Companies Combine Strengths to Develop Anti-Fibrotic Therapeutics

South San Francisco, California and Tokyo, Japan, September 11, 2001 - FibroGen, Inc. and Sankyo Co. Ltd. today announced that they have entered into a collaboration to discover and develop treatments for fibrotic conditions focusing on diabetic nephropathy, retinopathy, and other forms of renal fibrosis, as well as pulmonary fibrosis, organ transplant rejection, liver fibrosis, and atherosclerosis. The collaboration between FibroGen and Sankyo will increase resources applied to FibroGen's proprietary research discoveries and accelerate the development of small molecule drugs for use in treatment of fibrotic diseases. According to the United Sates Department of Health and Human Services, fibrotic disorders directly or indirectly result in close to 45% of all annual deaths in the U.S.

The research will focus on inhibitors of the pathways through which Transforming Growth Factor Beta ("TGF-beta") transcriptionally activates Connective Tissue Growth Factor ("CTGF") and on inhibitors of pathways by which CTGF signal transduction upregulates matrix production and other elements of fibrotic pathogenesis. CTGF is a novel cytokine proprietary to FibroGen. There is growing evidence that CTGF is fundamentally involved in a number of fibrotic conditions. Low molecular weight inhibitors of CTGF action could permit long-term therapy of these debilitating and often fatal diseases.

Under the terms of this global agreement, FibroGen will receive an upfront payment, committed research funding, and milestone payments as the program advances. Upon commercialization, Sankyo and FibroGen will co-promote compounds resulting from the research collaboration for use against renal fibrosis, cardiovascular disease, diabetic retinopathy, and hepatic fibrosis in North America. FibroGen will receive royalties on Sankyo's sales outside of the North American market for those indications. FibroGen retains global rights to all other indications.

"Through our own work and the work of our global collaborators, it is becoming very clear that CTGF is a critical mediator in the development of fibrotic diseases," said Thomas Neff, President and CEO of FibroGen. "We are particularly pleased to be in this collaborative arrangement with Sankyo, and to leverage our current and developing knowledge of the signal transduction pathways involved to create novel small molecule inhibitors to block chronic fibrotic conditions. Sankyo's deep interest in diabetes and diabetic nephropathy, which cause approximately 40% of kidney fibrosis and the resultant dialysis in the United States, as well as other significant disease states, was a critical factor in our decision to create this collaboration."

"This collaboration with FibroGen is a very important addition to our drug discovery program," said Sankyo's Executive Director of the Research Division. "FibroGen's proprietary and groundbreaking work in the field of CTGF and fibrosis together with Sankyo's research and developmental capabilities should significantly accelerate discoveries leading to the creation of drugs to address major unmet needs in large and growing disease states."

About Sankyo Company, Ltd.

Sankyo Company, Ltd. is the second largest pharmaceutical company in Japan. Headquartered in Tokyo and established in 1899, Sankyo employs nearly 7000 people. Sankyo also has marketing activities in the U.S., in Europe and in Asia through its branch offices and joint ventures. As a research-based developer, manufacturer, and marketer, Sankyo has introduced to the international market several breakthrough drugs from its own research, including pravastatin (Mevalotin^TM or Pravachol^TM), an anti-hyperlipidemic agent; cefpodoxime proxetil (Banan^TM or Vantin^TM), an oral anti-infective agent; and loxoprofen sodium (Loxonin^TM), the largest anti-inflammatory drug in Japan. Sankyo's website address is www.sankyo.co.jp.

About FibroGen Inc.

FibroGen, Inc., is a private biotechnology company developing novel drugs to arrest fibrotic diseases in both chronic and acute conditions, such as renal and liver fibrosis, as well as the fibrotic complications of diabetes, for which there are no therapies today. Additionally, leveraging its knowledge of extracellular matrix biology, FibroGen has developed the only known commercially viable method for production of recombinant human collagens as well as specific synthetic gelatins based on portions of collagen molecules. Collagens and gelatins are sourced today from animal tissue and are widely used by the pharmaceutical, medical device, technology and food industries.

FibroGen has a number of collaborations with pharmaceutical companies worldwide, including Aventis Pasteur, a unit of Aventis SA, and Taisho Pharmaceutical as well as Feasibility Agreements with more than thirty companies evaluating its novel biomaterials.