Pirfenidone for the Reduction of Metabolic, Inflammatory and Fibrogenic Activity in Complicated Silicosis

Overview

Silicosis is one of the leading causes of occupational respiratory disease worldwide. It is due to inhalation of respirable crystalline silica and can lead to progressive massive fibrosis (PMF), respiratory failure, and death. It is estimated that it causes more than 10,000 deaths a year worldwide, mainly in developing countries, although the level of underdiagnosis is high. In developed countries the incidence of the disease has been progressively decreasing in recent years, mainly due to the implementation of effective prevention measures, better occupational health surveillance systems and the displacement of mining activity to other countries, in a way that in the United Kingdom 216 cases were reported from 1996 to 2017. At the moment, there is no curative treatment for the disease, and the only therapeutic option is lung transplantation (when the disease evolves to PMF and subsequent respiratory failure). Meanwhile, the only accepted treatment is supportive treatment, with the administration of oxygen therapy in case of respiratory failure, early treatment of respiratory infections, vaccinations and respiratory rehabilitation. In recent years, molecules with antifibrogenic capacity have been developed and have demonstrated their ability to decrease pulmonary fibrogenic activity in diseases such as Idiopathic Pulmonary Fibrosis (IPF). This has been a milestone in the treatment of this disease and, therefore, its possible application to other diseases that share fibrogenic mechanisms with IPF, as PMF. The two molecules with the most clinical experience and approved for IPF are nintedanib and pirfenidone. The antifibrotic properties of pirfenidone have raised great expectations and many clinical trials are currently being carried out in other lung diseases that cause fibrosis, that is why we decide to study the efficacy of pirfenidone in reducing metabolic, inflammatory, and fibrogenic lung disease in patients with artificial stone silicosis and progressive massive fibrosis (PMF).

Hypothesis: Pirfenidone reduces pulmonary metabolic activity in patients with Progressive Massive Fibrosis (PMF). Objetives: Main objetive: To evaluate the efficacy of pirfenidone in reducing pulmonary metabolic activity quantified by PET-CT Scan (F-FDG) in patients with Progressive Massive Fibrosis (PMF). Secundary objetives: 1. To evaluate the efficacy of pirfenidone in reducing pulmonary inflammatory and fibrogenic activity in patients with Progressive Massive Fibrosis (PMF), quantified by cell biomarkers, and the relation with the pulmonary metabolic activity. 2. To assess changes brought about by pirfenidone in the different cells biomarkers patterns and metabolic activity resulted by PET/TC with 18-FDG 3. To assess radiological changes in HRCT (High Resolution Computed Tomography) that occur after administration of pirfenidone and the relation with biomarkers and with 18F FDG acquisition. 4. To assess wheter administration of pirfenidone generates changes on standard funtional respiratory explorations, and the relation with inflammatory and metabolic activity. 5. To assess clinical changes (if any) and safety of pirfenidone after administration to patients with PMF. Methodology: An Open, Randomised, Controlled, 2 arms and Unicenter Clinical Trial to Assess the Efficiency of Pirfenidone for the Reduction of Pulmonary Metabolic, Inflammatory and Fibrogenic Activity in Patients With Silicosis Due to Artificial Stone and PMF.