Gene therapy of cancer in the clinic: good news in sight from Asia?

The field of gene therapy offers promising treatment innovations that may prove to be fundamental in helping cancer patients. In this review, recent advances in this field are discussed, with particular emphasis on new trends that have emerged in clinical trials between 2005 and 2006. Notably, among these trials only 5% were phase III trials, reflecting a lack of sound clinical advancement and, possibly, underscoring reduced enthusiasm and financial support by pharmaceutical companies in western countries. Viral vectors continue to be the preferred delivery system, with an increase in exploitation of oncolytic viruses. Nevertheless, the persistent crucial hurdle--the transfer of the therapeutic gene into sufficient numbers of tumor cells--remains. Future clinical trials will aim to identify promising combinations of genetic and conventional medicine. Multicenter trials with a broad patient enrolment will be mandatory to establish definitive proof of efficacy. In this regard, China has recently emerged as a country with growth potential in this sector and it may be the country where evidence of clinical efficacy of cancer gene therapy will first be achieved.