GOSH Professor helps develop game-changing gene therapy

20 May 2021, 12:21 p.m.

Sarah looking to camera

A new study has revealed the successful results of a stem cell gene therapy clinical trial for ADA-SCID at GOSH and the University of California, Los Angeles (UCLA).

Two to three years after the treatment, all 50 children treated with the new gene therapy are alive and well.

48 are no longer showing symptoms of ADA-SCID, although they will have lifelong monitoring.

In the two cases in which treatment wasn’t successful, both children were able to return to current standard treatments. One received a bone marrow transplant.

Dr Claire Booth, Mahboubian Associate Professor in Gene Therapy, led the UK-side of the clinical trials. Dr Booth's work is supported by GOSH Charity.

ADA- SCID explained

ADA-SCID stands for severe combined immunodeficiency due to adenosine deaminase deficiency. It's a rare, life-threatening disease.

As children with ADA-SCID have no immune system, it prevents children from living a normal life.

If left untreated, the condition can be fatal within the first two years of life. Day-to-day activities like going to school or playing with friends can lead to a dangerous infection.

Game-changing treatment

Currently, the standard treatment for ADA-SCID involves once or twice weekly injections of the ADA enzyme. This is until a matched bone marrow donor – usually a close family member – can be found.

If a matched bone marrow donor isn't available, patients need lifelong ADA injections. This is along with preventative medicines. These treatments are expensive and therefore out of reach for patients in many countries.

If approved, gene therapy that has been developed by the teams at GOSH and UCLA would be a welcome new treatment option for ADA-SCID. It's a one-time procedure that has the potential to provide life-long results.

Success for four-year-old Sarah

One of the patients treated with the new gene therapy was four-year-old Sarah from South Yorkshire. She was less than ten days old when her mum Maria became concerned about her daughter’s weight loss and sore, bleeding nappy rash that wouldn’t heal. Tests revealed Sarah had ADA-SCID:

“I remember the exact time I saw the paper that had the blood test results on and the diagnosis. I saw it was SCID and I was incredibly upset… I wasn’t allowed to kiss my daughter or sleep next to her. Everything had to be highly sterilised to keep her safe. It was horrible to not be able to do normal things with my own daughter.”

Sarah arrived at GOSH for gene therapy and several years after her treatment is doing very well.

Sarah’s treatment has had a huge impact on the whole family, but it also inspired Maria to go back to studying and train to become a nurse.

Further development at the Zayed Centre for Research into Rare Disease in Children

Ten of the children in the study were treated at UCLA using a frozen preparation of corrected stem cells. These children experienced similar outcomes to the children treated with cells that were not frozen.

This approach - using frozen preparation - may allow children to have their stem cells collected locally. This could possibly remove the need to travel long distances to specialist centres.

A trial of the cryopreserved treatment is now underway at the Zayed Centre for Research into Rare Disease in Children.

The Zayed Centre for Research brings together pioneering research and world-leading clinical care.

The centre drives new tests, treatments and cures for children with rare and complex diseases, from lab bench to bedside.

You can read more about this exciting breakthrough on gosh.nhs.uk.