included major workforce reductions, restructuring, and the termination of the lease for the company's longtime Mission Bay headquarters. In 2025, FibroGen sold its Chinese subsidiary to AstraZeneca for approximately $220 million in total consideration, including enterprise value and cash held in China. The transaction was intended to repay an approximately $81 million loan and extend the company's financial runway. After the sale, the pipeline was concentrated primarily in FG-3246, an antibody-drug conjugate acquired from Fortis Therapeutics at no upfront cost and aimed at metastatic castration-resistant prostate cancer. On January 8, 2026, FibroGen changed its corporate name to Kyntra Bio and its Nasdaq ticker to KYNB. Under the new identity, the company remains a substantially smaller, development-stage biotechnology business whose prospects depend heavily on the advancement of its remaining oncology assets and on the limited further development of roxadustat in narrowly defined indications such as lower-risk myelodysplastic syndromes.
History
Kyntra Bio originated as FibroGen in 1993, founded by Thomas B. Neff and Kari Kivirikko. The early company pursued synthetic and recombinant collagen, establishing FibroGen Europe Oy in Oulu, Finland, in 1996. That subsidiary was intended to develop recombinant-collagen technologies and was briefly considered for a possible public offering around 2000, although the offering never occurred and the operation later became dormant. During the 2000s, FibroGen's research moved toward pharmacological stimulation of red-blood-cell production. Its leading compound, initially designated FG-4592 and later named roxadustat, emerged from anti-fibrosis research. The compound inhibited hypoxia-inducible factor prolyl hydroxylase, reproducing aspects of the body's response to low oxygen and stimulating erythropoiesis. This mechanism created the possibility of treating chronic-kidney-disease anemia with an oral medicine rather than conventional injectable erythropoietin-based products. FibroGen built an international development network through agreements with Astellas in 2004 and 2006. These agreements granted Astellas rights in Japan and subsequently in Europe, the Commonwealth of Independent States, the Middle East, and South Africa. FibroGen retained rights in other major territories and shared portions of United States development and patent work. In 2011, it established FibroGen China to conduct Phase 3 work and pursue Chinese approval. A 2013 agreement with AstraZeneca covered development and commercialization in the United States, China, and territories not assigned to Astellas. China became roxadustat's first major regulatory and commercial market. Chinese regulators approved the drug in December 2018 for chronic-kidney-disease anemia in non-dialysis patients and expanded the approval to dialysis patients in August 2019. Commercial launch began in July 2019. Roxadustat quickly became the company's principal source of commercial momentum and was included in China's national medical-insurance system. The drug was also approved in Japan in September 2019 and in the European Union in August 2021, where Astellas marketed it under the name Evrenzo. The medicine's international development was notable because China approved it before the United States, European Union, or Japan. The company's public-market profile rose with the roxadustat program. Its market capitalization was reported at approximately $4 billion in 2018–19. Neff, who had served as chief executive and chairman from the company's founding, died unexpectedly on August 25, 2019, shortly after the Chinese approval and commercial launch milestone. The subsequent period was marked by regulatory and clinical reversals. In 2021, FibroGen disclosed that data analyses provided to the FDA had been manipulated to make roxadustat's safety and efficacy profile appear more favorable. The disclosure produced regulatory investigations, investor lawsuits, and a major loss of confidence. In August 2021, the FDA rejected the United States application, citing safety-data concerns. A later Phase 3 study of roxadustat in lower-risk myelodysplastic syndrome also failed in 2023, although the company continued to explore a narrower population with a high transfusion burden. FibroGen's second major program, pamrevlumab, followed a similarly difficult path. The monoclonal antibody targeted connective tissue growth factor and was studied in idiopathic pulmonary fibrosis, pancreatic cancer, and Duchenne muscular dystrophy. After multiple mid- and late-stage studies, Phase 3 programs