A 30-year-old San Francisco biotech that built a global anemia drug, then reinvented itself around a first-in-class cancer therapy. Same company, sharper focus.
In January 2026, a company that had spent 33 years chasing fibrosis, anemia and rare disease did something biotechs rarely manage: it narrowed its aim. FibroGen, Inc. became Kyntra Bio - a new name, a new Nasdaq ticker (KYNB), and a single organizing idea. Cancer.
FibroGen was founded in 1993 by Thomas Neff, an investment banker who bet a company on fibrosis at a time most of the industry treated the disease category as untreatable. He assembled scientists steeped in collagen chemistry and prolyl hydroxylase biology, and over the following decades that expertise produced two notable molecules: roxadustat, an oral pill for anemia, and pamrevlumab, an antibody aimed at scarring diseases. Neff led the company for roughly 26 years until his death in 2019.
The company's science was real; its commercial luck was uneven. Roxadustat became a genuine success abroad - approved in China, Japan and across Europe for anemia tied to chronic kidney disease - yet it never won approval in the United States, where the FDA issued a Complete Response Letter in 2021. Pamrevlumab, once framed as the future, missed the mark in three Phase 3 trials in 2023. What followed was not a quiet wind-down but a deliberate reconstruction.
At its core, the company discovers, develops and commercializes first-in-class medicines - drugs built on biology that no one else has turned into an approved therapy yet. For most of its life that meant hypoxia-inducible factor (HIF) science, the pathway roxadustat exploits to nudge the body into making more red blood cells without injected hormones. Today the center of gravity is oncology: antibody-drug conjugates that carry a toxic payload directly to a marker found on cancer cells.
Figures drawn from company press releases and public filings (Nasdaq: KYNB, SEC CIK 921299). The ~$220M China divestiture closed in August 2025; runway guidance from company statements.
The portfolio pairs a lead cancer program with a repositioned legacy asset - and, notably, a diagnostic built to match the therapy.
A first-in-class CD46-targeting antibody-drug conjugate, in-licensed from Fortis Therapeutics. In a Phase 2 monotherapy trial for metastatic castration-resistant prostate cancer, with an interim analysis expected in the second half of 2026.
A CD46-targeted PET imaging biomarker designed to pair with FG-3246 - so the same target can be both seen on a scan and treated. Diagnose, then deliver.
An oral HIF-PHI for anemia of chronic kidney disease, approved in China, Japan and Europe. Now repositioned as a Phase 3-ready asset for anemia in lower-risk myelodysplastic syndromes, with FDA Orphan Drug Designation.
A galectin-9-targeting monoclonal antibody for solid tumors. The FDA cleared its investigational new drug application in June 2024; a Phase 1 study is planned.
| Asset | Type | Indication | Status |
|---|---|---|---|
| FG-3246 | CD46 antibody-drug conjugate | Metastatic prostate cancer (mCRPC) | Phase 2 |
| FG-3180 | PET imaging biomarker | Prostate cancer (companion) | Early dev |
| Roxadustat | Oral HIF-PHI | Anemia in lower-risk MDS | Phase 3-ready |
| Roxadustat | Oral HIF-PHI | Anemia of CKD (ex-US) | Approved |
| FG-3165 | Galectin-9 antibody | Solid tumors | Phase 1 (IND cleared) |
| Pamrevlumab | Anti-CTGF antibody | IPF / DMD / pancreatic | Discontinued |
Who its customers are. The end users are patients. Roxadustat reaches a large multinational base of people with anemia tied to kidney disease, prescribed through partners Astellas and AstraZeneca across China, Japan and Europe. The oncology pipeline is aimed at people with metastatic castration-resistant prostate cancer and other solid tumors, delivered through oncologists and cancer centers. Its commercial counterparties are large pharmaceutical partners.
The problems it solves. Anemia in kidney disease has long meant injected erythropoiesis-stimulating agents; roxadustat offered an oral alternative. In cancer, the problem is precision - chemotherapy hits healthy and diseased cells alike. Antibody-drug conjugates like FG-3246 are designed to concentrate a payload where a target such as CD46 is overexpressed, sparing more of the body.
How it's different. CD46 is a comparatively fresh target in prostate cancer, and FG-3246 is described as first-in-class - meaning the direct competition for that specific mechanism is thin. Pairing the therapy with FG-3180, a matching imaging agent, is a diagnose-and-treat approach that not every ADC developer carries. And the company's decades in HIF biology give roxadustat a defined, already-approved footprint abroad.
