List of Excipients in Branded Drug PEDMARK

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Fennec Pharmaceuticals Inc	PEDMARK	sodium thiosulfate	73077-010	BORIC ACID	2029-09-20
Fennec Pharmaceuticals Inc	PEDMARK	sodium thiosulfate	73077-010	HYDROCHLORIC ACID	2029-09-20
Fennec Pharmaceuticals Inc	PEDMARK	sodium thiosulfate	73077-010	SODIUM HYDROXIDE	2029-09-20

PEDMARK Excipient Strategy and Commercial Opportunities

Last updated: August 3, 2026

PEDMARK is a ready-to-use intravenous formulation of sodium thiosulfate developed by Fennec Pharmaceuticals to reduce the risk of cisplatin-induced ototoxicity in pediatric patients with localized, nonmetastatic solid tumors. Its commercial position depends less on complex excipient chemistry than on dosing timing, sterile presentation, pediatric administration, clinical evidence, orphan-drug exclusivity, and hospital integration. The formulation is relatively simple, which creates opportunities for manufacturing efficiency but limits the strength of a composition-of-matter patent strategy.

What is PEDMARK and how does its formulation work?

PEDMARK is sodium thiosulfate injection, supplied as a sterile intravenous product containing 12.5 g of sodium thiosulfate in 100 mL, equivalent to 125 mg/mL. The product is administered intravenously six hours after completion of cisplatin infusion. This timing is central to the product's clinical and regulatory value because earlier administration could reduce cisplatin's antitumor activity.

The FDA-approved indication covers pediatric patients aged 1 month and older with localized, nonmetastatic solid tumors receiving cisplatin-containing chemotherapy when the regimen does not include cisplatin administered by intra-arterial infusion.[1]

Attribute	PEDMARK profile
Active ingredient	Sodium thiosulfate
Dosage form	Sterile intravenous injection
Strength	12.5 g/100 mL
Concentration	125 mg/mL
Administration	Intravenous infusion
Timing	Six hours after cisplatin completion
Target population	Pediatric patients with localized, nonmetastatic solid tumors
Sponsor	Fennec Pharmaceuticals
FDA approval	August 2022
Regulatory status	Approved drug, orphan designation
Principal clinical value	Reduction of cisplatin-associated hearing loss

PEDMARK is distinct from sodium thiosulfate products historically used for cyanide poisoning and other medical applications. The commercial product is positioned around a defined pediatric oncology regimen, a specific post-cisplatin administration window, and supporting clinical evidence.

What excipients are used in PEDMARK?

PEDMARK uses a relatively limited excipient system. The FDA prescribing information identifies sodium chloride and pH-adjusting agents among the inactive ingredients, with water for injection as the solvent system.[1] The formulation is designed to deliver a high sodium thiosulfate load through a ready-to-use sterile intravenous presentation.

Formulation component	Functional role
Sodium thiosulfate	Active pharmaceutical ingredient and otoprotective agent
Sodium chloride	Tonicity and solution-property adjustment
Sodium hydroxide and hydrochloric acid	pH adjustment
Water for injection	Sterile vehicle

The excipient strategy has four commercial implications:

1. Low formulation complexity. The product does not depend on a sophisticated lipid carrier, polymer system, depot technology, or device-integrated delivery platform.

2. High payload requirement. The product must accommodate a large sodium thiosulfate dose in an acceptable infusion volume. Concentration, osmolality, pH, precipitation risk, and container compatibility are central development parameters.

3. Sterility and stability are important value drivers. Because the product is administered intravenously in oncology settings, sterile manufacturing, particulate control, extractables and leachables testing, and validated shelf life carry more commercial significance than proprietary excipient selection.

4. Limited excipient-based differentiation. A generic manufacturer may be able to replicate the basic solution architecture if it can establish pharmaceutical equivalence, bioequivalence or applicable waiver criteria, container compatibility, and manufacturing control.

How strong is the PEDMARK formulation strategy?

The PEDMARK formulation strategy is commercially credible but technically narrow. Its strongest protections are likely to arise from the integrated product package rather than the excipients alone.

Technical strengths

• Ready-to-use presentation reduces pharmacy compounding.
• A fixed concentration supports standardized pediatric oncology protocols.
• The formulation avoids complex reconstitution steps.
• High-dose delivery is compatible with an oncology infusion workflow.
• The product is designed around a defined six-hour interval after cisplatin.
• A commercial vial reduces handling burden compared with hospital preparation from bulk or alternative sodium thiosulfate products.

