For children with leukemia that doesn’t respond to standard treatment, options can run out quickly. In 2022, doctors at Great Ormond Street Hospital in London reported that a 13-year-old girl had gone into remission after receiving a world-first therapy made from donor immune cells that had been precisely edited using a technique called base editing.
A hard-to-treat leukemia
The patient had T-cell acute lymphoblastic leukemia (T-ALL), a cancer of T cells, a type of white blood cell that normally helps the immune system find and destroy infected or abnormal cells. Despite chemotherapy and a bone marrow transplant, her leukemia came back, and her family had been told that palliative care might be the only option left.
T-cell leukemia is especially tricky to treat with immune therapies. Many cell therapies work by turning T cells into cancer hunters, but when the cancer itself is made of T cells, the engineered cells risk attacking each other or being destroyed themselves.
How the therapy worked
The team, led by immunologist Professor Waseem Qasim at University College London and Great Ormond Street Hospital, used healthy T cells from a donor and made several changes:
- Base editing. Unlike earlier gene-editing methods that cut DNA, base editing changes single “letters” of the genetic code with high precision. The team used it to switch off certain genes in the donor cells.
- Preventing friendly fire. The edits stopped the engineered cells from attacking each other and helped them avoid being rejected or destroyed by the patient’s treatment.
- Targeting the cancer. The cells were also given a CAR (chimeric antigen receptor), which directs them to seek out and kill T cells, including the leukemia cells.
Because the therapy kills T cells broadly, including healthy ones, the patient then received a second bone marrow transplant to rebuild her immune system.
The results
About six months after treatment, the teenager remained in remission, and the results were presented at the American Society of Hematology’s annual meeting. Researchers described it as an “off the shelf” universal cell therapy, since it was made from a donor rather than the patient’s own cells, which could make it faster and easier to provide in the future.
What comes next
This was one patient, and a single success doesn’t prove a treatment works for everyone. The team planned a clinical trial enrolling up to 10 children and adults with T-cell leukemia who had run out of other options. Like other powerful cell therapies, base-edited treatments can carry serious side effects, including severe infections and immune reactions, and need careful monitoring in specialized centers.
Why it matters
Base editing is one of the newest tools in genetic medicine. This case was among the first to show it could be used to build a working cancer therapy in a patient. Researchers hope similar approaches could help with other hard-to-treat cancers and genetic diseases.
What this means for families
- Ask about clinical trials. If standard treatments haven’t worked, a cancer specialist can help you find trials that may be an option.
- Seek a specialist center. Children’s hospitals and major cancer centers often have access to the newest therapies and trials.
- Look for support. Childhood cancer is overwhelming for families. Hospital social workers, patient organizations and support groups can help.
- Know the warning signs. Symptoms of leukemia in children can include unusual tiredness, pale skin, frequent infections, easy bruising or bleeding, bone pain and swollen glands. These have many causes, but they’re worth checking with a doctor.
The bottom line
A teenager with treatment-resistant T-cell leukemia went into remission after receiving donor immune cells reprogrammed with base editing, a world first. It’s early and based on one patient, but it’s a hopeful step for precision gene-editing therapies.
This article is for general information and isn’t medical advice. Talk with your healthcare provider about your individual needs.
