List of Excipients in Branded Drug KANJINTI

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Last updated: August 21, 2026

Kanjinti (trastuzumab-anns) uses a conventional, low-complexity excipient system built around histidine buffering, trehalose stabilization, and polysorbate 20 control of interfacial stress. The strategy supports a lyophilized intravenous biosimilar with storage stability comparable to Herceptin while limiting formulation differentiation. Commercial opportunity is therefore concentrated in cost control, global supply, hospital contracting, vial economics, and future delivery-system development rather than in proprietary excipient claims.

Kanjinti Excipient Strategy, Formulation Patents, Commercial Opportunities, and Biosimilar Market Position

What is Kanjinti and who markets it?

Kanjinti is the U.S. brand name for trastuzumab-anns, a biosimilar to Genentech’s Herceptin (trastuzumab). Amgen and Allergan developed the product as ABP 980. The FDA approved Kanjinti on June 13, 2019, for the same major HER2-positive breast cancer and HER2-positive metastatic gastric or gastroesophageal junction cancer indications covered by the reference product’s approval history.[1]

Amgen acquired Allergan’s biosimilars business in 2019. Kanjinti has been commercialized within Amgen’s oncology portfolio.

Attribute	Kanjinti
Active ingredient	Trastuzumab-anns
Reference product	Herceptin, trastuzumab
Drug class	HER2-targeted monoclonal antibody
FDA pathway	351(k) biosimilar application
FDA approval	June 13, 2019
Dosage form	Sterile lyophilized powder for intravenous infusion
Strengths	150 mg and 420 mg single-dose vials
U.S. interchangeability	Not designated interchangeable in the original FDA approval
FDA listing system	Purple Book, not Orange Book
Primary commercial buyers	Hospitals, oncology practices, group purchasing organizations, specialty distributors

The product’s commercial value comes from biosimilar pricing and supply competition. The formulation itself is not positioned as a differentiated delivery platform.

What excipients are used in Kanjinti?

Kanjinti contains four principal formulation excipients:

Excipient	Function in Kanjinti
L-histidine	Buffer component
L-histidine hydrochloride monohydrate	Co-buffer and pH control
Trehalose dihydrate	Lyoprotectant and stabilizer
Polysorbate 20	Surfactant that reduces aggregation and surface adsorption

The 150 mg and 420 mg presentations use the same core excipient system. The product is supplied as a sterile, preservative-free lyophilized powder for reconstitution with Sterile Water for Injection. The FDA prescribing information specifies reconstitution and dilution requirements, including use of compatible infusion solutions and avoidance of dextrose-containing solutions because of potential instability or incompatibility.[2]

Kanjinti’s excipient strategy follows the standard architecture used for many lyophilized monoclonal antibodies:

1. Histidine maintains a controlled pH environment.
2. Trehalose protects the antibody during freezing and drying and helps preserve the protein structure during storage.
3. Polysorbate 20 limits aggregation caused by agitation, air-liquid interfaces, and contact with container surfaces.
4. Lyophilization reduces the risk of degradation associated with long-term storage of a liquid antibody.

This composition is commercially rational because it uses well-established pharmaceutical excipients with extensive regulatory precedent.

Why does Kanjinti use a lyophilized formulation?

Kanjinti uses lyophilization to improve the stability of the trastuzumab antibody during refrigerated storage. Monoclonal antibodies can undergo aggregation, fragmentation, oxidation, deamidation, and surface adsorption in liquid formulations. Removing water through controlled freeze-drying can reduce certain degradation pathways and improve shelf-life management.

The principal commercial benefits are:

• Refrigerated storage rather than frozen distribution.
• Established manufacturing technology for hospital-administered antibodies.
• Compatibility with conventional vial-based oncology workflows.
• Reduced dependence on a liquid formulation that may require tighter control of agitation and temperature excursions.
• A presentation that aligns with the reference product and other trastuzumab biosimilars.

The tradeoff is that hospitals must reconstitute the product before dilution and infusion. This creates handling time, introduces a reconstitution step, and generates residual-volume and vial-waste issues.