Technical limitations

• Sodium thiosulfate is an established active ingredient.
• The excipient system is conventional.
• Competing manufacturers may be able to develop a similar aqueous injectable product.
• The product's high active concentration may create manufacturing, container-closure, and stability challenges but does not automatically create a durable formulation barrier.
• A formulation patent, if one is asserted, would need to distinguish the product through concentration, pH, stability, container system, impurity profile, dosing regimen, or another claim limitation.

The commercial moat is therefore stronger in clinical positioning and market access than in excipient novelty.

What FDA exclusivity protects PEDMARK?

PEDMARK received FDA approval on August 10, 2022, for pediatric cisplatin-induced ototoxicity risk reduction.[1] The product received orphan-drug designation, providing seven years of orphan-drug marketing exclusivity for the approved indication from the date of approval, subject to statutory exceptions.[2]

Protection category	PEDMARK position
FDA approval	Granted August 10, 2022
Orphan-drug exclusivity	Expected to run through August 2029 for the approved indication
Patent protection	Must be assessed from current USPTO and FDA Orange Book records
New chemical entity exclusivity	Not the primary commercial protection because sodium thiosulfate is an established active ingredient
Biosimilar protection	Not applicable; PEDMARK is a small-molecule drug
Pediatric exclusivity	No separate six-month extension should be assumed without an applicable FDA grant
Generic pathway	ANDA or other applicable abbreviated pathway, subject to exclusivity and product-specific requirements

Orphan exclusivity blocks FDA approval of another product containing the same active ingredient for the same orphan indication during the exclusivity period, unless the sponsor cannot assure sufficient supply or the competing product is clinically superior.[2] It does not create a blanket monopoly over sodium thiosulfate for every use.

When does PEDMARK lose exclusivity?

The principal statutory orphan-exclusivity date is August 2029, based on the August 2022 approval date. A generic applicant could face different timing depending on the proposed indication, the scope of any listed patents, FDA review status, and whether the applicant pursues a product for an indication outside the protected pediatric otoprotection use.

A practical entry timeline is:

Period	Commercial implication
2022-2029	Orphan exclusivity protects the approved pediatric indication, subject to statutory exceptions
Before 2029	Patent challenges or non-infringing products could affect market access, but orphan exclusivity remains a separate regulatory barrier
After 2029	Same-indication generic entry becomes more feasible if applicable patents and regulatory requirements do not block approval
Post-entry	Hospital formulary adoption, supply reliability, pediatric dosing, and contracting become primary competitive factors

The expiration date of any PEDMARK-specific formulation, method-of-use, or manufacturing patent should not be inferred from the orphan-exclusivity date. Patent terms can extend beyond or expire before regulatory exclusivity.

What patents protect PEDMARK?

PEDMARK's relevant intellectual-property categories can include:

• Use of sodium thiosulfate to reduce cisplatin-associated ototoxicity.
• Timing of administration after cisplatin.
• Pediatric dosing based on body surface area or weight.
• Concentrated injectable compositions.
• pH, osmolality, stability, or impurity specifications.
• Container-closure systems.
• Sterile manufacturing and fill-finish methods.
• Treatment protocols combining cisplatin and delayed sodium thiosulfate.

Method-of-use patents may be more commercially relevant than excipient patents because the product's differentiation is tied to the six-hour post-cisplatin protocol. A method claim covering a specific pediatric population, dose, interval, or treatment sequence could complicate a generic's label strategy.

An ANDA applicant could pursue a Paragraph IV certification against listed patents or use a section viii statement to omit patented use information, depending on the Orange Book listings and the proposed label. A product that seeks approval for the same pediatric otoprotection indication could face both orphan exclusivity and patent barriers. A product labeled for another sodium thiosulfate use may encounter a different regulatory analysis.

What is the Paragraph IV risk for PEDMARK?

Paragraph IV risk exists but is constrained by the product's regulatory profile. A generic applicant would normally evaluate:

1. Whether PEDMARK patents are listed in the FDA Orange Book.
2. Whether the claims cover the drug product, formulation, method of use, or manufacturing process.
3. Whether a proposed label would include the protected pediatric otoprotection indication.
4. Whether orphan exclusivity remains active.
5. Whether the applicant can design around formulation or dosing claims.
6. Whether the FDA could approve an alternative indication before orphan exclusivity expires.

