Page URL: https://www.bionews.org.uk/page_96265

Study uses genome editing inside patient for first time

20 November 2017
Appeared in BioNews 927

A new clinical trial in California marks the first time that genome editing has been used inside the body, rather than on cells such as blood or skin which can be extracted, edited outside the body, and then replaced.

A patient with the metabolic disorder Hunter syndrome was given an infusion containing a type of genome editing machinery called zinc finger nucleases as well as billions of DNA copies of the gene which codes for a protein they lack.

The treatment targets the liver cells. 'We cut your DNA, open it up, insert a gene, stitch it back up,' said Dr Sandy Macrae, president of Sangamo Therapeutics, which is running the trial. 'It becomes part of your DNA and is there for the rest of your life.'

People with Hunter syndrome lack a working copy of the gene that makes a protein called albumin. Without this enzyme, the body cannot break down complex sugars called mucopolysaccharides and so these molecules accumulate in the body's cells causing damage to the brain and many other organs.

The one-off treatment will not reverse damage already caused, but if successful will replace weekly intravenous infusions of the enzyme which can ease symptoms but do not prevent brain damage. Dr Paul Harmatz, leading the study at UCSF Benioff Children's Hospital in Oakland, California estimates that only one percent of liver cells need to be successfully edited for the patient to make an adequate quantity of the enzyme.

The therapy is being tested in adults, but if proved safe and effective will hopefully be available to child patients in future. By providing the treatment early in life it is hoped that the mucopolysaccharides will build-up and subsequent tissue damage can be minimised or avoided altogether.

The first recipient of the treatment was Brian Madeux from Arizona. He has had 26 surgeries so far in his life as a result of Hunter Syndrome, and says he took part in the trial because he is 'in pain every second of the day'.

'I'm willing to take that risk,' he told the Associated Press. 'Hopefully it will help me and other people.'

It will take about three months before tests show whether the treatment has been successful. 'I'm nervous and excited,' said Madeux. 'I've been waiting for this my whole life, something that can potentially cure me.'

'There's a lot of potential for treating liver diseases in this way,' said Professor Robin Lovell-Badge at the Francis Crick Institute in London, not involved in the trial. But he warned that the approach may not be applicable to other types of conditions: 'Taking it to more complex things like muscular dystrophy and cystic fibrosis will require a lot more work.'


The latest developments in genome editing will be discussed at the session 'What Next for Genome Editing? Politics and the Public', at the Progress Educational Trust's upcoming public conference 'Crossing Frontiers: Moving the Boundaries of Human Reproduction'.

The conference is taking place in London on Friday 8 December 2017. Full details - including sessions, speakers and how to book your place - can be found here.

SOURCES & REFERENCES
First gene-editing attempted in human body to cure disease
The Telegraph |  16 November 2017
Rewriting Life  A New Gene-Editing Therapy Would Benefit Kids Most—Here’s Why They Won’t Get It Yet
MIT Technology Review |  16 November 2017
US scientists try 1st gene editing in the body
AP News |  15 November 2017
RELATED ARTICLES FROM THE BIONEWS ARCHIVE
27 November 2017 - by Lea Goetz 
The Darwin lecture held at the UK's Royal Society of Medicine in London, and jointly organised with the Linnean Society, gives an annual look at topics in science and medicine....
13 November 2017 - by Paul Waldron 
A boy with a rare skin disease has been successfully treated by replacing most of his skin with grafts of stem cells modified by gene therapy.
30 October 2017 - by Jennifer Willows 
NICE has approved a gene therapy for children with a rare disorder that leaves them with no functioning immune system...
9 October 2017 - by Charlotte Spicer 
A new gene therapy has halted the progression of a fatal degenerative brain disease in a small study of affected boys...
11 July 2011 - by Dr Caroline Hirst 
Scientists have, for the first time, successfully treated a blood disorder by repairing errors in the DNA of a living animal. Researchers from The Children’s Hospital of Philadelphia, together with California-based Sangamo BioSciences, have applied an innovative genome editing technique to treat haemophilia B, which affects around one in 30,000 boys and men...
7 March 2011 - by Dr Lux Fatimathas 
American researchers have successfully created immune cells resistant to HIV. T cells, which are the main target of HIV, were isolated from six HIV positive patients and genetically manipulated to confer resistance. The cells were injected back into the same patients and were able to survive and multiply...
HAVE YOUR SAY
Log in to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions


Syndicate this story - click here to enquire about using this story.