By leveraging its powerful product engine based on recent biologic insights, Pliant Therapeutics has the potential to prevent or even reverse fibrosis caused by many disease processes. Bernard Coulie, M.D., Ph.D., has been appointed chief executive officer of Pliant and brings more than 15 years of drug development expertise, including six years in leadership positions at Johnson & Johnson, and most recently as co-founder and CEO of ActoGeniX. Perry Karsen joins as chairman of the board and brings more than 30 years of experience in the biopharmaceutical industry after recently retiring from his role as CEO of Celgene Cellular Therapeutics.

Pliant's programs build upon the vision of its founders, University of California, San Francisco (UCSF) researchers who together bring broad experience in fibrosis biology and small molecule chemistry:
¢ Dean Sheppard, M.D., professor of medicine and chief of the Division of Pulmonary, Critical Care, Allergy and Sleep at UCSF
¢ Bill DeGrado, Ph.D., professor in the Department of Pharmaceutical Chemistry at UCSF
¢ Hal Chapman, M.D., professor of medicine, Division of Pulmonary, Critical Care, Allergy and Sleep at UCSF
¢ Bradley Backes, Ph.D., associate professor in the Department of Medicine at UCSF

'Pliant's founders include world-renowned researchers from the University of California, San Francisco who have discovered key insights into the biology behind fibrosis and developed small molecule therapeutics to target this devastating disease process,' said Neil Exter, partner at Third Rock Ventures.

'Third Rock Ventures is very excited to have Dr. Coulie join these esteemed experts to bring forward an entirely new approach for fibrosis patients who currently have limited options.'

Unmet Need in Fibrotic Disorders
Fibrosis, a pathologic feature of many diseases, results from an accumulation of scar-like tissue in vital organs, causing irreparable damage and eventual organ failure. In contrast to the few current FDA-approved therapies that treat fibrotic disorders, Pliant is targeting the untapped therapeutic potential of integrin biology to prevent TGF-β activation. TGF-β is arguably the most critical regulator of physiological healing and pathologic fibrosis.

Pliant's approach focuses on the antagonism of cell- and tissue-specific TGF-β signaling, in turn reducing and possibly reversing the fibrotic effects of TGF-β. Targeting TGF-β broadly has yielded undesirable systemic side effects. By targeting TGF-β signaling in a tissue-specific manner through integrin inhibition, Pliant hopes to effectively modulate the fibrotic cascade, maximizing therapeutic effects while avoiding adverse events.

Product Engine and Pipeline
Pliant's product engine has the potential to address the needs of many patients by targeting fibrosis in a variety of organs and conditions, including the lungs (IPF), liver (NASH and cirrhosis), kidney (renal fibrosis), skin (scleroderma), heart (cardiac fibrosis) and the gastrointestinal tract (Crohn's disease).

Pliant is entering the fibrosis space initially targeting idiopathic pulmonary fibrosis (IPF), a highly lethal and rare disease that currently affects approximately 200,000 people in the U.S., resulting in 40,000 deaths per year. Patients diagnosed with IPF experience progressive breathlessness and eventually, complete respiratory failure.

Pliant's lead programs for IPF are small molecule inhibitors modulating cell-specific integrins, which selectively block activation of TGF-β, preventing, and possibly reversing, the growth of fibrotic tissue within the lung. Pliant has entered into a license agreement with UCSF to expand this technology. The company will evaluate clinical development candidates in the coming months and will progress to IND-enabling studies in 2017. Pliant is actively developing additional fibrosis programs leveraging small molecule inhibitors to prevent and potentially reverse pathologic fibrosis through novel mechanisms in multiple organs.

Patient Registry & Biomarker Discovery
Pliant is committed to building a patient registry that relies on a multicenter effort to collect clinical and laboratory data on individuals with IPF and other fibrotic diseases. The registry aims to both expand knowledge of the natural progression of the disease and fuel biomarker discovery. With this approach, Pliant intends to design efficient clinical trials leveraging validated clinical endpoints.

Management Team
Pliant's founding management team has deep expertise and a proven track record of building exceptional life science companies. Dr. Coulie joins Pliant from ActoGeniX, where he served as co-founder, chief executive officer and chief medical officer until the company's acquisition by Intrexon Corporation in February 2015. Prior to ActoGeniX, Dr. Coulie held various positions with increasing responsibilities in drug discovery and clinical development at Johnson & Johnson Pharmaceutical Research and Development Europe. Dr. Coulie holds an M.D. and Ph.D. from the University of Leuven, Belgium. He is a board-certified internist and received his M.B.A. from the Vlerick Management School, Leuven, Belgium.

In addition to Dr. Coulie, Pliant's management team includes: David Morgans, Ph.D., vice president of drug discovery and early development, who brings more than 25 years of experience in drug discovery and development of small molecules; Craig Muir, interim chief technology officer and partner at Third Rock Ventures, who brings more than 25 years of experience in technology development, implementation and application across the biotechnology and pharmaceutical industries; and Richard Gaster, M.D., Ph.D., director of translational medicine, a physician, scientist and entrepreneur who joins Pliant from Third Rock Ventures, where he served as a senior associate responsible for new company formation. Perry Karsen will serve as chairman of the board of directors alongside Third Rock Ventures partner Neil Exter and venture partner Charles Homcy, M.D.

About Pliant Therapeutics
Pliant Therapeutics is an early-stage biotechnology company harnessing the therapeutic capabilities of integrin biology and TGF-β signaling to develop breakthrough treatments for fibrotic diseases. By leveraging its powerful product engine, Pliant's mission is to prevent or even reverse fibrosis, restoring organ function. The company also aims to build a patient registry for certain areas of fibrotic disease to both increase understanding of natural disease progression and fuel biomarker discovery for efficient clinical trial design. Founded by a group of seasoned experts in fibrosis biology and medicinal chemistry, Pliant Therapeutics was launched in 2016 by Third Rock Ventures and is headquartered in Redwood City, California. For more information, please visit www.pliantrx.com.

About Third Rock Ventures
Third Rock Ventures is the leading healthcare venture firm focused on disruptive areas of science and medicine to discover, launch and build companies that make a dramatic difference in people's lives. By combining our team's scientific vision, strategic leadership, operational expertise and innovative deal-making capabilities, we nurture bold ideas that translate into successful business enterprises. Recognizing that the best way to create value for our investors is to create value for patients, our companies are built on a solid foundation of science, medicine, people and business strategy. For more information, please visitwww.thirdrockventures.com.

About UCSF
UC San Francisco (UCSF) is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care. It includes top-ranked graduate schools of dentistry, medicine, nursing and pharmacy; a graduate division with nationally renowned programs in basic, biomedical, translational and population sciences; and a preeminent biomedical research enterprise. It also includes UCSF Health, which comprises three top-ranked hospitals - UCSF Medical Center, UCSF Benioff Children's Hospital San Francisco and UCSF Benioff Children's Hospital Oakland - and other partner and affiliated hospitals and healthcare providers throughout the Bay Area. Please visit www.ucsf.edu/news.

The UCSF - Pliant technology licensing deal was negotiated by UCSF's Office of Innovation, Technology & Alliances (ITA). The ITA coordinates UCSF's efforts in forging collaborations and licensing technologies that translate cutting-edge science on campus into therapies and products that directly benefit patients worldwide.