Rare Daily Staff

The United Kingdom National Institute for Health and Care Excellence, issued a positive recommendation for GlaxoSmithKline’s Strimvelis, a gene therapy for the rare immunodeficiency condition known as ADA-SCID, or bubble baby syndrome.

The drug value watchdog found that the one-time $698,000 therapy (€594,000) deserved a positive recommendation, even though it called its cost-effectiveness “uncertain.”

The committee concluded that although Strimvelis was a high-cost technology and there remained uncertainties in the clinical evidence, it is likely to provide important clinical benefits for people with ADA–SCID at a cost that is manageable and value for money in the context of a highly specialized service,” wrote NICE Chair Peter Jackson in the evaluation document.

The decision provides hope for developers of a number of gene therapies working their way toward market as there have been concerns about how payers would view the value of the potentially life-saving therapies that carry high, one-time costs.

ADA-SCID is a very rare disorder caused by a faulty gene inherited from both parents. The faulty gene stops production of adenosine deaminase (ADA), an essential protein need to produce lymphocytes, a type of white blood cell. Children born with ADA-SCID do not develop a properly functioning immune system. As a result, they are unable to fight off everyday infections, which result in severe and life-threatening illness. Without treatment, the disorder often proves fatal within the child’s first year of life.

ADA–SCID accounts for about 10 to 15 percent of all diagnoses of severe combined immunodeficiency. The overall annual incidence is estimated to be between 1 in 200,000 and 1 in 1,000,000 live births, although the incidence varies widely between populations. In England, GSK estimates that three people a year would be diagnosed with ADA–SCID each year and that on average one would be treated on average.

The NICE committee considered the innovative nature of Strimvelis in making its decision. It noted that it is the only ex vivo gene therapy to gain marketing authorization from the European Medicines Agency. It also noted it is a significant advance because it eliminates the need for a stem cell donor and the risk it carries of graft-vs-host disease, a potentially fatal immune rejection.

Strimvelis is only administered once and does not rely on a third-party stem cell donor. With Strimvelis, the patient’s own bone marrow cells are removed, and a vector is used to insert a normal copy of the ADA gene into the cells in a process known as transduction. The gene-corrected cells are then re-introduced to the patient via an intravenous infusion, after which some of the cells return to the bone marrow. In order to improve the engraftment of the gene-modified cells in the patient’s bone marrow, patients are also pre-treated with low dose chemotherapy.

October 23, 2017

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