Teenage girl with leukemia cured a month after pioneering cell-editing treatment

Alyssa the day she received base-edited cell therapy

A teenage girl is recovering from leukemia after becoming the world’s first patient to receive an innovative cell-editing treatment.

The 13-year-old girl, named Alyssa, from Leicester, was diagnosed with T-cell acute lymphoblastic leukaemia, which could not be treated with chemotherapy or bone marrow transplant.

Running out of options, doctors at Great Ormond Street Hospital in London attempted a breakthrough experimental therapy in which donated immune T-cells were genetically modified to target his cancer.

The technique, known as base editing, is the first time a cancer treatment has changed the fundamental building blocks of DNA.

Experts have altered the genetic code of immune cells to allow them to hunt down and kill cancerous T cells while leaving themselves alone.

After just 28 days, Alyssa was in remission and after a second bone marrow transplant to restore her immune system, the leukemia is now undetectable. She is recovering at home and hopes to return to school soon.

Professor Waseem Qasim, Professor of Cell and Gene Therapy at UCL GOS ICH and Consultant in Immunology at GOSH, said: “This is a great demonstration of how, with expert teams and infrastructure, we we can combine state-of-the-art technologies in the laboratory with real results in the hospital for the sick.

Prof Waseem Qasim

Prof Waseem Qasim

“This is our most sophisticated cellular engineering to date and paves the way for other new treatments and ultimately a better future for sick children.”

To create the cells, healthy donor T cells had to be modified in four steps. First, receptors had to be removed from donated cells to avoid rejection.

Then a ‘flag’ known as CD7 that identifies them as T cells was removed so the altered cells don’t end up destroying each other.

In the third step, a second “flag”, called CD52, was cut to make the edited cells invisible to drugs administered to the patient during the treatment process.

Finally, a receptor was added allowing the cells to recognize leukemic T lymphocytes.

These changes were achieved by “base editing” – by chemically converting single nucleotide bases or DNA code letters, which carry instructions.

For example, changing the nucleotide bases of the CD7 gene from a cytosine to a thymine creates the equivalent of a complete genetic point and prevents the immune system from attacking T cells.

Alyssa was diagnosed with T-cell leukemia in May 2021, after a long period of what the family thought were colds, viruses and general fatigue.

Alyssa decided to donate her hair when she found out she would lose it anyway

Alyssa decided to donate her hair when she found out she would lose it anyway

Despite months of treatment in hospitals in Leicester and Sheffield, doctors failed to bring his cancer under control and put him into remission.

Kiona, Alyssa’s mum said: “To be honest, we’re on a strange cloud nine – it’s amazing to be home.

“The doctors said the first six months are the most important and we don’t want to be too cavalier, but we kept thinking ‘If they can get rid of her, just once, she’ll be fine.’ And maybe we’ll be right.

“I hope this proves that the research works and that they can offer it to more children – it must all have served some purpose. It’s so insane.

“Alyssa wants to go back to school and it could soon become a reality.”

Ongoing clinical trial

A clinical trial for this treatment is currently open and aims to enroll up to 10 patients with T-cell leukemia who have exhausted all conventional treatment options.

If successful, bone marrow transplant and CAR T-cell therapy teams at GOSH hope it can be offered to children earlier when they are less ill.

Dr Robert Chiesa, consultant in bone marrow transplantation and CAR T-cell therapy at GOSH, said: “This is quite remarkable, although it is still a preliminary result, which needs to be monitored and confirmed over the next few months.

“The entire GOSH team is extremely happy for Alyssa and her family and it has been a privilege to work with them over the past few months. “

The results are being presented this weekend at the annual meeting of the American Society of Hematology in New Orleans, USA.

Leave a Reply

Your email address will not be published. Required fields are marked *