SillaJen

About SillaJen

SillaJen is a South Korean biotechnology company operating in the oncolytic immunotherapy market, developing treatments that use viruses to target and destroy cancer cells. The company's history is significantly marked by its acquisition of Jennerex, Inc. in March 2014, a San Francisco-based clinical-stage biotechnology company founded in 2003. Before the acquisition, SillaJen had been a contract research partner and the largest shareholder of Jennerex since 2007.

The company's core technology is the SOLVE™ (Selective Oncolytic Vaccinia Engineering) platform. This platform engineers a vaccinia virus (the same virus used in the smallpox vaccine) to selectively infect and replicate within cancer cells, which have common genetic defects that the virus can exploit. The process leads to the direct breakdown of cancer cells (oncolysis), cuts off the tumor's blood supply, and stimulates the patient's own immune system to attack the cancer.

SillaJen's lead product candidate developed from this platform was Pexa-Vec (JX-594), an oncolytic virus aimed primarily at treating advanced liver cancer (hepatocellular carcinoma). After promising Phase 2 results, SillaJen advanced Pexa-Vec to a global Phase 3 clinical trial in late 2015. However, in August 2019, the trial was halted on the recommendation of an independent monitoring committee because the drug failed to demonstrate a sufficient survival benefit for patients.

Following the clinical trial setback, SillaJen faced significant challenges, including the indictment of its former CEO, Moon Eun-sang, on charges of embezzlement and breach of trust, which led to a suspension of its stock trading on the KOSDAQ market in May 2020. After a period of uncertainty and facing a delisting risk, M2N Co., Ltd. became the largest shareholder in July 2021, providing new capital and leadership. The company is now advancing other pipeline candidates, including BAL0891, a dual TTK/PLK1 kinase inhibitor in-licensed from Basilea Pharmaceutica, for which it has initiated Phase 1 clinical trials in the U.S. for solid tumors and acute myeloid leukemia. SillaJen also continues to develop its next-generation oncolytic virus platforms, such as the SJ-600 series, designed to improve intravenous delivery and evade the immune system.