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Pioneering T-Cell Treatment Saves Baby Girl from “Incurable” Leukaemia
One-year-old Layla Richards has been treated for an extremely aggressive form of Acute Lymphoblastic Leukaemia (ALL) using a therapy that is still in the preclinical stage. The treatment, which involves editing the genes in donated T-cells, has so far been a success and Layla is now cancer free.
The treatment, developed by Great Ormond Street Hospital and the University College London Institute of Child Health, is based on another therapy currently in clinical trials. The original treatment involves reprogramming the patient’s T-cells to identify and target cancer cells. Unfortunately, in cases like Layla’s, patients who have already undergone chemotherapy often have insufficient T-cells for harvesting. This new therapy uses T-cells from healthy donors, referred to as UCART19 cells.
First, new genes are added to the donor cells to “arm them against leukaemia”, according to GOSH. Then, the team used TALEN® tools developed by Cellectis, which act like “molecular scissors”. They cut certain genes so that the cells would only attack leukaemia cells. These cuts also make the T-cells invisible to a cancer drug that would normally wipe them out.
The UCART19 cells were delivered to Layla intravenously, a process that took around 10 minutes. She was then isolated for a period of months to protect her weakened immune system. It only took weeks for positive signs to appear, and once the doctors were certain that the leukaemia cells had been eradicated, she was given a bone marrow transplant.
At the moment Layla is regularly attending GOSH for checkups, but her treatment team are confident. Lead clinician Professor Paul Veys, who is GOSH’s Director of Bone Marrow Transplant, describes the results as being “almost a miracle” given how aggressive the ALL was.
This therapy had never been used on a human subject before, having only been tested in preclinical trials on mice. Supplies of donor cells were being produced in preparation for clinical trials when Layla’s parents were told that her condition was too severe to be treated. As Lisa Foley, Layla’s mother, said: "We didn’t want to accept palliative care and give up on our daughter… so we asked the doctors to try anything." Professor Waseem Qasim, a Consultant Immunologist at GOSH and Professor of Cell and Gene Therapy at the University College London Institute of Child Health, came up with the idea of trying the new treatment. He said it was “highly experimental and we had to get special permissions, but [Layla] appeared ideally suited for this type of approach."
With funding from Cellectis, clinical trials of this treatment are set to start on large groups at the beginning of next year. The success of the UCART19 therapy, even in such a small sample group, offers exciting possibilities for cancer treatment in the near future.