Rilonacept - Biologic Drug Details

Summary for rilonacept

Tradenames:	1
High Confidence Patents:	3
Applicants:	1
BLAs:	1
Suppliers: see list	1
Recent Clinical Trials:	See clinical trials for rilonacept

Recent Clinical Trials for rilonacept

Identify potential brand extensions & biosimilar entrants

Sponsor	Phase
Mayo Clinic	PHASE2
Johns Hopkins University	PHASE2
Kiniksa Pharmaceuticals, Ltd.	Phase 3

See all rilonacept 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 brand-side disclosures

These patents were identified from searching 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 rilonacept Derived from Brand-Side Litigation

No patents found based on brand-side litigation

2) High Certainty: US Patents for rilonacept 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		2038-09-26	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2015-11-27	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2019-05-19	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249		2022-10-28	DrugPatentWatch analysis and company disclosures

3) Low Certainty: US Patents for rilonacept 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 rilonacept

Country	Patent Number	Estimated Expiration
Poland	348529
Brazil	0315652
Hong Kong	1035377
Mexico	PA05004333
Australia	758970

Supplementary Protection Certificates for rilonacept

Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
91680	Luxembourg		91680, EXPIRES: 20241023
SZ 15/2010	Austria		PRODUCT NAME: RILONACEPT
SPC/GB10/027	United Kingdom		PRODUCT NAME: RILONACEPT; REGISTERED: UK EU/1/09/582/001 20091023
300448	Netherlands		PRODUCT NAME: RILONACEPT; REGISTRATION NO/DATE: EU/1/09/582/001 20091023
372	Finland

Market Dynamics and Financial Trajectory for the Biologic Drug Rilonacept

Last updated: July 27, 2025

Introduction

Rilonacept, marketed as Arcalyst, is a recombinant fusion protein biologic agent developed by Regeneron Pharmaceuticals. It functions as an interleukin-1 (IL-1) inhibitor, primarily used for rare inflammatory diseases such as cryopyrin-associated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome (FCAS) and Muckle-Wells syndrome (MWS). Understanding the evolving market landscape and financial trajectory of rilonacept involves examining its clinical indications, competitive positioning, regulatory developments, and commercial potential within the broader biologic therapeutics space.

Market Landscape and Therapeutic Indications

Current Approved Uses

Rilonacept secured FDA approval in 2008 for treating CAPS, with subsequent approvals expanding its indications to other immune-mediated inflammatory diseases. Its on-label use remains predominantly in rare diseases, given the ultra-orphan nature of these conditions. These indications target a niche segment, impacting its revenue scale compared to blockbuster biologics.

Emerging and Off-label Uses

While the primary indication remains rare cytokine-driven autoinflammatory syndromes, ongoing research explores broader applications in diseases involving IL-1 pathways. Notably, investigational studies are examining rilonacept’s potential in gout, systemic juvenile idiopathic arthritis, and proliferative disorders, although these indications face regulatory and market entry hurdles.

Market Size and Patient Populations

The absolute patient population for CAPS is exceedingly small, estimated at fewer than 10,000 globally. This confines the drug's market size, making it highly sensitive to shifts in regulatory landscape, pricing negotiations, and access policies. For example, in the US, the prevalence of CAPS is approximately 1 to 3 per million, translating to limited but high-value patient access.

Market Dynamics

Regulatory Environment and Approvals

The rarity of CAPS contributes to a favorable regulatory environment, with the Orphan Drug Act incentivizing development and marketing. Regulatory agencies have maintained supportive stances, facilitating market exclusivity and potential expedited review pathways for rare disease therapies. Recent developments include the FDA’s approval of rilonacept's use in recurrent pericarditis, broadening its therapeutic relevance (FDA, 2021).

Competitive Landscape

The competitive landscape for IL-1 inhibitors includes agents like anakinra (Kineret) and canakinumab (Ilaris), both of which hold broader label indications and are more established in certain inflammatory conditions. Canakinumab, in particular, has more extensive clinical data and a stronger market presence, challenging rilonacept’s market share. The competition is intensifying as newer biologics with similar mechanisms of action enter the market, along with biosimilars potentially impacting launch dynamics.

Pricing and Reimbursement

Pricing strategies for rilonacept align with other biologics targeting rare diseases, generally commanding high per-dose costs. Achieving favorable reimbursement depends on demonstrating clinical efficacy and cost-effectiveness, especially against competitors. Payer resistance to high-cost therapies in small populations underscores the importance of demonstrating tangible clinical benefits and economic value.

