List of Excipients in Branded Drug ILUMYA

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ILUMYA Excipient Strategy and Commercial Opportunities

Last updated: September 26, 2026

ILUMYA (tildrakizumab-asmn) is a refrigerated, subcutaneous monoclonal-antibody product supplied as a 100 mg/mL single-dose prefilled syringe. Its formulation uses a conventional biologic excipient system: sucrose for stabilization, histidine and histidine hydrochloride for buffering, and polysorbate 80 as a surfactant. The strongest commercial opportunities are in biosimilar development, excipient and container-closure supply, improved stability, device optimization, cold-chain reduction, and analytical comparability services.

What excipients are used in ILUMYA?

ILUMYA contains four inactive ingredients in an aqueous formulation:

Excipient	Primary formulation role	Commercial relevance
Sucrose	Stabilizes the antibody during freezing, storage, and agitation	Commodity excipient with opportunities in high-purity biologic grades
L-histidine	Provides buffering capacity	Requires control of pH, concentration, and lot variability
L-histidine monohydrochloride monohydrate	Completes the histidine buffer system	Supports pH control in the finished drug product
Polysorbate 80	Limits adsorption and aggregation at air-liquid and container interfaces	High-value risk area because oxidation and hydrolysis can generate degradation products

The formulation is a sterile, preservative-free solution for subcutaneous administration. The FDA prescribing information identifies sucrose, histidine, histidine hydrochloride monohydrate, and polysorbate 80 as inactive ingredients.[1]

ILUMYA is supplied at 100 mg/mL in a single-dose prefilled syringe. The product is stored at 2°C to 8°C, protected from light, and must not be frozen or shaken. The label permits limited room-temperature handling under specified conditions.[1]

How does the ILUMYA formulation work?

The formulation is designed to preserve a concentrated antibody solution during refrigerated storage and subcutaneous injection.

Sucrose provides preferential hydration around the protein and reduces conformational stress. It also supports stability during transportation and brief temperature excursions. Histidine buffer maintains the product within the target pH range without introducing a high ionic-strength environment that could increase aggregation or injection discomfort.

Polysorbate 80 protects tildrakizumab against adsorption to the syringe surface and air-liquid interfaces. This function is important for a prefilled syringe because the product contacts the barrel, stopper, needle system, and headspace during storage and administration.

The main technical liabilities are typical for monoclonal-antibody products:

• Aggregation under thermal or mechanical stress
• Oxidation or hydrolysis of polysorbate 80
• Subvisible and visible particle formation
• Protein adsorption to container surfaces
• Changes caused by silicone oil or elastomer components
• Increased viscosity or injection force at high antibody concentration
• Potential immunogenicity changes after formulation or device modification

The excipient system is commercially attractive because it is familiar to regulators and contract manufacturers. It is less differentiated than a formulation using specialized amino-acid, polyol, or surfactant combinations.

What formulation patents protect ILUMYA?

No single public Orange Book listing establishes the formulation-patent position for ILUMYA because ILUMYA is a biologic, not a small-molecule drug. FDA-approved biologics are identified in the Purple Book, while patent and exclusivity analysis is handled through the Biologics Price Competition and Innovation Act framework rather than the Orange Book patent-listing system.[2,3]

Potentially relevant patent categories include:

1. Tildrakizumab composition-of-matter patents.
2. Antibody sequence and binding patents.
3. Pharmaceutical-composition patents covering concentration, pH, buffer, sugar, or surfactant combinations.
4. Subcutaneous administration patents.
5. Prefilled-syringe and container-closure patents.
6. Manufacturing, purification, or cell-culture patents.
7. Method-of-use patents covering plaque psoriasis and dosing schedules.

The presence of sucrose, histidine, or polysorbate 80 in a competing product does not by itself establish infringement. Patent exposure depends on the exact claim language, concentrations, pH range, formulation architecture, manufacturing steps, and jurisdiction.

A biosimilar sponsor should not treat the ILUMYA excipient list as a freedom-to-operate analysis. Public labeling identifies qualitative ingredients but usually does not disclose every formulation parameter needed to map a product against a patent claim.

When does ILUMYA lose exclusivity?

