Editing Herpes Virus



{{TreatmentInfo
|drug_name=Herpes Virus
|category=Oncolytic virotherapy
|book_text=Another virus used in cancer therapy is a modified form of the herpes virus. Initial trials
used a retrovirus version, which infects only those cells dividing when the virus was
infused. Subsequent trials have used an adenovirus version, which infects both dividing
and non-dividing cells. Because the herpes virus can be lethal to the brain if allowed to
proliferate, soon after the virus infusion patients receive ganciclovir, an effective
anti-herpes agent. In one study using this technique performed at Mt. Sinai Hospital in
New York (170), median survival of 12 patients with recurrent GBM tumors was 59 weeks
from the point of treatment, with 50% of the patients alive 12 months after the treatment.
The authors also reported the absence of toxicity from the treatment, which was a major
concern due to significant brain damage when the procedure was tested with monkeys.
Why the difference from the monkey study's results is unclear.

More recent research with the herpes virus has been focused on forms of the virus that
have been engineered to retain the anti-cancer effects of the virus but without its property
of producing neurological inflammation. The first use of this modified virus in a clinical
trial was in Glasgow, Scotland. Nine patients with recurrent glioblastomas received the
virus injected directly into the tumor. Four were alive at the time of the report of the
study, 14-24 months after the treatment (171).
}}