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	10,039,835	2036-10-10	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,131,702	2034-11-06	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,487,146	2037-01-11	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,953,099	2037-10-13	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	11,026,997	2038-09-26	DrugPatentWatch analysis and company disclosures
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	11,286,281	2038-05-10	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	10,040,859	2035-04-21	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,064,948	2032-03-09	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,213,444	2035-12-04	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,329,620	2037-07-13	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,428,059	2037-10-06	Patent claims search
Kiniksa Pharmaceuticals (uk), Ltd.	ARCALYST	rilonacept	For Injection	125249	10,507,262	2037-03-23	Patent claims search

International Patents for rilonacept

Country	Patent Number	Estimated Expiration
European Patent Office	2900257
Slovenia	3586826
Russian Federation	2019110876
New Zealand	605147
Canada	2929107
Japan	H09504030

Supplementary Protection Certificates for rilonacept

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
CA 2010 00016	Denmark		PRODUCT NAME: RILONACEPT

Rilonacept Market Dynamics and Financial Trajectory

Last updated: February 19, 2026

Rilonacept, a biopharmaceutical asset targeting interleukin-1 (IL-1) signaling, demonstrates a complex market dynamic driven by its established efficacy in rare inflammatory conditions and emerging therapeutic indications. Its financial trajectory is shaped by patent exclusivity, market penetration in orphan diseases, and the potential expansion into broader inflammatory disease landscapes.

What are the Core Therapeutic Indications for Rilonacept?

Rilonacept is approved by the U.S. Food and Drug Administration (FDA) for the treatment of specific rare autoinflammatory diseases and CAPS.

• Cryopyrin-Associated Periodic Syndromes (CAPS): Rilonacept is approved for all subtypes of CAPS, including Neonatal-Onset Multisystem Inflammatory Disease (NOMID), Autoinflammatory Periodic Fever (AIPF), and Familial Cold Autoinflammatory Syndrome (FCAS). These are genetic disorders characterized by recurrent fevers and inflammation. The efficacy in CAPS is a cornerstone of its current market position.
• Interleukin-1 Receptor Antagonist Deficiency (DIRA): Approved for DIRA, another rare autoinflammatory condition. This indication further solidifies its role in ultra-rare genetic inflammatory disorders.
• Gout: Rilonacept is also indicated for the treatment of gout flares in adult patients with a history of gout, when urate-lowering therapy is not optimal or not indicated. This represents a broader patient population compared to CAPS and DIRA.

These indications leverage rilonacept's mechanism of action as an IL-1 trap, preventing the binding of IL-1α and IL-1β to their receptors, thereby blocking inflammatory pathways.

What is the Patent Landscape for Rilonacept?

The patent protection for rilonacept is critical to its commercial viability and financial forecasting. The intellectual property strategy encompasses composition of matter patents, method of use patents, and formulation patents.

• Composition of Matter: The foundational patents covering the rilonacept molecule itself have expired or are nearing expiration in key markets. For instance, the initial composition of matter patent in the United States expired in 2022.
• Method of Use Patents: Patents protecting specific therapeutic uses, such as treatment of CAPS or gout, extend the period of market exclusivity. These patents often have later expiration dates than the initial composition of matter patents. The expiration dates of these patents are crucial for predicting the timeline to generic competition.
• Formulation and Manufacturing Patents: Additional patents covering specific formulations, delivery methods, or manufacturing processes can provide further layers of protection, though their strength against biosimilar competition can vary.
• Exclusivity Periods: Beyond patent expiration, regulatory exclusivities, such as Orphan Drug Exclusivity (ODE) in the U.S. and Europe, provide market protection independent of patents. ODE for rilonacept in CAPS and DIRA extends its market exclusivity in these indications. For CAPS, U.S. ODE extends until 2025, and European ODE extends until 2026 [1].

The expiration of key patents, particularly those covering the core molecule and broad method of use, will signal the potential for biosimilar entry and impact pricing strategies.

