CYSTARAN Drug Patent Profile

Which patents cover Cystaran, and when can generic versions of Cystaran launch?

Cystaran is a drug marketed by Leadiant Biosci Inc and is included in one NDA.

The generic ingredient in CYSTARAN is cysteamine hydrochloride. There are six drug master file entries for this compound. Two suppliers are listed for this compound. Additional details are available on the cysteamine hydrochloride profile page.

Summary for CYSTARAN

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	82
Patent Applications:	2,842
Drug Prices:	Drug price information for CYSTARAN
What excipients (inactive ingredients) are in CYSTARAN?	CYSTARAN excipients list
DailyMed Link:	CYSTARAN at DailyMed

See drug prices for CYSTARAN

Pharmacology for CYSTARAN

Drug Class	Cystine Depleting Agent
Mechanism of Action	Cystine Disulfide Reduction

US Patents and Regulatory Information for CYSTARAN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Leadiant Biosci Inc	CYSTARAN	cysteamine hydrochloride	SOLUTION/DROPS;OPHTHALMIC	200740-001	Oct 2, 2012		RX	Yes	Yes

Last updated: August 2, 2026

Cystaran is a small, high-value orphan ophthalmic product with limited volume, high switching friction, and a structurally narrow patient base. Its commercial position weakened after Cystadrops entered the U.S. market in 2020 with less frequent dosing. Cystaran’s public financial performance is not disclosed, and its orphan exclusivity expired in 2019. The product remains commercially relevant because cystinosis is rare, corneal crystal disease requires chronic treatment, and generic substitution is constrained by formulation, handling, supply, and regulatory requirements.

Cystaran Market Dynamics, Patent Position, Competition, and Financial Trajectory

What is Cystaran and which patients use it?

Cystaran is cysteamine hydrochloride ophthalmic solution 0.44%, approved by the U.S. Food and Drug Administration for the treatment of corneal cystine crystal accumulation in patients with cystinosis.[1]

Cystinosis is a lysosomal storage disorder caused by pathogenic variants affecting cystine transport. Cystine accumulates in multiple organs, including the cornea. Without topical cysteamine treatment, corneal crystals can cause photophobia, pain, blepharospasm, keratopathy, and progressive visual impairment.

Cystaran is not a general dry-eye or anti-inflammatory ophthalmic drug. Its commercial market is limited to patients with cystinosis who require topical cysteamine for corneal disease.

Product attribute	Cystaran
Active ingredient	Cysteamine hydrochloride
Strength	0.44%
Dosage form	Ophthalmic solution
FDA indication	Corneal cystine crystal accumulation in cystinosis
U.S. approval	2012
Original sponsor	Sigma-Tau Pharmaceuticals
Current commercial structure	Associated with Leadiant Biosciences and its rare-disease portfolio
Dosing burden	One drop in each eye every waking hour
Storage	Refrigerated
Open-bottle handling	Bottle must be discarded after the labeled period
Market category	Ultra-orphan ophthalmology

The hourly dosing requirement is clinically significant. It creates adherence challenges, but it also produces recurring demand and makes product substitution less straightforward than substitution among conventional ophthalmic generics.

How large is the Cystaran market?

The addressable population is small, but annual treatment value per patient can be high. Cystinosis prevalence estimates vary by geography and methodology, commonly ranging from approximately one patient per 100,000 to one per 200,000 people.[2]

The relevant market is smaller than the total cystinosis population because:

1. Some patients may have limited corneal involvement.
2. Pediatric and adult treatment patterns differ.
3. Patients may receive cysteamine through different products or channels.
4. Cystinosis prevalence is concentrated in specialized treatment centers.
5. Some patients may experience treatment interruptions caused by supply, affordability, or adherence problems.

No audited public source reports Cystaran unit sales, net sales, patient count, or gross-to-net adjustments. Leadiant is privately held, and Cystaran is not reported as a standalone product in a public-company filing.

A reasonable commercial profile is a low-volume, high-revenue-per-patient orphan product. The economics depend less on market expansion than on:

• Retaining existing patients.
• Maintaining reimbursement.
• Preventing treatment migration to Cystadrops.
• Avoiding supply interruptions.
• Preserving access through specialty pharmacies.
• Managing payer pressure after orphan exclusivity expiration.

When did Cystaran lose FDA orphan exclusivity?

Cystaran received FDA orphan-drug designation and approval in 2012. Orphan-drug exclusivity generally lasts seven years from approval under Section 527 of the Federal Food, Drug, and Cosmetic Act.[3]

On that basis, Cystaran’s primary U.S. orphan exclusivity period expired in 2019. The expiration did not automatically terminate the product’s FDA approval or remove other possible patent, regulatory, or commercial protections.

Milestone	Date or status
FDA approval	August 30, 2012
Seven-year orphan exclusivity	Expired in 2019
Cystadrops U.S. approval	2020
Current status	FDA-approved product with continuing commercial availability
Public product revenue	Not separately disclosed

The expiration of orphan exclusivity increased theoretical entry risk. Actual entry remains difficult because a competing product must address the same rare disease, demonstrate pharmaceutical equivalence or clinical similarity through an appropriate FDA pathway, establish reliable sterile ophthalmic manufacturing, and obtain sufficient commercial scale.

