Details for Patent: 10,413,569

Which drugs does patent 10,413,569 protect, and when does it expire?

Patent 10,413,569 protects LOKELMA and is included in one NDA.

This patent has fifty-two patent family members in thirty-two countries.

Summary for Patent: 10,413,569

Title:	Microporous zirconium silicate for the treatment of hyperkalemia
Abstract:	The present invention relates to novel microporous zirconium silicate compositions that are formulated to remove toxins, e.g. potassium ions, from the gastrointestinal tract at an elevated rate without causing undesirable side effects. The preferred formulations are designed avoid increase in pH of urine in patients and/or avoid potential entry of particles into the bloodstream of the patient. Also disclosed is a method for preparing high purity crystals of UZSi-9 exhibiting an enhanced level of potassium exchange capacity. These compositions are particularly useful in the therapeutic treatment of hyperkalemia.
Inventor(s):	Donald Jeffrey Keyser, Alvaro F. GUILLEM
Assignee:	ZS Pharma Inc
Application Number:	US14/692,287
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 10,413,569
Patent Claim Types: see list of patent claims	Composition; Compound;

US Patent 10,413,569: Claim Scope, ZS-9 Protection, Expiration and Patent Landscape

US Patent 10,413,569 protects specific particulate zirconium silicate compositions associated with ZS-9, the active pharmaceutical ingredient in Lokelma (sodium zirconium cyclosilicate). Its core limitations are approximately 3-angstrom microporosity, selective potassium-exchange capacity of at least 1.7 mEq/g, sodium content below 12% by weight, and defined particle-size distributions in certain claims. The patent is composition-focused rather than method-of-treatment focused.

The patent creates infringement risk for a competing zirconium-silicate product that reproduces the claimed chemical structure and measured performance characteristics, even if the product is manufactured by a different process. It does not, by itself, cover every potassium binder, every zirconium silicate, or every formulation containing sodium zirconium cyclosilicate.

What does US Patent 10,413,569 cover?

US Patent 10,413,569 covers particulate zirconium silicate compositions with a defined microporous structure and potassium-exchange performance. The patent identifies the covered material through both structural and functional limitations.

The principal limitations are:

Limitation	Claims 1-7	Claims 8-9	Claims 10-14
Particulate zirconium silicate	Yes	Yes	Yes
Uniform microporosity	Yes	Yes	Yes
Approximately 3 Å pore diameter	Yes	Yes	Not expressly stated in claim 10
Selective potassium exchange capacity	At least 1.7 mEq/g	At least 1.7 mEq/g	1.7-3.7 mEq/g
Sodium content	Below 12% by weight	Below 12% by weight	Below 12% by weight
Defined zirconium-silicate formula	Yes	Yes	Yes
Median particle size above 3 microns	No	Yes	Claims 11-12
Particles below 3 microns	Not specified	Less than 7%, or less than 3% in claim 9	Less than 7%, or less than 3% in claim 12
ZS-9 expressly recited	Claim 5	No	Claim 13

The patent uses the formula:

ApMxZr1-xSinGeyOm

The formula permits a broad range of exchangeable cations and framework metals. The claim set allows potassium, sodium, rubidium, cesium, calcium, magnesium, hydronium, or mixtures as the exchangeable species. It also permits framework metals including hafnium, tin, niobium, titanium, cerium, germanium, praseodymium, and terbium.

The broad chemical formula is narrowed by the performance requirements. A product must satisfy the claimed pore, capacity, and sodium-content limitations to fall within the independent claims.

How do the independent claims differ?

Claim 1

Claim 1 is the broadest independent claim in the patent. It requires:

1. A particulate zirconium silicate composition.
2. Uniform microporosity with a pore diameter of approximately 3 angstroms.
3. Selective potassium-exchange capacity of at least 1.7 mEq/g.
4. Sodium content below 12% by weight.
5. The specified zirconium-silicate formula.

Claims 2 through 7 narrow claim 1 by adding capacity ranges, lower sodium content, or the ZS-9 designation.

Claim 1 is potentially important because it does not require a particular particle-size distribution. A competing product could avoid claims 8 and 10-14 by using a different particle-size profile while still facing claim 1 if the pore, sodium, capacity, and chemical-formula limitations are met.

Claim 8

Claim 8 adds particle-size limitations to the composition of claim 1. The median particle size must be greater than 3 microns, and less than 7% of the particles may have a diameter below 3 microns.

Claim 9 further tightens the sub-3-micron fraction to less than 3%.