ILUMYA's commercial protection has several components:

Protection category	Relevance to ILUMYA
FDA biologic exclusivity	Limits approval of a biosimilar for the statutory exclusivity period
Patent protection	May cover the antibody, formulation, use, manufacture, or delivery system
Regulatory exclusivity for pediatric indications	Depends on FDA-granted pediatric extensions
Market position	Prescriber familiarity, payer contracting, and psoriasis treatment guidelines
Manufacturing know-how	May create practical barriers even after patent expiry

The BPCIA provides an approved reference product with 12 years of reference-product exclusivity from first licensure, subject to statutory rules and exceptions.[3] Patent expiry dates require a current patent-family review across the United States and other target markets. A single expiry date cannot reliably describe ILUMYA's loss of exclusivity because different patents may expire at different times and may cover different aspects of the product.

ILUMYA was approved by FDA in March 2018 for moderate-to-severe plaque psoriasis in adults who are candidates for systemic therapy or phototherapy.[1] Its primary market is therefore governed by biologic exclusivity, patent families, and the timing of biosimilar development rather than by a conventional Hatch-Waxman generic timetable.

What is the Orange Book and Purple Book status of ILUMYA?

ILUMYA does not have the standard Orange Book status associated with small-molecule products. The relevant FDA reference is the Purple Book, which identifies licensed biological products, reference products, biosimilars, and interchangeable biosimilars.[2]

A competitor cannot file an ANDA for tildrakizumab. The relevant pathway is a section 351(k) biosimilar application. The sponsor must demonstrate that the proposed product is highly similar to the reference product and that there are no clinically meaningful differences in safety, purity, and potency.[4]

The FDA does not require a biosimilar to use identical excipients. An excipient difference can be acceptable if analytical, functional, pharmacokinetic, immunogenicity, and clinical evidence support the proposed product.

What excipient strategy should a tildrakizumab biosimilar use?

The lowest regulatory-risk strategy is to begin with a close formulation match:

Formulation element	Reference-oriented strategy	Opportunity for differentiation
Buffer	Histidine-based system	Optimize buffer concentration or pH only if comparability supports it
Stabilizer	Sucrose	Evaluate trehalose or alternative polyols for improved thermal stability
Surfactant	Polysorbate 80	Consider polysorbate 20 or a nonionic alternative
Concentration	100 mg/mL reference presentation	Develop a lower-volume or higher-concentration presentation if injection performance permits
Container	Single-dose prefilled syringe	Add autoinjector or enhanced-use presentation
Storage	Refrigerated	Seek extended room-temperature stability
Administration	Subcutaneous injection	Improve injection force, needle comfort, and handling time

A close-match strategy can reduce development risk, but it may leave little commercial differentiation. A modified excipient system may create a stronger product proposition if it delivers measurable improvements in stability, usability, or supply-chain economics.

The most defensible development sequence is:

1. Reproduce the reference product's critical quality attributes.
2. Establish the role of each excipient through forced-degradation and stress studies.
3. Compare polysorbate degradation, particle formation, aggregation, charge variants, and potency.
4. Test container-closure compatibility with the proposed syringe or autoinjector.
5. Evaluate subcutaneous injection performance at intended temperature and hold times.
6. Select the formulation with the best balance of similarity, stability, manufacturability, and device performance.

Which excipient opportunities have the greatest commercial value?

Polysorbate replacement

Polysorbate 80 is the highest-value formulation target. It can undergo oxidation and hydrolysis, producing degradation products that may affect protein stability and particle formation. Suppliers of high-purity polysorbate 80 with controlled peroxide and aldehyde profiles can compete on:

• Low peroxide content
• Lot-to-lot consistency
• Trace-metal control
• Defined fatty-acid distribution
• Reduced degradation during long-term storage
• Improved compatibility with prefilled syringes

Alternative surfactants may offer better chemical stability, but substitution requires a full comparability package. The commercial opportunity is strongest where a supplier can provide both the excipient and validated analytical methods.

Extended room-temperature stability

ILUMYA's refrigerated storage requirement creates logistics costs for wholesalers, specialty pharmacies, clinics, and patients. An excipient or formulation change that extends allowable room-temperature exposure could reduce cold-chain losses and improve patient handling.

This opportunity has practical limits. A longer room-temperature claim would require stability data, container-closure studies, shipping validation, and regulatory approval. It cannot be created through labeling alone.

