PBI-4050 is a therapy that Prometic Life Sciences is developing for the lung scarring that characterizes idiopathic pulmonary fibrosis.

IPF is a chronic lung disease. Its hallmark is tissue scarring, or fibrosis, that leads to lungs becoming stiffer and thicker, making it harder to breathe. IPF usually affects middle-aged adults. It isn’t clear how it develops. There is no cure, and patients have a poor outlook.

How PBI-4050 works

It is designed to slow the lung tissue scarring, thickening, and inflammation involved in IPF. It does this by preventing the over-activation of lung cells known as interstitial fibroblasts and alveolar epithelial cells. Reining in these cells reduces the production of cytokines, or chemicals that promote lung scarring.

PBI-4050 in clinical trials

Studies in mouse models of pulmonary fibrosis showed that it reduces levels of connective tissue growth factor and collagen, chemicals that promote lung scarring. This led to a significant alleviation of the disease.

Prometic completed a Phase 2 clinical trial (NCT02538536) of PBI-4050 in January 2017. The study involved 40 IPF patients, aged 40 and over, at six sites in Canada.

All received four 200-mg oral capsules of PBI-4050 daily for five months. One group took PBI-4050 by itself, another group PBI-4050 and Esbriet (pirfenidone), and still another PBI-4050 and Ofev (nintedanib). Both Esbriet and Ofev are approved oral treatments for the lung scarring in IPF.

All three groups experienced a less than 10 percent decline in a lung function measure known as forced vital capacity — the amount of air a person can forcibly exhale from their lungs after a deep breath.

All of the treatment regimens were safe, researchers said. The most common side effect was diarrhea. Reduced blood levels of Esbriet were found in patients taking the PBI-4050-Esbriet combo, suggesting a potential drug interaction between the two.

Prometric obtained U.S. Food and Drug Administration approval in January 2018 to start a Phase 2/3 trial to further test PBI-4050. Patients with mild to moderate IPF can participate in the trial if they have not been taking Esbriet — because of its possible interaction with PBI-4050. Patients are eligible whether or not they have been taking Ofev.

Researchers will give the participants either 800 mg or 1,200 mg of PBI-4050 for a year, with an interim safety analysis at six months.

Additional information

The FDA granted fast track status to it n November 2017. The designation is aimed at accelerating its development and regulatory review. Both the FDA and European Union have granted it an orphan drug, a designation aimed at promoting the development of therapies for rare diseases.

Prometic is also conducting trials of PBI-4050 as a potential treatment for other conditions, including Alström syndrome (NCT03184584 and NCT02739217), cystic fibrosis (NCT02955888), and type 2 diabetes with metabolic syndrome (NCT02562573 and NCT03081598).


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