New insight into when CAR T is effective against childhood leukaemia
24 May 2021, 4 p.m.
Scientists and clinicians at UCL and Great Ormond Street Hospital (GOSH) studying the effectiveness of CAR T-cell therapies in children with leukaemia, have discovered a small sub-set of T-cells that are likely to play a key role in whether the treatment is successful.
Researchers say ‘stem cell memory T-cells’ appear critical in both destroying the cancer at the outset and for long term immune surveillance and exploiting this quality could improve the design and performance of CAR T therapies.
Explaining the study, published in Nature Cancer, lead author Dr Luca Biasco from UCL Great Ormond Street Institute of Child Health (UCL GOS ICH), said: “During clinical trials we have seen some very encouraging results in young patients with leukaemia, however it’s still not clear why CAR T-cells continue to be present in the long-term for some patients, stopping the cancer from returning, while others remain at a high risk of relapse.
“To ensure that a leukaemia treatment works any CAR T-cell therapy must have a prolonged effect on the way that the body recognises and removes cancer cells. In this study we tried to find the origin and nature of the T-cells that control these long-term responses.”
How does Car T therapy work?
In CAR T therapy, immune cells (T-cells) are genetically engineered to contain a molecule called a chimeric antigen receptor (CAR) on their surface which can specifically recognise cancerous cells.
Researchers assessed the CAR T-cells of patients involved in the CARPALL Phase I Study, which used a new CAR molecule known as CAT-19 developed between UCL Cancer Institute and UCL GOS ICH, for treatment in children with acute lymphoblastic leukaemia (ALL).
The team compared CAR T-cells from patients who still had CAR T-cells detectable in the blood more than two years after their treatment, with individuals who had lost their CAR T-cells in the one to two months post treatment.
Using a technique called ‘insertion site barcoding’, researchers were able to study the fate of different types of CAR T-cells in patients after they were given.
Corresponding author Professor Persis Amrolia, based at UCL GOS ICH and Consultant in Bone Marrow Transplant at GOSH, said: “Using this barcoding technique, we were able to see ‘stem cell memory T-cells’ play a central role both during the early anti-leukaemic response and in later immune surveillance, where the body recognises and destroys cancer cells.
“This suggests that this small sub-group of T-cells are critical to the long-term success of the therapy.”
Researchers say, this work indicates that the teams caring for patients could measure the types of CAR T-cells present after some someone has had their anti-leukaemia therapy, to gain an indication of whether they will be able to preserve their CAR T-cells into the future, avoiding relapse.
Professor Amrolia added: “This new insight may help us to improve our CAR T-cell therapy and work out which patients are at a higher risk of relapse and may benefit from a stem cell transplant after CAR T-cell therapy.”
Dr Biasco added: “It was extremely rewarding to see how the application of our new barcoding technology to study CAR T-cells is unveiling such important information about what happens to these cells after they are given to patients. We now plan to expand the technology we established at UCL and validate these findings in larger groups of patients.”
All research at Great Ormond Street is supported by the NIHR GOSH Biomedical Research Centre.
First lockdown sees rise in numbers of children swallowing small objects
The number of children referred to Great Ormond Street Hospital for Children between March and September 2020 after swallowing a small object was more than double that recorded in the same period the year before, according to new research published today.
GOSH DEN Launches
We are very excited to announce the launch of our brand new Virtual Learning Environment GOSH DEN (Digital Education Network)!
Gene therapy offers hope to children with rare and fatal brain diseases
Scientists and doctors at UCL GOS ICH and GOSH have given hope of a gene therapy cure to children with a rare degenerative brain disorder called Dopamine Transporter Deficiency Syndrome (DTDS)
Consolidation of genomic testing improves care for children with cancer at GOSH
Doctors at Great Ormond Street Hospital for Children NHS Foundation Trust (GOSH) have started using a new service available as part of the North Thames Genomics Laboratory Hub (NTGLH) laboratory service to help better diagnose and manage childhood cancers