Genetic engineering has been used for the first time to seek out and destroy leukaemia cells, giving hope of a highly-targeted, side-effect free cancer killer.

Doctors in the UK used the “highly experimental” technique, which is not yet approved for widespread use, to save one-year-old Layla, who would otherwise have died.

The genetic expert who oversaw the “landmark” treatment hailed the positive outcome as “staggering”.

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“The approach was looking incredibly successful in laboratory studies, and so when I heard there were no options left for treating this child’s disease, I thought ‘why don’t we use the new UCART19 cells?'” Professor Waseem Qasim of Great Ormond Street Hospital said in a statement.

The UCART19 cells were white blood cells taken from a healthy donor and injected into Layla. Before injection, experts used a gene editing technique called TALEN to cut away specific genes in the cells, which rendered them invisible to the baby’s immune system and weaponised to find and kill the leukaemia growing in her bone marrow.

A chance of no side effects

Leukaemia suppresses the production of normal blood cells. Photo: Shutterstock

The hope is that this case is not a lucky one-off, but the beginning of a new range of highly-targeted cancer killers to replace the blanket treatments currently in use.

Chemotherapy treatments are indiscriminate. They attack healthy and cancerous cells alike, with the hope that malignancies die and healthy cells replenish. The beauty of genetically engineered treatments is that healthy cells might be left untouched, negating any side effects.

For now, Layla is in remission. No leukaemia cells have been detected. But it will take up to three years to declare her cured.

An Australian genetic expert told The New Daily the case was “intriguing” with the potential to “radically alter” the treatment of any cancer.

“On the assumption that this is not a one-off, this could herald a significant breakthrough in the treatment of, certainly this disease, but probably a lot of other diseases as well,” Professor Rodney Scott, head of medical genetics at the University of Newcastle, said.

“The implication is that you now have the potential to create cells that can target particular types of cancer due to the sorts of molecules that they may express on their cell surface, which would then be used to destroy those cells specifically.”

Leukaemia cells would be easier to treat with this technique than the solid tumours common to other types of cancer, according to Professor Scott. But it was a crucial first step, he said.

“It’s a first step along the way of eventually getting to those solid tumours and effecting a change there.”

Wait and see

Layla’s family will have to wait three years to know if she’s been cured. Photo: Great Ormond Street Hospital

A scientist, who previously researched genetic tests for leukaemia, told The New Daily the treatment had “promise” and described the technology used as “ground-breaking”, but urged caution.

“Theoretically, it’s got promise. Technically, it’s maestro stuff. It’s very difficult to do and we’re extremely lucky when it works,” Dr Michael Brisco, an affiliated lecturer at Flinders University.

“It’s very early days to say whether it’s working or not as a cancer treatment.

“The big question for leukemia is, how long does the effect last? Does it just produce short-term remission or does it cure them? It’s too early to know what this one’s going to do.

“Lots of treatments produce short-term remission, but then it comes back. Every week there’s a new treatment. You’ve really got to wait and see.”