What is the Orange Book status of Cystaran?

Cystaran is an FDA-approved prescription drug, but its commercial protection cannot be assessed from orphan exclusivity alone. Orange Book patent listings, if any, must be evaluated against the specific approved product, dosage form, and NDA.

The key regulatory distinction is that Cystaran’s approval does not guarantee a broad barrier against all cysteamine ophthalmic competitors. A competitor could seek approval through a pathway that differs from a conventional small-molecule ANDA, particularly where formulation, inactive ingredients, labeling, stability, container closure, and clinical use differ.

Cystaran’s principal barriers are therefore mixed:

Protection category	Cystaran position
FDA approval	Remains in force
Orphan exclusivity	Expired
Patent protection	Requires claim-by-claim review of current Orange Book and patent records
Method-of-use protection	Potentially relevant but limited to enforceable claims and listed uses
Formulation protection	Important if claims cover concentration, stability, preservatives, or delivery
Manufacturing protection	Potentially important because sterile ophthalmic manufacturing is specialized
Brand and prescriber familiarity	Meaningful in an ultra-rare disease
Distribution infrastructure	Important because patients use specialty channels

Public business disclosures do not establish a single, current, fully blocking Cystaran patent position. Commercial risk is better measured through the combination of market size, development cost, formulation complexity, and competitor positioning.

What formulations are protected by Cystaran’s commercial position?

Cystaran’s formulation has several practical attributes that can deter rapid substitution:

• A 0.44% cysteamine hydrochloride concentration.
• Sterile ophthalmic delivery.
• Refrigerated storage.
• Limited in-use stability.
• Frequent administration.
• Product-specific labeling and handling requirements.

Cysteamine is chemically prone to oxidation, creating stability and packaging challenges. A competitor must control degradation, maintain sterility, establish shelf life, and demonstrate acceptable ocular tolerability.

These requirements create a manufacturing barrier even if broad composition-of-matter patent protection is absent. The barrier is operational rather than necessarily legal. A technically viable product still needs an FDA-approved manufacturing process, reliable supply, and reimbursement acceptance.

How does Cystaran compare with Cystadrops?

Cystadrops is the most direct U.S. competitor. It contains cysteamine hydrochloride at 0.37% and was approved by the FDA in 2020 for corneal cystine crystal accumulation in adults and children with cystinosis.[4]

The main competitive advantage of Cystadrops is lower dosing frequency. Its labeled regimen is four times daily, compared with hourly dosing for Cystaran.

Attribute	Cystaran	Cystadrops
Active ingredient	Cysteamine hydrochloride	Cysteamine hydrochloride
Strength	0.44%	0.37%
FDA indication	Corneal cystine crystals in cystinosis	Corneal cystine crystals in cystinosis
U.S. approval	2012	2020
Labeled dosing burden	Every waking hour	Four times daily
Commercial implication	Established product with high administration burden	Newer product with adherence advantage
Competitive status	Incumbent	Direct branded challenger

Cystadrops creates the largest strategic risk to Cystaran because it competes for the same patients and prescribers. The products are not interchangeable in the ordinary generic-substitution sense. Physicians may choose between them based on dosing, tolerability, patient age, access, clinical response, and payer coverage.

Cystaran may retain patients who are stable on therapy, have established pharmacy access, or respond adequately despite the dosing burden. New diagnoses and patients with poor adherence have stronger incentives to use Cystadrops.

Which companies are challenging Cystaran?

Recordati Rare Diseases, through Cystadrops, is the principal branded competitor in the United States. The competitive set also includes:

• Potential generic cysteamine ophthalmic developers.
• Compounded cysteamine products, where legally and clinically available.
• International cysteamine ophthalmic products.
• Systemic cysteamine products used for the underlying disease, although systemic therapy does not replace topical corneal treatment.

A conventional generic challenge is commercially difficult because the patient population is small. Development costs for sterile ophthalmic products can be substantial relative to the number of patients available to support the entrant.

No publicly established high-volume Paragraph IV campaign has defined Cystaran’s market. The absence of a prominent Paragraph IV dispute does not eliminate generic risk. It indicates that market size, formulation complexity, regulatory requirements, or patent economics may have limited the attractiveness of a challenge.

What patent litigation and settlement agreements affect Cystaran?

No major public patent litigation or settlement agreement has become a central market event for Cystaran comparable to disputes involving high-volume branded drugs.

For investment and licensing analysis, the relevant litigation questions are narrower:

1. Whether the current NDA has active Orange Book-listed patents.
2. Whether those patents cover the formulation, use, or manufacturing process.
3. Whether a generic applicant has submitted a Paragraph IV certification.
4. Whether the sponsor has initiated a Hatch-Waxman action within 45 days.
5. Whether any settlement restricts generic launch timing.

