Treating brain cancer with novel viral vector

UC San Diego Moores Cancer Center researchers and surgeons are among the first in the US to treat patients with recurrent brain cancer by directly injecting an investigational viral vector into their tumour. The treatment is being developed by a local San Diego Company, Tocagen Inc.

''This clinical trial targets glioblastoma – one of the deadliest forms of brain tumour,'' said principal investigator Santosh Kesari, MD, PhD, director of neuro-oncology in the Moores Cancer Center and in the department of neurosciences at the University of California, San Diego.  ''Clinical trials of investigational therapies such as this may lead to new treatment options for patients battling this deadly disease.''

The current standard of care for a newly diagnosed, high-grade glioma includes surgically removing as much of the tumour as possible, followed by radiation therapy and chemotherapy.  Despite these measures, the tumour usually recurs making this trial a high priority.

The trial is investigating the use of Toca 511 (vocimagene amiretrorepvec), for injection in combination with Toca FC (flucytosine), extended-release tablets.  Toca 511 is a retroviral replicating vector (RRV) that is designed to deliver a cytosine deaminase (CD) gene selectively to cancer cells.

After allowing time for the administered Toca 511 to spread through the cancerous tumour those cancer cells expressing the CD gene can convert flucytosine into the anti-cancer drug 5-fluorouracil (5-FU).  In this study, patients receive cycles of oral Toca FC monthly for up to six months.