What formulation and excipient patents protect Kanjinti?

Kanjinti’s principal regulatory protection is based on biosimilarity to trastuzumab, not on a publicly marketed, stand-alone excipient invention. The product’s excipient combination is conventional and generally difficult to protect broadly through composition-of-matter claims.

Patent protection for the formulation

Potential formulation claims could cover:

• A defined trastuzumab concentration.
• A specified histidine buffer range.
• Trehalose concentration or sugar-to-protein ratio.
• Polysorbate 20 concentration.
• Lyophilization cycle parameters.
• Reconstitution time or residual moisture.
• Stability thresholds for aggregates, fragments, or charge variants.
• Container-closure combinations.
• A specific pH and osmolality range.

These claims would likely be narrow and vulnerable to invalidity or non-infringement challenges if the formulation uses standard excipients. The more defensible intellectual property generally resides in the manufacturing process, analytical controls, container system, or stability data rather than in the mere presence of histidine, trehalose, and polysorbate 20.

Manufacturing know-how is more important than excipient patents

For Kanjinti, protected or confidential know-how may include:

• Cell-line and upstream culture conditions.
• Purification sequence and viral-clearance controls.
• Removal or control of host-cell proteins and DNA.
• Aggregation control during concentration and filtration.
• Polysorbate degradation monitoring.
• Freeze-drying cycle design.
• Reconstitution performance.
• Control of oxidation, deamidation, and charge heterogeneity.
• Fill-finish operating ranges.
• Comparability protocols supporting biosimilarity.

This information is typically protected through trade secrets, regulatory confidentiality, and process controls. It does not appear in the same form as a conventional small-molecule patent estate.

What is the regulatory and exclusivity status of Kanjinti?

Kanjinti was approved under the FDA’s abbreviated biologics pathway. The FDA concluded that it was highly similar to Herceptin and had no clinically meaningful differences in safety, purity, and potency.[1]

The reference product’s 12-year U.S. biologics exclusivity period began with Herceptin’s original approval in 1998 and expired before Kanjinti entered the market. Kanjinti therefore did not receive a new 12-year reference-product exclusivity period. Its commercial position depends on approval, patent resolution, manufacturing capacity, and contracting.

Kanjinti does not rely on Orange Book listing because biologics approved under the Public Health Service Act are tracked through the FDA’s Purple Book. The Purple Book identifies reference products, biosimilars, and interchangeable biosimilars.[3]

Regulatory issue	Kanjinti status
Reference-product exclusivity	Herceptin’s 12-year period expired before Kanjinti approval
Biosimilar designation	Yes
Interchangeable designation	No original FDA interchangeable designation
Orange Book listing	Not applicable
Purple Book listing	Applicable
Paragraph IV certification	Not applicable in the small-molecule Orange Book sense
Patent-resolution framework	BPCIA patent-exchange and litigation procedures
Substitution at pharmacy level	Generally limited absent interchangeable designation and state law authorization

Did Kanjinti face Paragraph IV challenges or patent litigation?

Kanjinti did not use a conventional Paragraph IV certification because Paragraph IV is an abbreviated new drug application mechanism under the Federal Food, Drug, and Cosmetic Act. Biosimilar applicants instead use the patent-disclosure and litigation framework associated with the Biologics Price Competition and Innovation Act.

The relevant legal issues for Kanjinti included patent disputes involving trastuzumab and the reference product’s sponsor. Amgen and Allergan pursued the product against the background of Genentech and Roche patent rights covering trastuzumab-related subject matter, formulations, uses, and manufacturing processes. The parties resolved patent disputes through agreements that permitted biosimilar entry before the expiration of every potentially relevant patent.

The commercial result was more important than a single patent expiry date: Kanjinti entered the U.S. market in July 2019, subject to the agreed resolution of patent disputes. The settlement structure reduced launch uncertainty but did not eliminate future litigation risk for manufacturing, labeling, delivery, or newly asserted patents.

When did Kanjinti lose exclusivity and when can generics enter?

