SillaJen, Inc. engages in the development and commercialization of oncolytic immunotherapy products. The company's lead product is Pexa-Vec, which is in Phase II clinical trial for the treatment of advanced liver cancer. It also develops JX-970 for the treatment of tumor tissues; and JX-900 is a series of modified vaccinia vaccine. The company was founded in 2006 and is headquartered in Seoul, South Korea.