WASHINGTON, Aug. 10 (Xinhua) -- The United States Food and Drug Administration (FDA) approved on Friday for the first time a new class of drugs called small interfering RNA treatment.
The agency gave a green light to Onpattro infusion for the treatment of peripheral nerve disease caused by hereditary transthyretin-mediated amyloidosis (hATTR) in adult patients, affecting about 50,000 people worldwide.
This is also the first FDA-approved treatment for this rare, debilitating and often fatal genetic disease characterized by the buildup of abnormal amyloid protein in peripheral nerves, the heart and other organs.
"This approval is part of a broader wave of advances that allow us to treat disease by actually targeting the root cause, enabling us to arrest or reverse a condition, rather than only being able to slow its progression or treat its symptoms," said FDA Commissioner Scott Gottlieb.
Gottlieb said that new technologies like RNA inhibitors, which alter the genetic drivers of a disease, have the potential to transform medicine to better confront and even cure debilitating illnesses.
RNA acts as a messenger within the body's cells, carrying instructions from DNA for controlling the synthesis of proteins and RNA interference is a process that occurs naturally within our cells to block how certain genes are expressed.
This new class of drugs, called siRNAs, work by silencing a portion of RNA involved in causing the disease, according to FDA.
More specifically, Onpattro encases the siRNA into a lipid nanoparticle to deliver the drug directly into the liver, in an infusion treatment, to alter or halt the production of disease-causing proteins.
The new drug is designed to interfere with RNA production of an abnormal form of the protein transthyretin (TTR). By preventing the production of TTR, the drug can help reduce the accumulation of amyloid deposits in peripheral nerves, according to FDA.
Its efficacy of Onpattro was shown in a clinical trial involving 225 patients, 148 of whom were randomly assigned to receive an Onpattro infusion once every three weeks for 18 months, and 77 of whom were randomly assigned to receive a placebo infusion at the same frequency.
The patients who received Onpattro had better outcomes on muscle strength, sensation, reflexes and autonomic symptoms like blood pressure, heart rate, and digestion.
Onpattro-treated patients also scored better in terms of walking, nutritional status and the ability to perform activities of daily living.