Rilonacept is a dimeric fusion protein consisting of the ligand-binding domains of the extracellular portions of the human interleukin-1 receptor component (IL-1RI) and IL-1 receptor accessory protein (IL-1RAcP) linked in-line to the Fc portion of human IgG1. Rilonacept has a molecular weight of approximately 251 kDa. Rilonacept is expressed in recombinant Chinese hamster ovary (CHO) cells.
ARCALYST is supplied in single-use, 20-mL glass vials containing a sterile, white to off-white, lyophilized powder. Each vial of ARCALYST is to be reconstituted with 2.3 mL of Sterile Water for Injection. A volume of up to 2 mL can be withdrawn, which is designed to deliver 160 mg for subcutaneous administration only. The resulting solution is viscous, clear, colorless to pale yellow, and essentially free from particulates. Each vial contains 220 mg rilonacept. After reconstitution, each vial contains 80 mg/mL rilonacept, 40 mM histidine, 50 mM arginine, 3.0% (w/v) polyethylene glycol 3350, 2.0% (w/v) sucrose, and 1.0% (w/v) glycine at a pH of 6.5 ± 0.3. No preservatives are present.
ARCALYST® (rilonacept) is an interleukin-1 blocker indicated for the treatment of Cryopyrin-Associated Periodic Syndromes (CAPS), including Familial Cold Auto-inflammatory Syndrome (FCAS) and Muckle-Wells Syndrome (MWS) in adults and children 12 and older.
Published Studies Related to Arcalyst (Rilonacept)
Long-term safety and efficacy of rilonacept in patients with systemic juvenile
idiopathic arthritis. 
idiopathic arthritis (JIA)... CONCLUSION: Sustained improvements in clinical and laboratory measures of the
Rilonacept (interleukin-1 trap) in the prevention of acute gout flares during
initiation of urate-lowering therapy: results of a phase II randomized,
double-blind, placebo-controlled trial. 
initiation of urate-lowering therapy... CONCLUSION: The current findings indicate that rilonacept significantly reduces
Efficacy and safety of rilonacept (interleukin-1 Trap) in patients with
cryopyrin-associated periodic syndromes: results from two sequential
placebo-controlled studies. 
autoinflammatory syndrome (FCAS) and Muckle-Wells syndrome (MWS)... CONCLUSION: Treatment with weekly rilonacept provided marked and lasting
Rilonacept for colchicine-resistant or -intolerant familial Mediterranean fever:
a randomized trial. 
FMF... CONCLUSION: Rilonacept reduces the frequency of FMF attacks and seems to be a
Clinical Trials Related to Arcalyst (Rilonacept)
Rilonacept for Treatment of Familial Mediterranean Fever (FMF) [Completed]
Familial Mediterranean fever (FMF) is a genetic disease resulting in recurrent attacks of
fever, abdominal pain, chest pain, arthritis and rash. There are 5-15% of patients who
continue to have FMF attacks despite treatment with colchicine or who cannot tolerate
colchicine. Currently there are no alternatives to colchicine. Pyrin, the protein that has a
defect in FMF has an important role in the regulation of a molecule called interleukin
(IL)-1 beta production and activity. This molecule is very important in the process of
inflammation in FMF.
Therefore we propose to use IL-1 Trap (Rilonacept), a medication that binds and neutralizes
We will enroll in this study 17 subjects from the age of 4 years, including adults with
active FMF despite colchicine therapy. Subjects will receive in random order two 3-month
courses of Rilonacept at 2. 2 mg/kg (maximum 160 mg) by weekly subcutaneous injection and two
3-month courses of placebo injection. If patients have at least two FMF attacks during a
treatment course they will be able to get if they choose the other treatment until the end
of that treatment course. Our hypothesis is that Rilonacept will decrease the number of
acute FMF attacks and will be safe to use. This study may confirm the importance of IL-1 in
the cause of FMF.
Funding source - FDA Office of Orphan Products Development
Rilonacept (Arcalyst ï¿½) in the Treatment of Subacromial Bursitis [Completed]
To date no trials have been performed looking at whether or not intra-bursal injection of an
IL-1 antagonist provides pain relief similar to that of a corticosteroid injection. The
subcutaneous injection of anakinra, an IL-1 receptor antagonist, in patients with shoulder
pain due to rotator cuff tendonitis and subacromial bursitis was efficacious in relieving
pain but this information was presented as a case series in a letter to the editor format,
so the validity of these results would require additional testing [Omoigui S, et al. 2004].
Based mainly on the data from the intra-articular administration of anakinra, there have not
been any adverse trends in outcomes or safety to suggest that intra-bursal injection of
rilonacept will carry an increase risk of adverse events. The purpose of this trial is to
compare the improvement in pain and function of patients with clinical symptoms and signs of
subacromial bursitis of rilonacept vs. corticosteroid injection (standard of care).
Cold Contact Urticaria Treatment With Rilonacept [Recruiting]
Cold contact urticaria (CCU) is a frequent form of physical urticaria that is characterized
by the development of wheal and flare type skin reactions due to the release of histamine
and other proinflammatory mast cell mediators following exposure of the skin to cold.
Typically, symptoms occur within minutes after cold contact, including exposure to cold air,
liquids or objects and are limited to cold exposed skin areas.
The investigators postulate that there is an overlap between acquired cold urticaria and
cold-induced autoinflammatory syndromes, and that cold urticaria patients unresponsive to
antihistamines will benefit from IL-1 targeting treatment strategies.
This study will evaluate the efficacy and safety of the IL-1 transfusion protein rilonacept
in patients with cold contact urticaria who could not be successfully treated with
first-line medication such as antihistamines.
This is a double-blind placebo-controlled parallel group phase II study of the efficacy and
safety of rilonacept in subjects with CCU. A total of 20 patients will be included by the
Urticaria specialty clinics of ACC. The total duration of the study course for each patient
is 14 weeks and is divided in:
1. Screening period (2 weeks, days - 14-0)
2. Placebo-controlled double-blind phase (Part A, 6 weeks, days 0-42)
3. Open label phase (Part B, 6 weeks, days 42-84) All eligible patients will be randomized
(1: 1 randomization) to one of two groups: 1) Rilonacept 160mg/week or 2) Placebo, and
will receive the respective dose subcutaneously. Following the placebo-controlled
double-blind phase patients will enter the open-label phase and receive rilonacept
open-label treatment (160mg or 320mg depending on treatment response during part A).
Rilonacept in Diabetes Mellitus Type 1: Safety Study [Completed]
This study is being done to see if an investigational drug called rilonacept is safe to use
in patients with type 1 diabetes, and if it can slow the loss of the body's ability to
secrete insulin in patients who are still able to make a small amount of insulin.
Rilonacept for Treatment of Cryopyrin-Associated Periodic Syndromes (CAPS) [Completed]
Inflammatory symptoms of Cryopyrin-Associated Periodic Syndrome (CAPS) are due to mutations
in a the NLRP-3 gene (previously known as Cold Induced Autoinflammatory Syndrome-1 or
CIAS1). These mutations result in the body's overproduction of interleukin-1 (IL-1), a
protein that stimulates the inflammatory process. IL-1 Trap (rilonacept) was designed to
bind to the interleukin-1 cytokine and prevent it from binding to its receptors in the body.
Page last updated: 2014-11-30