Luxturna gene therapy to cure rare blindness

A drug, which is claimed to cure a rare form of blindness is set to become one of the most expensive medicines ever sold at $850,000 (£630,000).

The drug, Luxturna is injected directly into to the eye to address the root cause of visual impairment by replacing a defective gene in the retina. The gene therapy, the first approved for use in the US, was approved by the US Food & Drug Administration last month, but the price of the medication has only just been revealed.

Spark Therapeutics, the company which is pioneering the treatment, had earlier claimed the treatment was worth $1 million, citing the cost of a lifetime of blindness in lost earnings and wages for caregivers.

However, it added that it had settled for the lower price of $850,000, or $425,000 per eye. It will also offer ways to spread the cost to health insurers, but health insurers remain doubtful about their ability to cover the expense.

''We wanted to balance the value and the affordability concerns with a responsible price that would ensure access to patients,'' said Spark Therapeutics' chief executive, Jeff Marrazzo, The Guardian reported.

According to commentators, Luxturna is among an  emerging line of gene therapies and works differently from more established medicines administered over a period of time. Such treatments involve a one-off procedure to alter defective DNA, which allows the body to repair the problem itself.

The Food and Drug Administration approved Luxturna last month, after a dramatic hearing where teenagers said they could see the stars in the night sky for the first time in years. Eye doctors with no links to the company, who were present had pleaded for the approval.

Luxturna works to restore vision in people who have mutation in a gene called RPE65. The condition is very rare and affects only a few thousand people in the US.

The mutation causes gradual disruption of the cells located in the back of the eye forming the retina, which leads to blindness. There is no cure for the disease.

A modified cold virus, one called an adeno-associated virus is injected directly into the eye to deliver corrected genes to the retina.

Most of the 21 volunteers who were treated reported reversal of vision loss almost immediately.