Ascletis, an emerging biotechnology company, and San Francisco-based clinical-stage pharmaceutical company, Presidio have entered into an exclusive licensing agreement for Presidio’s clinical stage, HCV NS5A inhibitor PPI-668, also known as ASC16. The agreement provides Ascletis with exclusive rights to develop and commercialize PPI-668 in Greater China.  Presidio will retain all rights in the rest of the world.

“This licensing agreement for PPI-668 adds a fourth drug candidate in late-stage development to the Ascletis pipeline, which aims to provide innovative therapeutics for important medical needs in China,” said Jinzi J. Wu, Ph.D., Ascletis president and chief executive officer. “Based on the clinical data to date, we believe that PPI-668, in combination with our current direct acting antiviral agent (DAA), danoprevir or ASC08, which has completed phase 2, offers a potentially effective interferon-free regimen for HCV-infected patients in China.”


“PPI-668 is a pan-genotypic HCV NS5A inhibitor that has shown high SVR rates in combination with other DAAs in a phase 2 study,” said Richard Colonno, Ph.D., Presidio’s chief scientific officer, “We look forward to our collaboration with Ascletis to provide HCV patients with this highly active inhibitor.”

Under the terms of the agreement, Ascletis will fund clinical development, manufacturing and commercialization of PPI-668 in greater China and Presidio will receive upfront and development milestone payments, as well as tiered royalties based on product net sales in Greater China.


Ascletis is an emerging biotechnology company, dedicated to discovering, developing and commercializing important new treatments for infectious diseases and cancer.  

Presidio Pharmaceuticals, Inc. is a San Francisco-based clinical-stage pharmaceutical company dedicated to the discovery and development of small-molecule antiviral therapeutics.