Shaun Busby used to be in constant pain as a boy growing up.
He would miss school regularly because he suffered from haemophilia, meaning his blood did not clot properly.
He suffered from frequent bleeding in his joints, which would need regular injections so they did not become swollen and incapacitate him.
In the end, the 33-year-old from Tooting had to have a knee replacement because the damage became so bad. And he had to have regular injections of Factor 8, the blood clotting ingredient.
But he started taking part in a groundbreaking medical trial at Guy’s and St Thomas’ Hospital – and now he has a career as an engineer and can lead an almost normal life.
He said: “I feel more alive after the trial and it has had a huge impact on my quality of life. I have to pinch myself all the time – four years ago I was struggling – having bleeds and worrying about pain medication and Factor 8 injections.
“Living with haemophilia is very difficult because you are forever in and out of hospital clinics and appointments. As a child I lost time from school despite trying my best not to. During my adult life I have had severe problems with my knee and have required a knee replacement due to recurrent bleeds.
“It is mentally uplifting for me as I now don’t have to worry about all the things I used to. I have joint bleeds only occasionally and need Factor 8 injections much less frequently.
“I can go away on holidays and go to music festivals without worrying too much about joint bleeds.”
Hundreds of haemophilia A patients in the UK could benefit from the treatment – the first-ever gene therapy for the condition.
The four-year trial has shown that patients with the rare haemophilia A condition continue to show a positive and sustained response to gene therapy.
Haemophilia A patients cannot produce a key clotting protein called Factor 8. This leads to severe pain from joint bleeds, bruising and prolonged bleeding from wounds.
Usually an inherited condition, there are more than 2,000 severe haemophilia A patients in the UK. These patients have to be treated with Factor 8 injections three times a week – or even more frequently.
Gene therapy has existed for around 15 years for haemophilia B, in which Factor 9 is deficient. But haemophilia A has proved more difficult because the Factor 8 gene is very large in comparison to the Factor 9 gene.
The missing protein clotting Factor 8 gene has to be inserted into a virus which is used as a vehicle to carry it after being injected into the patient’s blood as a single infusion. It then circulates to the patient’s liver and induces it to start producing the missing Factor 8.
Scientists have made this possible by truncating the Factor 8 gene so that only the much smaller active part is retained and it can fit into the virus.
This new gene therapy for haemophilia A has been tested at several hospitals in the UK, including Guy’s and St Thomas’ NHS Foundation Trust, and has shown very positive results. Shaun was one of the first patients to take part in the phase one trial at Guy’s and St Thomas’. He first received the treatment in February 2016.
The new three to four-year follow-up data is ‘very impressive,’ according to the principal investigator on the gene therapy trial at Guy’s and St Thomas’, consultant haematologist Dr Bella Madan.
Dr Madan said: “It has been extremely successful and beyond our wildest dreams. These are the first patients with haemophilia A to be treated with gene therapy.
“Our patient’s life has been transformed remarkably since receiving a single infusion of gene therapy in February 2016.
“He has infrequent bleeds and copes well with a very physically demanding job as an engineer. He is no longer dependent on three-times-a-week injections that he was previously requiring, and needs Factor 8 injections only occasionally.”