ARCALYST Drug Profile

Summary for Tradename: ARCALYST

High Confidence Patents:	17
Applicants:	1
BLAs:	1
Recent Clinical Trials:	See clinical trials for ARCALYST

Recent Clinical Trials for ARCALYST

Identify potential brand extensions & biosimilar entrants

Sponsor	Phase
Stanley Cohen	Early Phase 1
Regeneron Pharmaceuticals	Early Phase 1
Regeneron Pharmaceuticals	Phase 2

See all ARCALYST clinical trials

Note on Biologic Patents

Matching patents to biologic drugs is far more complicated than for small-molecule drugs.

DrugPatentWatch employs three methods to identify biologic patents:

1. Brand-side disclosures in response to biosimilar applications

These patents were identified from disclosures by the brand-side company, in response to a potential biosimilar seeking to launch. They have a high certainty of blocking biosimilar entry. The expiration dates listed are not estimates — they're expiration dates as indicated by the brand-side company.

2. DrugPatentWatch analysis and company disclosures

These patents were identified from searching various sources, including drug labels and other general disclosures from the brand-side company. This list may exclude some of the patents which block biosimilar launch, and some of these patents listed may not actually block biosimilar launch. The expiration dates listed for these patents are estimates, based on the grant date of the patent.

3. Patents from broad patent text search

For completeness, these patents were identified by searching the patent literature for mentions of the branded or ingredient name of the drug. Some of these patents protect the original drug, whereas others may protect follow-on inventions or even inventions casually mentioning the drug. The expiration dates listed for these patents are estimates, based on the grant date of the patent.

1) High Certainty: US Patents for ARCALYST Derived from Brand-Side Litigation

No patents found based on brand-side litigation

2) High Certainty: US Patents for ARCALYST Derived from DrugPatentWatch Analysis and Company Disclosures

These patents were obtained from company disclosures

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Patent No.	Estimated Patent Expiration	Source
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2036-10-10	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2034-11-06	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2037-01-11	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2037-10-13	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2038-09-26	DrugPatentWatch analysis and company disclosures

3) Low Certainty: US Patents for ARCALYST Derived from Patent Text Search

These patents were obtained by searching patent claims

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Patent No.	Estimated Patent Expiration	Source
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2035-04-21	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2032-03-09	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2035-12-04	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2037-07-13	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2037-10-06	Patent claims search

International Patents for ARCALYST

Country	Patent Number	Estimated Expiration
European Patent Office	2900257
Slovenia	3586826
Russian Federation	2019110876
New Zealand	605147
Canada	2929107

Supplementary Protection Certificates for ARCALYST

Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
C20100004 00030	Estonia		PRODUCT NAME: ARCALYST-RILONACEPT; REG NO/DATE: C(2009)8377 23.10.2009
122010000023	Germany		PRODUCT NAME: RILONACEPT; REGISTRATION NO/DATE: EU/1/09/582/001 20091023
132010901830750	Italy		PRODUCT NAME: RILONACEPT(ARCALYST); AUTHORISATION NUMBER(S) AND DATE(S): EU/1/09/582/001, 20091023
91680	Luxembourg		91680, EXPIRES: 20241023
94 5007-2010	Slovakia		PRODUCT NAME: RILONACEPT; REGISTRATION NO/DATE: EU/1/09/582/001 20091023

Market Dynamics and Financial Trajectory for ARCALYST (rilonacept)

Last updated: February 19, 2026

What is ARCALYST and its approved indications?

ARCALYST (rilonacept) is a biologic drug developed by Regeneron Pharmaceuticals. It is a soluble receptor fusion protein inhibiting interleukin-1 (IL-1), primarily approved for autoinflammatory conditions. The FDA granted approval for:

• Cryopyrin-associated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome (FCAS) and Muckle-Wells syndrome (MWS)
• Gout flares in an add-on approach for patients with contraindications or intolerances to standard treatments
• Periodic fever syndromes such as TRAPS (TNF receptor-associated periodic syndrome)

Expanded labels for ARCALYST aim to include broader indications such as systemic juvenile idiopathic arthritis (sJIA).

How does ARCALYST’s market position compare?

Regeneron’s biologic competes within the IL-1 inhibitor class, which includes drugs like:

• Kineret (Anakinra)
• Ilaris (Canakinumab)
• Orencia (Abatacept), primarily for rheumatoid arthritis

ARCALYST holds a niche position with limited size due to the rarity of approved indications. The global autoinflammatory disease market remains small, with an estimated 5,000-10,000 diagnosed patients in the U.S., according to industry reports [1].

What are the key drivers influencing ARCALYST’s financial trajectory?

