Prescription medicine
Rilonacept Brand names: Arcalyst
Rilonacept (Arcalyst) is a prescription medicine with an FDA approval on record since 2008. No generic is listed in FDA's NDC Directory.
- No generic listed
Check it at the source: the rilonacept FDA label on DailyMed (effective December 16, 2025); the BLA 125249 record on Drugs@FDA; every rilonacept label on DailyMed.
Highlights of the record
FDA label of December 16, 2025; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026
Used for
From the label: indications and usageARCALYST (rilonacept) is an interleukin-1 blocker indicated for: Treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Autoinflammatory Syndrome (FCAS), and Muckle-Wells Syndrome (MWS) in adults and children 12 years and older ( 1.1 , 14.1 ) Maintenance of remission of Deficiency of Interleukin-1 Receptor Antagonist (DIRA) in adults and pediatric patients weighing 10 kg or more ( 1.2 ,
Forms and strengths
- 160 mg/2ml
Injection (powder) (lyophilized) for solution.
On the market
- Earliest approval on file
- February 27, 2008 Arcalyst, Kiniksa Pharmaceuticals (Uk), Ltd.; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- No generic approved
- Labelers listed (NDC)
- 1 of which 0 under generic applications, 1 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- Not in the survey
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 1,121 through July 30, 2026
What is rilonacept used for?
From the label: indications and usageARCALYST (rilonacept) is an interleukin-1 blocker indicated for: Treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Autoinflammatory Syndrome (FCAS), and Muckle-Wells Syndrome (MWS) in adults and children 12 years and older ( 1.1 , 14.1 ) Maintenance of remission of Deficiency of Interleukin-1 Receptor Antagonist (DIRA) in adults and pediatric patients weighing 10 kg or more ( 1.2 , 14.2 ) Treatment of recurrent pericarditis (RP) and reduction in risk of recurrence in adults and children 12 years and older ( 1.3 , 14.3 ) 1.1 Cryopyrin-Associated Periodic Syndromes, Familial Cold Autoinflammatory Syndrome and Muckle-Wells Syndrome ARCALYST ® (rilonacept) is […]
Source: FDA drug label (Arcalyst), Kiniksa Pharmaceuticals (UK), Ltd., effective December 16, 2025 (SPL set ad965f38-dd22-4607-a673-2fb92f3b527a), via openFDA; the full label on DailyMed
What does the patient leaflet for rilonacept say first?
The FDA-approved Medication Guide or Patient Information that comes with the medicine, in its own words.
From the patient leaflet: What is the most important information I should know about ARCALYST?ARCALYST can affect your or your child's immune system. ARCALYST can lower the ability of your or your child's immune system to fight infections. Serious infections, including life-threatening infections and death, have happened in people taking ARCALYST. Taking ARCALYST can make you or your child more likely to get infections, including life-threatening serious infections, or may make any infection that you or your child have worse. You or your child should not begin treatment with ARCALYST if you or your child have an infection or have infections that keep coming back (chronic infection). After starting ARCALYST , if you or your child get an infection, any sign of an infection, including a fever, cough, flu-like symptoms, or have any open sores on your body, call the healthcare provider right away. Treatment with ARCALYST should be stopped if you or your child get a serious infection. You or your child should not take medicines that block tumor necrosis factor (TNF), such as Enbrel ® (etanercept), Humira ® (adalimumab), or Remicade ® (infliximab), while you or your child are taking ARCALYST. You or your child should also not take other medicines that block interleukin-1 (IL-1), such as Kineret ® (anakinra), while taking ARCALYST. Taking ARCALYST with any of these medicines may increase your or your child's risk of getting a serious infection. Before starting treatment with ARCALYST , tell the healthcare provider if you or your child: think you have an infection. are being treated for an infection. have signs of an infection, such as fever, cough, or flu-like symptoms. have any open sores on your body. have a history of infections that keep coming back. have asthma. People with asthma may have an increased risk of infection. have diabetes or an immune system problem. […]
From the patient leaflet: How should I store ARCALYST?Keep ARCALYST in the carton it comes in to protect from light. Store ARCALYST in the refrigerator from 36°F to 46°F (2°C to 8°C). Call your pharmacy if you have any questions. Refrigerated ARCALYST can be used until the expiration date printed on the vial and carton. ARCALYST may be kept at room temperature after mixing with Sterile Water for Injection, USP, and should be used within 3 hours of mixing. Keep ARCALYST away from light. Keep ARCALYST, injection supplies, and all other medicines out of the reach of children. General Information about the safe and effective use of ARCALYST. Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use ARCALYST for a condition for which it was not prescribed. Do not give ARCALYST to other people even if they have the same symptoms that you have. It may harm them. […]
Source: FDA drug label (Arcalyst), Kiniksa Pharmaceuticals (UK), Ltd., effective December 16, 2025 (SPL set ad965f38-dd22-4607-a673-2fb92f3b527a), via openFDA; the full label on DailyMed
Is there a generic for rilonacept (Arcalyst)?
No generic rilonacept is approved (Drugs@FDA, October 8, 2026).
- 2008 earliest approval on file
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What does the rilonacept label say about other medicines?
The rilonacept label names 1 other medicine in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Warfarin | drug interactions | This is clinically relevant for CYP450 substrates with a narrow therapeutic index, where the dose is individually adjusted (e.g., warfarin). |
Source: FDA drug label (Arcalyst), Kiniksa Pharmaceuticals (UK), Ltd., effective December 16, 2025 (SPL set ad965f38-dd22-4607-a673-2fb92f3b527a), via openFDA; the full label on DailyMed
What do FAERS reports show for rilonacept?
The FDA Adverse Event Reporting System holds 1,121 reports that list rilonacept among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 24 are coded as a death and 122 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What next?
- Rilonacept side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other