First ever RNA-based gene-silencing drug approved by FDA, and it's not cheap

Twenty years after the breakthrough discovery illustrating how RNA interference can be used to silence certain genes, and over a decade after the research won a Nobel prize, the U.S. Food and Drug Administration has approved the first drug utilizing this method for adult clinical treatment. 

The condition, hereditary transthyretin-mediated amyloidosis (hATTR), is rare and the drug is not a cure but rather an ongoing treatment that will reportedly cost up to US$450,000 per year for a single patient.

Development of these siRNA clinical treatments has been slower than initially hoped, with researchers spending the better part of the last two decades searching for effective ways to both deliver these molecules to specific target organs and producing nanoparticles that can shield the siRNA from degradation while it its moving through the bloodstream.

The latest FDA approval for the siRNA drug is groundbreaking but incredibly narrow, focusing on a rare condition that only afflicts around 50,000 people worldwide. The drug is called Onpattro (patisiran), and it disrupts the RNA mechanism producing transthyretin, a protein that promotes an accumulation of amyloid deposits in the body.

Alnylam, the company behind the development of Onpattro, currently has three more siRNA drugs in late-stage trials, and the hope is to have those treatments approved within the next one to two years. Alongside the FDA approval, the EU is set to pass Onpattro for public use very soon.