List of Excipients in Branded Drug KHAPZORY

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Acrotech Biopharma Inc	KHAPZORY	levoleucovorin	72893-004	MANNITOL	2039-03-25
Acrotech Biopharma Inc	KHAPZORY	levoleucovorin	72893-004	SODIUM HYDROXIDE	2039-03-25
Acrotech Biopharma LLC	KHAPZORY	levoleucovorin	72893-006	MANNITOL	2039-03-25

KHAPZORY Excipient Strategy and Commercial Opportunities

Last updated: August 30, 2026

KHAPZORY is an injectable levoleucovorin calcium product used for methotrexate rescue and in combination with 5-fluorouracil for advanced colorectal cancer. Its commercial profile is driven less by novel excipient protection than by sterile manufacturing, supply reliability, vial economics, preparation time, and compatibility with oncology workflows. The formulation uses a conventional aqueous parenteral platform with sodium chloride, water for injection, and pH adjustment agents. [1]

What is KHAPZORY and how is it formulated?

KHAPZORY contains levoleucovorin calcium, the active pharmacologic isomer of leucovorin. It is administered intravenously and is supplied as a single-dose sterile injection. The labeled product is a clear yellow solution at a concentration of 10 mg/mL. [1]

Attribute	KHAPZORY profile
Active ingredient	Levoleucovorin calcium
Dosage form	Sterile injectable solution
Route	Intravenous
Labeled concentration	10 mg/mL
Commercial vial	175 mg/17.5 mL single-dose vial
Primary indications	Methotrexate rescue; colorectal cancer with 5-fluorouracil
Preservative status	Single-dose, preservative-free injectable presentation
Original sponsor	Spectrum Pharmaceuticals
Current commercial platform	Acrotech Biopharma-related oncology portfolio
FDA approval	NDA 210861, approved in 2018

The inactive ingredients identified in the prescribing information are sodium chloride, sodium hydroxide, hydrochloric acid, and water for injection. Sodium hydroxide and hydrochloric acid are used for pH adjustment rather than as principal formulation excipients. [1]

What excipients are used in KHAPZORY?

KHAPZORY uses a low-complexity excipient system:

Excipient	Function	Commercial relevance
Sodium chloride	Tonicity adjustment	Supports intravenous tolerability and conventional saline-based manufacturing
Water for injection	Vehicle	Standard parenteral solvent
Sodium hydroxide	pH adjustment	Controls product stability and solution properties
Hydrochloric acid	pH adjustment	Fine-tunes final pH during manufacture

The formulation does not rely on a proprietary surfactant, lipid carrier, polymer, cosolvent, preservative, or lyophilized cake-forming system. That reduces excipient-related regulatory complexity but also limits the scope for conventional formulation patenting.

The main technical risks are likely to involve:

• levoleucovorin chemical stability in aqueous solution;
• pH control;
• light sensitivity and solution coloration;
• calcium-salt behavior;
• container-closure compatibility;
• particulate control;
• adsorption to manufacturing and administration surfaces;
• in-use stability after dilution;
• compatibility with 5-fluorouracil and infusion materials.

The label directs healthcare professionals to inspect the solution for particulate matter and discoloration before administration. [1]

What is the best excipient strategy for a KHAPZORY competitor?

The strongest strategy is a platform strategy rather than an attempt to create a materially different excipient composition.

1. Preserve the simple saline-based formulation

A competitor should first evaluate a formulation close to the established product architecture: aqueous levoleucovorin calcium, isotonic sodium chloride, water for injection, and controlled pH. This approach reduces development risk and makes an ANDA or other abbreviated pathway more practical.

A materially different excipient system could create avoidable questions involving:

• comparative stability;
• extractables and leachables;
• local tolerance;
• infusion compatibility;
• dilution behavior;
• new impurity profiles;
• novel excipient justification.

For a mature injectable product, lower formulation complexity generally has greater commercial value than a technically sophisticated excipient package.

2. Use pH and buffer selection as a stability-development lever

A buffer-free or minimally buffered formulation can offer a cleaner regulatory profile, but pH drift may increase during storage or after vial puncture. A buffered product could improve robustness, although the buffer may alter calcium-salt behavior or create compatibility issues.

