List of Excipients in Branded Drug SUSVIMO

SUSVIMO Excipient Strategy and Commercial Opportunities

Last updated: August 7, 2026

SUSVIMO is a long-acting ophthalmic drug-device combination that uses ranibizumab in a surgically implanted Port Delivery System (PDS). Its commercial excipient opportunity is concentrated in high-purity, low-variability materials that support protein stability, preservative-free delivery, sterile manufacturing, and prolonged residence in an ocular implant.

The approved SUSVIMO formulation contains ranibizumab, histidine, polysorbate 20, sucrose, and water for injection. The product is supplied as a 100 mg/mL solution for intravitreal administration through the ocular implant.[1] Unlike conventional injectable ranibizumab, SUSVIMO is refilled periodically through the implant, reducing administration frequency for approved retinal indications.

What excipients are used in SUSVIMO?

SUSVIMO contains a conventional protein-stabilizing excipient system adapted for a high-concentration ophthalmic biologic.

Component	Function in SUSVIMO	Commercial relevance
Ranibizumab	Anti-VEGF active ingredient	High-concentration biologic requiring control of aggregation and potency
Histidine	Buffer and pH control	Requires low bioburden, low metals, and tight pH specifications
Polysorbate 20	Surfactant that limits interfacial adsorption and aggregation	High-value excipient because oxidation, hydrolysis, and peroxide levels can affect protein quality
Sucrose	Tonicity and protein-stabilizing agent	Commodity-scale material with pharmaceutical-grade quality requirements
Water for injection	Vehicle	Must meet sterile manufacturing and endotoxin requirements

SUSVIMO does not use a preservative in the implant refill formulation. That design is commercially important because preservatives can create ocular tolerability issues and may interact with the implant, protein, or delivery system.

The formulation challenge is not simply maintaining ranibizumab stability in a vial. The product must remain chemically and physically stable during storage, filling, handling, implantation, and extended residence in the PDS reservoir. The excipient system also must avoid clogging, precipitation, excessive viscosity, particle formation, and adsorption to the implant materials.

How does the SUSVIMO excipient system support long-acting delivery?

The excipients support protein stability but do not independently create the six-month dosing interval. The sustained exposure is primarily generated by the implant’s reservoir, refill mechanism, diffusion characteristics, and ranibizumab concentration.

Histidine buffer

Histidine maintains the formulation pH within a range compatible with ranibizumab stability and ocular administration. For an implantable product, buffer capacity must be sufficient to control pH drift without creating unnecessary ionic strength or compatibility problems.

Commercial opportunities include:

• High-purity histidine with controlled metal content
• Low-endotoxin and low-bioburden grades
• Consistent particle-size and dissolution profiles
• Regional supply qualification for biologics manufacturing
• Custom specifications for ocular implant formulations

Metal control is relevant because trace metals can accelerate oxidation pathways in proteins and surfactants. Supplier documentation, elemental impurity control, and lot-to-lot consistency are therefore more important than nominal compendial compliance alone.

Polysorbate 20

Polysorbate 20 limits adsorption of ranibizumab to manufacturing surfaces, container closures, and implant-contacting materials. It also helps reduce agitation-induced aggregation during filling and handling.

Polysorbate 20 is the most commercially differentiated excipient in the formulation. Key risks include:

• Peroxide formation during storage
• Fatty-acid composition variability
• Hydrolytic degradation
• Subvisible particle generation
• Interaction with elastomers, plastics, or implant materials
• Potential effects on protein aggregation and potency

Suppliers with low-peroxide, low-variability polysorbate 20 grades can compete on more than price. Relevant product claims include tighter oxidation specifications, improved storage stability, reduced lot variability, and stronger analytical characterization.

The best commercial position is likely a biologics-grade polysorbate 20 platform supported by orthogonal testing for peroxide value, free fatty acids, subvisible particles, and degradation products. A supplier that can provide formulation-specific compatibility data with PDS materials has a stronger position than a supplier selling a generic compendial grade.

