Jennerex Biotherapeutics

The company's core business was the development of genetically engineered oncolytic viruses designed to treat solid tumors. This approach represented a multi-pronged attack on cancer: directly killing tumor cells through lysis, stimulating the patient's own immune system against the cancer, and destroying the tumor's blood supply. Jennerex's business model focused on advancing its product candidates through clinical trials, funded by over $46.9 million raised across multiple financing rounds, including a Series F in 2013. The company's strategy involved forming partnerships with other pharmaceutical companies for development and commercialization in specific territories.

Jennerex's lead product was Pexa-Vec (formerly JX-594), an oncolytic virus derived from the vaccinia virus strain used for vaccinations. Pexa-Vec was engineered to selectively replicate in and destroy cancer cells while also expressing GM-CSF, a protein that stimulates an anti-tumor immune response. A key feature of Pexa-Vec was its ability to be administered intravenously, allowing it to target metastatic tumors systemically, a significant advantage over direct tumor injection methods. The company advanced Pexa-Vec into mid-stage clinical trials for various cancers, including liver, colorectal, and kidney cancer. Milestones included receiving Orphan Drug Designation for Pexa-Vec for liver cancer from the European Medicines Agency in 2009 and the U.S. FDA in 2013.

In March 2014, after a long-standing collaboration, Jennerex was acquired by its South Korean partner, SillaJen, Inc., for approximately $150 million. Following the acquisition, Jennerex became a wholly-owned subsidiary, and SillaJen was subsequently renamed SillaJen Biotherapeutics, solidifying its position in the oncolytic immunotherapy field and continuing the development of the combined pipeline, including Pexa-Vec.