A healthcare provider may prescribe Arcalyst to help reduce inflammation in people who have a rare hereditary group of conditions called cryopyrin-associated periodic syndromes. Specifically, Arcalyst can be used for treating familial cold autoinflammatory syndrome and Muckle-Wells syndrome in adults and children as young as 12 years old. This medication is also sometimes prescribed off-label to treat gout or rheumatoid arthritis.
What Is Arcalyst Used For?Arcalyst® (rilonacept) is a prescription medication approved to treat conditions known as cryopyrin-associated periodic syndromes (CAPS). This medication is considered an interleukin-1 beta (IL-1β) blocker. It is given as an injection just under the skin (subcutaneously).
CAPS are a group of rare hereditary conditions that include familial cold autoinflammatory syndrome (FCAS) and Muckle-Wells syndrome (MWS). The diseases are associated with a mutation (change) in a certain gene that is passed down through generations (inherited). The mutated gene causes cryopyrin (a protein in the body) to become overactive, usually in response to certain triggers like cold temperatures.
The overactive cryopyrin tells the body to make too much interleukin-1 beta (Il-1β), an immune system protein. This leads to inflammation in the body, and to the symptoms of CAPS. General symptoms may include but are not limited to:
- Muscle and joint pain
- Conjunctivitis (swelling of the membrane lining the eyelids or conjunctiva).
People with CAPS typically have one of three diseases. These three diseases include:
- Familial cold autoinflammatory syndrome (FCAS)
- Muckle-Wells syndrome (MWS)
- Neonatal-onset multisystem inflammatory disease (NOMID).
FCAS is the least severe form of CAPS. It is also the most common. When symptoms are triggered, they usually last no longer than 24 hours.
MWS is a more severe form of CAPS than FCAS. Symptoms not only occur more frequently, but generally last one to three days. In some cases, hearing loss may develop.
NOMID is the most severe form of CAPS. Symptoms usually begin at birth, are progressive, and can lead to severe complications, such as:
- Hearing loss
- Vision loss
- Joint damage
Arcalyst can be given to treat FCAS and MWS; it has not been studied in people with NOMID.