A new study recently published in the journal Nature Medicine reports that a genetically-engineered virus (Pexa-Vec or JX-594) can kill tumors and inhibit the new tumors from growing.
Sixteen patients who were given a high dose of Pexa-Vec survived for 14.1 months on average, compared to 6.7 months for 14 patients who were given a low dose.
According to AFP, the four-week trial may hold promise for the treatment of advanced tumors.
“Despite advances in cancer treatment over the past 30 years with chemotherapy and biologics, the majority of solid tumors remain incurable once they are metastatic [have spread to other organs],” the authors wrote in the study.
“For the first time in medical history we have shown that a genetically-engineered virus can improve survival of cancer patients,” study co-author David Kirn told AFP.
"Pexa-Vec is designed to multiply in and subsequently destroy cancer cells, while at the same time making the patients’ own immune defense system attack cancer cells also.
“The results demonstrated that Pexa-Vec treatment at both doses resulted in a reduction of tumour size and decreased blood flow to tumors. The data further demonstrates that Pexa-Vec treatment induced an immune response against the tumor.”
Pexa-Vec was engineered by the California-based biotherapy company Jennerex from the vaccinia virus, which has been used as a vaccine for decades and even eradicated smallpox.
A larger trial must be done to confirm the results. A follow-up phase with about 120 patients has already begun. Pexa-Vec is also being tested in other types of cancer tumors.