Market Access Challenges

Access to rilonacept varies geographically, influenced by national healthcare policies, reimbursement frameworks, and provider familiarity. Supply chain logistics, patient affordability, and physician awareness are critical factors affecting sales and utilization trends.

Financial Trajectory

Revenue Generation and Growth

Rilonacept’s revenue is primarily derived from its approval in CAPS and recurrent pericarditis. Since its initial launch, sales have been modest, constrained by the small patient population and competition. Data from Regeneron’s earnings reports suggest incremental growth driven by increased awareness, expanded indications, and clinical trial data supporting broader uses.

R&D Investment and Pipeline Progress

Regeneron continues investing in expanding rilonacept’s therapeutic profile, with ongoing phase 2/3 trials exploring its role in gouty arthritis and other inflammatory conditions. Pipeline diversification may influence future revenue streams positively but also introduces uncertainties related to clinical success and regulatory approval timelines.

Pricing Trends and Market Penetration

The high cost structure typical of biologics supports premium pricing but also invites scrutiny from payers. Successful pricing negotiations and expanded indications could improve top-line figures; however, market saturation in its niche remains limited without significant breakthrough approvals or indications.

Strategic Acquisition and Partnerships

Strategic collaborations with healthcare providers, payers, and patient advocacy groups enhance market access. Partnering with specialty pharmacies and leveraging digital health tools for patient monitoring may improve product utilization and retention, positively impacting financial outcomes.

Future Outlook and Market Opportunities

Growth Drivers

• Expansion into New Indications: Positive phase 3 trial results in recurrent pericarditis and potential expansion into gout and other inflammatory diseases could elevate sales.
• Regulatory Milestones: Approval in additional markets and indications would improve global revenue potential.
• Enhanced Patient Access: Improved awareness, higher clinician adoption, and favorable reimbursement could expand treatment rates.

Challenges and Risks

• Intense Competition: Canakinumab’s broader indication scope and established market share pose significant hurdles.
• Pricing Pressures: Payer pushback on high biologic costs may limit revenue growth.
• Limited Patient Population: The ultra-orphan status confines upside potential unless new indications substantially broaden the addressable market.

Key Takeaways

• Rilonacept remains a niche, high-value biologic due to its targeted use in rare autoinflammatory conditions.
• Although regulated and supported by orphan drug incentives, sales are constrained by small patient populations and stiff competition from broader IL-1 inhibitors.
• Expanding indications, regulatory achievements, and strategic partnerships are critical to its long-term financial viability.
• Market dynamics indicate moderate growth prospects, contingent upon successful clinical trial outcomes and market access strategies.
• The future of rilonacept’s financial trajectory depends heavily on the ability to broaden its clinical footprint beyond its current indications.

FAQs

Q1: What are the primary clinical indications for rilonacept?
A: Rilonacept is predominantly indicated for cryopyrin-associated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome (FCAS) and Muckle-Wells syndrome (MWS), and has received recent approval for recurrent pericarditis.

Q2: How does rilonacept compare with its competitors?
A: Compared to canakinumab and anakinra, rilonacept's niche position is due to its specific indications and delivery mechanism. However, canakinumab’s broader approved indications and stronger clinical data often provide it with a competitive edge.

Q3: What factors influence the pricing and reimbursement of rilonacept?
A: Its high per-dose cost, demonstrated clinical efficacy in rare diseases, payer reimbursement policies, and market access strategies shape its pricing and reimbursement landscape.

Q4: Are there ongoing efforts to expand rilonacept’s therapeutic applications?
A: Yes, ongoing clinical trials aim to evaluate its efficacy in gout, systemic juvenile idiopathic arthritis, and other inflammatory conditions, potentially expanding its market footprint.

Q5: What are the key risks affecting rilonacept’s financial outlook?
A: Risks include intense competition from other IL-1 inhibitors, limited patient populations, pricing pressures, and regulatory hurdles in obtaining approvals for new indications.

---

Sources:

[1] FDA. (2021). FDA Approves Rilonacept for Recurrent Pericarditis.
[2] Regeneron Pharmaceuticals. (2022). Annual Financial Reports.
[3] Orphanet. (2023). Cryopyrin-Associated Periodic Syndromes (CAPS).
[4] MarketWatch. (2022). Biologic Drug Market Trends.