Sucrose

Sucrose contributes to tonicity and stabilizes the protein during storage and processing. It is widely used in injectable biologics and is less differentiated than polysorbate 20.

Commercial opportunities remain in:

• Low-endotoxin sucrose
• Consistent osmolality performance
• Low particulate burden
• Secure global supply
• Validated compatibility with sterile filtration and fill-finish processes

Sucrose is unlikely to be the primary source of formulation exclusivity. Its value is more likely to come from reliable supply, regulatory documentation, and integration into a complete excipient package.

What formulation patents protect SUSVIMO?

SUSVIMO protection is likely divided among four technical layers:

Protection layer	Subject matter	Commercial impact
Active ingredient	Ranibizumab composition and therapeutic use	Limits direct biologic substitution
Formulation	Concentrated ranibizumab with buffer, surfactant, stabilizer, and defined quality attributes	Can restrict formulation-matched competitors
Drug-device combination	PDS reservoir, refill needle, septum, implant geometry, and delivery characteristics	Creates the main barrier to copying the administration system
Method of use	Treatment of neovascular age-related macular degeneration, diabetic macular edema, and diabetic retinopathy with periodic refills	Supports indication-specific enforcement

The strongest protection is likely the combination of formulation and device. A competitor could reproduce the active ingredient and use similar excipients but still lack the implant, refill procedure, sterility controls, and clinical data required for a comparable product.

SUSVIMO is regulated as a biologic drug-device combination under a Biologics License Application. It is not a conventional small-molecule drug listed through an Abbreviated New Drug Application. The FDA-approved product is associated with BLA 761197.[1]

What is the Orange Book status of SUSVIMO?

SUSVIMO is not expected to have the same Orange Book listing profile as a small-molecule drug. The Orange Book primarily records approved drug products eligible for abbreviated new drug applications, while SUSVIMO is approved under the biologics framework.

The relevant U.S. competitive pathway is therefore biosimilar and interchangeable-biologic regulation, not a standard Paragraph IV generic filing. Patent disputes may still arise under the Biologics Price Competition and Innovation Act, including the statutory patent-exchange process commonly called the patent dance.[4]

Excipient suppliers should not assume that the absence of an Orange Book listing removes commercial protection. The device, manufacturing process, formulation, and biologic comparability package can create substantial entry barriers outside the Orange Book system.

When does SUSVIMO lose regulatory exclusivity?

SUSVIMO received FDA approval in October 2021. The U.S. reference product exclusivity period for a new biologic is generally 12 years from first licensure, subject to statutory rules and product-specific interpretation.[3]

Milestone	Date or status
FDA approval of SUSVIMO	October 2021
BLA	761197
Reference-biologic exclusivity framework	12 years from first licensure
Earliest general biosimilar approval timing	Governed by the BPCIA, including the four-year submission and 12-year approval framework
Approved indications	Retinal vascular and neovascular diseases, as reflected in the current FDA labeling

Regulatory exclusivity does not establish the precise expiry of every patent. Patent-term adjustment, patent-term extension, continuation applications, terminal disclaimers, and litigation settlements can change practical market-entry timing.

What biosimilar risk exists for SUSVIMO?

The principal biosimilar risk is indirect rather than immediate. A ranibizumab biosimilar can compete with conventional ranibizumab injections without reproducing the PDS. A biosimilar sponsor seeking to compete directly with SUSVIMO would face additional questions involving:

• Device compatibility
• Implant refill procedures
• Drug-device combination comparability
• Sterility assurance
• Extractables and leachables
• Protein stability during extended implant residence
• Clinical performance of the delivery system
• Interchangeability and substitution mechanics

A biosimilar that matches ranibizumab but uses monthly or bimonthly injection remains a different commercial proposition from a six-month refill implant. This gives SUSVIMO a delivery-system advantage, although the advantage depends on surgical adoption, adverse-event management, reimbursement, and physician preference.

How do formulation patents compare with device patents?

Device patents are likely to be more commercially important than basic excipient patents.

