A one-year-old baby suffering from leukaemia is said to be cancer free and doing well after a new treatment known as 'molecular scissors'.

The treatment, previously only tested in labs, is used to edit genes and create designer cells to hunt out and kill drug-resistant leukaemia.

Layla (1) was being treated at London's Great Ormond Street Hospital and had relapsed acute lymphoblastic leukaemia.

The breakthrough comes from UCL Institute of Child Health's (ICH) and the Great Ormond Street Hospital research teams - who are developing treatments and cures for some of the rarest childhood diseases.

The treatment works by adding new genes to healthy donor T-cells, which arm against leukaemia.

Using molecular tools that act like scissors, specific genes are then cut in order to make the T-cells behave in specific ways.

The hospital says: "Chemotherapy successfully treats many patients with leukaemia but it can be ineffective in patients with particularly aggressive forms of the disease where cancer cells can remain hidden or resistant to drug therapy".

"Recent developments have led to treatments where immune cells, known as T-cells, are gathered from patients and programmed using gene therapy to recognise and kill cancerous cells".

"Multiple clinical trials are underway, but individuals with leukaemia, or those who have had several rounds of chemotherapy, often don't have enough healthy T-cells to collect and modify meaning this type of treatment is not appropriate".

Layla is said to be doing well | Image: Great Ormond Street Hospital

A team at the hospital has now used modified T-cells from donors - known as UCART19 cells - to treat Lyala, who had unsuccessful chemotherapy and for whom palliative care was deemed the only option left.

Professor Waseem Qasim, consultant immunologist at Great Ormond Street Hospital, explains: "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?'".

"The treatment was highly experimental and we had to get special permissions, but she appeared ideally suited for this type of approach".

Layla's mother, Lisa, says: "We didn't want to accept palliative care and so we asked the doctors to try anything for our daughter, even if it hadn't been tried before".

Full clinical trials are now being planned to test UCART19 cells in larger groups of patients - and are set to begin early in 2016.