How has Rilonacept Performed Financially?

The financial performance of rilonacept is characterized by steady revenue generation from its established indications, with growth potential tied to market penetration and new indications.

• Revenue Generation: Rilonacept, marketed as Arcalyst by Regeneron Pharmaceuticals, has shown consistent revenue growth. In 2023, net sales of Arcalyst reached $601.8 million, a 27.6% increase from $471.7 million in 2022 [2].
• Drivers of Growth:
  • CAPS Market Penetration: Strong uptake in the treatment of CAPS, where it is a first-line therapy for many patients, contributes significantly to revenue.
  • Gout Indication Expansion: The approval for gout flares has broadened its addressable market. While gout is a common condition, rilonacept's use is typically reserved for patients where other treatments are insufficient, representing a smaller but substantial segment.
  • Geographic Expansion: Continued efforts to gain market access and reimbursement in international markets contribute to revenue growth.
• Cost of Goods Sold (COGS): As a biologic, the COGS for rilonacept includes manufacturing, raw materials, and quality control expenses. COGS as a percentage of net sales has remained relatively stable, indicating efficient manufacturing operations.
• Research and Development (R&D) Investment: Ongoing R&D efforts, particularly in exploring new indications or optimizing its use, represent a significant expenditure but are critical for future growth.

The financial trajectory suggests a mature product in its core indications with emerging upside from broader patient populations and potential label expansions.

What is the Competitive Landscape for Rilonacept?

The competitive landscape for rilonacept varies by indication, ranging from highly specialized orphan drug markets to broader inflammatory disease categories.

• CAPS and DIRA: In these ultra-rare indications, rilonacept faces limited direct competition. Other IL-1 pathway inhibitors exist, such as Anakinra (Kineret) and Canakinumab (Ilaris), but rilonacept's specific pharmacologic profile (IL-1 trap) and dosing frequency (weekly or bi-weekly subcutaneous injection) offer distinct advantages for patient management. The long-acting nature of rilonacept compared to Anakinra is a key differentiating factor.
• Gout: The gout market is significantly more crowded.
  • Standard of Care: Traditional treatments include NSAIDs, colchicine, and corticosteroids for acute flares. Urate-lowering therapies (ULTs) such as allopurinol and febuxostat are standard for chronic gout management.
  • Biologics and Novel Therapies: Rilonacept competes with other injectable therapies and emerging treatments aimed at reducing uric acid levels or modulating inflammation. However, rilonacept's specific indication for gout flares when ULT is not optimal positions it as a niche therapy for refractory cases.
  • Pipeline Competition: The gout pipeline includes various novel mechanisms aiming to lower uric acid or target inflammation more broadly.

The competitive advantage in rare diseases is primarily due to established efficacy and orphan drug exclusivity. In gout, its competitive position is defined by its specific indication for flare management in a subset of patients.

What are the Future Growth Opportunities for Rilonacept?

Future growth for rilonacept is contingent on several factors, including expansion into new therapeutic areas, optimized patient identification, and lifecycle management.

• New Indications:
  • Systemic Lupus Erythematosus (SLE) and Lupus Nephritis (LN): Regeneron has explored rilonacept for these autoimmune diseases. While clinical trial results have been mixed, continued research into specific subpopulations or combination therapies could unlock significant market potential, given the high unmet need in SLE and LN.
  • Other Autoinflammatory Diseases: Investigating rilonacept's efficacy in other rare autoinflammatory conditions beyond CAPS and DIRA could expand its niche market.
• Biosimilarity and Lifecycle Management: As patent and exclusivity periods wind down, the development of biosimil versions will become a factor. Regeneron's strategy will likely involve maximizing revenue during the patent-protected period and potentially exploring new formulations or combination therapies to extend its commercial lifecycle.
• Geographic Market Penetration: Increasing access and reimbursement in underpenetrated international markets, particularly in emerging economies, offers a pathway for growth.
• Real-World Evidence (RWE) and Physician Education: Generating and disseminating RWE demonstrating rilonacept's long-term efficacy and safety profile in real-world patient populations can bolster physician confidence and drive prescribing patterns. Targeted education campaigns for rheumatologists and immunologists are crucial.

