The drug Cameron received, Spinraza, was approved in the U.S. just before Christmas and may become the first blockbuster in a novel category of drugs called RNA therapeutics, after the genetic messenger molecule from which they are constructed.
Drugs made of RNA have been in development for more than 20 years. What drugs like Spinraza seek to do instead is use RNA to block, modify, or add to, the existing RNA messages in a cell. RNA drugs have also been beset by serious side effects, and several have been pulled from human tests over safety concerns. In January, in a paper published in the New England Journal of Medicine, it showed that one of its drugs could lower cholesterol levels for six months with one shot.
Rachel Meyers, previously a senior executive at Alnylam, says one problem facing RNA drugs is that companies have too often tried to use them to treat diseases where other options exist.
Last year, two drugs that work along these lines were approved in the U.S. The other, Exondys 51, developed by Sarepta Therapeutics, was approved to treat muscular dystrophy after becoming the focus of impassioned lobbying by parents of affected boys, who prevailed on the U.S Food and Drug Administration to allow it on the market despite limited evidence of its benefits.