The most plausible early challenge would focus on conventional formulation or non-infringement arguments if listed patents cover concentration, excipients, or container systems. A direct same-indication generic launch before orphan exclusivity ends would face a higher regulatory barrier than an ordinary small-molecule ANDA launch.

No public litigation or settlement conclusion should be assigned without a current review of PACER, FDA Orange Book listings, USPTO records, and Fennec's latest securities filings. The absence of a widely reported challenge does not establish that no patent certifications or private disputes exist.

What commercial opportunities exist for PEDMARK excipients?

The principal excipient opportunity is not a high-margin novel excipient. It is the supply and manufacturing platform around a high-dose sterile injectable.

Ready-to-use hospital presentation

Hospitals may value a product that eliminates bedside or pharmacy preparation from alternative sodium thiosulfate sources. A ready-to-use vial can reduce preparation time, dosing errors, and handling requirements. This benefit is strongest in pediatric oncology centers with established cisplatin pathways.

Container and closure optimization

A high-concentration sodium thiosulfate solution requires compatibility assessment for glass, elastomeric closures, labels, overwraps, and secondary packaging. Suppliers with validated container systems can create switching friction even where the formulation itself is simple.

Shelf-life extension

Stability improvements can reduce waste and expand distribution to community hospitals. Commercial opportunities include:

• Longer refrigerated or controlled-room-temperature shelf life.
• Reduced sensitivity to light or temperature excursions.
• Lower particulate formation.
• Improved compatibility with infusion components.
• More flexible shipping and storage conditions.

Dose-size and presentation expansion

Potential commercial extensions include:

• Smaller pediatric vial sizes.
• Ready-to-administer infusion bags.
• Weight-based or body-surface-area dosing presentations.
• Institutional multi-vial packaging.
• International presentations aligned with local oncology pharmacy practice.

Any new presentation would require FDA review and could create additional product-specific intellectual property if supported by a meaningful technical difference.

How does PEDMARK compare with generic sodium thiosulfate?

Factor	PEDMARK	Generic sodium thiosulfate
Clinical positioning	Pediatric cisplatin otoprotection	May be marketed for other approved uses
Label	Specific post-cisplatin use and pediatric population	Depends on approved label
Presentation	Commercially packaged, ready-to-use oncology product	May require different concentration or preparation
Evidence	Pediatric cisplatin ototoxicity clinical data	May not include the same indication
Orphan exclusivity	Applies to approved orphan indication	Can restrict same-indication approval during exclusivity
Formulation differentiation	Limited but commercially optimized	Potentially similar aqueous formulation
Hospital value	Protocol integration and supply convenience	Price and availability
Main risk to PEDMARK	Post-exclusivity substitution	Regulatory and clinical-label limitations

The key competitive distinction is not the identity of the active ingredient. It is whether a competitor can offer an FDA-authorized product for the same pediatric cisplatin otoprotection use with equivalent operational convenience.

What is the biosimilar risk for PEDMARK?

PEDMARK has no biosimilar risk. Sodium thiosulfate is a small molecule, so competition would arise through generic-drug pathways rather than the Public Health Service Act biosimilar pathway.

The relevant substitutes are:

• Generic sodium thiosulfate injection.
• Hospital-compounded sodium thiosulfate, where legally and operationally available.
• Alternative cisplatin regimens or ototoxicity mitigation approaches.
• Changes in pediatric oncology protocols that reduce cisplatin exposure.

Clinical adoption depends on whether physicians and hospital pharmacies regard the branded product's label, sterility assurance, dosing convenience, and supply reliability as worth a premium over lower-cost alternatives.

Which licensing and partnership opportunities are available?

Potential licensing opportunities cluster around regional commercialization, sterile manufacturing, and pediatric oncology distribution.

Regional commercial licenses

Fennec or a successor rights holder could license PEDMARK in markets where cisplatin remains widely used in pediatric solid tumors and where pediatric hearing-loss monitoring is clinically established. The most relevant regions include Europe, Japan, South Korea, Australia, and selected Middle Eastern and Latin American markets.

Manufacturing partnerships

A contract manufacturing organization with sterile injectable capacity could provide:

• Sodium thiosulfate solution compounding.
• Aseptic filling.
• High-concentration solution handling.
• Container-closure validation.
• Regional packaging and serialization.
• Supply redundancy.