The business model is the familiar one for a company whose products are still being proven: fund research through the public equity markets, supplement it with milestone and royalty income from partnered drugs, and, when the moment is right, monetize assets. FibroGen did all three - and in 2025 added a large one-time move, selling its China business to AstraZeneca for roughly $220 million. The proceeds retired a term loan and pushed the company's cash runway into 2028, the single most important number for any clinical-stage biotech: how long it can operate before it must raise again.
Where does it fit in the market? On the anemia side, roxadustat sits in the HIF-PHI category against GSK's daprodustat, Akebia's vadadustat and Bayer's molidustat - a competitive field of oral drugs chasing the same patients. On the oncology side, it enters the crowded, fast-moving world of antibody-drug conjugates, but with a differentiated target in CD46 for prostate cancer. The strategic logic of the rebrand was to stop straddling both worlds and plant a flag in the second.
Historically from roxadustat commercialization and partner payments (Astellas, AstraZeneca). Reported revenue fell to roughly $8.3M through Q3 2025 after the China divestiture.
Completed the largest US biotech IPO in 12 years in 2014 (~$172M net). The 2025 China sale (~$220M) reset the balance sheet.
Three decades of depth in hypoxia-inducible factor and connective tissue growth factor science, now redirected toward antibody-drug conjugates.
Thomas Neff builds the company around fibrosis and collagen / prolyl hydroxylase biology.
Collaboration agreements cover roxadustat in Japan, then Europe and other regions.
A global deal for roxadustat spanning the US, China and other territories.
FibroGen completes the largest US biotech IPO in 12 years, raising ~$172M net.
China (2018), Japan (2019) and Europe (2021) clear the drug for anemia of CKD.
Roxadustat fails to win US approval despite approvals across three continents.
Trials in IPF and Duchenne muscular dystrophy miss endpoints; the program is wound down.
Sells FibroGen China to AstraZeneca for ~$220M, repays its term loan, and launches the FG-3246 Phase 2 trial.
Adopts the Kyntra Bio name and Nasdaq ticker KYNB, focused on oncology and rare disease.
"We begin this year as Kyntra Bio, a name that captures our company journey and evolution."
Thane Wettig, CEO - Jan 7, 2026"Kyntra Bio is laser-focused on our mid- and late-stage assets... we are thrilled to move forward with renewed purpose."
Thane Wettig, CEOHow a 30-year-old company shed its legacy and rebuilt its thesis around oncology.
The commercial paradox of roxadustat - approved abroad, blocked at home.
The science behind a first-in-class antibody-drug conjugate.
The China divestiture that paid off debt and bought runway into 2028.
Three failed Phase 3 trials and the strategic subtraction that followed.
Why coupling a cancer therapy with a companion PET imaging agent matters.
A field guide to the oral anemia drugs competing for the same patients.
How an anemia drug earned an Orphan Drug Designation and a new indication.
No. FibroGen rebranded as Kyntra Bio, Inc. on January 7, 2026, and its stock trades on Nasdaq under the ticker KYNB (formerly FGEN). It is the same legal entity.
Historically, roxadustat - an oral HIF-PHI for anemia of chronic kidney disease, approved in China, Japan and Europe. Its current lead asset is FG-3246, a CD46-targeting antibody-drug conjugate for metastatic prostate cancer.
The rebrand reflected a strategic shift toward oncology and rare disease after the company divested its China business, paid off debt, and concentrated on its FG-3246 and roxadustat programs.
No. The FDA issued a Complete Response Letter in 2021 for anemia in chronic kidney disease, so roxadustat is not approved in the US, though it is approved in China, Japan, Europe and other markets.
In San Francisco, California. After the 2025 China divestiture, it operates as a lean, focused clinical-stage biopharmaceutical company.
Investor updates and pipeline overviews on YouTube.
▶ SearchThe HIF-PHI mechanism behind the anemia drug.
▶ SearchThe target and technology behind the lead asset.
This profile draws only on publicly reported information from company press releases, Nasdaq/SEC filings and reputable news outlets. Some legacy figures (for example, headcount) reflect the company before its 2025 China divestiture and may be higher than the current lean operation. Executive quotes are from the January 7, 2026 rebrand announcement.