These claims are directed to a particle-engineering profile intended to control handling, dispersion, gastrointestinal delivery, and potentially tolerability. They create a more measurable infringement screen because particle-size distributions can be tested using laser diffraction, microscopy, or related analytical methods.

Claim 10

Claim 10 covers a zirconium silicate composition with a potassium-exchange capacity from 1.7 to 3.7 mEq/g and sodium content below 12% by weight. It does not expressly include the approximate 3-angstrom pore-diameter limitation stated in claim 1, although it retains the uniform-microporosity requirement.

Claims 11 and 12 add the particle-size limitations. Claim 13 identifies ZS-9, and claim 14 reduces sodium content below 9% by weight.

The supplied text for claim 10 contains the expression "1≤+y≤12." The chemically coherent limitation is likely "1≤n+y≤12," consistent with the formula in claims 1 and 8. The issued patent text, not a transcription, should control claim construction.

What is the technical scope of the ZS-9 claims?

ZS-9 is a crystalline sodium zirconium cyclosilicate material with a molecular sieve-like pore structure. Its approximately 3-angstrom pores preferentially exchange potassium ions while limiting the movement of larger ions. The commercial product is supplied as sodium zirconium cyclosilicate and is marketed as Lokelma.

The claims do not rely solely on the trade name ZS-9. Most of the claim scope comes from measurable physical and chemical properties:

• Pore diameter of approximately 3 angstroms.
• Uniform microporosity.
• Selective potassium-exchange capacity.
• Low sodium content.
• Particle-size distribution.
• The zirconium-silicate framework formula.

Claim 5 and claim 13 expressly recite ZS-9, but a competitor could still infringe broader claims without using the ZS-9 label if its product meets the claimed characteristics.

What patents protect Lokelma and sodium zirconium cyclosilicate?

Lokelma protection is distributed across multiple patent families covering the active ingredient, compositions, particle engineering, manufacturing, and therapeutic use. US Patent 10,413,569 is one composition patent within that broader estate.

Representative patents associated with sodium zirconium cyclosilicate and Lokelma include:

Patent	General subject matter	Relevance
US 8,877,497	Zirconium silicate compositions and related uses	Foundational composition and therapeutic platform
US 9,561,197	Zirconium silicate composition technology	Composition and performance characteristics
US 9,956,189	Sodium zirconium cyclosilicate-related compositions and uses	Product and formulation protection
US 10,413,569	Particulate zirconium silicate with defined porosity, potassium exchange, sodium content, and particle size	Directly relevant to ZS-9 composition scope
US 10,500,208	Additional zirconium-silicate product protection	Related commercial product protection

The precise Orange Book listing for Lokelma must be evaluated patent by patent because not every patent in the broader family necessarily has the same FDA listing status. The FDA Orange Book identifies patents submitted for approved drug products, while the patent specification and prosecution history determine the enforceable claim scope.[1]

When does US Patent 10,413,569 lose exclusivity?

The patent has a nominal 20-year term measured from the earliest effective nonprovisional filing date in its priority chain. Based on the patent family chronology, the nominal expiration is in December 2035, subject to any patent-term adjustment, patent-term extension, terminal disclaimer, or other term calculation appearing in the official USPTO record.[2]

Event	Date or period
Patent family priority	2014
US patent grant	October 8, 2019
Nominal statutory term	Approximately 20 years from the effective nonprovisional filing date
Nominal expiration	December 2035
FDA approval of Lokelma	May 18, 2018
Product exclusivity	Separate from patent term and governed by FDA exclusivity rules

The patent’s expiration does not necessarily mark the earliest possible generic launch date. A generic applicant could launch before expiration if it obtains a favorable court decision, reaches a settlement with the patent owner, or successfully certifies that its product does not infringe.

What is the Orange Book status of US Patent 10,413,569?

US Patent 10,413,569 is associated with Lokelma, whose approved active ingredient is sodium zirconium cyclosilicate. The Orange Book status should be checked against the current FDA listing because patent submissions, delistings, and product-specific listing information can change over time.[1]

The key regulatory point is that US 10,413,569 is a drug-substance or drug-product composition patent, not merely a method-of-use patent. A Paragraph IV certification against this type of patent would challenge the patent protection for the product itself.

The patent does not automatically block every abbreviated new drug application. An ANDA applicant can avoid infringement through a formulation, particle-size distribution, composition, or manufacturing design that falls outside every asserted claim. The applicant must also address any other unexpired Orange Book patents listed for Lokelma.

What Paragraph IV challenges or litigation affect US 10,413,569?

A Paragraph IV challenge would be the principal pathway for an ANDA applicant seeking approval before patent expiration. The relevant certification could assert that:

• The patent is invalid.
• The patent is unenforceable.
• The proposed generic does not infringe.