including ZEPHYRUS, LELANTOS, and LAPIS failed to establish the intended benefits. The final pancreatic-cancer studies failed their overall-survival endpoints, and the company discontinued pamrevlumab in 2024. The decision was accompanied by a workforce reduction of approximately three quarters and a broader restructuring. As the company's pipeline contracted, it reduced its physical and financial footprint. In October 2024, FibroGen paid approximately $10 million to terminate the lease on its long-standing Mission Bay headquarters, reflecting lower office-space requirements. AstraZeneca returned the United States roxadustat commercial rights in February 2024, while the China partnership continued. In August 2025, FibroGen completed the sale of FibroGen China to AstraZeneca for approximately $220 million. The proceeds helped repay an approximately $81 million Morgan Stanley Tactical Value loan and supported operations into 2028. The remaining portfolio became concentrated around FG-3246, also known as FOR46, an antibody-drug conjugate acquired from the defunct Fortis Therapeutics without an upfront payment. The asset targets CD46 and delivers the cytotoxic payload MMAE to cancer cells in metastatic castration-resistant prostate cancer. The company also retained FG-3180 as an imaging-related oncology asset, although the supplied material does not provide enough detail to describe its development status fully. On January 8, 2026, FibroGen changed its name to Kyntra Bio and adopted the Nasdaq symbol KYNB. The renamed company represents the continuation of the former FibroGen business in a much smaller, development-stage form, with future value dependent mainly on remaining oncology programs and carefully limited clinical opportunities for roxadustat.
- 2026
Renamed Kyntra Bio
[1]FibroGen changed its corporate name to Kyntra Bio and its Nasdaq ticker to KYNB.
- 2025
Chinese subsidiary sold
[1]FibroGen sold FibroGen China to AstraZeneca for approximately $220 million.
- 2024
Pamrevlumab discontinued
[1]Failed pancreatic-cancer studies ended development of the company's principal anti-fibrotic and oncology antibody program.
- 2021
Roxadustat regulatory setback
[1]FibroGen disclosed manipulated analyses, and the FDA later rejected the United States application.
- 2019
Chinese launch and founder's death
[1]Roxadustat launched in China, and founder Thomas B. Neff died on August 25.
- 2018
Roxadustat approved in China
[1]Chinese regulators approved roxadustat for chronic-kidney-disease anemia in patients not receiving dialysis.
- 2014
Nasdaq public offering
[1]FibroGen completed its Nasdaq initial public offering during the expansion of its roxadustat program.
- 2013
AstraZeneca collaboration announced
[1]AstraZeneca received broad development and commercialization rights for roxadustat, including the United States and China arrangements.
- 2011
FibroGen China established
[1]The company created a Chinese subsidiary to conduct late-stage roxadustat trials and seek local approval.
- 2006
Astellas regional rights expanded
[1]Astellas received additional rights covering Europe and several surrounding regions.
Products and positioning
A development-stage biopharmaceutical company focused on differentiated therapies for anemia, fibrosis, and cancer, with a historical emphasis on mechanism-driven medicines and partnerships with multinational pharmaceutical companies.
Oral HIF prolyl hydroxylase inhibitor · 2019
Roxadustat
Roxadustat, originally designated FG-4592, is an oral medicine designed to treat anemia associated with chronic kidney disease. By inhibiting hypoxia-inducible factor prolyl hydroxylase, it activates cellular responses associated with low oxygen and stimulates endogenous red-blood-cell production. It was approved in China in 2018 and launched there in 2019, later receiving approvals in Japan and the European Union under the Evrenzo brand. The United States application was rejected in 2021 after concerns about safety analyses. FibroGen continued evaluating the compound in narrower myelodysplastic-syndrome populations.
Monoclonal antibody
Pamrevlumab
Pamrevlumab is a monoclonal antibody targeting connective tissue growth factor. FibroGen studied it in idiopathic pulmonary fibrosis, pancreatic cancer, and Duchenne muscular dystrophy. The program included multiple Phase 1 and Phase 2 studies and later advanced to Phase 3 trials, including ZEPHYRUS, LELANTOS, and LAPIS. The late-stage studies did not establish the required clinical benefit, and the company discontinued the program in 2024 after pancreatic-cancer trials failed their overall-survival endpoints.
