Safety and Effectiveness Study of G207, a Tumor-Killing Virus, in Patients With Recurrent Brain Cancer

Overview

This clinical trial will study the safety and effectiveness of an engineered herpes virus, G207, administered directly into the brain of patients with recurrent brain cancer. G207 has been modified from the herpes virus that causes cold sores (called herpes simplex virus type 1 or HSV-1). G207 has been designed so that it should kill tumor cells, but not harm normal brain cells. G207 has been shown to be safe in animal testing completed to date and in previous studies in patients with brain tumors. This is a phase Ib/II study. In the phase Ib portion of the study, patients will receive G207 at a dose that is higher than tested in previous human studies. Patients will initially receive 15% of the assigned dose injected directly into the brain tumor. Approximately two days later, as much of the tumor as possible will be surgically removed, and more G207 will be injected into the brain tumor bed. Patients will be monitored, and medical tests will be done at specific study timepoints. The phase II portion will begin only if there are no safety concerns in the phase Ib portion. The goals of the phase II portion of the study are to determine the safety of G207 and to study patient survival at six months after G207 dosing. In the phase II portion of the study, patients will receive a single dose of G207 at the highest dose determined to be safe in the phase Ib portion of the study. The tumor will be removed, and G207 will be injected into any remaining tumor tissue in the brain tumor bed. Patients will be closely monitored, medical tests will be performed at specific study visits, and survival will be evaluated.

Protocol NG1-003 is an open-label, phase Ib/II study of the safety and efficacy of G207, a genetically engineered herpes simplex type-1 virus. Up to 21 patients will be enrolled in the phase Ib portion and will receive doses of G207 that are higher than tested in the previous trials. The highest G207 dose tested in a previous phase I trial (NG1-001) was 3E9 plaque forming units (pfu). G207 was generally well tolerated and safe in NG1-001, and there was no dose-limiting toxicity. Patients' deaths were due to progressive cancer disease except for one (due to radiation necrosis), and two patients remain alive today. Patients in the phase Ib portion of NG1-003 will receive G207 in divided doses. Initially, 15% of the assigned dose will be injected into the tumor. Two days later, the tumor will be removed, and the assigned dose of G207 will be injected into the tumor bed at the time of resection. The assigned doses are as follows: 1E9, 3E9, and 1E10 pfu. Patient status will be followed by MRI, Karnofsky performance, neurologic examination and the presence of G207 virus in the body, in addition to other medical tests done at specific study visits. The phase II portion of protocol NG1-003 is a two-stage study. The phase II portion will begin only if there are no safety concerns in the phase Ib portion. The goals are to determine the safety of G207 and survival at six months. Enrollment of up to 14 patients is planned for stage one. Additional patients will be enrolled (up to 30 additional patients and 44 overall) in stage II if at least 6 of the 14 patients in stage 1 survive 6 months or longer. Participants in phase II will receive a single dose of G207 at the highest dose determined to be safe from phase Ib. G207 will be injected into the tumor bed at the time of resection. Again, patient status will be followed as previously described and survival will be evaluated.