Kanjinti is a biologic, so the relevant competitive threat is another biosimilar rather than a conventional generic. A second applicant can seek approval through the 351(k) pathway by demonstrating biosimilarity to trastuzumab or by relying on another appropriate reference-product strategy.

There is no single Kanjinti “patent cliff” comparable to a small-molecule product. Competitive entry depends on:

• Patents held by Amgen or other parties.
• Manufacturing patents and trade secrets.
• FDA approval timing.
• State substitution rules.
• Payer and hospital contracting.
• Whether a competing product receives interchangeable status.
• Capacity to supply oncology providers consistently.

The key market-entry window began with Kanjinti’s 2019 launch and expanded as additional trastuzumab biosimilars entered the U.S. market. Products including Ogivri, Herzuma, Ontruzant, and Trazimera created a multi-biosimilar market rather than a single successor to Herceptin.

How does Kanjinti compare with competing trastuzumab biosimilars?

Kanjinti competes primarily on net price, availability, contracting, clinical confidence, and operational reliability. The core excipient systems across trastuzumab biosimilars are similar because the products must match the reference molecule’s quality profile and clinical performance.

Product	Sponsor	Active ingredient	U.S. approval period	Interchangeability position
Kanjinti	Amgen/Allergan origin	Trastuzumab-anns	2019	Not originally designated interchangeable
Ogivri	Viatris and Biocon	Trastuzumab-dkst	2017	Not originally interchangeable
Herzuma	Celltrion/Teva	Trastuzumab-pkrb	2018	Not originally interchangeable
Ontruzant	Samsung Bioepis/Organon	Trastuzumab-dttb	2019	Not originally interchangeable
Trazimera	Pfizer	Trastuzumab-qyyp	2019	Not originally interchangeable

The competitive differences are more likely to arise from formulation details outside the label-level excipient list:

• Reconstitution time.
• Vial sizes.
• Storage and shipping performance.
• Ready-to-use or lower-handling alternatives.
• Stability after dilution.
• Manufacturing capacity.
• Contracting strategy.
• Pharmacovigilance and medical support.

What commercial opportunities exist for Kanjinti excipients?

The strongest excipient-related opportunities are adjacent to Kanjinti rather than embedded in its existing vial formulation.

1. Ready-to-use liquid trastuzumab

A liquid formulation could eliminate reconstitution and reduce preparation errors. The technical challenge is maintaining antibody stability during refrigerated storage and distribution. Key development targets include:

• Lower aggregate formation.
• Reduced subvisible particles.
• Stable polysorbate performance.
• Reduced oxidation and deamidation.
• Extended in-use stability after dilution.
• Compatibility with infusion bags and tubing.

A successful liquid presentation could command value through labor savings and reduced preparation complexity even if the active ingredient remains a biosimilar.

2. Subcutaneous or device-enabled delivery

Herceptin Hylecta uses trastuzumab with hyaluronidase for subcutaneous administration. A Kanjinti-related commercial strategy could explore subcutaneous delivery, wearable injection, or other administration systems, although this would require substantial development, device validation, human-factors work, and regulatory assessment.

The opportunity is higher for products that reduce chair time and infusion-center labor. The barriers include delivery volume, viscosity, local tolerability, device compatibility, and the need to demonstrate an appropriate clinical bridge to the approved intravenous product.

3. Low-silicone and low-particle packaging

Container-closure improvements can reduce protein adsorption and particle generation. Commercially relevant technologies include:

• Low-binding vial surfaces.
• Optimized elastomer stoppers.
• Low-silicone syringes.
• Prefilled or cartridge-based systems.
• Improved reconstitution devices.
• Closed-system transfer components.

These technologies may create procurement advantages without changing the active formulation.

4. Polysorbate alternatives

Polysorbate 20 is established but can undergo hydrolysis and oxidation, producing degradation products that may affect antibody stability. Alternative surfactants, such as poloxamers or other nonionic systems, could support differentiated stability profiles. The regulatory burden is higher because any excipient substitution can alter immunogenicity risk, degradation behavior, and comparability requirements.