Protection type	Ease of design-around	Expected commercial value
Histidine, sucrose, and polysorbate 20 composition	High	Low to moderate
Narrow excipient concentration ranges	Moderate	Moderate
Stability and impurity specifications	Moderate	Moderate
Ranibizumab concentration and formulation	Moderate	High
PDS structure and refill mechanism	Low to moderate	Very high
Implant-plus-formulation combination	Low	Very high
Method of use and refill interval	Moderate	High

A competitor may avoid a formulation claim by changing buffer concentration, surfactant type, or stabilizer. It is harder to avoid a device claim while retaining the same reservoir, septum, refill, and long-term delivery characteristics.

For excipient companies, the commercial goal should therefore be to link the excipient to performance attributes that matter to the combination product. These include lower aggregation, reduced adsorption, improved implant-material compatibility, and longer in-device stability.

What commercial opportunities exist for excipient manufacturers?

Low-peroxide polysorbate 20

This is the clearest opportunity. A supplier can differentiate through:

• Controlled peroxide values
• Reduced hydrolysis during storage
• Defined fatty-acid distribution
• Better lot-to-lot consistency
• Packaging that limits oxidation
• Stability data in high-concentration ranibizumab systems

A supplier that supports a drug master file, robust change-control program, and regulatory comparability package can become difficult to replace after commercial qualification.

Excipient combinations

A prequalified package containing polysorbate 20, histidine, and sucrose can reduce formulation-development time. The package could include:

• Analytical methods
• Forced-degradation data
• Protein aggregation profiles
• Compatibility with sterile filtration
• Container-closure compatibility
• Extractables and leachables data
• Global regulatory documentation

This model has greater value than selling individual raw materials because biologic manufacturers face significant change-control costs after approval.

Implant-compatible excipients

Excipient suppliers can develop formulations specifically tested against:

• Silicone-based components
• Polymer reservoirs
• Elastomeric septa
• Titanium or other implant materials
• Refill needles and connectors

The relevant development endpoint is not only protein stability in a glass vial. It is stability and recovery after contact with the entire drug-delivery system.

Alternative surfactants

Poloxamers, other polysorbates, and newer protein-stabilizing surfactants may create future opportunities. However, replacing polysorbate 20 would require extensive comparability work. A new surfactant would need to demonstrate acceptable ocular tolerability, protein stability, implant compatibility, sterility performance, and regulatory acceptability.

Manufacturing services

Contract manufacturers can offer value through:

• Aseptic filling of high-concentration ranibizumab
• Low-shear processing
• Low-particle filling lines
• Specialized inspection for protein products
• Container-closure integrity testing
• Device assembly and drug-device integration
• Stability programs for in-implant storage

The PDS creates a manufacturing opportunity that is more specialized than standard prefilled-syringe production.

What manufacturing and IP barriers affect market entry?

The principal barriers are technical and regulatory:

1. Maintaining ranibizumab potency and low aggregation at 100 mg/mL.
2. Controlling polysorbate degradation and particle formation.
3. Demonstrating compatibility with implant and refill materials.
4. Validating aseptic filling and sterility over the product’s shelf life.
5. Controlling extractables and leachables from the PDS.
6. Establishing reliable drug recovery from the implant.
7. Generating clinical evidence for long-acting ocular delivery.
8. Managing combination-product quality systems.
9. Protecting device and formulation manufacturing know-how.
10. Establishing a reimbursement model that supports implantation and periodic refills.

These barriers make a direct copy more difficult than a conventional ranibizumab biosimilar. They also increase the value of excipient suppliers that can provide validated, formulation-specific technical packages.

What revenue exposure does SUSVIMO create for Roche and suppliers?

