SYLVANT Drug Profile

Summary for Tradename: SYLVANT

High Confidence Patents:	8
Applicants:	1
BLAs:	1
Recent Clinical Trials:	See clinical trials for SYLVANT

Recent Clinical Trials for SYLVANT

Identify potential brand extensions & biosimilar entrants

Sponsor	Phase
United States Department of Defense	Phase 2
Recordati Rare Diseases	Phase 2
Massachusetts General Hospital	Phase 2

See all SYLVANT clinical trials

Pharmacology for SYLVANT

Mechanism of Action	Interleukin-6 Antagonists
Established Pharmacologic Class	Interleukin-6 Antagonist

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 SYLVANT Derived from Brand-Side Litigation

No patents found based on brand-side litigation

2) High Certainty: US Patents for SYLVANT 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
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2026-08-15	DrugPatentWatch analysis and company disclosures
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2022-03-22	DrugPatentWatch analysis and company disclosures
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2029-07-15	DrugPatentWatch analysis and company disclosures
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2029-01-09	DrugPatentWatch analysis and company disclosures

3) Low Certainty: US Patents for SYLVANT 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
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2034-02-07	Patent claims search
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2036-08-10	Patent claims search
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2037-02-13	Patent claims search
Eusa Pharma (uk) Limited	SYLVANT	siltuximab	For Injection	125496		2037-02-03	Patent claims search

International Patents for SYLVANT

Country	Patent Number	Estimated Expiration
Australia	5882898
Japan	6062477
World Intellectual Property Organization (WIPO)	2013048022
Spain	2654543

Supplementary Protection Certificates for SYLVANT

Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
92543	Luxembourg		PRODUCT NAME: SILTUXIMAB
1490052-6	Sweden		PRODUCT NAME: SILTUXIMAB; REG. NO/DATE: EU/1/14/928 20140522
5022-2014	Slovakia		PRODUCT NAME: SILTUXIMAB; REGISTRATION NO/DATE: EU/1/14/928 20140522
C300687	Netherlands		PRODUCT NAME: SILTUXIMAB; REGISTRATION NO/DATE: EU/1/14/928/001-002 20140522

Market Dynamics and Financial Trajectory for SYLVANT (siltuximab)

Last updated: April 17, 2026

What is SYLVANT and its approved indications?

SYLVANT (siltuximab) is a monoclonal antibody designed to target interleukin-6 (IL-6). Approved by the FDA in June 2014, it treats multicentric Castleman’s disease (MCD) in patients negative for human herpesvirus-8 (HHV-8). European regulators approved SYLVANT in 2014 for MCD indications as well.

What is the current market size and growth driver?

The global market for IL-6 inhibitors, including SYLVANT, is driven by increased diagnosis of Castleman’s disease, expansion into other indications, and the rising prevalence of inflammatory diseases. The MCD segment remains niche, with an estimated market value of $200 million in 2022 according to Evaluate Pharma estimates. Projected compound annual growth rate (CAGR) for this segment is approximately 6% through 2030.

Potential expansion into rheumatoid arthritis (RA), cytokine release syndrome (CRS), and other inflammatory conditions could widen the market. However, no broader regulatory approvals for these indications have been secured as of early 2023.

How does competitive positioning influence market dynamics?

SYLVANT’s main competitors include:

• Actemra (tocilizumab) by Roche/Chugai: approved for RA, CRS, and juvenile idiopathic arthritis.
• Kevzara (sarilumab) by Sanofi/Regeneron: approved for RA.
• Other emerging IL-6 inhibitors targeting specific inflammatory diseases.

Market share remains limited for SYLVANT due to competition from these broader-acting agents with wider approved indications and established treatment algorithms.

What are the key factors affecting the financial trajectory of SYLVANT?

Pricing and reimbursement

• Average annual treatment cost for MCD patients runs roughly $87,000 based on current dosing standards.
• Reimbursement approvals vary by country, impacting sales volume.
• As of 2022, US pricing remains stable, around $7,300 per 400 mg dose, with potential for discounts or formulary negotiations to pressure margins.

Sales performance

• Clinical trial data supports SYLVANT’s efficacy in MCD, with overall response rates approximately 55% in pivotal trials.
• Sales grew modestly from approximately $70 million in 2018 to nearly $125 million in 2022, according to company financial reports.
• Growth has been constrained by the small patient population and limited expansion beyond MCD.

Regulatory risk and label expansion

• No recent requests for label expansion; potential approval in other inflammatory indications would significantly influence sales.
• Regulatory delays or failure to expand indications could restrict revenue growth.

Patent and exclusivity

• Patent protection extends into the late 2020s, providing limited exclusivity.
• Biosimilar development is underway globally, risking future market share.

Market entry barriers

• The rarity of MCD limits large-scale commercialization efforts.
• Competition from existing IL-6 inhibitors with broader indications challenges market penetration.

What are the financial projections based on current and anticipated trends?

Year	Estimated Revenue	Growth Rate	Notes
2022	$125 million	—	Base year, steady sales for MCD indication
2023	$130–140 million	4–12%	Minor growth driven by new markets, price stability
2025	$150–180 million	8–14%	Potential approval in additional indications
2030	$200 million+	10% CAGR	Target with successful expansion efforts

Actuals depend on regulatory developments, competitive dynamics, and payer acceptance.

Summary of critical market and financial parameters

Parameter	Details
Market size (2022)	~$200 million for IL-6 inhibitor MCD segment
CAGR (2022–2030)	6% for the IL-6 segment
Key competitors	Actemra, Kevzara
Price per dose (2022)	~$7,300 per 400 mg dose
Sales (2022)	~$125 million
Patent expiry	Late 2020s, with biosimilar threats
Main growth drivers	Indication expansion, increased diagnosis, reimbursement policies

Key takeaways

• SYLVANT’s sales depend heavily on its niche indication for MCD.
• Market growth is constrained by small patient population and competitive IL-6 inhibitors.
• Expansion into other indications remains unapproved but could significantly influence future revenues.
• Patent protection and biosimilar entry are financial risks.
• Overall, the drug exhibits moderate growth prospects contingent upon regulatory and market expansion efforts.

FAQs

1. How likely is SYLVANT to expand into new indications?
Unlikely in the near term; no regulatory submissions are publicly planned as of 2023. Expansion depends on clinical trial success, regulatory approval, and commercial viability.

2. What is the primary competition for SYLVANT?
Actemra (tocilizumab) and Kevzara (sarilumab) offer broader indications with established markets in RA and CRS.

3. How vulnerable is SYLVANT’s market share to biosimilars?
Significant; biosimilar development underway globally for IL-6 inhibitors will erode exclusivity protections from late 2020s onward.

4. Can pricing strategies influence SYLVANT’s revenue potential?
Yes. Price discounts, reimbursement negotiations, and payer coverage will impact patient access and sales volume.

5. What is the long-term outlook for SYLVANT?
Dependent on indication expansion, regulatory success, and biosimilar competition. Without diversification, growth remains limited.

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References

1. Evaluate Pharma. (2022). Market Data & Forecasts.
2. U.S. Food and Drug Administration. (2014). SYLVANT approval letter.
3. European Medicines Agency. (2014). Summary of product characteristics.
4. Lazic, Z. et al. (2022). IL-6 inhibitors in inflammatory diseases. Clinical Immunology.
5. Pharmaprojects. (2023). Pipeline and biosimilar development data.