The 30-month stay under the Hatch-Waxman framework depends on the timing of the patent-owner litigation and the filing of the ANDA notice. The stay is not an automatic extension of the patent term.

For this patent, likely litigation issues would include:

Claim construction

The parties would likely dispute:

• The meaning of "uniform microporosity."
• The scope of "about 3 angstroms."
• The testing method for potassium-exchange capacity.
• Whether sodium content is measured on a dry basis or another specified basis.
• The meaning of "selective potassium exchange capacity."
• The effect of the "x is 0 or approaching 0" language.
• The particle-size measurement method used to determine the 3-micron thresholds.

Infringement testing

A patent owner would likely test an accused product for:

• Crystal structure and pore size.
• Elemental composition.
• Sodium loading.
• Potassium-exchange capacity.
• Median particle size.
• Percentage of particles below 3 microns.

Validity defenses

Potential defenses could include anticipation or obviousness based on earlier zirconium silicate compositions, lack of written description for the full formula and performance range, indefiniteness of relative terms such as "about" and "uniform," and enablement of the broad framework-metal and cation ranges.

The combination of structural and functional limitations strengthens the patent against a simple prior-art composition but gives an accused generic multiple avenues for noninfringement.

How strong is the patent estate for ZS-9?

US 10,413,569 has moderate-to-strong product-level relevance because it targets characteristics closely associated with the commercial ZS-9 material. Its strength depends on whether a generic product can reproduce the potassium-binding function without satisfying the claimed pore and composition parameters.

Strength factor	Assessment
Direct coverage of ZS-9	Strong through claims 5 and 13
Broad chemical formula	Broad, but constrained by performance limitations
Functional capacity limitation	Useful for infringement, but dependent on testing methodology
Particle-size claims	Narrower but analytically objective
Sodium-content limits	Objective and relatively easy to test
Manufacturing-process protection	Limited in these claims
Method-of-use protection	Not the focus of this patent
Design-around potential	Meaningful through particle size, sodium loading, pore structure, or capacity
Biosimilar barrier	Not applicable; product is a small-molecule/inorganic drug
Generic challenge pathway	ANDA with Paragraph IV or post-expiration filing

The patent is stronger against a copy of sodium zirconium cyclosilicate than against a chemically distinct potassium binder. It is less likely to block patiromer, sodium polystyrene sulfonate, or an unrelated ion-exchange resin because those products do not use the claimed zirconium-silicate framework.

How does Lokelma compare with competing potassium binders?

Product	Active ingredient	Technology	Regulatory pathway	Main IP risk
Lokelma	Sodium zirconium cyclosilicate	Inorganic crystalline ion exchanger	NDA	ZS-9 composition, formulation, manufacturing, and use patents
Veltassa	Patiromer sorbitex calcium	Organic polymer ion exchanger	NDA	Patiromer composition, formulation, and use patents
Kayexalate and generic sodium polystyrene sulfonate	Sodium polystyrene sulfonate	Organic resin	Legacy drug product	Older product and formulation rights
Emerging potassium binders	Varies	Product-specific	NDA or other pathway	Depends on molecular and formulation platform

Lokelma and Veltassa compete clinically in chronic hyperkalemia, but their patent estates are technically separate. A Veltassa generic does not ordinarily create direct infringement risk under US 10,413,569.

What generic launch scenarios exist?

Launch after patent expiration

This is the lowest-risk pathway if all Orange Book patents have expired and regulatory exclusivities have ended.

Paragraph IV launch

An ANDA applicant may challenge US 10,413,569 before expiration. The applicant would need a claim-by-claim noninfringement or invalidity position and could face a 30-month stay if the patent owner files an infringement action within the statutory period.

Design-around launch

A competing zirconium-based binder could attempt to avoid infringement by changing one or more of the following:

• Pore diameter.
• Microporosity uniformity.
• Sodium loading.
• Potassium-exchange capacity.
• Particle-size distribution.
• Framework-metal composition.
• Exchangeable cation profile.

A successful design-around must avoid all asserted claims, not merely claims 8-14.

Authorized generic or settlement launch

A settlement could establish an agreed launch date before patent expiration. A licensing arrangement or authorized generic agreement could also reduce litigation exposure, although the commercial terms would require antitrust and regulatory review.

Are biosimilar risks relevant to Lokelma?

No. Lokelma is not a biologic and is not subject to the biosimilar pathway under the Public Health Service Act. The relevant competitive pathway is an ANDA for a generic version of sodium zirconium cyclosilicate, subject to Hatch-Waxman certifications and FDA requirements.

