"Our goal in the current HSV1716 trial is to light a fire to the cancer so that the virus replicates and spreads to the cancer cells," Dr. Cripe explained. "We have to take this one step at a time and the initial phase of the trial focuses on making sure the virus doesn't cause adverse side effects. It has been tested in Europe in adults with brain cancer, squamous cell carcinoma and melanoma and shown in those trials to be safe."

HSV1716 has also been tested extensively for safety in animal models at Cincinnati Children's Hospital by Dr. Cripe and in Europe prior to it being tested in people.

The Phase I trial will include up to 18 patients and is expected to last three years. The optimum safe dosing for this virus is unknown, so the study will sequentially increase dosing levels in small groups of patients and observe for side effects as the trial proceeds. This earliest phase tests the lowest dose on older children and young adults with solid tumor cancers who have limited or no standard therapy options available.

The researchers plan to add younger patients with earlier stages of cancer as the trial proceeds. They will not be able to determine if the safety trial is successful until all patients have received treatment and the results analyzed. As with all clinical trials of new anticancer therapies in patients, many factors can influence the risk for severe side effects and anticancer activity. Even though HSV1716 may cause tumor shrinkage in mouse models of pediatric cancer, it may not have antitumor effect in patients.

Source: Cincinnati Children's Hospital Medical Center