ICH GTDG Oncolytics Considerations - Revised version - comment 17 Sept

INTERNATIONAL CONFERENCE ON HARMONISATION OF TECHNICAL REQUIREMENTS FOR REGISTRATION OF PHARMACEUTICALS FOR HUMAN USE ICH Considerations Oncolytic Viruses September 17, 2009 1. Introduction Oncolytic viruses (OV) were first observed in early clinical studies in patients with malignancies where tumour regressions were observed to coincide with viral infections or with live virus vaccinations. Since these early reports, studies using OV have progressed from anecdotal and controlled infections to specifically selecting or genetically modifying viruses for cancer treatment. OV are intended to replicate selectively in tumour tissue and spread, destroying the tissue without causing excessive damage to normal tissues. OV can be wild type or naturally attenuated strains of viruses that possess an inherent property of selective replication and lysis of cancer cells. Additionally, viruses can be genetically modified to selectively replicate and lyse cancer cells. These modifications can include 1) the mutation of the viral coding genes that are critical for viral replication in normal cells, 2) the control of early gene expression by using tumour-specific promoters, 3) a change in the viral tissue tropism and/or cell entry process, and 4) the incorporation of transgenes into the viral genome. Examples of OV include adenovirus, measles virus, vesicular stomatitis virus (VSV), reovirus, Newcastle disease virus, herpes simplex (HSV), poxvirus, ...