Alfie Slater’s life-saving bone marrow operation has been cancelled.

The three-year-old – who was due to have the procedure on Monday – has instead been put on a drug’s trial taking treatment only licensed for adults.

The Bridport boy’s care has been transferred from Southampton to the Royal Marsden cancer specialist hospital in London.

Anxious mum Holly said it was hard to adjust to the news that Alfie wouldn’t get his bone marrow transplant.

She was told a match had been found – just after doctors dropped the bombshell that the drugs he was taking were not working on his rare chronic myloid leukaemia.

Holly said: “We have had to take him off the drugs he was on for a week then go up to London on Tuesday and they want to start him on a new drug – licensed for adults, not children.

“I don’t really know how I feel about that. I had just got my head around the whole transplant situation and now they want to do this with him.

“He might be on these new drugs for four years – we are not sure. He is going to need a bone marrow transplant eventually no matter what. They want to hold that off as long as possible before they try the transplant so he can get stronger but obviously your body can reject the bone marrow anyway even if it is a match.”

Alfie will have to be in hospital for two days for the first session and then he and Holly will go every week for the next six weeks.

At least Holly will get hospital transport to the hospital but Alfie’s two-year-old sister Ellie May will have to stay with relatives.

“It feels like we are right back at the beginning again,” Holly added. “It really came out of the blue.”

It was at the end of March after a bone marrow test when Holly got the devastating news that Alfie’s medicines were not killing any of the chromosomes they were meant to and a bone marrow match was his last chance.

Alfie’s story has touched readers and the brave boy has been given gifts of his favourite toys – tractors – and a handmade quilt donated by Angela Hartle of Project Linus to take on his hospital visits,.

Holly said it was lovely that people were thinking of her son but she also made a plea for people to sign up for the Antony Nolan Trust.

She said: “People get put off the idea of donating their bone marrow because they think it hurts but Alfie has coped with having needles stuck in his spine and he is only three.”

In the UK less than five children under the age of five are diagnosed with the type of cancer Alfie has each year.