Potential development programs include:

• optimizing pH within the established clinical range;
• comparing citrate, acetate, phosphate, or histidine systems;
• testing buffer-free versus low-capacity buffered formulations;
• evaluating stability after dilution in common infusion fluids;
• quantifying degradation products under light and thermal stress.

Any buffer-based product would require particular attention to calcium complexation and precipitation risk. A composition that reduces free calcium or changes the levoleucovorin calcium equilibrium could create new analytical and clinical comparability issues.

3. Avoid preservatives unless the delivery model requires them

A multidose presentation could reduce packaging waste but would introduce preservative toxicity, compatibility, sterility, and regulatory burdens. Oncology injectables are commonly supplied in single-dose containers, and the commercial value of a multidose vial is uncertain.

A preservative-free single-dose vial remains the lower-risk design for hospital use.

4. Improve container-closure performance

The most defensible technical differentiation may come from the container-closure system rather than the bulk excipient composition. Development options include:

• low-sorption glass or polymeric containers;
• improved stopper formulations;
• reduced tungsten or metal-particulate exposure;
• light-protective secondary packaging;
• ready-to-withdraw vial geometry;
• smaller-volume high-concentration presentations;
• standardized vial adapters.

These changes can support product-specific patent claims if they produce measurable stability, handling, or administration benefits.

What formulation patents could protect a KHAPZORY follow-on?

The basic sodium chloride and water-for-injection composition is unlikely to provide a strong blocking patent position by itself. A commercially meaningful formulation patent would need a narrower technical feature with demonstrated performance.

Potential claim categories include:

Claim area	Possible protected subject matter
Composition	Defined levoleucovorin concentration, pH, ionic strength, and buffer system
Stability	Reduced degradation under specified temperature or light conditions
Container closure	Specific vial, stopper, coating, or low-sorption combination
Dilution	Stable admixture with specified infusion fluids
Administration	Ready-to-use or reduced-preparation presentation
Manufacturing	Controlled oxygen, light, metal-ion, or particulate conditions
Packaging	Light-protective or temperature-managed packaging configuration
Device	Transfer adapter, syringe system, or closed-system administration kit

A patent strategy should focus on measurable differences, such as longer labeled shelf life, reduced preparation steps, or improved compatibility. Broad claims covering "levoleucovorin in an aqueous solution" would face substantial prior-art risk because injectable folinate formulations are established products.

When does KHAPZORY lose exclusivity?

KHAPZORY does not have biosimilar exclusivity because levoleucovorin is a small-molecule drug, not a biologic. Generic competition proceeds through the ANDA pathway rather than through a biosimilar application.

FDA approval in 2018 did not create a durable new-chemical-entity exclusivity position for levoleucovorin. The active ingredient was already established in the leucovorin market. Any limited clinical-investigation exclusivity associated with the approval would not be expected to remain a primary market barrier.

The commercial exclusivity analysis therefore depends mainly on:

1. active Orange Book listings;
2. remaining listed patent terms;
3. paragraph IV certifications;
4. first-filer status;
5. litigation stays;
6. supply and contracting advantages.

The FDA Orange Book is the controlling public source for listed patents and regulatory exclusivity associated with an approved drug. [2]

What is the Orange Book status of KHAPZORY?

KHAPZORY is an approved small-molecule injectable drug subject to the Orange Book framework. The key diligence issue is whether the product has active listed patents covering:

• the levoleucovorin composition;
• the injectable formulation;
• a method of use for methotrexate rescue;
• use with 5-fluorouracil;
• a specific dosage or administration schedule.

Method-of-use patents may be relevant even when formulation patents are weak. A generic applicant can certify against listed use patents and may seek a label that omits protected indications, subject to FDA requirements and litigation risk.

A current Orange Book review should distinguish:

• patents listed against the KHAPZORY NDA;
• patents listed against other levoleucovorin products;
• patents that have expired;
• patents withdrawn by the sponsor;
• patents that do not cover the proposed generic product;
• use claims that can be carved out of labeling.

