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Inside Pediatrics Podcast

Oncolytic Virotherapy for Children
Jeff Bailey, RadioMD Staff Writer

Clinical trials are key to cancer treatment development. New therapies pave the way for cancer eradication.

Oncolytic virotherapy uses a virus to target and kill cancer cells. A clinical trial at Children’s of Alabama in Birmingham utilizes an engineered herpes simplex virus to target cancer cells in brain tumors.

Herpes simplex typically causes cold sores but has been made safe for normal cells in this study.

Turning Virus Into Warrior

Dr. Gregory Friedman, a pediatric neuro-oncologist at Children’s of Alabama, associate professor of pediatrics at University of Alabama at Birmingham, and associate scientist at UAB’s Comprehensive Cancer Center, explains how oncolytic virotherapy works.

“The virus replicates when it gets inside the cell. It then spreads to nearby cells and kills them. At the same time, the virus stimulates the patient’s immune system within the area, because the immune system recognizes the virus as abnormal.”

The immune system then turns its attention to killing the cancer cells.

The procedure for viral engineering is safe. A specific gene that causes a virus to harm a normal cell is removed, rendering it safe for normal cells while acting as a warrior against cancer cells.

Clinical Trial Eligibility

The first step of the clinical trial screening process involves various labs and an MRI of the tumor. There must be a safe route for getting a biopsy of the tumor. The clinical trial team meets with the family to discuss the surgical procedure for treatment.

Once a child is selected for the study, a biopsy is taken immediately. This confirms that there is an actual tumor that can be treated. A pathologist views the tumor while still in the operating room for confirmation.

A verified tumor prompts the next stage of treatment right away. One to four small, thin catheters are placed into the tumor. These catheters extend out of the skin and scalp. The child recovers in the ICU as with any neurosurgical procedure.

The following day, a scan confirms the correct placement of the catheters. The pharmacy team mixes the right concentration of the virus. The virus is infused over six hours. Catheters are removed by the neurosurgery team when the procedure is complete.

The child is monitored over the next few days. Upon release from the hospital, the patient is checked weekly for a few weeks. Visits switch to monthly and then every few months.

The beginning of the process is very intense and involved, but the hope is that additional chemotherapy, radiation or other treatments are unnecessary.

“A phase-one study is looking at safety and tolerability to make sure that this approach is safe in children,” shares Dr. Friedman. Response in patients and improved survival are the goals.

While the study is still in early stages, there is some evidence that the virus is replicating and killing cancer cells.

For more information on the study, search for G207 at http://www.clinicaltrials.gov/

*To listen to an interview with Dr. Gregory Friedman, a pediatric neuro-oncologist at Children’s Hospital, associate professor of pediatrics at University of Alabama at Birmingham, and associate scientist at UAB’s Comprehensive Cancer Center, please follow this link: https://radiomd.com/childrensalabama/item/36469