A genetically-modified vaccine used to eradicate smallpox decades ago, is now being used in the treatment of liver cancer, a study suggests.
The study was conducted on a small scale with 30 patients diagnosed with liver cancer. They were treated with the vaccine Pexa-Vec or JX-594. Divided in two groups, the first group with 16 patients was injected a high dose of the therapy that increased the survival rate by 14.1 months and the second group with 14 patients was injected a low dose, which increased survival rate by 6.7 months, according to Medical Xpress. The four week trial did show a significant improvement in the treatment of advanced tumors.
"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.
The authors noted that most of the tumors in metastatic state remained incurable despite the advanced treatments in cancer with chemotherapy and biologics over the last three decades. "More potent active immunotherapies" are needed.
Kirn from California-based biotherapy company, Jennerex, explained how Pexa-Vec functions to destroy the cancer cells. Pexa-Vec "is designed to multiply in and subsequently destroy cancer cells, while at the same time making the patients' own immune defence system attack cancer cells also."
"The results demonstrated that Pexa-Vec treatment at both doses resulted in a reduction of tumor size and decreased blood flow to tumors," said a Jennerex statement, reports Medical Xpress. "The data further demonstrates that Pexa-Vec treatment induced an immune response against the tumor."
Pexa-Vec has been engineered from vaccinia virus, vaccine that helped eradicate small pox, says the report.
During the trials it was noted that treatment with Pexa-Vec led to some flu like symptoms despite its efficient effort to kill the cancer cells. All patients lasted the flu like symptoms for maximum a day or two except one who had severe nausea and vomiting.
Authors suggest a trial be conducted on a larger scale to confirm the results.
The findings of the study are published in the journal Nature Medicine.
