Scientists have achieved a historic medical breakthrough by successfully curing a form of blood cancer that was long considered incurable. Researchers from University College London and Great Ormond Street Hospital have used a revolutionary technology known as DNA base editing to treat T-cell acute lymphoblastic leukaemia, a rare and aggressive cancer that primarily affects children and young adults. This marks the first time base-edited cells have been used in humans to achieve long-term cancer remission, opening new possibilities for future cancer treatments.
T-cell acute lymphoblastic leukaemia is caused by the uncontrolled growth of abnormal white blood cells, which crowd out healthy cells in the bone marrow and blood. Traditional treatments often fail in advanced cases because the cancer affects the same immune cells that are needed to fight infections. Conventional CAR-T therapy, which modifies immune cells to attack cancer, has shown limitations in T-cell cancers as it can also destroy healthy T-cells, leaving patients dangerously vulnerable.
To overcome this challenge, scientists employed DNA base editing, a highly precise form of CRISPR technology that alters individual DNA letters without cutting the DNA strand. This method significantly reduces unintended damage and improves safety. In this study, researchers made four carefully targeted genetic edits to donor T-cells to create a powerful and safer cancer-fighting therapy.
The first step involved removing immune identity markers that would cause the patient’s body to reject the donor cells, allowing them to function as universal cells suitable for any patient. The scientists then removed a key surface protein found on both healthy and cancerous T-cells, ensuring that the modified donor cells were not destroyed during treatment. Another edit made the cells resistant to a commonly used leukemia drug, ensuring their survival during therapy. Finally, researchers added a specially engineered receptor that enables the edited cells to recognize and destroy cancerous T-cells with precision.
The treatment process begins with chemotherapy to clear the patient’s existing immune cells. The edited cells are then infused into the body, where they rapidly multiply and eliminate cancerous cells. A stem cell transplant follows, helping rebuild a healthy immune system. The early clinical trial involved 11 patients, most of them children, who had exhausted all other treatment options. Remarkably, all participants achieved initial remission, with the majority reaching deep remission within weeks. Many of them have remained cancer-free for years, including the first patient treated, who has now returned to a normal life after battling the disease since childhood.
Although some side effects such as immune reactions and temporary infection risks were observed, doctors say the benefits far outweigh the risks for patients with no other options. Beyond curing individual cases, this breakthrough demonstrates the potential of universal gene-edited cells that could make advanced cancer therapies faster, safer, and more affordable in the future. This landmark achievement not only offers hope to families facing devastating diagnoses but also signals a new era in precision medicine, where genetic editing could transform how previously incurable diseases are treated worldwide.