The presence of an Orange Book listing does not by itself establish that the patent blocks every generic presentation.

What paragraph IV challenges and litigation risks affect KHAPZORY?

A generic levoleucovorin applicant could submit an ANDA with a paragraph IV certification if it determines that a listed patent is invalid, unenforceable, or not infringed. The patent holder could then file an infringement action within 45 days, potentially triggering a 30-month FDA approval stay under the Hatch-Waxman framework. [3]

The main litigation issues would likely be:

• whether the proposed injectable composition falls within the asserted claims;
• whether the applicant's pH and excipient ranges are materially different;
• whether the generic label induces use for a patented indication;
• whether the patent claims are anticipated by earlier leucovorin products;
• whether the asserted patent is invalid for obviousness;
• whether the patent is enforceable after Orange Book listing and regulatory-history review.

Because KHAPZORY uses conventional excipients, a generic applicant may have credible non-infringement positions if it uses different pH-adjustment ranges, container systems, or formulation parameters. The sponsor's strongest claims would likely be narrow claims tied to stability, packaging, or a specific manufacturing process.

What commercial opportunities exist in KHAPZORY excipients and delivery?

The principal opportunities are product improvements that lower hospital handling costs or reduce drug waste.

Ready-to-use presentations

A ready-to-use, high-concentration vial can reduce dilution steps, pharmacy labor, and preparation errors. The 10 mg/mL injectable concentration already supports relatively compact packaging, but additional presentations could improve dose matching.

Potential formats include:

• 50 mg or 100 mg smaller vials;
• 175 mg commercial vial optimization;
• prefilled syringes for controlled institutional use;
• premixed infusion bags;
• closed-system transfer-compatible packaging.

The economics depend on dose distribution, pharmacy workflow, and wastage. A smaller vial can improve dose utilization but raise packaging and manufacturing costs.

Extended in-use stability

Hospitals value products that remain stable after dilution or controlled-temperature storage. A competitor that demonstrates longer in-use stability in common diluents could obtain formulary preference, particularly if the data support pharmacy batching.

The evidence package should cover:

• concentration ranges;
• diluents;
• bags and syringes;
• temperature;
• light exposure;
• microbial hold times;
• assay and impurity limits;
• visible and subvisible particles.

Supply-chain differentiation

Injectable oncology products are exposed to recurring manufacturing shortages. A supplier with dual fill-finish sites, redundant active-ingredient sourcing, and reliable hospital allocation can compete even without a superior formulation.

Commercial differentiation may include:

• domestic or regional fill-finish;
• dual-source packaging components;
• inventory buffers;
• predictable allocation policies;
• smaller minimum order quantities;
• direct-to-hospital contracting;
• group purchasing organization participation.

Low-waste packaging

Levoleucovorin is often used according to body-surface-area dosing. Fixed vial sizes can generate residual product. A two-size vial portfolio may reduce waste more effectively than a new excipient system.

The commercial case should quantify:

• average residual volume per dose;
• vial sharing restrictions;
• pharmacy batch size;
• discarded drug value;
• packaging cost;
• cold-chain and storage requirements.

How does KHAPZORY compare with competing levoleucovorin products?

KHAPZORY competes with other levoleucovorin calcium injections and with conventional leucovorin products. The competitive distinction is usually based on product availability, concentration, vial size, price, and contracting rather than on pharmacologic differentiation.

Competitive factor	KHAPZORY implication
Active ingredient	Limited differentiation among levoleucovorin products
Excipient system	Conventional and potentially replicable
Dosage form	Injectable, suitable for oncology infusion settings
Patent barrier	More likely to depend on narrow formulation or use claims
Generic risk	Meaningful once ANDA approvals and supply capacity develop
Biosimilar risk	Not applicable
Hospital preference	Driven by price, supply continuity, vial utilization, and handling
Formulation opportunity	Stability, packaging, ready-to-use delivery, and waste reduction

Traditional leucovorin may compete in some clinical settings, but it is not a direct substitute in every prescribing context because levoleucovorin contains the active isomer and has different dosing conventions.