A replacement strategy must demonstrate that the new excipient does not introduce:

• Increased aggregation.
• New degradation pathways.
• Extractables or leachables.
• Immunogenicity concerns.
• Unexpected container interactions.
• Poorer dilution or infusion performance.

5. Trehalose and sugar-system optimization

Trehalose is a standard lyoprotectant, but the broader commercial opportunity includes optimization of:

• Trehalose concentration.
• Trehalose-sucrose combinations.
• Mannitol or amino-acid bulking systems.
• Cake structure and reconstitution time.
• Residual moisture.
• Freeze-drying cycle duration.

The value is most likely to arise from manufacturing efficiency and shelf-life improvement rather than from a broad excipient patent.

What generic and biosimilar launch risks exist for Kanjinti?

Kanjinti faces several forms of competitive pressure.

Price erosion

Multiple trastuzumab biosimilars can produce rapid price competition, particularly in hospital channels. Net prices may differ materially from published wholesale acquisition cost because of rebates, group purchasing agreements, distributor arrangements, and payer formularies.

Interchangeability pressure

A competing trastuzumab biosimilar with interchangeable status could obtain stronger substitution potential. Kanjinti’s non-interchangeable status may limit automatic substitution in certain settings, although oncology biologics are often selected through institutional protocols and payer policy rather than retail pharmacy substitution alone.

Manufacturing disruption

Trastuzumab is a complex biologic. Production interruptions can affect hospital supply and create contracting risk. The relevant barriers include cell-culture scale, purification yield, viral clearance, sterile fill-finish capacity, and global cold-chain execution.

Formulation and device competition

A competitor with a ready-to-use liquid, longer post-reconstitution stability, smaller vial waste, or subcutaneous delivery may compete on total treatment cost rather than acquisition price alone.

Label and indication strategy

Biosimilar sponsors may pursue broader indication coverage, extrapolation, or updated labeling. Differences in approved indications, naming, pharmacovigilance presentation, and administration instructions can affect hospital adoption.

How strong is the Kanjinti patent estate?

Kanjinti’s patent position is stronger in process execution and regulatory know-how than in the basic excipient combination.

IP category	Relative strength	Commercial relevance
Trastuzumab molecule claims	Low for Kanjinti as a biosimilar	Reference-product patents largely expired or resolved
Histidine-trehalose-polysorbate formulation	Low to moderate	Narrow claims may be possible
Lyophilization process	Moderate	Can protect cycle design and product quality
Manufacturing process	Moderate to strong	High practical importance and difficult to design around
Container-closure system	Moderate	Can support lifecycle management
Delivery device	Potentially strong	Relevant to future subcutaneous or ready-to-use products
Trade secrets	Strong operational value	Central to yield, consistency, and cost

The formulation is therefore best viewed as an enabler of biosimilar comparability and supply economics, not as the primary exclusivity asset.

What is the revenue exposure associated with Kanjinti?

The product participates in the large trastuzumab market, which historically generated multibillion-dollar annual sales for Herceptin before biosimilar erosion. Kanjinti’s revenue exposure is tied to:

• U.S. hospital and oncology-practice uptake.
• European tender outcomes.
• Treatment duration and indication mix.
• Biosimilar price erosion.
• Amgen’s contracting strategy.
• Supply reliability.
• Competitive switching among trastuzumab products.

Revenue cannot be inferred from unit sales alone because biosimilar net pricing varies substantially across channels and countries. The most valuable commercial assets are likely to be manufacturing scale, payer access, and differentiated administration rather than a higher-cost excipient system.

Which geographic markets offer the best excipient and formulation opportunities?

The United States offers the strongest opportunity for formulation and administration differentiation because hospitals face high labor costs and payers increasingly manage biosimilar selection.

Europe is more exposed to tender pricing and centralized procurement. A formulation that reduces preparation time or improves supply reliability can help, but price remains a dominant purchasing factor.

Emerging markets may favor:

• Longer refrigerated shelf-life.
• Robust cold-chain tolerance.
• Lower-cost vial configurations.
• Reduced wastage.
• Simplified reconstitution.
• Local fill-finish or regional manufacturing.

