Promising gene therapy vectors The development of innovative, more efficient gene vectors for the treatment of cancer has been the objective of many research teams worldwide. Health © PhotoDisc The EC-funded TARGETED GENE VECTOR brought together different sets of skills in order to develop gene therapy vectors targeting brain and liver cancers. The aim is to arrive at novel vectors with an improved safety profile but highly efficient at the same time. Spanish-based, University of Navarra, carried out a series of studies in order to evaluate a set of targeted adenoviral vectors in terms of efficiency and safety. Murine liver tumour models were used. The vectors carried the genetic information to express IL-12, a potent anticancer molecule. Expression of IL-12 was under the control of RU486. In other words, gene therapy was active only in the presence of RU486. Animals that were treated with the vector at the highest tested dose and RU486 showed complete tumour regression. Lower vector doses resulted in the animals' death due to metastases. Phase I trials of the tested vector, named HC-AdRS25, have been planned based on these favourable data. The scientific team is keen to gain further support for the initiation of phase I/II trials.