According to the initial findings of a phase I trial, a new genetically modified virus has dealt a double blow against advanced cancers. The researchers discovered that RP2, a modified version of the herpes simplex virus, showed signs of effectiveness in a quarter of patients with various types of advanced cancers. Larger and longer studies will be needed, but experts say the injection could ultimately offer a lifesaver to more people with advanced cancers. Scientists have genetically modified a strain of the herpes virus to act as an agent that kills cancer in humans.
The results of an initial human trial are encouraging, as the experimental treatment has proven to be safe and promisingly effective. A patient in a trial testing a herpesvirus-based cancer treatment saw his cancer completely disappear and has remained cancer-free in the 15 months since his treatment began, announced the Institute for Cancer Research (ICR) in London. Oncolytic herpes simplex viruses (OHSV) are among the few oncolytic viruses that have passed phase III clinical trials. He explained that there were also approved medications available that could treat a herpes infection if the virus ended up replicating in places where it shouldn't, even though that hadn't happened in the tests.
This is not the first time that we have developed a modified herpesvirus to fight cancer. Modified versions of HSV-1 have already proven successful against melanoma and brain cancer. The drug is a weakened form of the cold sores virus (herpes simplex) that has been modified to kill tumors. When patients' tumors were biopsied before and after the injection, they found evidence that herpes was activating the immune system, with more immune cells present around the tumor.
Herpesviruses, which also include the viruses behind chickenpox and genital herpes, have developed a number of remarkable abilities, such as the trick of infecting and hiding in nerve cells, from which they emerge periodically to cause outbreaks of sores or skin rashes, such as shingles. Harrington told Medical News Today in an interview that the herpes virus really offered the “complete package” as a candidate for genetic modification to create such treatments. McFaddent said that one limitation of the use of herpes viruses as a basis for these treatments was that they had to be injected directly into the tumor, while it was expected that treatments based on smallpox viruses could be administered intravenously. A brief treatment with the virus, which is a specially modified version of the herpes virus that normally causes cold sores, seems to have eliminated your cancer.
The oncolytic herpes simplex virus (OHSV) can be genetically modified to attack cancer cells while preserving normal cells. The herpes simplex virus (HSV), which belongs to the Herpesviridae family, has a large dsDNA (152 kb) that is encapsulated within an enveloped icosahedron capsid. Viruses that have been used as oncolytic viruses include the herpes simplex virus, adenoviruses, smallpox viruses and the Coxsackie virus, and genetic modifications are used to introduce transgenes to improve their ability to kill cancer cells.