FibroGen Inc. (FibroGen) recently presented complete data from a clinical study involving the experimental drug FG-3019 in patients with idiopathic pulmonary fibrosis (IPF.) A large group of patients treated with FG-3019 showed a decrease in lung fibrosis. The data was presented during the 18th International Colloquium on Lung and Airway Fibrosis (ICLAF) held in Mont Tremblant, Quebec from September 20-24 at a poster session entitled, “Safety and Efficacy of Anti-CTGF Monoclonal Antibody FG-3019 for Treatment of Idiopathic Pulmonary Fibrosis (IPF): Combined Results for Two Cohorts Treated for One YearPoster.”
Idiopathic Pulmonary Fibrosis (IPF) is a disease of the lung characterized by progressive scarring of the lung tissue, which leads to a decrease of functional lung volume and oxygen uptake. The origin of IPF is not known. Many people with the disease live only for 3 to 5 years after diagnosis, and the disease has no cure. The main cause of death in IPF patients is respiratory failure.
FG-3019 is an experimental therapeutic human monoclonal antibody that inhibits the activity of connective tissue growth factor (CTGF), crucial factor involved in chronic fibrotic and proliferative disorders, characterized by persistent and excessive scarring that can lead to organ dysfunction and failure. FibroGen is a private biotechnology company based in San Francisco, CA, focused on the research, development, and commercialization of therapeutic compounds, such as FG-3019, for treatment of proliferative diseases, such as pancreatic cancer and liver fibrosis.
The clinical trial was designed as a Phase 2 open-label study to evaluate the safety and efficacy of FG-3019 in patients with a broad range of IPF severity by evaluating changes in both pulmonary function and fibrosis. The patients were divided in two cohorts according to severity of the disease, assessed by the percentage of forced vital capacity (FVC), and the measurement of the lung function quantified by the amount of air a person can exhale from the lungs after taking a very deep breath. The first cohort included patients with a wide range of disease severity, from mild to severe (FVC % predicted 45-85%), while in the second cohort patients had mild to moderate (FVC % predicted =55%). The majority of patients in cohort 1 with severe disease left the trial before its completion.
Patients from both cohorts were treated with two intravenous doses of FG-3019 of either 15 mg/kg or 30 mg/kg every three weeks for 45 weeks. The assessment of changes in pulmonary function was completed in 74 and 66 patients, respectively, after they had completed 24 and 66 weeks of treatment. After the 24th and 66th week of treatment, 17 of the 74 patients in the first cohort and 16 of the 66 patients in the second cohort had improved changes in pulmonary fibrosis measured by quantitative high resolution computed tomography (HRCT). HRCT is a precise and reproducible computer-based method to quantify fibrotic changes in lung tissue. This quantitative method has been used in peer-reviewed publications, where a positive correlation was discovered between pulmonary fibrosis and mortality in IPF. Notably, in this clinical trial it was also observed that, on average, patients with improved or stable fibrosis had improved pulmonary function. In general, the treatment was well tolerated by patients.
FibroGen says that this is the first trial to demonstrate improved fibrosis in IPF. The company is currently conducting a randomized placebo controlled Phase 2 trial in IPF and in the near future this trial will be extend outside of the US.