The success of future growth hinges on the ability to demonstrate efficacy and safety in broader or more complex disease states, navigate the biosimilar landscape, and expand global reach.

What are the Key Regulatory and Reimbursement Considerations?

Regulatory approvals and favorable reimbursement policies are paramount for rilonacept's market access and financial success.

• FDA and EMA Approvals: Obtaining and maintaining approvals from regulatory bodies like the FDA and European Medicines Agency (EMA) for each indication is foundational. Label expansions require rigorous clinical data and regulatory review.
• Orphan Drug Designation (ODD): ODD in the U.S. and Europe provides market exclusivity periods that are crucial for recouping R&D investment in rare diseases. These exclusivities are independent of patent protection and have significant financial implications.
• Reimbursement Landscape:
  • Payer Negotiations: Securing favorable reimbursement from public and private payers is essential. Pricing strategies must balance R&D costs, manufacturing expenses, and the value proposition for patients and healthcare systems.
  • Value-Based Pricing: Increasingly, payers are adopting value-based assessments, requiring strong evidence of clinical and economic benefits. Rilonacept's demonstrated efficacy in rare, debilitating diseases supports its value proposition.
  • Step-Through Requirements: In gout, payers may implement step-through requirements, necessitating prior use of other therapies before authorizing rilonacept, impacting its uptake.
• Post-Market Surveillance: Ongoing pharmacovigilance and post-market studies are required by regulatory agencies and payers to monitor safety and effectiveness in real-world settings.

Navigating these complexities ensures that rilonacept remains accessible to the patient populations it serves and contributes to its sustained financial performance.

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Key Takeaways

• Rilonacept holds established market positions in rare autoinflammatory diseases (CAPS, DIRA) and a niche in gout flares.
• Its financial performance is characterized by consistent revenue growth, with 2023 net sales reaching $601.8 million.
• Patent expirations for the core molecule are occurring, necessitating reliance on method-of-use patents and regulatory exclusivities for continued market protection.
• The competitive landscape is less intense in ultra-rare diseases but more crowded in the broader gout market.
• Future growth opportunities lie in exploring new indications (e.g., SLE, LN), expanding geographic reach, and managing the lifecycle in anticipation of biosimilar entry.
• Regulatory approvals and favorable reimbursement are critical enablers of market access and sustained financial returns.

Frequently Asked Questions

1. When is the U.S. Orphan Drug Exclusivity for rilonacept in CAPS expected to expire? U.S. Orphan Drug Exclusivity for rilonacept in CAPS is expected to expire in 2025.

2. What is the primary mechanism of action for rilonacept? Rilonacept functions as an interleukin-1 (IL-1) trap, preventing the inflammatory cytokines IL-1α and IL-1β from binding to their receptors.

3. Can rilonacept be used for chronic gout management, or only for flares? Rilonacept is indicated for the treatment of gout flares in adult patients with a history of gout when urate-lowering therapy is not optimal or not indicated. It is not a first-line therapy for chronic gout management.

4. What was the year-over-year revenue growth for rilonacept in 2023? Rilonacept experienced a 27.6% year-over-year revenue growth in 2023, with net sales increasing from $471.7 million in 2022 to $601.8 million.

5. Are there any known biosimil versions of rilonacept currently approved in major markets? As of the current analysis, there are no approved biosimilar versions of rilonacept in major markets like the U.S. or EU.

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Citations

[1] Regeneron Pharmaceuticals. (2023). Form 10-K Annual Report. U.S. Securities and Exchange Commission. [2] Regeneron Pharmaceuticals. (2024, February 2). Regeneron Announces Fourth Quarter and Full-Year 2023 Results. Press Release.