Higher-concentration formulations

A 100 mg/mL antibody solution already represents a concentrated biologic presentation. Further concentration may reduce injection volume but can increase viscosity, injection force, aggregation risk, and device complexity.

Commercial value would depend on whether a higher-concentration product enables:

• Smaller injection volume
• Shorter administration time
• Autoinjector compatibility
• Less painful administration
• More convenient home dosing

A high-concentration formulation could support lifecycle management, but it could also create new patent and regulatory exposure.

Autoinjector and device integration

ILUMYA's prefilled-syringe presentation leaves room for device-based differentiation. Potential products include an autoinjector, a needle-safety system, or a device with improved dose confirmation and handling.

The key technical variables are:

• Injection force
• Delivery time
• Needle gauge
• Syringe break-loose and glide forces
• Silicone oil interaction
• Dose accuracy
• Human-factors performance
• Compatibility after refrigerated storage and room-temperature exposure

A device change may support a new commercial product even when the underlying excipient system remains similar.

How strong is the ILUMYA formulation estate?

The formulation estate should be assessed as moderate from a technical perspective and potentially meaningful from a litigation perspective.

The formulation uses widely used excipients, which limits differentiation based solely on ingredient identity. Patent strength may increase if claims require a narrow combination of:

• Tildrakizumab at a defined concentration
• A specific histidine buffer range
• A defined sucrose level
• Polysorbate 80 within a specified concentration window
• A particular pH range
• A specified container or administration system

Broad claims covering conventional sucrose, histidine, and polysorbate formulations may face validity and obviousness challenges, particularly where the ingredients are standard in monoclonal-antibody development. Narrow claims tied to demonstrated stability, reduced aggregation, or a specific device may be more difficult to design around.

For a competitor, the highest-risk claims are likely to be those that combine formulation parameters with a particular antibody sequence or use. For an innovator, the strongest commercial protection may come from a layered estate covering formulation, device, manufacturing, and dosing rather than from an excipient claim standing alone.

What generic entry risks exist for ILUMYA?

The relevant entry risk is biosimilar competition, not conventional generic competition.

Biosimilar risk

A biosimilar sponsor could pursue a close formulation match and rely on analytical similarity supported by pharmacokinetic and immunogenicity studies. The sponsor may avoid selected formulation or device claims by:

• Using a different surfactant
• Adjusting buffer composition
• Selecting a different syringe
• Omitting an autoinjector
• Using a distinct manufacturing process
• Pursuing a non-interchangeable biosimilar first

Formulation design-around risk

The reference excipient list is publicly available. That reduces uncertainty for a biosimilar developer but does not eliminate development risk. The critical challenge is reproducing the reference product's quality profile, including attributes not fully disclosed in the label.

Market-entry timing

Biosimilar entry depends on:

• Reference-product exclusivity
• Patent litigation under the BPCIA
• Patent settlements
• Manufacturing readiness
• FDA review timing
• Payer adoption
• Prescriber switching behavior
• Interchangeability strategy

A first entrant with a lower-cost prefilled syringe could compete without duplicating every lifecycle-management feature of the originator.

Which companies are positioned to compete with ILUMYA?

ILUMYA competes within the IL-23 p19 inhibitor class and the broader biologic psoriasis market. Relevant products include:

Product	Active ingredient	Sponsor	Competitive relevance
ILUMYA	Tildrakizumab	Sun Pharma	Reference product for tildrakizumab biosimilar development
TREMFYA	Guselkumab	Janssen/J&J	IL-23 p19 competitor with psoriasis and other indications
SKYRIZI	Risankizumab-rzaa	AbbVie	Major IL-23 p19 competitor
SOTYKTU	Deucravacitinib	Bristol Myers Squibb	Oral TYK2 competitor
STELARA	Ustekinumab	Janssen/J&J	Established IL-12/23 competitor with biosimilar activity

The excipient strategy of a competing product can influence market positioning. A stable room-temperature product, lower-volume injection, or autoinjector may gain value in specialty-pharmacy channels even when clinical efficacy is similar.

What licensing and manufacturing opportunities exist?

