Irish haemophilia patients given ‘functional cure’

New gene therapy gives patients ‘working copy’ of genes for clotting factor protein

Haemophilia is a group of inherited blood disorders in which there is a defect in the clotting mechanism of the blood. Photograph: iStock

Haemophilia is a group of inherited blood disorders in which there is a defect in the clotting mechanism of the blood. Photograph: iStock

 

Three Irish people with haemophilia have been given a “functional cure” for the condition using ground-breaking gene therapy.

The three are among 54 patients worldwide who participated in a trial for severe haemophilia that started earlier this year.

The positive early results of the trial are being presented at the prestigious annual meeting of the American Society of Haematology on Tuesday.

Haemophilia is a group of inherited blood disorders in which there is a defect in the clotting mechanism of the blood. Patients can be treated with a clotting factor, but this requires weekly injections.

The new gene therapy provides patients with a new “working copy” of the genes for clotting factor protein. Once this is administered there is no need for injections for at least 10 years.

‘No side-effects’

The Irish patients were dosed last spring at St James’s Hospital and have been monitored closely since then, despite Covid-19 restrictions.

They received the gene therapy in a single intravenous dose to the liver and it started to produce the missing clotting factor.

One of the patients, Irish Haemophilia Society head Brian O’Mahony, describes himself as “functionally cured”.

“I’ve had no side-effects and my factor IX level has stayed normal. After living my entire life with severe haemophilia, at the moment I don’t have it.”

The pandemic posed a challenge because it was known some patients might have to be administered steroids to prevent liver inflammation and this could increase their risk of getting Covid-19.

In the event, only nine out of the 54 patients, and none in Ireland, required steroid treatment.

Lasting protection

Dr Niamh O’Connell from the National Coagulation Centre in St James’ Hospital says the new therapy provides patients with a constant and lasting level of protection for the first time.

The potential of gene therapy for creating the condition had long been known but it has taken 20 years to realise, she says.

About 30 people with haemophilia B will benefit from the treatment; new gene therapies are also being developed for haemophilia A.

In the 1980s, hundreds of Irish people with haemophilia were infected with HIV and hepatitis C after being given contaminated blood products supplied by the State.