Idiopathic Pulmonary Fibrosis Treatment, PLN-74809, Granted Orphan Drug Designation

The US Food and Drug Administration (FDA) has granted an orphan drug designation to Pliant Therapeutics, Inc’s anti-fibrotic lead compound, PLN-74809, for the treatment of idiopathic pulmonary fibrosis (IPF), a rare chronic lung disorder estimated to affect 5 million individuals worldwide.

"Achieving this important regulatory milestone provides Pliant an early vote of confidence as we prepare our investigational new drug application and plan the first-in-human trials for PLN-74809,” said Éric Lefebvre, MD, chief medical officer of Pliant Therapeutics, in a recent statement. “We are eager to initiate clinical development of this product candidate early next year as a potential treatment option for patients with IPF.”

PLN-74809 is a dual selective inhibitor of the αVβ1 and αVβ6 integrins. Pliant's therapeutic approach focuses on fibrotic tissue-specific inhibition of integrins and the TGF-β pathway. In preclinical studies, PLN-74809 exhibited the ability to prevent the growth of fibrotic tissue within the lung and liver, as it modulates fibrotic tissue-specific integrins.

Pliant plans to further evaluate PLN-74809 in patients with primary sclerosing cholangitis (PSC).

IPF is characterized by the thickening, stiffening, and scarring of lung tissue. As such, those with IPF typically experience shortness of breath and progressive lung disease. The disorder ultimately leads to potentially life-threatening complications such as respiratory failure.

Two drugs were approved by FDA in 2014 for the treatment of patients with IPF—nintedanib, which has been shown to slow the decline in lung function in mild to moderate cases, and pirfenidone, which has been shown to slow the progression of mild to moderate IPF.