Sun Pharma obtained worldwide rights to tildrakizumab from Merck in 2014, with Sun responsible for development and commercialization and Merck eligible for milestone and royalty payments under the transaction structure.[5]

Commercial opportunities linked to ILUMYA include:

• Supply of high-purity polysorbate 80
• Alternative surfactant development
• Excipient analytical testing
• Protein aggregation and particle testing
• Prefilled-syringe components
• Autoinjector platforms
• Cold-chain packaging
• Contract sterile fill-finish
• Biosimilar formulation development
• Reference-product characterization
• Device human-factors studies
• Stability-indicating assay development

Manufacturing barriers remain significant. A competitor needs a validated mammalian-cell process, purification train, viral-clearance package, sterile fill-finish capability, and a quality system capable of controlling antibody heterogeneity. Excipient selection is only one part of the development barrier.

What patent litigation and settlement risks affect ILUMYA?

Potential disputes may involve antibody patents, formulation patents, method-of-use claims, manufacturing patents, and device patents. Under the BPCIA, a biosimilar sponsor may participate in the statutory patent-information exchange and litigation process, commonly called the patent dance, subject to the sponsor's disclosure decisions and applicable litigation strategy.[3]

A settlement could delay entry, permit entry before the latest asserted patent expires, or impose restrictions on a specific formulation, indication, or device. Settlement terms may not be fully public. Commercial analysis should therefore separate:

• FDA approval timing
• Reference-product exclusivity
• Patent litigation timing
• Settlement entry date
• Actual commercial launch date

Key Takeaways

• ILUMYA uses a conventional biologic formulation containing sucrose, histidine, histidine hydrochloride monohydrate, and polysorbate 80.
• Polysorbate 80 is the most commercially important excipient risk because of oxidation, hydrolysis, and particle-generation concerns.
• The product is a biologic, so biosimilar development under section 351(k), not an ANDA, is the relevant generic-entry pathway.
• ILUMYA does not have a conventional Orange Book patent profile. Purple Book status, BPCIA litigation, and patent-family analysis are more relevant.
• The strongest commercial opportunities are improved surfactants, extended room-temperature stability, higher-concentration delivery, autoinjectors, and analytical comparability services.
• Excipient similarity does not establish patent clearance. Exact formulation parameters, claims, devices, manufacturing methods, and jurisdictions control the analysis.
• A biosimilar could compete through a close formulation match or use a distinct excipient and device combination to reduce patent exposure.
• Manufacturing capability, sterile fill-finish capacity, device integration, and payer access may be as important as excipient selection in determining market entry.

FAQs

Can a biosimilar use different excipients from ILUMYA?

Yes. FDA biosimilar regulations do not generally require identical excipients. The sponsor must demonstrate that the difference does not create clinically meaningful differences in safety, purity, or potency.[4]

Is polysorbate 80 in ILUMYA a patentable product feature?

The presence of polysorbate 80 alone is unlikely to define a strong standalone commercial barrier. Patent risk depends on the claimed concentration, pH, antibody, stability result, container, and related formulation limitations.

Can ILUMYA be reformulated for room-temperature storage?

Potentially, but the change would require supporting stability, shipping, container-closure, and regulatory data. The formulation would need to maintain potency, purity, particle control, and immunogenicity performance across the proposed storage period.

What is the best device opportunity for a tildrakizumab competitor?

An autoinjector or other user-friendly delivery system is the clearest device opportunity. Its value depends on injection force, delivery time, dose accuracy, human factors, and compatibility with the antibody formulation.

Does ILUMYA have a conventional generic launch date?

No. ILUMYA is a biologic. Market entry would occur through a biosimilar pathway and would depend on biologic exclusivity, patent litigation, settlements, FDA approval, and commercial launch decisions.

References

1. U.S. Food and Drug Administration. (2024). ILUMYA (tildrakizumab-asmn) prescribing information. https://www.accessdata.fda.gov
2. U.S. Food and Drug Administration. (n.d.). Purple Book: Database of licensed biological products. https://purplebooksearch.fda.gov
3. U.S. Food and Drug Administration. (2020). Reference product exclusivity for biological products filed under the Public Health Service Act. https://www.fda.gov
4. U.S. Food and Drug Administration. (2015). Scientific considerations in demonstrating biosimilarity to a reference product: Guidance for industry. https://www.fda.gov
5. Sun Pharmaceutical Industries Ltd. (2014). Sun Pharma and Merck enter into license agreement for tildrakizumab. https://www.sunpharma.com