How does Onpattro (patisiran) work?

• Onpattro decreases levels of a protein called transthyretin (TTR)
• TTR levels are increased in people with hATTR amyloidosis, a rare condition that causes polyneuropathy, organ failure, and if left untreated, death
• Onpattro decreases TTR by breaking down mutated or wild-type genetic material that codes for TTR
• This mutant/wild type genetic material is prevalent in people with hATTR amyloidosis
• Onpattro aims to stop or reverse the progression of neuropathy associated with hATTR amyloidosis.

Onpattro (patisiran) works by decreasing a protein called transthyretin (TTR) which is made primarily in the liver.

It is approved for use in people with hereditary transthyretin-mediated amyloidosis (hATTR) which is a rare condition in which abnormal deposits of misfolded TTR protein build up in many parts of the body, interfering with normal nerve and organ function.

A build-up of these misfolded proteins affects not only nerves but multiple organs and body systems, such as the heart, nervous system, gastrointestinal tract, and kidneys.

Polyneuropathy (widespread nerve pain) is often the first sign of this rare condition and once a person is symptomatic, the neuropathy will progress, often rapidly, and cause severe disability. Left untreated hATTR amyloidosis with polyneuropathy is fatal.

Onpattro decreases TTR by breaking down mutated or wild-type genetic material that codes for the TTR protein. This mutant/wild type of genetic material is prevalent in people with hATTR.

Onpattro aims to stop or reverse the progression of neuropathy associated with hATTR amyloidosis. It can help reduce symptoms such as nerve pain, numbness, tingling, abnormal heartbeats, diarrhea, constipation, weakness, and problems with limb movement.

Onpattro is administered by a health care professional as an infusion every three weeks. The sooner treatment is started, the more effect it has.

Onpattro is the first-of-its-kind treatment and it was approved in 2018. Other treatments have also been approved for hATTR. Before these treatments, a liver transplant was the only known treatment of hATTR.