Kyntra Bio (formerly FibroGen) is a clinical-stage biopharmaceutical company developing two programs: an antibody-drug conjugate (ADC) for prostate cancer, and an oral drug for anemia in a rare blood disorder. The lead program, FG-3246, is an ADC that targets CD46, a protein overexpressed on prostate cancer cells, delivering MMAE, a cell-killing agent, directly to tumor cells. FG-3246 is being developed for metastatic castration-resistant prostate cancer (mCRPC), specifically in patients who have progressed on androgen receptor pathway inhibitors (ARPIs) but have not yet received chemotherapy. A Phase 2 dose-optimization trial in 75 patients launched in Q3 2025, with an interim readout expected in H2 2026. The second program, roxadustat, is an oral drug that stimulates red blood cell production and is already approved outside the U.S. for anemia in chronic kidney disease. Kyntra Bio is now pursuing roxadustat for anemia in lower-risk myelodysplastic syndromes (MDS), a bone marrow disorder. The FDA has aligned on a Phase 3 design of roughly 200 patients, and the company is evaluating whether to run that trial independently or via a partner. Kyntra Bio has no approved U.S. products and earns minimal revenue from a royalty-sharing collaboration with Astellas on roxadustat sales in Europe and Japan. The company has 34 employees and relies on contract manufacturers, with its cash runway funded primarily by the 2025 sale of its China operations to AstraZeneca for approximately $220M.