Project Update (October 2017)

Timothy Cripe, MD, PhD is studying how a genetically altered version of the herpes virus could be a non-toxic, effective treatment for children battling relapsed extracranial solid tumors like osteosarcoma, Ewing’s sarcoma and neuroblastoma.

Funding from ALSF was used to fund several positions including a Phase I Research Nurse, Phase I Lead Clinical Research Coordinator, and Phase I Lead Data Clinical Research Coordinator. Each of these individuals is responsible for the implementation of trial in conjunction with Dr. Cripe.

The treatment, called oncolytic virotherapy, converts viruses into therapeutic drugs, making the altered viruses into cancer cell killing powerhouses. Oncolytic virotherapy offers the potential for a safer alternative to harsh chemotherapy and radiation, especially for children who have already received high doses of both those treatments.

Creating an oncolytic virus began in the lab. Scientists altered the herpes virus by deleting the gene responsible for making the herpes virus infect healthy tissue. Called HSV1716, the altered virus has previously been tested in the treatment of adult brain tumors. Dr. Cripe’s trial is testing the safety of the drug for the treatment of children with relapsed solid tumors outside of the brain.

During phase I, the drug is administered in the clinic. Interventional radiologists map a child’s tumor with CT scans and ultrasounds to guide the needle and directly inject the altered virus into the tumor. Once inside the tumor, the virus goes to work killing cancer cells and triggering an immune response in the body.

A second part of the phase I trial, a group of patients will have the altered virus given intravenously—without the use of a targeted injection to the tumor. The hope is the virus will find the cancer cells and infect them, triggering an immune response in the same way the targeted injections of HSV1716 did. Unlike traditional chemotherapy and radiation, virotherapy does not come with harmful side effects.

“We’ve reached the limits of chemotherapy and radiation. Virotherapy offers a prospect of a treatment that is non-toxic,” said Dr. Cripe. “Once we can get virotherapy treatments to work, we think they will be safe.”

Phase I of the trial is now open, with the goal of testing the safety of the drug. Phase II will test combining virotherapy with other treatments.

Dr. Cripe’s preliminary phase I results are published online in Clinical Cancer Research.

Read more about Dr. Cripe’s work in the Fall 2017 newsletter.