Oxford BioMedica and researchers at Imperial College of Science and Technology, London announced in June 2002 that they had achieved very efficient gene transfer to mouse embryos in utero
The technology, if reproducible in man, creates the potential to cure diseases such as Duchenne muscular dystrophy (DMD) and cystic fibrosis (CF), diseases that are incurable at present.
These developments were presented at the American Society for Gene Therapy (ASGT) meeting in Boston on Saturday 8 June 2002 by Mike Themis of the gene therapy group, division of biomedical sciences at Imperial College, London.
Diseases that are caused by defects in single genes are obvious targets for gene therapy.
In fact it was is in this area that gene therapy was originally conceived.
Subsequently the applications of gene therapy have broadened to many other disease areas including cancer, cardiovascular disease and neurodegenerative diseases.
Recently, the news of successful treatment in the UK, by gene therapy, of a genetic deficiency in the immune system of a young boy demonstrated the feasibility of the approach.
However, part of the reason for this success was because the clinical benefit to the patient could be achieved by delivering the appropriate gene to a relatively small number of the patient's white blood cells.
In many other applications of gene therapy, gene transfer to the target cells must be much more efficient.
This includes, for example, neurodegenerative diseases and some single gene disorders such as DMD.
However, in DMD the challenge goes beyond increasing the efficiency of gene transfer.
One in three thousand males inherit a non-functional dystrophin gene and suffer from DMD.
Life expectancy is about 20 years and the patients are confined to a wheelchair from about the age of ten.
The disease causes severe muscle weakness and it affects every muscle in the body.
In order to correct the disease in children or adults every muscle would need to receive a functional dystrophin gene.
This is not feasible using many current gene therapy techniques because the tissue volume is too great.
A solution to this problem is to deliver the gene when the tissue volume is small.
That is, when the patient is a developing foetus in the womb.
The Imperial College team, using BioMedica's highly efficient LentiVector, has now shown that this is possible in animal models.
At the ASGT meeting Themis showed gene transfer to a wide range of tissues, including liver, brain and muscle, following administration of LentiVector to the foetal blood supply.
If this were to be recapitulated in humans it would provide a potential route to treating several genetic deficiencies.
Commenting on the results Themis said: "In utero, gene therapy opens many exciting opportunities to treat people with these severely debilitating and fatal diseases before suffering occurs.
"We hope that one day this may be offered to parents as an alternative to termination of pregnancy.
"In addition, the efficiency of the gene transfer that we see in animals enables us to study the function of genes in a way that has not been possible before.
"This may accelerate our understanding of a broad range of diseases and create new therapeutic strategies." professor Alan Kingsman, BioMedica's chief executive commented: "We are very pleased to have provided the gene delivery technology for this elegant work at Imperial College.
"We are currently evaluating product opportunities from these studies as well consulting broadly on the regulatory and ethical issues raised by such groundbreaking work."
