A new gene therapy developed by GlaxoSmithKline has been approved by the European Medicines Agency (EMA) for use in children with the ultra-rare genetic disease, adenosine deaminase severe combined immune deficiency (ADA-SCID). The therapy – called Strimvelis – is the first gene therapy for pediatric use to be approved in Europe.
Approximately 15 European children per year are born with ADA-SCID, which results in the inability to generate certain lymphocytes. As children with the ultra-rare disease are left with a severely underdeveloped – or completely absent – immune system, they often don’t survive beyond two years of life.
If a compatible bone marrow transplant is performed the prognosis is more promising, however a match cannot always be found. The EMA is therefore endorsing Strimvelis for patients for whom a matching bone marrow transplant is unavailable.
Analysts expect that Strimvelis will gain full marketing authorization from the European Commission in just a few months. This will be the second gene therapy to be approved in Europe, the first of which is UniQure’s Glybera – a therapy used to treat a rare adult blood disease.
The US Food and Drug Administration (FDA) has not yet approved any gene therapies, despite the presence of a number of US-based biotech companies – including Bluebird Bio – who have products in the pipeline. The field has had a tumultuous history full of failed clinical trials, however new techniques used to get functional copies of genes into their target cells has increased confidence in the technology.
Despite this latest approval, gene therapy remains in the early stages of clinical development. “We’re on page one of chapter one of a new medicine textbook,” Martin Andrews, head of GlaxoSmithKline’s rare diseases unit, told Reuters.
Biotechnology companies will still face a number of challenges, including the practice of delivering gene therapy to patients. For example, Strimvelis requires bone marrow cells to be harvested from patients, processed in the lab, and infused back into the individual.
Pricing will also be a complicated issue for these gene therapies, as the patient population is often extremely limited. Glybera – which was approved by the EMA in 2014 – became the first drug to carry a $1 million price tag.
While GlaxoSmithKline have yet to release the cost of Strimvelis, a spokesperson from the company said they anticipate it will cost “very significantly less than $1 million.” The company plans to apply for FDA approval sometime next year.