A baby girl with aggressive leukaemia has become the first in the world to be treated with designer immune cells that were genetically engineered to wipe out her cancer.

The one-year-old, Layla Richards, was given months to live after conventional treatments failed to eradicate the disease, but she is now cancer free and doing well, a response one doctor described as “almost a miracle”.



Specialists at Great Ormond Street Hospital (GOSH) in London treated the girl two months ago and stressed that it could be more than a year before they know for sure whether the therapy has cured the disease, or simply delayed its progression.



“We have only used this treatment on one very strong little girl, and we have to be cautious about claiming this will be a suitable treatment option for all children,” said Waseem Qasim, professor of cell and gene therapy at University College London’s (UCL) Institute of Child Health, and a consultant immunologist at GOSH.



“But this is a landmark in the use of new gene engineering technology and the effects for this child have been staggering,” he said.



Layla was born a healthy 7lb 10oz in June last year, but three months later developed a fast heartbeat, went off her milk and cried more than usual. Doctors suspected nothing more than a stomach bug, but blood tests revealed she had infant acute lymphoblastic leukaemia (ALL).



The family was sent to GOSH by ambulance and Layla went into intensive care with what doctors described as the most aggressive form of ALL they had ever seen. Sujith Samarasinghe, one of the doctors who cared for her, said that while cure rates are generally high for the disease, only about 25% of children survive the most aggressive forms. Layla began chemotherapy the next day and then had a bone marrow transplant to replace her damaged blood cells.



Despite several rounds of intensive chemotherapy, Layla still had leukaemia cells in her body when the transplant was performed, and seven weeks later the disease returned. Soon after, doctors told the family there were no other treatments that might cure Layla and suggested palliative care. But Layla’s parents, Lisa and Ashleigh, insisted that the doctors keep trying.



“We didn’t want to accept palliative care and give up on our daughter, so we asked the doctors to try anything for our daughter, even if it hadn’t been tried before,” Lisa said.



The hospital had been working on an experimental cell-based treatment for leukaemia. Researchers at UCL showed last year, and again in May, that the modified cells had an anti-cancer effect, but it had only been tested on mice with leukaemia. They had one vial of the cells to give to Layla, but to go ahead they needed approval from an emergency ethics committee and informed consent from her parents. The doctors explained there was no guarantee it would work even if approval was granted.

“It was scary to think that the treatment had never been used in a human before, but even with the risks there was no doubt that we wanted to try the treatment. She was sick and in lots of pain, so we had to do something,” said Ashleigh.



The ethics committee approved the treatment, and Layla received a 1ml infusion of the genetically engineered immune cells under UK special therapy regulations. The infusion took 10 minutes. “We thought that the little bit of liquid in the syringe was nothing and asked ‘what is that going to do when bags and bags of chemo haven’t worked?’,” Ashleigh said.



The cells came from frozen batches of donated T cells, or white blood cells, which play a central role in human immunity. Before they are infused, the cells are given an extra gene to make them target leukaemia cells. They then have other genes disabled to stop them attacking patients who receive them, and to make them invisible to a drug called alemtuzumab, which doctors use to suppress patients’ immune systems.



If the treatment worked, doctors expected Layla to develop a rash within one or two weeks of the infusion. But two weeks passed and no rash had appeared. Just as the staff prepared to send Layla home, the rash appeared: a sign that the cells were having an effect.



It was weeks later when Lisa was collecting the couple’s eldest daughter from school that Ashleigh called to say the consultants had been in touch and asked her to sit down. “I thought it was bad news,” said Lisa. “But then he said ‘it’s worked’ and I just cried happy tears.”



Layla was still clear of leukaemia two months later, allowing doctors to give her a second bone marrow transplant to replace her entire blood and immune system, which had been wiped out by the treatment. A month later, she was well enough to go home.



Paul Veys, director of bone marrow transplant at GOSH, said: “As this was the first time that the treatment had been used, we didn’t know if or when it would work and so we were over the moon when it did. Her leukaemia was so aggressive that such a response is almost a miracle.” One other patient is already receiving the treatment under the care of a different medical team.



The therapy could be suitable for five to 10 children with acute lymphoblastic leukaemia in Britain each year. But doctors are keen to modify the therapy to tackle other blood disorders and different types of cancer.



Clinical trials of the cells, funded by the French biopharmaceutical company, Cellectis, are due to begin in early 2016. “If replicated, it could represent a huge step forward in treating leukaemia and other cancers,” said Qasim.

Dr Alan Worsley at Cancer Research UK said: “It’s great news that Layla seems to be doing well so far.

“Re-engineering a patient’s immune cells to target cancer has shown real promise in a small number of patients with leukaemia. This trial has adapted this treatment so that it’s easier to make, and now we need to see if this new approach is effective. Finding a way to make this work in other types of cancer is the next big challenge.”