SUSVIMO’s revenue potential comes from reducing treatment frequency while preserving anti-VEGF efficacy. Conventional retinal anti-VEGF therapy can require frequent office-based injections. SUSVIMO is designed around periodic refilling, which can reduce administration events and create a differentiated reimbursement proposition.[1]

For Roche, commercial exposure includes:

• Retention of patients requiring chronic anti-VEGF treatment
• Competition with aflibercept, faricimab, brolucizumab, and conventional ranibizumab
• Surgical adoption of the implant
• Refill compliance
• Device-related safety and performance
• Reimbursement for implantation and refill procedures

For excipient suppliers, revenue is smaller in unit terms but can be durable because an approved biologic formulation is difficult to change. Once an excipient is incorporated into commercial manufacturing, replacement can require comparability studies, regulatory submissions, stability data, and process requalification.

How does SUSVIMO compare with conventional anti-VEGF products?

Attribute	SUSVIMO	Conventional anti-VEGF injection
Active ingredient	Ranibizumab	Ranibizumab, aflibercept, faricimab, or other agents
Delivery	Ocular implant with refill	Intravitreal syringe or vial
Dosing burden	Periodic refill	Frequent injections
Excipient challenge	Long-term in-device stability	Shorter in-syringe and in-vial stability
Device dependence	High	Moderate
Biosimilar substitution	More complex	More straightforward
Manufacturing complexity	High	Lower
Patent strategy	Formulation plus device plus method	Active, formulation, and method patents

Key Takeaways

• SUSVIMO uses ranibizumab with histidine, polysorbate 20, sucrose, and water for injection.
• Polysorbate 20 is the leading excipient opportunity because oxidation, hydrolysis, and particle formation can affect biologic quality.
• The strongest commercial protection is likely the combined formulation, implant, refill system, and method of use.
• SUSVIMO is governed by the biologics framework rather than the standard small-molecule Orange Book pathway.
• A ranibizumab biosimilar would not automatically reproduce SUSVIMO’s PDS-based commercial proposition.
• Excipient suppliers can differentiate through low-peroxide surfactants, implant compatibility data, regulatory packages, and change-control support.
• The main manufacturing barriers are protein stability, sterility, extractables and leachables, drug-device compatibility, and long-term in-implant performance.

FAQs

Can polysorbate 20 be replaced in SUSVIMO?

Potentially, but replacement would require evidence covering ranibizumab stability, ocular tolerability, implant compatibility, particle formation, sterility, and regulatory comparability. A replacement surfactant would face a higher development burden than a routine formulation change.

Is SUSVIMO an interchangeable biologic?

SUSVIMO is a biologic drug-device combination. Interchangeability of a ranibizumab biosimilar would not automatically establish interchangeability with the SUSVIMO implant system.

Do SUSVIMO excipients have standalone patent value?

Most individual excipients, including histidine and sucrose, are established pharmaceutical materials. Commercial value generally comes from the claimed combination, concentration range, stability profile, manufacturing process, or implant compatibility rather than ownership of the excipient itself.

What excipient is most important for SUSVIMO stability?

Polysorbate 20 is the most sensitive commercial excipient because its degradation can contribute to protein aggregation and particulate formation. Histidine and sucrose remain important for pH control, tonicity, and protein stabilization.

Can a generic manufacturer copy the SUSVIMO formulation without copying the implant?

A manufacturer could potentially develop a different ranibizumab presentation, but that product would not offer the same PDS-based delivery profile. It could also face formulation, method-of-use, manufacturing, and device-related patent claims.

References

1. U.S. Food and Drug Administration. (2024). SUSVIMO (ranibizumab injection) prescribing information. Genentech, Inc.

2. U.S. Food and Drug Administration. (2021). FDA approves Susvimo, the first and only eye implant for treatment of wet age-related macular degeneration. FDA.

3. U.S. Food and Drug Administration. (2023). Reference product exclusivity for biological products. FDA.

4. U.S. Food and Drug Administration. (2024). Biosimilar biological products. FDA.

5. International Council for Harmonisation. (2023). ICH Q5C: Quality of biotechnological products: Stability testing of biotechnological/biological products. ICH.

6. United States Pharmacopeia. (2024). General chapter <1047> ancillary materials for cell, gene, and tissue-engineered products. United States Pharmacopeial Convention.