Regulatory requirements differ by jurisdiction. A formulation change that is commercially attractive in one market may require separate comparability, stability, device, and labeling work elsewhere.

What is the best commercial strategy for Kanjinti excipients?

The most defensible strategy is a layered lifecycle plan:

1. Preserve the established histidine, trehalose, and polysorbate 20 formulation for cost-efficient biosimilar supply.
2. Improve freeze-drying yield, cycle time, and reconstitution performance through manufacturing know-how.
3. Develop a lower-waste vial or packaging configuration.
4. Evaluate a liquid formulation for reduced hospital handling.
5. Investigate device-enabled or subcutaneous delivery only if the clinical and regulatory economics support the investment.
6. Protect improvements through narrow formulation claims, process patents, device patents, and trade secrets.
7. Use supply reliability and total treatment cost as primary commercial differentiators.

The core Kanjinti excipient system is unlikely to create a durable premium by itself. The higher-value opportunities involve reducing preparation labor, limiting drug waste, improving cold-chain resilience, and enabling administration outside traditional infusion settings.

Key Takeaways

• Kanjinti contains L-histidine, L-histidine hydrochloride monohydrate, trehalose dihydrate, and polysorbate 20.
• Its lyophilized formulation is designed for antibody stability, refrigerated storage, and comparability with Herceptin.
• The excipients are conventional and unlikely to provide broad standalone patent protection.
• Manufacturing process controls, lyophilization know-how, container systems, and delivery devices have greater IP value.
• Kanjinti is regulated through the Purple Book, not the Orange Book.
• Paragraph IV certification does not apply; biosimilar patent disputes proceed under the BPCIA framework.
• Commercial competition comes from other trastuzumab biosimilars, price erosion, contracting, supply reliability, and interchangeability.
• The best lifecycle opportunities are ready-to-use liquid formulations, reduced-waste packaging, improved reconstitution, and subcutaneous or device-enabled delivery.
• Geographic value varies: the U.S. rewards labor-saving differentiation, while Europe places greater weight on tender price and supply performance.

FAQs About Kanjinti Formulation and Commercial Strategy

Is Kanjinti preservative-free?

Yes. Kanjinti is supplied as a sterile, preservative-free lyophilized powder in single-dose vials.[2]

Can Kanjinti be mixed with dextrose?

The FDA label directs users to reconstitute and dilute Kanjinti according to specified instructions and warns against using dextrose-containing solutions because of compatibility concerns.[2]

Does Kanjinti contain polysorbate 80?

No. The labeled surfactant is polysorbate 20, not polysorbate 80.[2]

Can a new excipient make a trastuzumab biosimilar interchangeable?

No. Excipient substitution alone does not establish interchangeability. Interchangeability requires a separate FDA determination based on the applicable statutory and regulatory standard.

Is Kanjinti a generic version of Herceptin?

No. Kanjinti is a biosimilar biologic, not a conventional generic drug. It was approved under the FDA’s 351(k) biosimilar pathway and is listed in the Purple Book.[1,3]

References

1. U.S. Food and Drug Administration. (2019, June 13). FDA approves first biosimilar to trastuzumab for treatment of certain breast and stomach cancers. https://www.fda.gov/news-events/press-announcements/fda-approves-first-biosimilar-trastuzumab-treatment-certain-breast-and-stomach-cancers

2. U.S. Food and Drug Administration. (2023). Kanjinti (trastuzumab-anns) prescribing information. Amgen Inc. https://www.accessdata.fda.gov/drugsatfda_docs/label/

3. U.S. Food and Drug Administration. (2024). Purple Book: Database of licensed biological products. https://purplebooksearch.fda.gov/

4. U.S. Food and Drug Administration. (2023). Questions and answers on biosimilar biological products. https://www.fda.gov/drugs/therapeutic-biologics-applications-bla/questions-and-answers-biosimilar-biological-products

5. U.S. Food and Drug Administration. (2023). Trastuzumab products and biosimilar biological products. FDA biosimilar product resources. https://www.fda.gov/drugs/biosimilars/approved-biosimilar-products