Alios BioPharma is a privately held, clinical stage, biotechnology company in South San Francisco, California that is developing novel medicines aimed at the treatment of viral diseases. In collaboration with Vertex Pharmaceuticals (NASDAQ: VRTX), Alios is developing VX-135 (formerly known as ALS-2200), a uridine nucleotide analog, for the treatment of chronic hepatitis C. VX-135 began Phase 2 clinical develpment with all-oral regimens in early 2013 and is expected to be in pivotal development beginning in 2014. Alios has developed a novel proprietary nucleoside/tide library to identify therapeutics for the treatment of several viral infections beyond HCV, including RSV, rhinovirus, norovirus, influenza and other emerging viral diseases. Additionally, Alios is developing non-nucleoside/tide small molecule therapeutics that will complement its nucleoside/tide portfolio. The overall goal for the Alios therapeutic platform is to maximize patient benefits in areas of high unmet medical need through optimization of potency, safety and tolerability.