Rilonacept (Arcalyst) inhibits inflammation by binding to Interleukin 1B receptors in patients with Cryopyrin-associated periodic syndromes (CAPS) which is a rare hereditary inflammatory condition.

Rilonacept Uses:

• Cryopyrin-associated periodic syndromes:

  • It is indicated for the treatment of cryopyrin-associated periodic syndromes in adults and children older than 12 years of age.
  • These include:
    • Familial cold autoinflammatory syndrome
    • Muckle-Wells syndrome.
    • Neonatal-onset multisystem inflammatory disease (NOMID).

Rilonacept (Arcalyst) Dose in Adults

Rilonacept (Arcalyst) Dose in the treatment of Cryopyrin-associated periodic syndromes: SubQ:

• Initial:

  • 320 mg administered subcutaneously as 2 separate injections of 160 mg or 2 mL per injection on the same day at two different sites

• Maintenance:

  • 160 mg once a week.

Note: Begin maintenance dose one week after the loading dose. Do not administer more than once a week.

Rilonacept (Arcalyst) Dose in Childrens

Rilonacept (Arcalyst) Dose in the treatment of Cryopyrin-associated periodic syndromes (CAPS):

• Children ≥12 years and Adolescents ≤17 years:

  • An initial loading dose of 4.4 mg/kg is administered subcutaneously. The maximum dose is 320 mg per dose.
  • Note: The loading dose may be divided into one or two separate injections administered on the same day at different sites. The maximum volume of injection should not exceed 2 mL or 160 mg/injection.
  • Maintenance dose:
    • Begin one week after the loading dose:
      • SubQ: 2.2 mg/kg/dose once a week up to a maximum dose of 160 mg/dose;
    • Note: Do not administer more than once a week.

• Adolescents ≥18 years:

  • Initial: Loading dose:
    • 320 mg administered as two separate subcutaneous injections of 160 mg each on the same day at different sites.
  • Maintenance:
    • Begin one week after the loading dose: 160 mg once a week;
    • Note: Do not administer more than once a week.

Pregnancy Risk Factor C

• Animal reproduction studies have shown that adverse events can be observed.

Use during breastfeeding:

• It is unknown if rilonacept can be excreted in breastmilk.
• It is recommended that you use it with caution if you are lactating.

Dose in Kidney Disease:

There are no dosage adjustments provided in the manufacturer’s labeling (it has not been studied in patients with kidney disease).

Dose in Liver disease:

There are no dosage adjustments provided in the manufacturer’s labeling (it has not been studied in patients with liver disease).

Common Side Effects of Rilonacept (Arcalyst):

• Immunologic:

  • Antibody Development

• Infection:

  • Increased Susceptibility To Infection

• Local:

  • Injection Site Reaction

• Respiratory:

  • Upper Respiratory Tract Infection

Less Common Side Effects of Rilonacept (Arcalyst):

• Central Nervous System:

  • Hypoesthesia

• Respiratory:

  • Cough
  • Sinusitis

Contraindication to Rilonacept (Arcalyst):

The manufacturer's labeling does not list any contraindications.

Warnings and precautions

• Anaphylaxis or hypersensitivity reactions

  • Hypersensitivity reactions can be severe for patients, including anaphylaxis.
  • Appropriate treatment should be initiated (including epinephrine) after discontinuation of the drug (prompt discontinuation of the drug is important).

• Infections

  • Patients could become more susceptible to infection. Patients with a history or ongoing infection should not use it.
  • If patients develop signs that could indicate infection, they should be closely monitored. If the infection is severe, treatment should be stopped.
  • Patients with active infections and patients with underlying chronic conditions should not be treated.
  • Therapy increases the risk of latent tuberculosis reactivation. Before starting treatment, patients should be closely monitored for signs of reactivation.

• Malignancy

  • Although the impact of the drug's use on malignant conditions is not known, it could impair anti-malignancy defenses.

• Hyperlipidemia:

  • The lipid profile should be monitored regularly by patients as the drug can cause an increase in total cholesterol, HDL and LDL.
  • For hyperlipidemia treatment, statins might be necessary.

Rilonacept: Drug Interaction

Monitoring parameters:

• Monitor CBC with differential counts and signs of infection
• Lipid profile,
• C-reactive protein (CRP),
• serum amyloid A;
• Signs of infection

How to administer Rilonacept (Arcalyst)?

• It is administered as a subcutaneous injection.
• The injection site should be rotated.
• It is best to administer in the anterior thighs, abdomen, and upper arm.
• Avoid injections at bruised sites, and sites that are tender, hard, or red.
• If two or more injections are needed to complete the loading dose, administer at different sites on the same day.
• Unused portions should be discarded.

Mechanism of action of Rilonacept (Arcalyst):

• Cryopyrin-associated period syndromes (CAPS), a rare hereditary inflammatory condition, encompasses three distinct genetic syndromes.
• Familial cold autoinflammatory syndrome (FCAS)
• Muckle-Wells syndrome (MWS),
• Neonatal-onset multisystem inflammation disease (NOMID).
• Recurrent urticaria, fever, and arthralgias are the symptoms. 
• It can be caused by mutations in the nucleotide binding domain, leucine rich family (NLR) and pyrin domain containing (3 (NLRP-33) genes or cold-induced immunoinflammatory syndrome-1 (CIAS1) genes.
• Cryopyrin, a protein that regulates interleukin-1b (IL-1b), activation. 
• Rilonacept binds IL-1b (some binding to IL-1a receptor antagonist and IL-1 receptor antagonist) but prevents it from interfering with cell surface receptors inhibiting inflammation.

The beginning of action:

• Steady-state reached by six weeks

Half-life elimination:

• 8.6 days.

International Brand Names of Rilonacept:

• Arcalyst

Rilonacept Brand Names in Pakistan:

No Brands Available in Pakistan.