FibroGen Announces Observations of Possible Disease Stabilization and Improvement in Interim Analysis of Phase 2 Study of FG-3019 as Treatment for Idiopathic Pulmonary Fibrosis

Treatment Duration Extended for Patients Who Are Benefiting from FG-3019

SAN FRANCISCO--()--FibroGen, Inc. (FibroGen), announced today that interim results from an ongoing open-label Phase 2 clinical study to evaluate FG-3019 as a treatment for idiopathic pulmonary fibrosis (IPF) continue to suggest that the investigational drug has the potential to stabilize and improve fibrosis in patients with the disease. The results substantiate earlier results reported in an oral presentation at the European Respiratory Society Annual Congress in September 2012.

“A substantial subset of IPF patients who received FG-3019 in the Phase 2 open label study experienced stabilization or improvement of lung fibrosis, based on computer-assisted high-resolution radiographic scores of lung fibrosis,” noted Frank H. Valone, M.D., Chief Medical Officer of FibroGen. “This observation of IPF fibrosis improvement is without clinical precedent and directly challenges the widely held belief that improvement in fibrosis is not a therapeutic possibility. Data from the Phase 2 FG-3019 study also suggest a correlation between improved fibrosis and improved pulmonary function. This evidence supports our belief in the potential clinical impact of FG-3019 across a number of IPF clinical outcomes.”

Treatment duration extended for patients who benefit from FG-3019

Patients enrolled in the study will be able to continue receiving FG-3019 after the conclusion of the study-period mandated in the protocol so long as their physician and the study medical monitor believe such treatment has the potential to provide clinical benefit.

Overview of Exploratory Studies to Date: Cohort 1, Cohort 1 Extension, and Cohort 2

In the Phase 2 open-label study of FG-3019, a first group (Cohort 1) of IPF patients was treated with FG-3019 at 15 mg/kg every 3 weeks for 45 weeks. Patients who experienced improved, stable, or modest decline in lung function after one year were allowed to continue in the trial for a second year of treatment at the same dose (Cohort 1 extension). A second cohort of patients was added to the trial and treated with FG-3019 at 30 mg/kg (Cohort 2).

The efficacy endpoints of the study include lung function, as measured every three months by change from baseline in forced vital capacity (FVC), and lung fibrosis, as measured every six months by change from baseline in quantitative high resolution computed tomography (HRCT) analysis of the entire lungs. HRCT was also used to measure total lung capacity (TLC) every six months. Overall health status was measured using the St. George Respiratory Questionnaire (SGRQ) a survey index used in evaluation of experimental therapies in patients with respiratory diseases.

Interim Analysis – Cohort 1

The open-label Phase 2 study enrolled 53 IPF patients in Cohort 1 with a wide range of disease severity (forced vital capacity (FVC) % predicted of 42.5% to 86.0% with mean and median values of 62.5% and 63.2%, respectively). On average, these patients are more severely ill than those typically enrolled in recent IPF trials involving other experimental therapies.

Observations included:

  • 16 patients with baseline FVC % predicted below 55% generally performed poorly in the trial.
  • Of the 37 patients with baseline FVC > 55% (% predicted), 33 (89%) completed 45 weeks of dosing.
    • Twelve of these patients (36%) had decreased pulmonary fibrosis in the week 48 with HRCT scan (mean decrease 2.83%) in contrast to the 21 patients who had stable or increased fibrosis (mean increase 5.24%).
    • Forced vital capacity on average increased by 0.02 L (1.28% predicted) in patients with decreased fibrosis, whereas FVC decreased by -0.20 L (-4.24% predicted) in patients with stable or increased lung fibrosis.
    • Patients with decreased lung fibrosis had increased total lung capacity.
    • Patients with decreased lung fibrosis tended to have improved symptoms when evaluated using the St. George Respiratory Questionnaire.

Of the patient group in Cohort 1 with FVC > 55% (% predicted), approximately 55% of patients who completed the first year of the trial continued for a second year of treatment based on physician and sponsor assessment of favorable average FVC test results at week 36 and week 48. Of those patients who completed the second year, 25% have FVC values greater than their baseline two years earlier.

About FG-3019

FG-3019 is an investigational therapeutic antibody developed by FibroGen to inhibit the activity of connective tissue growth factor (CTGF), a common factor in chronic fibrotic and proliferative disorders characterized by persistent and excessive scarring that can lead to organ dysfunction and failure. FibroGen is currently conducting clinical studies of FG-3019 in idiopathic pulmonary fibrosis, pancreatic cancer, and liver fibrosis. FG-3019 has been well tolerated, with no apparent safety signals, in more than nine clinical studies and more than 350 treated patients to date.

About IPF

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, and approximately two-thirds of IPF patients die within five years after diagnosis. Recent surveys indicate that there are approximately 83,000 IPF patients in the United States, however it is clear than many are misdiagnosed or do not understand how and where to seek treatment. While some of these patients have been treated with corticosteroids and immunosuppressive agents, no therapies have been clinically proven to improve survival or quality of life. It is thought that stabilization or improvement of lung fibrosis could stabilize or potentially restore lung function and diminish the impact of this devastating disease.

About FibroGen

FibroGen is a privately-held biotechnology company focused on the discovery, development, and commercialization of therapeutic agents for treatment of fibrosis, anemia, cancer, and other serious unmet medical needs. FibroGen’s FG-3019 monoclonal antibody is in clinical development for treatment of idiopathic pulmonary fibrosis and other proliferative diseases, including pancreatic cancer and liver fibrosis. Roxadustat (FG-4592), FibroGen’s small molecule inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase, is currently in clinical development for the treatment of anemia. FibroGen is also currently pursuing the use of proprietary recombinant human type III collagens in synthetic corneas for treatment of corneal blindness. For more information please visit: www.fibrogen.com.

Contacts

FibroGen, Inc.
Greg Mann, 415-978-1433
Corporate Communications
gmann@fibrogen.com

Contacts

FibroGen, Inc.
Greg Mann, 415-978-1433
Corporate Communications
gmann@fibrogen.com