Details for Patent: 11,992,530

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Which drugs does patent 11,992,530 protect, and when does it expire?

Patent 11,992,530 protects PEDMARK and is included in one NDA.

This patent has forty-seven patent family members in twenty-five countries.

Summary for Patent: 11,992,530

Title:	Therapeutic uses for sodium thiosulfate and formulations
Abstract:	Described herein is anhydrous sodium thiosulfate, methods for synthesizing anhydrous sodium thiosulfate, pharmaceutical compositions thereof, and methods of treating ototoxicity. Anhydrous sodium thiosulfate is synthesized from sodium sulfite, sulfur, and cetylpyridinium chloride. The anhydrous sodium thiosulfate is formulated into a pharmaceutical composition comprising a buffer and solvent. These compositions are useful for eliminating or reducing ototoxicity in pediatric patients receiving platinum-based chemotherapeutics.
Inventor(s):	Alexander Smith
Assignee:	Ads Pharma Consulting LLC , Fennec Pharn Ceuticals Inc , Avista Pharma Solutions Inc , Fennec Pharmaceuticals Inc
Application Number:	US17/992,707
Patent Claim Types: see list of patent claims	Use; Composition;

U.S. Patent 11,992,530: Claim Scope, Patent Strength, Orange Book Risk, and Generic Entry Analysis

U.S. Patent No. 11,992,530 protects a narrow method of using an aqueous sodium thiosulfate formulation to reduce cisplatin-related ototoxicity. The independent claim requires all of the following: a human cancer patient, a platinum-based chemotherapeutic, sodium thiosulfate at about 0.5 M, borate ions below 0.05%, and administration for ototoxicity reduction. Dependent claims narrow the method by adding pH ranges, hydrochloric acid or sodium hydroxide, pediatric age groups, cisplatin timing, infusion parameters, and specific pediatric cancers.

The patent is strongest against use of a qualifying sodium thiosulfate product in pediatric patients receiving cisplatin under the claimed six-hour post-treatment protocol. It is weaker against products with materially different sodium thiosulfate concentration, borate content, pH, timing, or administration instructions.

What does U.S. Patent 11,992,530 cover?

The patent covers a treatment method, not sodium thiosulfate as a chemical compound. Claim 1 requires a pharmaceutical composition comprising:

Required element	Claim limitation
Patient	Human patient
Disease context	Cancer sensitive to a platinum-based chemotherapeutic
Chemotherapy	Platinum-based chemotherapeutic
Therapeutic objective	Reduction of ototoxicity
Active pharmaceutical ingredient	Aqueous anhydrous sodium thiosulfate
Concentration	About 0.5 M
Borate content	Less than 0.05%
Administration	An effective amount of the composition

A competitor does not avoid the patent merely by using a different trade name. The relevant questions are whether its product and clinical instructions satisfy the concentration, borate, timing, patient, and therapeutic-use limitations.

The claim language also creates several potential construction issues:

1. Whether “about 0.5 M” covers a range materially above or below 0.5 M.
2. Whether “less than 0.05%” refers to weight/volume, weight/weight, molar concentration, or another analytical basis.
3. Whether “aqueous anhydrous sodium thiosulfate” distinguishes the dissolved sodium thiosulfate from hydrated solid forms used in manufacturing.
4. Whether the composition must be administered specifically to reduce ototoxicity or whether that purpose is satisfied by the treatment context.
5. Whether the platinum-based chemotherapy must be administered before the sodium thiosulfate in every embodiment.

These issues would materially affect infringement and validity analysis.

How do claims 1 through 6 protect the formulation and pH?

Claims 1 through 6 establish the core formulation and pH hierarchy.

Claim	Added limitation
1	Approximately 0.5 M sodium thiosulfate and borate below 0.05%
2	Hydrochloric acid
3	Sodium hydroxide
4	pH about 5 to about 9.5
5	pH about 6.5 to about 8.9
6	pH about 8.6 to about 8.8

Claim 1 is the broadest formulation claim. Claims 2 and 3 identify pH-adjusting agents. Claims 4 through 6 create nested pH ranges.

The pH claims have a conventional narrowing structure:

• Claim 4 covers the broadest pH range.
• Claim 5 narrows the range.
• Claim 6 is limited to a tight alkaline range.

A formulation with pH 8.7 would potentially satisfy claims 4, 5, and 6, assuming the other limitations are met. A formulation with pH 7.0 could potentially satisfy claims 4 and 5 but not claim 6.

The hydrochloric-acid and sodium-hydroxide claims may be difficult to enforce if those agents are present only as manufacturing residues or are not identified in the commercial product specification. Their relevance will depend on how the claims define “comprises” and whether the accused product contains the claimed components in detectable or functional amounts.

