Rilonacept (Arcalyst) is a medication used to treat a variety of inflammation disorders. Rilonacept is approved to treat Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Autoinflammatory Syndrome (FCAS) and Muckle-Wells Syndrome (MWS) in adults and children ages 12 and older. It is not FDA-approved for the treatment of neonatal onset multisystem inflammatory disease (NOMID).
Rilonacept is taken as an injection. In adults 18 years or older, it is first taken as a loading dose of two subcutaneous injections, as injections under the skin, on the same day at two different body sites; each injection has a dose of 160 mg, for a total of 320 mg. It is then followed by weekly subcutaneous injections of a single 160 mg dose.
In children 12-17 years of age, the initial dose is 4.4 mg/kg (up to 320 mg), delivered in either one or two subcutaneous injections. It is then followed by weekly subcutaneous injections of a single 2.2 mg/kg (up to 160 mg) dose.
Rilonacept lowers the body’s ability to fight infections, which may cause you to be more susceptible to viral and bacterial infections. The most common side effects of this drug are upper respiratory tract infections and injection site reactions. Symptoms of injection site reactions include redness, pain, itching, or swelling of the area.
Because rilonacept impairs your body’s ability to fight infection, tell your rheumatology provider if you develop a fever, or any signs or symptoms of an infection. Stop the drug if you develop a serious infection. Tell your rheumatology provider if you are pregnant or planning to conceive. You should discuss with your rheumatology provider before receiving any vaccinations. Live vaccines should be avoided while on this medication. You should discuss updating your vaccinations prior to starting this medication.
Updated December 2020 by Kanika Monga, MD, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.
This information is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.