Immune cell therapies and gene-editing
There are a number of treatments being developed at GOSH to treat leukaemia using immune cells, and some of these are being tested in clinical trials. These treatments are experimental and are only considered when routine chemotherapy treatments haven’t worked. One approach relies on collecting a patients’ own white blood cells and modifying them in a special clean room facility at the hospital, before returning them to the patient. Several studies in the US are carrying out similar clinical trials and have reported encouraging levels of remission of B-cell leukemias.One major issue, especially in infants, is the difficulty in collecting enough of the right type of immune cells (T cells). For such cases, new approaches are being tested that use T cells from a healthy donor but modify them using ‘gene-editing’ so they don’t need to be matched to the patient. This means the cells are ‘ universal’ and can be produced in advance and stored frozen, ready to be used in multiple patients.
The gene-edited T cells (called UCART19) are given to patients immediately after a course of chemotherapy and antibody therapy. They are expected to circulate around the body and fight any leukaemia carrying the CD19 marker. Responses are assessed after one month, and if remission had been achieved, the patient will proceed to have a bone marrow transplant. At that stage the cells are removed and do not persist long-term.
Two infants were treated using universal gene-edited T cells at GOSH in 2015, and both went on to have a successful bone marrow transplant and have remained free of leukaemia.
Clinical trials of UCART19 have been underway at GOSH since 2016 for children with difficult to treat B cell acute lymphoblastic leukaemia (ALL). The study is open for children receiving NHS treatment from across the UK if their specialist doctors think a bone marrow transplant will be required to treat the leukaemia and they aren’t suitable for other trials where their own cells would need to be collected. Five more children have been treated and details will be presented at the American Society of Hematology Annual Meeting in December 2017.
The trial is still ongoing to test if these treatments will be successful in larger numbers of patients. Everyone treated will subsequently be monitored throughout childhood.
How can I get this treatment at GOSH/be enrolled on to a gene editing trial?
Trials are currently underway to determine if the treatment is effective in more children from across the UK receiving NHS care. Please speak directly to your GOSH consultant or specialist haematologist about potential clinical trial options for your child. Specialists from across the UK are working closely to make sure the best trial options are provided for children depending on what type of leukaemia they have.
Can this treatment be used for other cancers?
The design of this particular treatment means that it is currently only effective for patients with B cell leukemias such as ALL.
Will this treatment replace current treatments for cancer?
Chemotherapy and radiotherapy remain the most effective ways to combat cancer and are highly successful for many children with leukaemia and other types of cancer. Cellular therapy is being trialled in “difficult to treat” leukaemia only after chemotherapy treatments have proved unsuccessful.
Is this treatment available for adults?
Great Ormond Street Hospital is a paediatric hospital and only treats children. Please speak directly to your specialist haematologist about clinical trials available in adult centres.
You can find out more about this treatment here.