Manufacturing agreements may be more valuable than excipient licenses because the product's supply chain is exposed to sterile injectable capacity, quality release, and cold-chain or controlled-temperature logistics.

Formulation development partnerships

A partner could develop improved presentations without changing the active ingredient, including smaller-dose formats, infusion bags, or stability-enhanced packaging. The strongest business cases would reduce pediatric dosing waste and simplify oncology pharmacy workflow.

What manufacturing and IP barriers affect PEDMARK?

The main manufacturing barriers are operational:

• High-dose active loading.
• Aseptic processing at commercial scale.
• Solution stability and impurity control.
• Container compatibility.
• Consistent pH and osmolality.
• Reliable supply of pharmaceutical-grade sodium thiosulfate.
• Quality systems for pediatric oncology injectables.
• Production redundancy for a niche but clinically important product.

The main IP barriers are likely to involve method of use, dosing timing, composition parameters, and regulatory exclusivity. A conventional excipient combination by itself is less likely to provide a durable barrier unless the sponsor can demonstrate an unexpected stability, safety, or administration advantage.

What revenue exposure and market expansion opportunities exist?

PEDMARK's revenue exposure is concentrated in pediatric oncology rather than the much larger adult cisplatin market. The addressable population is limited, but treatment value per patient can be meaningful because cisplatin-induced hearing loss is permanent, clinically consequential, and especially disruptive in children.

Commercial expansion opportunities include:

• Broader adoption across pediatric solid-tumor centers.
• Use in additional countries.
• Inclusion in institutional cisplatin protocols.
• Earlier use in patients at high risk of hearing loss.
• Contracting with children's hospitals and oncology networks.
• Development of lower-waste pediatric presentations.
• Potential future evidence in additional cisplatin-treated populations, subject to FDA requirements.

Expansion into adult indications would require clinical and regulatory support. It cannot be assumed from the pediatric approval.

Key Takeaways

• PEDMARK is a ready-to-use sodium thiosulfate injection for reducing cisplatin-induced ototoxicity in pediatric patients.
• Its excipient system is conventional, based on sodium chloride, pH adjusters, and water for injection.
• The strongest commercial advantages are ready-to-use delivery, protocol-specific timing, pediatric oncology evidence, and hospital workflow integration.
• FDA orphan-drug exclusivity is expected to protect the approved indication through August 2029.
• PEDMARK has no biosimilar risk; the relevant threat is generic sodium thiosulfate competition.
• Formulation patents may be narrower than method-of-use, dosing, timing, and manufacturing protections.
• The most attractive partnership opportunities involve sterile manufacturing, regional commercialization, container systems, and pediatric dose presentations.
• After orphan exclusivity, generic substitution risk will depend on Orange Book patents, label scope, clinical evidence, and hospital purchasing economics.

FAQs

Can sodium thiosulfate be substituted for PEDMARK in pediatric oncology?

Substitution depends on the alternative product's FDA-approved label, formulation, concentration, pharmacy policy, and clinical evidence. A generic sodium thiosulfate product is not automatically equivalent to PEDMARK for the labeled pediatric cisplatin otoprotection indication.

Does PEDMARK have a novel excipient?

No novel excipient is central to the marketed formulation. The product's formulation value comes from concentration, sterility, packaging, stability, and ready-to-use administration.

Can a generic launch PEDMARK before 2029?

A same-indication generic would face orphan-drug exclusivity until approximately August 2029, in addition to any applicable patent barriers. A product with a different label could be subject to a separate analysis.

Is PEDMARK protected by a formulation patent?

Potential formulation protection may cover concentration, pH, stability, impurity controls, container systems, or related parameters. Patent status must be determined from the current FDA Orange Book and USPTO records rather than inferred from the product label.

Could PEDMARK be used in adults?

The FDA indication is limited to pediatric patients aged 1 month and older with localized, nonmetastatic solid tumors receiving qualifying cisplatin therapy. Adult use would require separate clinical, regulatory, and reimbursement analysis.

References

1. U.S. Food and Drug Administration. (2022). PEDMARK (sodium thiosulfate) injection, prescribing information. FDA.

2. U.S. Food and Drug Administration. (2023). Orphan drug designation and exclusivity. FDA.

3. Fennec Pharmaceuticals Inc. (2024). Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. U.S. Securities and Exchange Commission.

4. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. FDA.