Stremvelis is a stem cell gene therapy created from the patient’s own cells. It was designated as an orphan medicinal product in August 2005.
It was originally developed by Ospedale San Raffaele (OSR) and Fondazione Telethon (Telethon), via their joint San Raffaele Telethon Institute for Gene Therapy (SR-TIGET).
GSK advanced the therapy under a collaboration agreement signed in 2010.
Strimvelis was studied in a clinical trial that involved 12 participants, who demonstrated a 100% survival rate three years after the treatment.
About 92% of the patients did not need any interventions such as enzyme replacement therapy to survive.
GSK head of the rare disease unit Martin Andrews said: "This positive opinion is a major milestone in GSK’s commitment to the development of innovative, transformative medicines.
"If approved, Strimvelis will become the first corrective ex-vivo gene therapy for children to achieve regulatory approval anywhere in the world."
The drugmaker said that the gene therapy is only administered once and does not depend on a third-party donor, preventing risk of graft versus host disease.
ADA-SCID is an immune disorder caused by a faulty gene avoiding the production of adenosine deaminase, which is required to manufacture lymphocytes, a type of white blood cell.
An estimated 15 children are born per year in Europe with ADA-SCID, and survival rates are low.
Image: GSK’s head office, Brentford, London TW8. Photo: courtesy of Ian Wilson.