Patisiran, sold under the brand name Onpattro, is a

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

used for the treatment of

polyneuropathy Polyneuropathy () is damage or disease affecting peripheral nerves (peripheral neuropathy) in roughly the same areas on both sides of the body, featuring weakness, numbness, and burning pain. It usually begins in the hands and feet and may prog ...

in people with

hereditary transthyretin-mediated amyloidosis Familial amyloid polyneuropathy, also called hereditary transthyretin amyloidosis (hATTR), or Corino de Andrade's disease, is an autosomal dominant neurodegenerative disease. It is a form of amyloidosis, and was first identified and described by ...

, a fatal

rare disease A rare disease is any disease that affects a small percentage of the population. In some parts of the world, the term orphan disease describes a rare disease whose rarity results in little or no funding or research for treatments, without financi ...

that is estimated to affect 50,000 people worldwide. It is the first

small interfering RNA Small interfering RNA (siRNA), sometimes known as short interfering RNA or silencing RNA, is a class of double-stranded RNA, double-stranded non-coding RNA, non-coding RNA, RNA molecules, typically 20–24 base pairs in length, similar to microR ...

-based drug approved by the U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA) and the first drug approved by the FDA to treat this condition. It is a

gene silencing Gene silencing is the regulation of gene expression in a cell to prevent the expression of a certain gene. Gene silencing can occur during either Transcription (genetics), transcription or Translation (biology), translation and is often used in res ...

drug that interferes with the production of an abnormal form of

transthyretin Transthyretin (TTR or TBPA) is a transport protein in the plasma and cerebrospinal fluid that transports the thyroid hormone thyroxine (T4) and retinol to the liver. This is how transthyretin gained its name: ''transports thyroxine and retinol' ...

. Patisiran utilizes a novel approach to target and reduce production of the TTR protein in the liver via the RNAi pathway. Patisiran was developed and is marketed by

Alnylam Alnylam Pharmaceuticals, Inc. is an American biopharmaceutical company focused on the discovery, development and commercialization of RNA interference (RNAi) therapeutics for genetically defined diseases. The company was founded in 2002 and is he ...

. The FDA considers it to be a

first-in-class medication A first-in-class medication is a prototype drug that uses a "new and unique mechanism of action" to treat a particular medical condition. While the Food and Drug Administration's Center for Drug Evaluation and Research tracks first-in-class medic ...

History

Patisiran was granted

orphan drug status An orphan drug is a pharmaceutical agent that is developed to treat certain rare medical conditions. An orphan drug would not be profitable to produce without government assistance, due to the small population of patients affected by the condition ...

, fast track designation,

priority review Priority review is a program of the United States Food and Drug Administration (FDA) to expedite the review process for drugs that are expected to have a particularly great impact on the treatment of a disease. The priority review voucher program ...

and breakthrough therapy designation due to its novel mechanism and the rarity of the condition it treats. It was approved for medical use in the United States and in the European Union in August 2018. The per-patient cost is between and per year, depending on the number of vials needed.

Formulation

The

siRNA Small interfering RNA (siRNA), sometimes known as short interfering RNA or silencing RNA, is a class of double-stranded non-coding RNA molecules, typically 20–24 base pairs in length, similar to microRNA (miRNA), and operating within the RN ...

active component of Patisiran is formulated into

lipid nanoparticles Lipid-based nanoparticles are very small spherical particles composed of lipids. They are a novel pharmaceutical drug delivery system (part of nanoparticle drug delivery), and a novel pharmaceutical formulation. There are many subclasses o ...

, which protect the

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

and facilitate its delivery to target tissues. The lipid

nanoparticle A nanoparticle or ultrafine particle is a particle of matter 1 to 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 100 nm in only two directions. At ...

formulation includes buffer components, as well as the

lipid Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing ...

components DLin-MC3-DMA,

Distearoylphosphatidylcholine Distearoylphosphatidylcholine is a phosphatidylcholine, a kind of phospholipid. It is a natural constituent of cell membranes, eg. soybean phosphatidylcholines are mostly different 18-carbon phosphatidylcholines (including minority of saturated DSP ...

cholesterol Cholesterol is the principal sterol of all higher animals, distributed in body Tissue (biology), tissues, especially the brain and spinal cord, and in Animal fat, animal fats and oils. Cholesterol is biosynthesis, biosynthesized by all anima ...

, and the PEGylated lipid

DMG-PEG 2000 DMG-PEG 2000 is a synthetic lipid formed by the PEGylation of myristoyl diglyceride. It is used to manufacture lipid nanoparticles that are used in mRNA vaccines, and in particular forms part of the drug delivery system for the Moderna COVID- ...

Society and culture

Economics

As of 2020, there were 1050 people globally receiving patisiran, generating $65.5M in net-revenues for

Alnylam Pharmaceuticals Alnylam Pharmaceuticals, Inc. is an American biopharmaceutical company focused on the discovery, development and commercialization of RNA interference (RNAi) therapeutics for genetically defined diseases. The company was founded in 2002 and is he ...

References

{{Portal bar , Medicine Biopharmaceuticals Orphan drugs small interfering RNA