What pediatric uses are protected by the patent?

Claims 7 through 26 create a pediatric-use subgenus. Claim 7 covers a pediatric patient, while claim 8 limits the patient to five years of age or younger.

The claims separately identify:

• Pediatric patients generally
• Patients five or fewer years of age
• Cisplatin treatment
• Cisplatin infusion over one to six hours
• Sodium thiosulfate administration approximately six hours after cisplatin completion
• Sodium thiosulfate infusion over approximately 15 minutes
• Hepatoblastoma
• Medulloblastoma
• Neuroblastoma
• Osteosarcoma
• Localized cancer
• Disseminated cancer
• Germ cell tumors
• Testicular cancer
• Ovarian cancer

Claims 18 through 26 are disease-specific dependent claims. They do not expand the patent beyond the limitations of claim 7. Each still requires a pediatric patient and the claim 1 formulation.

The most commercially relevant sequence is claims 7, 14, 16, and 17:

1. Pediatric patient.
2. Cisplatin.
3. Sodium thiosulfate approximately six hours after cisplatin completion.
4. Sodium thiosulfate infusion over approximately 15 minutes.

That sequence tracks the clinical-use profile of sodium thiosulfate products developed for pediatric cisplatin ototoxicity prevention.

What is the strongest infringement position under Patent 11,992,530?

The strongest infringement case would involve a product and label containing the following elements:

Infringement factor	Strong-match scenario
Patient	Pediatric oncology patient
Chemotherapy	Cisplatin
Timing	Approximately six hours after cisplatin ends
Administration	Approximately 15-minute infusion
Composition	Approximately 0.5 M sodium thiosulfate
Borate	Below 0.05%
pH	Between 8.6 and 8.8
Indication	Prevention or reduction of cisplatin ototoxicity
Cancer	One of the cancers listed in claims 18-26

A generic or follow-on product could avoid literal infringement by changing one or more limitations, such as:

• Using a sodium thiosulfate concentration outside the court-recognized scope of “about 0.5 M.”
• Using a formulation with borate at or above 0.05%.
• Using a pH outside the claimed ranges.
• Administering the product at a materially different time.
• Omitting pediatric ototoxicity from the label.
• Limiting use to adult patients or non-cisplatin platinum therapy.
• Using a different infusion duration.

Label changes do not automatically eliminate infringement risk. A product may face induced-infringement allegations if the manufacturer’s prescribing information, promotional materials, clinical protocols, or distribution practices encourage the claimed use. The Federal Circuit’s induced-infringement framework generally focuses on whether the accused party knowingly encouraged acts constituting infringement, not merely whether the product has substantial noninfringing uses. [4]

When does U.S. Patent 11,992,530 expire?

The patent’s expiration date cannot be calculated from the claims alone. U.S. utility patents generally expire 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and priority claims. [2]

The grant date does not establish the expiration date. The relevant record includes:

• Earliest effective nonprovisional filing date
• Continuation or divisional status
• Patent-term adjustment
• Patent-term extension
• Terminal disclaimer
• Patent-family priority documents

For commercial diligence, the expiration date should be taken from the USPTO Patent Center record and reconciled against any FDA Orange Book listing. An Orange Book-listed patent may have a different practical significance from a patent that is not listed, particularly for an ANDA applicant deciding whether to file a Paragraph IV certification.

What is the Orange Book status of Patent 11,992,530?

The claims are directed to a method of reducing cisplatin-related ototoxicity. That type of patent may be eligible for Orange Book listing if it claims an approved method of using the drug and is submitted in accordance with FDA listing requirements. However, the patent number and claim text alone do not establish that FDA has listed the patent for a particular reference product.

For a listed drug, Orange Book consequences depend on:

• The reference listed drug
• The approved labeling
• The patent-use code
• The listing date
• Whether the patent claims an approved method of use
• Whether the patent is product-specific or applies to a broader use

An ANDA applicant must assess whether its proposed labeling overlaps the relevant patent-use code. A Paragraph IV certification may trigger patent litigation under the Hatch-Waxman framework. [1, 3]

A method-of-use patent generally does not block an ANDA applicant from receiving approval for a noninfringing use if the applicant can carve out the patented indication or dosing instructions. The commercial value of the patent therefore depends heavily on whether the patented use is central to the product’s FDA labeling.

How does the patent relate to Pedmark and sodium thiosulfate products?

