Oxford BioMedica uses £500,000 of Government funds for gene therapy research into haemophilia
A modified horse virus has brought £500,000 of Government money to an Oxford biopharmaceutical company specialising in gene therapy.
The equine lentivirus technology, called LentiVector and developed at
Oxford BioMedica, will be used to deliver the Factor VIII gene in treatment
trials for haemophilia A.
Oxford BioMedica is the only commercial firm to benefit from the first £4m
handout from the Department of Health, announced earlier this month,
as part of its £50m commitment to genetics services within the
NHS for 2003–06.
Len Seymour, chairman of the British Society for Gene Therapy (BSGT),
explained that the modified equine lentivirus contains only a tiny piece
of viral nucleic acid, which plays a role in delivering the therapeutic
genes into target cells. “It really is a gutless virus that can’t
mediate its normal infectious pathology,” he said.
At the BSGT’s inaugural meeting held in Oxford earlier this year,
participants heard about progress with a number of viral vectors, including
the lentivirus system and the adeno-associated virus (AAV), for delivery
of gene therapy. The latter is another powerful but apparently harmless
viral vector that is good at carrying genes into cells without triggering
a destructive immune response that would limit its effectiveness.
AAV will be used for gene transfer in the inherited retinal blindness
research at the Institutes of Ophthalmology and Child Health, London,
awarded £900,000 by the Department.
“Ultimately, gene therapists would like to use non-viral vectors
because they should be safer. But at present they are not very effective
at getting
genes into cells, so in the short and medium term we need viruses for
gene therapy,” said Dr Seymour.
Retroviruses have proved popular tools in gene therapy because they are
highly effective at integrating into cellular DNA and delivering their
genetic cargo. However, if they insert themselves alongside an oncogene
or tumour suppressor gene they can trigger cancerous changes. The two
cases of leukaemia reported in a French gene therapy trial in X-linked
severe combined immunodeficiency syndrome (X-SCID) occurred when a retrovirus
was used as the vector.
“We need to find ways of ensuring that the viral vectors that we
use integrate at very specific, harmless places, but we haven’t
quite achieved that yet,” explained Dr Seymour.
Neither Oxford BioMedica nor any other UK-based pharmaceutical companies
will achieve the world first of getting a gene therapy product to market.
That honour has already gone to the little-known Chinese company, SiBiono
GeneTech. It was granted a licence last November in China to market its
p53 tumour suppressor gene product, Gendicine, for the treatment of head
and neck cancer. |
The
Pharmaceutical Journal
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