A pioneering treatment that can reverse a form of childhood vision loss by inserting DNA directly into the eye is on track for regulatory approval in the US, after a panel of scientists endorsed unanimously the “gene therapy” being developed by Spark Therapeutics.

If the US Food and Drug Administration accepts the recommendation of its advisory committee, as it tends to, it would mark the agency’s first approval of such a treatment and herald a new era of medicine where diseases are tackled by inserting functioning copies of genes that are missing or mutated.

Gene therapies seek to tackle illness at its biological source, opening up the possibility of drugs that can be delivered just once rather than on a regular basis. In a reference to the potentially curative properties of such treatments, Spark’s shares are listed on Nasdaq under the ticker ONCE.