What is IPF?
Idiopathic pulmonary fibrosis (IPF) is a disorder where fiber such as collagen is deposited on the alveolar walls (stroma) which leads to loss of flexibility in the lungs, resulting in respiratory failure.
Fibrosis progresses gradually, and is difficult to predict the course of disorder due to individual differences, however some cases may have rapid exacerbation in a short period (acute exacerbation).
IPF occurs frequently in males at 50 years or older. The average lifespan from the onset of subjective symptoms is said to be 3 to 5 years, and it is considered to be an intractable disease with no treatment drug available.
Mechanism of fibrosis
The cause of IPF is unknown at present, however the abnormality occurring in the repeated process of damage and repair in the alveolar epithelial cells (excessive repair) is thought to be the main cause. TGF-β1 and collagen are substances which play a particularly important role in the alveolar repair response. Collagen is a protein in fiber form which acts as scaffolding for cells to support the shapes of the tissues and organs, and it is also used as the repairing material to close wounds in the process of repairing damaged tissue. TGF-β1 is a molecule that triggers repairs of damage and induces the expression of collagen, however the excessive expression of TGF-β1 leads to excessive production of fiber protein such as collagen (excessive repair), and this promotes the fibrosis of the lungs
Current situations regarding the treatment of IPF
A new treatment drug for IPF has been developed in the recent years, and while this drug is reported to have an effect in suppressing the progression of the symptoms, it does not lead to complete recovery.
In addition, care is required in continuous administrations due to adverse drug reactions such as gastrointestinal disorders (including loss of appetite, gastric discomfort, and diarrhea), hepatic dysfunction, photosensitivity, and thromboembolism. Therefore, the treatment of idiopathic pulmonary fibrosis is still considered difficult at this stage.
And for this reason, research and development is taking place at various countries around the world to discover new drugs with higher efficacy and fewer adverse drug reactions.
Approach of Bonac to IPF
Bonac is currently conducting joint development with Toray Industries, Inc. on a new nucleic acid medicine (TRK-250) which targets the messenger RNA of TGF-β1.
We have conducted animal experiments using “mouse model with spontaneous onset of pulmonary fibrosis,” where human TGF-β1 is excessively expressed selectively in the lung, and found that TRK-250 suppresses the progression of pulmonary fibrosis and that no significant adverse drug reactions occur with this administration.
Since TRK-250 is administered locally to the lung through inhalation, the drug is not spread to the entire body. In addition, most of the components of TRK-250 consist as the substances found in the body. For these reasons, TRK-250 is expected to have a very low incidence of adverse drug reactions.