Pedmark is an FDA-approved sodium thiosulfate product for reducing the risk of ototoxicity associated with cisplatin in pediatric patients with localized or disseminated solid tumors. FDA approved Pedmark in 2022 for pediatric patients at least one month of age, subject to the product labeling and clinical-use conditions. [5]

The patent claims align closely with the clinical attributes associated with pediatric sodium thiosulfate treatment:

• Pediatric oncology use
• Cisplatin exposure
• Administration after completion of cisplatin
• Ototoxicity reduction
• Short sodium thiosulfate infusion
• Specific formulation and pH characteristics

That alignment increases the practical value of the patent if the commercial product satisfies the claimed concentration and borate limitations. It also creates a potential design-around pathway if a competing product uses a different formulation while preserving the same therapeutic mechanism.

The patent does not appear, from the supplied claims, to cover every sodium thiosulfate use. It does not expressly claim:

• Adult cisplatin patients
• Non-oncology uses
• Non-ototoxicity indications
• Sodium thiosulfate as a standalone composition without the claimed use
• All concentrations of sodium thiosulfate
• All pH levels
• All platinum agents without the claim 1 formulation limitations

How strong is the patent estate?

Patent strength depends on claim breadth, written-description support, prosecution history, prior art, and overlap with the approved product.

Strengths

The patent has several commercially relevant strengths:

1. The core claim combines formulation and clinical-use limitations.
2. The pediatric claims track a defined oncology population.
3. The cisplatin timing claims are operationally specific.
4. The claims cover both broad and narrow pH ranges.
5. The disease-specific claims provide fallback positions if broader pediatric claims are challenged.
6. A product label may supply direct evidence of intended use.

Weaknesses

The principal weaknesses are:

1. Claim 1 is narrow because it requires both approximately 0.5 M sodium thiosulfate and borate below 0.05%.
2. The claims depend on potentially contestable analytical terms, particularly “about 0.5 M” and “less than 0.05%.”
3. A formulation or label design-around may be possible.
4. Method claims generally require proof that the claimed steps occurred.
5. The six-hour and 15-minute limitations may not match every clinical protocol.
6. Prior art involving sodium thiosulfate for cisplatin otoprotection could create obviousness or anticipation issues, depending on the precise formulation and timing disclosures.

The patent is likely more valuable as a product-specific enforcement asset than as a broad platform patent.

Which companies could challenge the patent?

Potential challengers would include:

• Generic sodium thiosulfate manufacturers.
• Oncology injectable companies developing a competing product.
• Sponsors seeking an ANDA for a product referencing the approved sodium thiosulfate product.
• Companies developing alternative otoprotective agents.
• Contract manufacturers supplying a competing formulation.

A generic applicant could challenge through a Paragraph IV certification if the patent is listed in the Orange Book against the relevant reference product. The applicant could assert:

• Anticipation.
• Obviousness.
• Lack of written description.
• Lack of enablement.
• Indefiniteness of concentration or borate terms.
• Noninfringement based on formulation or label differences.

An inter partes review could also be considered for eligible patent claims, although method-of-treatment claims may present a different strategic profile from composition claims. [6]

No litigation, settlement, or Paragraph IV challenge should be treated as established solely from the supplied claims. Those facts require review of PACER, USPTO Patent Center, FDA Orange Book records, and the relevant company disclosures.

What generic launch scenarios exist?

Scenario	Regulatory path	Patent exposure
Full pediatric ototoxicity label	ANDA or 505(b)(2), depending on product	Highest risk
Pediatric label with timing outside six hours	ANDA or 505(b)(2)	Reduced risk under claims 16-17
Different pH formulation	ANDA or 505(b)(2)	Potential design-around
Different concentration	ANDA or 505(b)(2)	Potential design-around, subject to “about” construction
Label carve-out for patented use	ANDA with section viii statement	Potentially lower risk
Non-ototoxicity sodium thiosulfate use	Separate development path	Outside the principal claim focus
Adult-only use	ANDA or 505(b)(2)	Avoids pediatric-only claims, but not claim 1 if other limitations are met

A carve-out is commercially difficult if the approved product’s main value is pediatric cisplatin ototoxicity reduction. The applicant must assess whether the remaining label has a viable market and whether prescribers would use the product for the patented indication despite the carve-out.

What manufacturing and geographic barriers matter?

The patent does not claim a manufacturing process. It therefore does not directly block production of sodium thiosulfate through a particular synthesis, filling, sterilization, or packaging process.

Manufacturing risk may still arise from:

• Use of the claimed concentration.
• Borate levels below the claimed threshold.
• pH adjustment using hydrochloric acid or sodium hydroxide.
• A formulation substantially identical to the reference product.
• Manufacturing specifications disclosed in regulatory filings.
• Process patents or formulation patents in related family members.

