15 Dec 2025

Research blog: The rise of CRISPR

Last June, we introduced the concept of CRISPR in the context of CAR-T therapy and the rapid progress in immunotherapy. Today, CRISPR is moving from theory to practice, emerging as a real addition to the therapeutic arsenal for leukaemia patients. The latest breakthrough focuses on T-cell acute lymphoblastic leukaemia (T-ALL) – most commonly diagnosed in children and known as one of the most aggressive and difficult to treat leukaemias. 

Researchers are now leveraging an advanced form of CRISPR known as base editing to engineer immune cells into highly targeted cancer fighters. Instead of modifying a patient’s own cells, this strategy edits healthy donor T-cells, creating universal “living drugs”. 

Our immune system relies on white blood cells, which act as the body’s defence team against infections and abnormal cells. Among them, two key players are B cells and T cells, each with a different job. 

• B cells act like tiny factories that make antibodies – proteins that recognise and flag harmful invaders so the rest of the immune system can destroy them. 

• T cells, on the other hand, are more like specialised soldiers. Some T cells kill infected or cancerous cells directly, while others help coordinate the wider immune response. 

Because T cells can hunt down and destroy cancer cells, scientists can harness and re-engineer them to create powerful new treatments like BE-CAR7. So far this has been done in the form of CAR-T cell therapy for B-cell ALL. Here healthy T-cells are removed from the patients – who have a B-cell cancer – reengineered to attack B-cells and then returned to the body. But this has never been possible to use for T-cell cancer such as T-ALL.  

The experimental therapy we’re talking about, called BE-CAR7, has been created through a partnership between GOSH (Great Ormond Street Hospital) and UCL (University College London).  

BE-CAR7 is exciting for two major reasons: 

• Specially engineered donor T-cells: Scientists edit healthy donor immune cells so they won’t be rejected by the patient, won’t attack each other, and can precisely seek out and kill cancer cells. 

• Ready-made “off-the-shelf” treatment: Because these cells don’t have to be taken from the patient and customised, they can be prepared in advance – meaning treatment could be given more quickly and to more people. 

Although BE-CAR7 isn’t available yet and is still in clinical trials, the early results have caught the attention of the medical world. This is especially important for a type of leukaemia that hasn’t seen a major breakthrough in many years. 

Here’s what early studies have shown: 

• In the first trial, 11 patients – 9 children and 2 adults with a form of aggressive leukaemia that had stopped responding to other treatments – received BE-CAR7. 

• Around 82% went into deep remission, and almost two-thirds are still cancer-free up to three years later. 

• Some side effects were reported, such as low blood counts and rashes, but these were generally manageable. 

This research shows that CRISPR-enhanced immunotherapy can succeed where conventional treatments failed – potentially offering a new path to long-term remission without lifelong drugs. As more research continues, this approach could expand to other blood cancers and transform how we treat them. 

Conclusion: 

BE-CAR7 marks a breakthrough for patients with T-cell cancers, a group that has long stood apart from the progress seen in B-cell treatments. By pairing base-edited donor cells with an off-the-shelf model, it opens the door to faster, more reliable, and more widely accessible therapy. 

While early, this approach signals a new era in engineered cell therapies – one where treatment is not limited by a patient’s own cells and where historically hard-to-treat cancers may finally have a clear path forward. The hope is that BE-CAR7 becomes the first of many innovations to redefine what is possible for T-cell malignancies. 

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