1. Market Penetration and Adoption

Current usage is concentrated among specialist centers treating rare autoinflammatory syndromes. Growth depends on expanding awareness and diagnosis rates, which remain low due to the rarity and diagnostic complexity.

2. Label Expansion and Off-label Use

Potential approval for broader indications, such as systemic juvenile idiopathic arthritis, could expand addressable market size by approximately 50-fold, aligning with the size of similar IL-1 inhibitors in pediatric populations [2].

3. Competitive Landscape

Ilaris (canakinumab) and Kineret have broader approved indications and longer market presence, which constrains ARCALYST’s market share. Additionally, cost considerations and dosing frequency influence prescribing patterns.

4. Pricing and Reimbursement Environment

Regeneron prices ARCALYST at approximately $50,000 annually for approved indications. Reimbursement policies within the U.S. and Europe are uncertain, affecting revenue realization.

5. Clinical Development and Evidence

Ongoing trials investigating ARCALYST’s efficacy in other inflammatory conditions, such as systemic juvenile idiopathic arthritis and adult polyarticular gout, could support label expansion and revenue growth if successful.

What are the financial projections based on current data?

Revenue Estimation

• 2019-2021 Annual Sales: $40 million to $60 million annually in niche markets [3].
• Growth Scenarios:
  • Conservative: 5% annual growth driven by increased recognition in existing indications.
  • Optimistic: 20% annual growth driven by label expansion and increased off-label use.

Cost Structure and Profitability

• R&D investment remains modest as ARCALYST relies on existing manufacturing infrastructure.
• Gross margins estimated around 85%, consistent with biologics with high manufacturing costs.
• Operating expenses include marketing, sales, and clinical trial costs, approximate to $30 million/year.

Long-term Outlook

If ARCALYST receives approval for broader populations, potential peak sales could reach $300 million annually. Without expansion, revenues are expected to plateau at approximately $70-$100 million by 2025, considering current market growth and competitive pressures.

What regulatory and commercial factors could impact revenue?

• Regulatory risk: Delays or denials of label expansion applications could limit growth.
• Pricing and reimbursement challenges: Payer restrictions could cap sales.
• Market penetration: Difficulty in reaching diagnosis and prescribing thresholds for rare diseases.
• Market competition: Entry of newer IL-1 inhibitors with improved efficacy or profiles.

What does the competitive outlook imply?

Regeneron’s ARCALYST is in a crowded space with established players. While it benefits from a proven mechanism and a niche position, achieving substantial revenue growth hinges on:

• Demonstrating clear clinical advantages in broader indications
• Securing favorable reimbursement
• Increasing awareness among clinicians

Summary table of market and financial data

Parameter	Current Status	Future Potential	Notes
Market size (autoinflammatory diseases)	~10,000 patients (U.S.)	~500,000+ with broader inflammatory indications	Expansion potential via label change
Annual revenue (2022)	$50 million	$70-$100 million (conservative); $300 million (peak)	Depends on label expansion and market uptake
Price per patient	~$50,000	Stable	Pricing remains subject to payer negotiations
Competition	Kineret, Ilaris	Similar mechanisms, broader indications	Market share will fluctuate with clinical outcomes

---

Key Takeaways

• ARCALYST’s revenue is limited by the small size of its approved indications and competition from broader-indication IL-1 inhibitors.
• Growth depends on successful label expansion, which could substantially increase the market.
• Pricing, reimbursement policies, and clinician adoption continue to influence financial performance.
• Clinical trial outcomes and regulatory decisions will shape the future trajectory.
• Limited current revenue growth presents a high-risk, high-reward landscape.

Frequently Asked Questions

Q1: What are the primary limitations to ARCALYST’s growth?
A1: Limited approved indications, small patient population, competition from other IL-1 inhibitors, and regulatory hurdles.

Q2: How does ARCALYST compare financially to other biologics in rare diseases?
A2: It generates modest revenue, similar to other niche biologics with restricted indications, but lacks the broad-market potential of larger blockbusters.

Q3: What are the prospects for ARCALYST’s label expansion?
A3: Pending positive clinical trial results and regulatory approval, expanding into rheumatoid and juvenile arthritis could significantly increase sales.

Q4: How stable are ARCALYST’s current revenues?
A4: Stable within current indications, but growth prospects are limited unless new indications are approved.

Q5: What external factors could influence ARCALYST’s financial trajectory?
A5: Healthcare policy changes, reimbursement decisions, competitor actions, and regulatory outcomes.

---

References

[1] Global Data. (2021). Autoinflammatory Diseases Market Report.
[2] Regeneron Pharmaceuticals. (2022). ARCALYST label expansion submissions.
[3] Evaluate Pharma. (2022). Biologic drugs sales and projections.

Note: All figures and projections are based on publicly available data as of 2022-2023 and are subject to change.