The cause of fibrosis, the hardening and thickening of connective tissue in organs, isn’t known and it has few treatments. Pliant Therapeutics aims to bring patients who have this chronic and life-threatening condition in the lungs or the liver a new treatment option—and it now has $62 million to test its lead drug in humans.
Cowen Healthcare Investments led the Series B round of investment for Pliant, based in South San Francisco, CA. The financing included cash from so-called crossover investors, institutions that invest in both private and public companies. Crossover investment is viewed as a sign that a company is considering an IPO.
Fibrosis in the lungs is called idiopathic pulmonary fibrosis (IPF). The condition is rare, affecting an estimated 200,000 people in the U.S. each year, and causing approximately 40,000 deaths, according to Pliant. Two drugs are FDA approved for treating this form of fibrosis: nintedanib (Ofrev), made by Boehringer Ingelheim, and pirfenidone (Esbriet), from Roche. Fibrosis in the bile ducts of the liver is called primary sclerosing cholangitis (PSC). This form of fibrosis affects an estimated 30,000 in the U.S. PSC has no FDA-approved therapies, so treatment involves addressing the symptoms, according to the National Organization for Rare Disorders.
Pliant aims to treat fibrosis with a drug that targets a family of proteins called integrins that research has linked to the development of fibrous tissue. By selectively blocking two integrins, the company says its approach could prevent, or perhaps even reverse, fibrosis. The company plans to develop a pipeline of drugs to treat fibrosis in various organs; the forms affecting the lungs and liver are its first targets.
In animal studies, Pliant says its drug, an oral pill, blocked the activation of a protein thought to play a role in fibrosis development. The company now aims to see if it can do the same in humans. Pliant’s technology is based on the research of its scientific founders, who are experts in fibrotic disease and integrin chemistry at the University of California San Francisco.
Integrin-blocking drugs have already been approved for other diseases. The multiple sclerosis drug natalizumab (Tysabri), from Biogen (NASDAQ: BIIB), and the Merck (NYSE: MRK) blood thinner eptifibatide (Integrilin) are integrin inhibitors. Both are injectable antibody drugs. Morphic Therapeutic, a Harvard University spinout, raised $51.5 million in a Series A financing round two years ago to develop integrin blockers in a pill form that could treat fibrosis, cancer, autoimmune disease, and vascular disorders.
A number of other companies are also pursuing new fibrosis treatments. Last year, San Francisco-based FibroGen (NASDAQ: FGEN) released positive Phase 2 results for its IPF drug, pamrevlumab. Meanwhile, Lung Therapeutics of Austin, TX, has an IPF compound in preclinical development. But some IPF efforts have faltered. Last year, Global Blood Therapeutics (NASDAQ: GBT) stopped work on its fibrosis drug after clinical studies failed to show enough benefit to patients.
Pliant launched in 2016, backed $45 million in Series A financing from Third Rock Ventures. The company later expanded that round by $11 million. To date, Pliant has raised $118 million.
Other investors disclosed in the latest financing included Eventide Asset Management, Schroder Adveq, Menlo Ventures, SCubed Capital, and Agent Capital.
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