Rilonacept is a medication used to treat certain inflammatory conditions. It belongs to a class of drugs known as interleukin-1 (IL-1) inhibitors. IL-1 is a protein in the body that plays a role in inflammation and immune responses. By inhibiting IL-1, rilonacept helps to reduce inflammation and symptoms associated with conditions such as cryopyrin-associated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome and Muckle-Wells syndrome. Rilonacept is typically administered by injection under the skin (subcutaneously).

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:

Starting Dose:

• You'll get a total of 320 mg of Rilonacept.
• This is given as 2 separate injections, each containing 160 mg (2 mL) of the medication.
• Both injections are given on the same day but at different spots on your body.

Maintenance Dose:

• After the initial dose, you'll switch to a maintenance dose.
• This is 160 mg given once a week.
• Start the maintenance dose one week after the initial loading dose.
• Don't take it more often than once a week.

Rilonacept (Arcalyst) Dose in Children

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

For Children (12 to 17 years old):

• Initial Dose:
  • A loading dose of 4.4 mg/kg, up to a maximum of 320 mg per dose.
  • The loading dose can be given in 1 or 2 separate injections on the same day, at different spots.
• Maintenance Dose:
  • Start one week after the loading dose.
  • It's 2.2 mg/kg per dose, up to a maximum of 160 mg per dose.
  • Don't take it more often than once a week.

For Adolescents (18 years and older):

• Initial Dose:
  • A loading dose of 320 mg, given as 2 separate injections (160 mg each) on the same day, at different spots.
• Maintenance Dose:
  • Start one week after the loading dose.
  • It's 160 mg once weekly.
  • Don't take it more often than once a week.

Pregnancy Risk Factor C

• When it comes to pregnancy, Rilonacept falls into category C, meaning there have been adverse effects noted in animal studies related to reproduction.

Use during breastfeeding:

• It's uncertain whether rilonacept passes into breast milk.
• Because of this uncertainty, caution is advised when giving rilonacept to nursing mothers, according to the manufacturer's recommendation.

Dose in Kidney Disease:

• The manufacturer's instructions don't include any specific adjustments in dosage for people with kidney problems because this aspect hasn't been studied.

Dose in Liver disease:

• The manufacturer's instructions don't offer any dosage changes for individuals with liver issues because this aspect hasn't been thoroughly studied.

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):

• According to the manufacturer's instructions, there are no specific situations where the use of rilonacept is prohibited.

Warnings and precautions

Anaphylaxis or hypersensitivity reactions

• Although rare, rilonacept can sometimes lead to severe allergic reactions known as anaphylaxis or hypersensitivity reactions.
• If you experience such a reaction, it's essential to stop using rilonacept and seek appropriate medical treatment right away.

Infections

• Before using rilonacept, it's important to be cautious if you have a history of infections or conditions that make you prone to infections.
• If you develop a new infection while using rilonacept, it's crucial to be closely monitored.
• If the infection becomes severe, treatment with rilonacept should be stopped.
• Rilonacept should not be started if you have an active or chronic infection.
• Additionally, there's a risk of latent tuberculosis reactivating, so it's necessary to follow current guidelines for evaluating and treating latent tuberculosis before starting rilonacept therapy.

Malignancy

• Using rilonacept might weaken your body's ability to defend against cancer.
• However, how it affects the development and progression of cancer is not entirely understood yet.

Hyperlipidemia:

• Taking rilonacept might lead to higher levels of cholesterol, both the good (HDL) and bad (LDL) kinds, as well as triglycerides.
• It's important to regularly check your lipid profile while using rilonacept.
• In some cases, starting medication to lower cholesterol levels may be needed.

Rilonacept: Drug Interaction

Monitoring parameters:

• Complete Blood Count (CBC) with Differential: Keep an eye on your blood cell levels.
• Lipid Profile: Regularly check your cholesterol levels, including HDL, LDL, and triglycerides.
• C-reactive Protein (CRP) and Serum Amyloid A: Monitor these markers for inflammation.
• Signs of Infection: Watch out for any signs or symptoms of infection and report them promptly.

How to administer Rilonacept (Arcalyst)?

• Rotate Injection Sites: Alternate between your thigh, abdomen, and upper arm for each injection.
• Avoid Problem Areas: Don't inject into areas that are bruised, red, tender, or hard.
• Loading Dose Administration: If you need two injections for the loading dose, make sure they're given at different sites on the same day.
• Dispose of Unused Portion: Any leftover medication should be discarded properly.

Mechanism of action of Rilonacept (Arcalyst):

Understanding Cryopyrin-associated periodic syndromes (CAPS):

• CAPS are rare genetic syndromes caused by mutations in genes like NLRP-3 or CIAS1.
• These mutations affect the cryopyrin protein, encoded by these genes, which regulates the activation of interleukin-1 beta (IL-1β).
• Without proper cryopyrin function, there's an overactive inflammatory response, leading to symptoms of CAPS.
• Rilonacept works by binding to IL-1β (and partly to IL-1α and IL-1 receptor antagonist), preventing its interaction with cell surface receptors, thereby reducing inflammation.

The beginning of action:

• It takes about 6 weeks for rilonacept to reach a steady state, where its effects stabilize.

Half-life Elimination:

• Rilonacept has a half-life of elimination of approximately 8.6 days, meaning it takes about that long for half of the drug to be cleared from the body. (Source: Miyamae 2012)

International Brand Names of Rilonacept:

• Arcalyst

Rilonacept Brand Names in Pakistan:

No Brands Available in Pakistan.