The main barriers are pharmaceutical equivalence, bioequivalence or applicable product-specific requirements, control of the crystalline material, particle-size reproducibility, impurity limits, and patent clearance.

What manufacturing and IP barriers matter most?

The commercial difficulty is not limited to reproducing the chemical formula. A generic manufacturer would need to control:

• Crystallinity and phase purity.
• Pore-size distribution.
• Sodium content.
• Potassium-exchange performance.
• Particle-size distribution.
• Residual process impurities.
• Batch-to-batch uniformity.
• Stability and packaging.
• The finished dosage form and inactive ingredients.

Manufacturing know-how may create a practical barrier even where patent claims can be designed around. Trade secrets, process patents, supplier qualification, and analytical methods can extend the commercial advantage beyond the expiration of US 10,413,569.

What is the commercial exposure associated with this patent?

Lokelma is a material AstraZeneca product in the chronic hyperkalemia market. AstraZeneca reported Lokelma sales in the hundreds of millions of dollars annually in recent reporting periods.[3] The economic exposure from US 10,413,569 is therefore tied to the timing of generic entry, not only to the legal validity of the individual claims.

The most significant risk is a successful generic challenge that clears US 10,413,569 while other Lokelma patents do not independently block launch. Conversely, a generic may prevail against this patent but remain delayed by another unexpired composition, formulation, method-of-use, or manufacturing patent.

Key Takeaways

• US 10,413,569 is a product-composition patent directed to particulate zirconium silicate associated with ZS-9.
• The central limitations are approximately 3-angstrom microporosity, potassium-exchange capacity, low sodium content, and a defined zirconium-silicate formula.
• Claims 8-14 add particle-size and narrower capacity limitations.
• Claims 5 and 13 expressly identify ZS-9, but broader claims may capture equivalent products without that label.
• The nominal patent term extends into December 2035.
• Lokelma is subject to a broader patent estate; clearance requires reviewing every unexpired Orange Book-listed patent.
• Biosimilar analysis is irrelevant because sodium zirconium cyclosilicate is not a biologic.
• A generic applicant’s strongest strategies are Paragraph IV litigation and design-around using pore structure, sodium loading, potassium capacity, or particle-size differences.
• The decisive technical disputes are likely to involve analytical testing, claim construction, and whether the accused product satisfies the functional limitations.

FAQs

Is US 10,413,569 a method-of-treatment patent?

No. The claims supplied are composition claims. They do not principally require administering zirconium silicate to a patient or treating hyperkalemia.

Does using a different manufacturing process avoid infringement?

No. A different process does not avoid a composition claim if the resulting product satisfies every limitation of an asserted claim.

Can a zirconium-silicate product avoid the patent by changing sodium content?

Potentially, but only if the change places the product outside all asserted claims. Claims 1-13 require sodium below 12% by weight, while claim 14 requires sodium below 9% by weight.

Is ZS-9 itself a patentable chemical name?

ZS-9 is a designation for a zirconium-silicate material. The enforceable scope comes from the patent claims, not from the trade designation alone.

What is the most important evidence in a US 10,413,569 dispute?

The key evidence would be validated analytical data for pore structure, potassium-exchange capacity, sodium content, chemical composition, and particle-size distribution, combined with the patent’s prosecution history and the accused product’s manufacturing records.

References

1. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov
2. United States Patent and Trademark Office. (2019). U.S. Patent No. 10,413,569, zirconium silicate compositions and methods of use thereof.
3. AstraZeneca PLC. (2024). Annual report and Form 20-F. https://www.astrazeneca.com
4. U.S. Food and Drug Administration. (2018). FDA approves Lokelma for treatment of hyperkalemia. https://www.fda.gov
5. U.S. Food and Drug Administration. (2024). Lokelma prescribing information. AstraZeneca Pharmaceuticals LP.

Drugs Protected by US Patent 10,413,569

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Astrazeneca	LOKELMA	sodium zirconium cyclosilicate	FOR SUSPENSION;ORAL	207078-001	May 18, 2018	AB	RX	Yes	No	10,413,569			Y
Astrazeneca	LOKELMA	sodium zirconium cyclosilicate	FOR SUSPENSION;ORAL	207078-002	May 18, 2018	AB	RX	Yes	Yes	10,413,569			Y

International Family Members for US Patent 10,413,569

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	2673237		300976	Netherlands
European Patent Office	2673237		LUC00111	Luxembourg
European Patent Office	2673237		PA2019010	Lithuania
European Patent Office	2673237		CA 2019 00014	Denmark
European Patent Office	2673237		122019000036	Germany