The US Food and Drug Administration (FDA) has granted Orphan Drug Designation to FibroGen's FG-3019, the human monoclonal antibody against connective tissue growth factor (CTGF), for the treatment of idiopathic pulmonary fibrosis (IPF).

IPF is a progressive and fatal lung disease for which there are no FDA-approved therapies.  FG-3019 was developed to inhibit the activity of CTGF, a matricellular protein that plays a key role in fibrosis.  More than a decade of research conducted by FibroGen and others has established the critical role of CTGF as a final common pathway in chronic fibrotic diseases, in which persistent and excessive scarring leads to organ dysfunction and failure.

Orphan Drug Designation is generally granted to drugs or biologics intended for treatment of rare diseases and disorders, i.e., those affecting fewer than 200,000 people in the US.  This designation conveys special incentives to the sponsor, including tax credit for fifty percent of the cost of clinical trials, prescription drug user fee waiver, and seven years of US market exclusivity for the drug or biologic upon FDA approval.  

“The granting of FibroGen’s request for Orphan Drug Designation constitutes a major milestone in the development of FG-3019 for pulmonary fibrosis,” said Thomas B. Neff, Chief Executive Officer of FibroGen.  “We have been encouraged by early results from our ongoing phase 2 studies suggesting that sufficiently high bloodstream levels of FibroGen’s FG-3019 antibody may prevent predicted decline in lung function and even increase lung capacity in some cases.  We are committed to further clinical evaluation of FG-3019 in hopes of developing a safe and effective therapy that will provide IPF patients with a superior treatment outcome.”

FG-3019 has been the subject of clinical studies involving over 200 patients to date, including a Phase 1 study of patients with IPF.  FibroGen is currently conducting an open-label Phase 2 study of FG-3019 in patients with IPF as well as two other clinical studies in different diseases.  One is a study in Hong Kong in patients with liver fibrosis as a manifestation of hepatitis B.  Reversal of liver fibrosis would prevent liver failure and reduce the risk of developing hepatocellular carcinoma. The other is a study in patients with pancreatic cancer, a disease in which extensive fibrosis associated with pancreatic tumors and metastases is thought to make this aggressive form of cancer highly resistant to chemotherapy.  FG-3019 has been well tolerated in all clinical studies to date with no apparent safety signals.

IPF is a debilitating and life-threatening lung disease characterized by a progressive scarring of the lungs that diminishes functional lung volume and hinders oxygen uptake.  The cause of IPF is not known.  As scarring progresses, patients with IPF experience shortness of breath (dyspnea) and difficulty with performing routine functions, such as activities of daily living.  Approximately 40,000 cases of IPF are diagnosed annually in the US and Canada, where the overall prevalence is estimated to be 150,000.  There are no FDA-approved treatments for IPF, and approximately two-thirds of patients die within five years after diagnosis.  Patients are often treated with corticosteroids and immunosuppressive agents, however, no therapies have been clinically proven to improve survival or quality of life.  It is thought that stabilization or reversal of lung fibrosis could stabilize lung function and diminish the impact of this devastating disease.

FibroGen, Inc., was founded to discover and develop anti-fibrotic therapeutics.  FibroGen has applied its expertise in the field of tissue fibrosis – with matricellular proteins, such as connective tissue growth factor (CTGF), and with matrix assembly enzymes, such as prolyl hydroxylases – to the clinical development of anti-CTGF agents and prolyl hydroxylase inhibitors in therapies meeting serious unmet medical needs.