Data Presented at the American Society of Hematology 2005 Annual Meeting Are Results of the Longest Dosing Period Reported to Date for FG-2216

Atlanta, Georgia - December 13, 2005 - FibroGen today announced results from a preclinical study indicating that FG-2216, the Company's lead investigational HIF-PH inhibitor for treating anemia, administered orally twice weekly for six months was safe and well tolerated in non-human primates and stimulated increases in hemoglobin levels, which were dose-dependent and stable for the duration of therapy at each dose level. In addition, FG-2216 prevented reduction in hemoglobin levels due to phlebotomy in this model of chronic anemia. There were no clinical adverse events or significant changes in serum chemistry or renal or hepatic parameters observed over the treatment period. The study was conducted by the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Heart, Lung, and Blood Institute and presented at the American Society of Hematology (ASH) annual meeting (Abstract #570; Abstract).

"These results demonstrate that oral dosing of FG-2216 for six months, which is a clinically relevant period of time for treating many types of anemia, including chemotherapy-induced anemia, was well tolerated and showed no evidence of causing toxicity in treated animals," said David Y. Liu, Ph.D., Vice President of Research at FibroGen. "In addition, the weekly doses used in this study were four- to seven-fold higher than doses of FG-2216 associated with significant increases in hemoglobin levels in anemic patients with chronic kidney disease. Our research also indicates that anemic subjects require less FG-2216 therapy to stimulate erythropoiesis than non-anemic counterparts. Taken together, these observations suggest that there may be a significant safety margin for FG-2216 for treating anemic patients."

This dose-escalation study randomized experimental animals to receive either placebo or FG-2216 as an oral dose twice a week on Monday and Thursday, starting with 40 mg/kg for two months, followed by dose escalation to 60 mg/kg. Animals treated with FG-2216 exhibited an increase in total hemoglobin from a mean baseline of 12.0 g/dL to 13.2 g/dL at 40 mg/kg and a further increase to 14.6 g/dL at 60 mg/kg. After approximately two months of twice weekly therapy at 60 mg/kg, weekly phlebotomy (15-20% reduction in blood volume) was introduced for six to eight weeks while FG-2216 dosing was continued. The average hemoglobin levels in the phlebotomized animals treated with FG-2216 were in excess of 2.5 g/dL higher than the hemoglobin levels in phlebotomized animals receiving placebo.

"The data also indicate that management of hemoglobin rate of rise and maintenance of the corrected hemoglobin level were predictable and dose-dependent," said Dr. Liu. "We expect that by modulating the dosing schedule of FG-2216, we can successfully manage hemoglobin correction to treat anemic patients, and phase 2 studies of FG-2216 are underway to determine the optimal dosing regimen."

About FG-2216

FG-2216 is an orally active, small molecule inhibitor of hypoxia-inducible factor-prolyl hydroxylase (HIF-PH), an enzyme that regulates the stability and activity of HIF. FG-2216 is designed to stabilize HIF and selectively activate the body's natural process of HIF-2-mediated erythropoiesis, including the induction of endogenous EPO, the mobilization and utilization of iron stores, and suppression of the inhibitory effects of inflammatory cytokines on erythropoiesis, features essential to the formation of new oxygen-carrying red blood cells and the treatment of anemia.

In 2004, FibroGen entered an agreement to license FG-2216 (and other compounds) to Astellas Pharma Inc. for development and sale in Japan for the treatment of anemia. FibroGen retains rights to all prolyl hydroxylase inhibitors for the treatment of anemia in the rest of the world.

About FibroGen

FibroGen, Inc., is a biotechnology-based drug discovery company using its expertise in the fields of tissue fibrosis, connective tissue growth factor (CTGF), and hypoxia-inducible factor (HIF) biology to discover, develop, and commercialize novel therapeutics for fibrotic disorders, diabetic complications, anemia, ischemic disease, cancer, and other areas of unmet medical need. FibroGen also develops and produces recombinant human collagens and gelatins using unique production technology that provides the basis for FibroGen's proprietary cosmetic dermal filler and biomaterials supply business.

For more information about FibroGen, Inc., please visit www.fibrogen.com.

Contact: Laura Hansen 650-866-7828 or lhansen@fibrogen.com