A 13-year-old UK teenager has become ‘leukemia-free’ after she received the world’s first treatment of a new type of cell-engineering technology using ‘base-edited’ cells.

Alyssa, from Leicester, had undergone both chemotherapy and a bone marrow transplant in order to fight leukemia. Unfortunately, the treatments were unsuccessful and palliative care was the only option that was left for the girl.

But fate had something else in mind. Alyssa’s parents enrolled their daughter in a unique cell therapy. She was given an infusion of donated, healthy T-cells that were tweaked with the help of a technique known as base editing. Six months following the administration, Alyssa has remained in remission.

“We are in a strange cloud nine, to be honest. It’s amazing,” said her mother, Kiona, reported The Guardian.

“This is our most sophisticated cell engineering so far, and it paves the way for other new treatments and ultimately better futures for sick children,” immunologist Professor Waseem Qasim, one of the leaders of the project, said.

The results of the clinical trial will be presented at the American Society of Haematology meeting in New Orleans this weekend.

Alyssa was diagnosed with T-cell acute lymphoblastic leukemia (T-ALL) in 2021. It is a type of cancer that affects white blood cells called T-cells. These cells detect and destroy defective cells in the body.

She was given universal CAR (Chimeric Antigen Receptor) T-cells that had been pre-manufactured from a healthy volunteer donor in May this year

To counter the cancerous T-cells in Alyssa’s blood, the CAR T-cells were collected from a healthy donor and programmed to target other T-cells and kill them, including both normal and leukemia cells in the patient’s body. The T-cells were altered by base editing, which involves a single change in the multiple letters of DNA code. Changes were made in T-cells so that they do not kill each other in ‘friendly fire.’

“Once I do it, people will know what they need to do, one way or another, so doing this will help people – of course, I’m going to do it,” Alyssa said regarding the new therapy.

After infusion of base-edited T-cells, Alyssa underwent another bone-marrow transplant to replenish her depleted white blood cells reservoir.

“Hopefully this can prove the research works and they can offer it to more children – all of this needs to have been for something,” Alyssa’s mother commented.

The teenager was treated at Great Ormond Street Hospital for Children (GOSH) in London.

“This is an ‘off the shelf’ universal cell therapy and – if replicated – will mark a huge step forward in these types of treatments,” Dr. Louise Jones of the Medical Research Council, which funded the project, said.

Now, the team involved in the trial will recruit up to 10 patients with T-cell leukemia who, just like Alyssa, have tried all conventional treatment options for a clinical trial using the new cell therapy technique.