Gendicine s hire
for the first time in the world, a gene therapy for cancer has been given the go-ahead for commercialisation. The development could usher in a new era to treat the fatal disease. China's State Food and Drug Administration has approved the therapy after it achieved promising results during a clinical trial. SiBiono GeneTech, a Guangdong province-based company, will commercialise the treatment in January 2004.
The therapy, called Gendicine, involves inserting adenoviruses consisting of the gene p53 in the cancerous cells. The gene codes for a protein that triggers cell suicide when the cells start to run amok, thereby preventing them from becoming cancerous. Many tumours arise after the mutation or inactivation of p53.
During the clinical trial, SiBiono tested the treatment for head and neck cancers, as p53 is mutated in over 60 per cent of these tumours. Such types of cancers are also common in China. During the trial, 120 patients were given either Gendicine or radiotherapy. The viruses were injected directly into the tumours once every seven days for eight weeks, and most patients were monitored for more than a year. In 64 per cent of the patients given Gendicine, there was a complete regression of the primary tumours, at a rate three times greater than those patients given radiotherapy. The only side effect was fever in about one-third of the patients. Zhaohui Peng, SiBiono's head, says the treatment has no long-term adverse effects because the virus is unable to integrate into the genome of cells. This was the problem encountered during the controversial French gene therapy trial that was halted in 2002 after two boys developed leukaemia.
A dose of Gendicine will cost us $360, and can be easily administered by any doctor. But the treatment is being criticised by researchers who think it is too early introduce gene therapy, especially after conducting a small-scale trial. They assert that the approach, when tried out in the us on an experimental basis, two years ago showed mixed results. But with 300,000 new cases of head and neck cancer each year, China thinks Gendicine's benefits far outweigh its risks. SiBiono plans to launch the therapy across Southeast Asia soon.