What manufacturing and intellectual-property barriers exist?

The principal barriers are operational rather than excipient-related.

Manufacturing barriers

A commercial entrant must control:

• sterile compounding;
• aseptic fill-finish;
• endotoxin and particulate limits;
• calcium-salt raw-material quality;
• pH reproducibility;
• light and oxygen exposure;
• container-closure integrity;
• analytical methods for degradation products;
• process validation;
• stability data across the proposed shelf life.

Injectable manufacturing failures can eliminate the commercial value of an otherwise approvable product.

Intellectual-property barriers

Potential IP barriers include:

• formulation patents;
• container-closure patents;
• use patents;
• process patents;
• device patents;
• trade secrets involving impurity control or fill-finish conditions;
• supplier agreements for specialized packaging.

Trade-secret protection may be more relevant than composition patents where the formulation is simple and the manufacturing process controls product quality.

What is the revenue exposure and generic launch risk?

KHAPZORY revenue is exposed to generic entry because the product has a conventional small-molecule injectable formulation and no biosimilar barrier. The largest price erosion risk would arise if multiple ANDA applicants obtain approval and have adequate sterile manufacturing capacity.

Launch scenarios are:

Scenario	Market effect
One approved generic	Moderate price pressure; sponsor may retain share through contracting
Two or more reliable generics	Greater price erosion and hospital tender competition
Generic approval during supply shortage	Limited immediate erosion if supply is constrained
Label carve-out for a patented use	Partial competition by indication
Differentiated ready-to-use product	Potential premium in high-throughput oncology centers
Manufacturing disruption	Temporary share shifts toward available suppliers

The revenue impact depends on net price, hospital channel mix, vial wastage, wholesaler inventory, and whether competitors can maintain uninterrupted supply. Public revenue estimates should be based on company filings and audited market data rather than prescription volume alone.

Key Takeaways

• KHAPZORY uses a conventional aqueous injectable platform based on levoleucovorin calcium, sodium chloride, water for injection, and pH-adjustment agents.
• The formulation has limited standalone excipient differentiation.
• The strongest commercial opportunities are ready-to-use delivery, optimized vial sizes, extended in-use stability, low-waste packaging, and supply reliability.
• A follow-on product should prioritize formulation simplicity and sterile-manufacturing control.
• Formulation patents are more likely to succeed when tied to defined stability, container-closure, dilution, or manufacturing performance.
• KHAPZORY has small-molecule generic risk, not biosimilar risk.
• Orange Book patents, paragraph IV certifications, litigation stays, and use-label carve-outs determine the practical timing of generic entry.
• Hospital purchasing decisions are likely to emphasize price, availability, vial utilization, and pharmacy workflow.

FAQs

Can KHAPZORY be reformulated with a different buffer?

Yes, but a different buffer could affect calcium compatibility, pH stability, degradation, particulate formation, and ANDA comparability. A buffer change is commercially useful only if it produces a measurable stability or handling advantage.

Is KHAPZORY a preservative-free injectable?

The labeled presentation is a single-dose injectable and does not rely on a conventional antimicrobial preservative system. [1]

Can a competitor patent a smaller KHAPZORY vial?

A smaller vial alone may be difficult to protect broadly. Patentability would be stronger if the vial size is linked to reduced waste, improved stability, a specific concentration, or a validated administration benefit.

Are levoleucovorin products eligible for biosimilar approval?

No. Levoleucovorin is a small-molecule drug. Competing products generally use the ANDA pathway rather than the biosimilar pathway.

What is the most attractive commercial improvement for KHAPZORY?

The most practical opportunity is a low-waste, ready-to-use injectable presentation supported by strong dilution stability and dependable supply. That proposition directly addresses oncology pharmacy costs without introducing unnecessary excipient complexity.

References

1. U.S. Food and Drug Administration. (2018). KHAPZORY (levoleucovorin) injection, prescribing information.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Food and Drug Administration. (2017). Guidance for industry: 180-day exclusivity when multiple ANDA applicants are eligible for 180-day exclusivity.