Antibody-drug conjugate
FG-3246 (FOR46)
FG-3246, also known as FOR46, is an experimental antibody-drug conjugate for metastatic castration-resistant prostate cancer. The program targets CD46 on cancer cells and uses the MMAE cytotoxic payload to deliver chemotherapy to tumors. FibroGen acquired the asset from Fortis Therapeutics without an upfront payment, with a substantial milestone obligation tied to possible advancement into Phase 3. It became the company's principal remaining development asset after the discontinuation of pamrevlumab and the sale of the Chinese subsidiary.
Oncology imaging candidate
FG-3180
FG-3180 is an oncology-related imaging asset associated with the former FibroGen pipeline. The supplied reference identifies it as a PET imaging candidate but does not provide sufficient information about its target, clinical stage, development partner, or current status.
Controversies
2021
Roxadustat data manipulation controversy
FibroGen acknowledged that analyses submitted to the FDA had been altered in a manner that made roxadustat appear safer and more effective. The disclosure triggered regulatory scrutiny, investor lawsuits, and rejection of the United States application.
Marketing campaigns
- 2019Roxadustat China launch
China
FibroGen and AstraZeneca launched roxadustat in China after regulatory approval. The medicine benefited from inclusion in the national medical-insurance catalog and became the company's leading commercial product.
Outcome. The launch produced strong Chinese sales and made China the central commercial market for roxadustat.
Brand decisions
2026
Rebrand as Kyntra BioStrategyBackground
The former FibroGen business had contracted from a diversified anemia and fibrosis developer into a smaller company centered largely on early-stage oncology assets.
Action taken
The company changed its name to Kyntra Bio and changed its Nasdaq ticker to KYNB.
Aftermath
The renamed company continued as a development-stage biotechnology business with a narrower pipeline and a reduced commercial footprint.
2025
Sell FibroGen China to AstraZenecaM&ABackground
The transaction followed the concentration of roxadustat's commercial success in China and the company's need to strengthen liquidity after clinical and regulatory setbacks.
Action taken
FibroGen sold its Chinese subsidiary to AstraZeneca for approximately $220 million, including enterprise value and cash held in China.
Aftermath
The proceeds supported repayment of an approximately $81 million loan and extended the company's expected operating runway into 2028.
Transaction consideration. Approximately $160 million initially announced → Approximately $220 million final consideration (2025)
2024
Discontinue pamrevlumabOtherBackground
Late-stage pamrevlumab studies in pancreatic cancer failed to meet their overall-survival primary endpoints after earlier failures in pulmonary fibrosis and Duchenne muscular dystrophy.
Action taken
FibroGen ended development of pamrevlumab and carried out a major workforce reduction and restructuring.
Aftermath
The company became more dependent on roxadustat and its remaining oncology assets, particularly FG-3246.
Recent events
- 2026
FibroGen adopts the Kyntra Bio name and KYNB ticker[1]
Leadership change
The company changed its corporate name from FibroGen to Kyntra Bio and changed its Nasdaq ticker from its former symbol to KYNB.
- 2025
FibroGen sells Chinese subsidiary to AstraZeneca[1]
M&A
FibroGen sold FibroGen China to AstraZeneca for approximately $220 million, including enterprise value and cash, using the proceeds to repay debt and extend its financial runway.
- 2024
Pamrevlumab program discontinued after pancreatic-cancer failures[1]
Other · Bankruptcy
After the LAPIS and Precision Promise studies failed to meet their overall-survival primary endpoints, FibroGen ended development of pamrevlumab and reduced its workforce substantially.
- 2024
AstraZeneca returns United States roxadustat rights[1]
M&A
AstraZeneca returned the United States commercial rights for roxadustat to FibroGen while retaining its China collaboration.
- 2021
FDA rejects roxadustat application[1]
Regulation · Other
The FDA issued a Complete Response Letter declining approval of roxadustat for chronic-kidney-disease anemia, citing concerns about the safety data.
Sources1 sources
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