RAC OKs Targeted Genetics' CF Gene Therapy

Targeted Genetics has received the first approval to carry out a gene therapy trial using an adeno-associated virus vector from the National Institutes of Health's Recombinant DNA Advisory Committee. As a result, the company plans to file an Investigational New Drug for an AAV-based cystic fibrosis gene therapy protocol with the US Food and Drug Administration by the end of the year, said James Johnson, vice president of finance at the company, at the Medical Investments Northwest conference in Seattle, USA.

The importance of AAV as a delivery vector for genes is that it readily infects non-dividing cells (unlike retroviruses for example) and has no known pathological characteristics. Furthermore, AAV has no viral genes, which reduces the likelihood for immune rejection of the vector. The company has published the only available in vivo data to date on AAV delivery to cells, and these data show stable gene expression in host DNA for relatively long periods of time (at least six months, which is longer than expression seen with adenoviruses) with no apparent side effects.

The first studies were carried out in rabbits, and Targeted Genetics is in the midst of repeating these protocols in primates. The company anticipates that human trials will involve 16 CF patients, who will receive aerosolized therapy to one lung and the nasal passages (the other lung will serve as a control group).