Gene therapy cure for haemophilia A approved for use in patients

A pioneering treatment, which effectively cures the blood clotting disorder haemophilia A, has been approved for use in the USA.

This landmark moment comes after years of research. The lead for this in Southampton is Dr Rashid Kazmi.

It will mean patients no longer need to have regular injections, or avoid certain activities, to prevent potentially life-threatening bleeds.

Living in fear of bleeds

When most people bleed, for example after an injury, clotting factors in their blood mix with blood cells called platelets to form a clot. This naturally stops the bleeding.

In people with haemophilia A, a lack of clotting factor VIII means they bleed for longer than usual. This not only happens with visible cuts and bruises on their skin, but also with internal bleeding.

“The hallmark of the condition, with severe haemophilia A, is that they will bleed spontaneously into their large joints,” Dr Kazmi explains. “That cripples the patients.”

Patients currently need to inject themselves with Factor VIII concentrate and need to be under regular frequent surveillance by their haematologist. This means they need to fit their lives around these appointments.

While this works, it results in ‘peaks and troughs’ of the levels of the clotting factor in their blood, Dr Kazmi explains. They are most at risk in the days before they are due their next injection.

“Even though giving factor concentrate is very helpful, and they are able to live a ‘normal’ life, it’s not normal,” he says. “They won’t have spontaneous bleeds, but they could still have trauma-related bleeds.

“This puts constraints on their lifestyle - they can’t play contact sports like rugby, boxing, judo or karate. It also limits their career choices.

“And psychologically, they might live in perpetual fear of having a bleed.”

Developing a cure

Haemophilia A is caused by a fault in the gene which produces clotting Factor VIII.

Previous treatments have only sought to replace the clotting factor VIII patients lack. More recently non-factor agents have also been launched. But gene therapy aims to target the root cause of the condition.

“Gene therapy is an attempt to cure the condition,” explains Dr Kazmi. “The principle is that the gene for factor VIII should be replaced or mended.”

The treatment, known as Roctavian, has now been approved by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) for patients with the condition. It comes after years of research, which provided the evidence required to support its approval.

It follows FDA approval for another gene therapy for haemophilia B. The Medicines and Healthcare products Regulatory Agency (MHRA) have also approved this, which means UK patients will be able to access it through private healthcare. It is awaiting a decision from the National Institute for Health and Care Excellence (NICE). This will determine whether it can be given to patients on the NHS.

While Roctavian is extremely expensive – costing around $2.9 million – it offers a cure. Following a one-off treatment, patients can produce their own clotting factor VIII. This means they no longer need injections, and can live a completely normal life.

“It has the potential to transform the life of the patient completely,” says Dr Kazmi. “This is just completely a new world for us, because for years we didn’t have much to offer patients.”