Geographic coverage is territorial. U.S. Patent 11,992,530 creates no direct infringement liability for conduct occurring entirely outside the United States. Separate patent rights may exist in Europe, Japan, China, Canada, or other jurisdictions through related applications. Each country requires a separate status, scope, and expiry analysis. [2]

How does this patent compare with a broad sodium thiosulfate patent?

Issue	U.S. Patent 11,992,530	Broad composition patent
Claim type	Method of treatment	Composition or formulation
Required patient	Human, with pediatric dependent claims	Usually none
Required disease	Platinum-sensitive cancer and ototoxicity reduction	Usually none
Required chemotherapy	Platinum-based agent; cisplatin in dependent claims	Usually none
Required concentration	Approximately 0.5 M	May cover a broader range
Borate limitation	Below 0.05%	May or may not apply
Timing limitation	Six hours after cisplatin in dependent claims	Usually none
Design-around potential	Moderate to high	Depends on composition breadth
Enforcement evidence	Label, use instructions, clinical practice	Product testing and manufacturing evidence

The patent has strong relevance to the labeled clinical use but limited reach outside that use.

Key Takeaways

• Patent 11,992,530 is a method-of-treatment patent focused on sodium thiosulfate for reducing platinum-based chemotherapy ototoxicity.
• Claim 1 requires approximately 0.5 M aqueous anhydrous sodium thiosulfate and borate below 0.05%.
• The dependent claims add pH ranges, hydrochloric acid, sodium hydroxide, pediatric use, cisplatin, six-hour timing, 15-minute infusion, and specified pediatric cancers.
• The strongest infringement case involves a pediatric cisplatin label matching the claimed formulation and timing.
• The principal design-around routes are concentration, borate content, pH, timing, infusion duration, and label carve-out.
• The patent does not, from the supplied claims, cover sodium thiosulfate generally or every use of Pedmark.
• Orange Book listing, patent expiration, litigation, settlement, and Paragraph IV status require confirmation from FDA, USPTO, and court records.
• The patent’s commercial value is concentrated in pediatric cisplatin ototoxicity prevention rather than the broader sodium thiosulfate market.

FAQs

Does Patent 11,992,530 cover all sodium thiosulfate injections?

No. The claims require a specific therapeutic use and formulation limitations, including approximately 0.5 M sodium thiosulfate and borate below 0.05%.

Can a competitor avoid the patent by changing the sodium thiosulfate pH?

Potentially. A pH outside the claimed ranges could avoid the pH-dependent claims, but claim 1 does not itself recite a pH limitation. The competitor would still need to assess concentration, borate, timing, and the doctrine of equivalents.

Does the patent cover adult cisplatin patients?

Claim 1 is not expressly limited to pediatric patients. Claims 7 through 26 are pediatric-specific. An adult use could potentially implicate claim 1 if every formulation and treatment limitation is satisfied.

Does a six-hour delay appear in the independent claim?

No. The approximately six-hour interval appears in dependent claim 16 through claims 14, 15, and 16. Claim 1 does not expressly require that timing.

Is the patent a manufacturing patent?

No. The supplied claims are method-of-treatment claims. They do not claim a synthesis process, filling process, sterilization procedure, container, or manufacturing method.

References

1. U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations. FDA.
2. U.S. Patent and Trademark Office. (2024). Manual of Patent Examining Procedure, Chapter 2700: Patent term. USPTO.
3. U.S. Food and Drug Administration. (2024). Orange Book: Approved drug products with therapeutic equivalence evaluations. FDA.
4. Federal Circuit. (2011). Global-Tech Appliances, Inc. v. SEB S.A., 563 U.S. 754.
5. U.S. Food and Drug Administration. (2022). Pedmark prescribing information. FDA.
6. U.S. Patent and Trademark Office. (2024). Patent Trial and Appeal Board trial proceedings. USPTO.
7. U.S. Patent No. 11,992,530, claims 1-26 (2024).

Drugs Protected by US Patent 11,992,530

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Fennec Pharms Inc	PEDMARK	sodium thiosulfate	SOLUTION;INTRAVENOUS	212937-001	Sep 20, 2022		RX	Yes	Yes	11,992,530					USE OF A PHARMACEUTICAL COMPOSITION HAVING ABOUT 0.5M AQUEOUS ANHYDROUS SODIUM THIOSULFATE AND A CONCENTRATION OF BORATE IONS OF LESS THAN 0.05% FOR REDUCING OTOTOXICITY IN A PEDIATRIC PATIENT RECEIVING CISPLATIN FOR TREATMENT OF LOCALIZED CANCER

International Family Members for US Patent 11,992,530

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2019299216
Australia	2019299217
Australia	2025204721
Brazil	112021000021
Brazil	112021000022
Canada	3103982