Vaccine company Jennerex has raised $5.1 million in a Series C round of financing. The money will allow Jennerex to continue advancing its pipeline of virus-based oncology products. A second closing is expected on September 15. The San Francisco-based company has not identified its investors. Jennerex's lead product is JX-594, designed to treat liver and colorectal cancer. JX-594 attacks tumors using a genetically modified version of the virus that is the basis of the smallpox vaccine. The product takes two different approaches to fighting cancer: It is engineered to both destroy the tumor and stimulate immune response, decreasing the likelihood that the cancer will become resistant to the treatment. A Phase I trial demonstrated that JX-594 effectively destroyed tumors in liver cancer and lung cancer patients. JX-594 is currently undergoing a Phase II trial in the United States, South Korea, and Canada. Endocare, Delcath Systems, Metabasis Therapeutics, Medical Device Works, BioSphere Medical, and SIRTeX Medical are a few of the other companies developing novel treatments for liver cancer, which approximately half a million people around the world are diagnosed with per year. According to the American Cancer Society, more than 90 percent of people diagnosed with liver cancer are over 45 years of age.