The commercial absence of a major public dispute supports a view that Cystaran’s protection is driven more by orphan-market economics and product complexity than by a well-publicized patent blockade.

What is Cystaran’s financial trajectory?

Cystaran’s revenue trajectory is not publicly reported on a standalone basis. The product’s financial performance must therefore be inferred from market structure rather than audited sales data.

Early commercialization

Cystaran entered a highly specialized market with limited patient numbers and no direct FDA-approved U.S. competitor for several years. That environment supported strong pricing power and concentrated prescribing through rare-disease specialists.

The business model likely depended on high revenue per treated patient, specialty distribution, reimbursement support, and patient-assistance programs rather than prescription volume.

Post-2019 exclusivity period

After orphan exclusivity expired, the theoretical ceiling on pricing power declined. The product still benefited from:

• An established safety and efficacy record.
• Prescriber familiarity.
• Existing patient continuity.
• Rare-disease diagnostic concentration.
• High barriers to sterile ophthalmic development.

The key negative factor was the end of regulatory exclusivity, which increased the probability of branded and generic competition.

Post-Cystadrops period

Cystadrops changed the competitive equation in 2020. Its four-times-daily regimen directly addresses Cystaran’s most visible weakness.

Cystaran’s likely financial trajectory after Cystadrops is characterized by:

• Lower patient acquisition potential.
• Increased retention spending.
• Greater payer scrutiny.
• Higher risk of switching among newly diagnosed patients.
• Continued value from patients already stable on treatment.
• Greater importance of supply reliability and specialty support.

The product could remain profitable at low volume if net pricing remains high and manufacturing costs are controlled. Revenue deterioration would be more likely to result from patient switching than from broad substitution by commodity generics.

What generic launch risks exist for Cystaran?

Generic entry risk is moderate in theory but constrained in practice.

Legal risk

Orphan exclusivity has expired. Any active patents, listed claims, or regulatory exclusivities must be evaluated separately.

Regulatory risk

A generic applicant must address ophthalmic sterility, formulation equivalence, stability, container closure, impurities, and labeling. Cysteamine degradation and refrigerated handling add technical complexity.

Commercial risk

The total patient pool is small. A generic entrant would need to capture enough prescriptions to justify development, FDA fees, manufacturing validation, pharmacovigilance, and specialty distribution.

Clinical substitution risk

Even after approval, automatic substitution may not operate as simply as it does for widely used oral tablets. Product differences in dosing, concentration, formulation, and handling can lead prescribers to manage switches deliberately.

What is the revenue exposure for the product owner?

Cystaran is strategically important if it contributes disproportionately to a rare-disease portfolio despite limited absolute sales. The exposure has three dimensions:

Exposure	Commercial effect
Patient concentration	A small number of treatment centers and patients can drive most demand
Product concentration	Supply failures can have an immediate effect on revenue and patient continuity
Competitive concentration	Cystadrops is a direct alternative rather than a distant therapeutic competitor
Pricing exposure	Payers may resist high orphan-drug pricing after exclusivity expiration
Manufacturing exposure	Sterile ophthalmic failures can create shortages and reputational damage

A product-level valuation should not assign Cystaran a conventional mass-market growth multiple. The appropriate framework is a declining or stable orphan annuity, adjusted for patient retention, net price, supply continuity, Cystadrops switching, and the probability of generic entry.

How strong is the Cystaran patent estate?

Cystaran’s overall commercial protection is moderate rather than clearly strong.

The product has meaningful non-patent advantages: rare-disease specialization, prescriber familiarity, treatment continuity, and manufacturing complexity. Its primary weakness is that seven-year orphan exclusivity has expired and the market has a direct branded competitor.

Patent strength depends on the scope and remaining life of any active claims covering:

• Cysteamine ophthalmic composition.
• Concentration and excipient system.
• Stability or oxidation control.
• Corneal cystine treatment methods.
• Packaging and storage.
• Manufacturing or purification steps.

Without a currently verified patent schedule tied to the active NDA, a precise expiration-date forecast would be unreliable. The commercial assessment remains clear: Cystaran is protected more by market scarcity and execution than by demonstrably broad regulatory exclusivity.

What is the outlook for Cystaran?

Cystaran is likely to remain a durable niche product, but its growth outlook is limited. The market has reached a more competitive phase following Cystadrops’ approval and the expiration of orphan exclusivity.

The main scenarios are:

Scenario	Result
Stable incumbent	Cystaran retains established patients and generates recurring orphan revenue
Gradual erosion	New patients favor Cystadrops, while existing patients switch slowly
Generic entry	Price and share pressure increase, but substitution remains constrained
Supply disruption	Short-term patient switching and permanent account loss become possible
Portfolio support	Patient services and specialist relationships preserve commercial relevance

Key Takeaways

• Cystaran is an FDA-approved cysteamine ophthalmic solution for corneal cystine crystals in cystinosis.
• Its orphan exclusivity expired in 2019.
• Cystadrops is the principal direct competitor and has a lower labeled dosing frequency.
• Cystaran revenue, patient numbers, and profitability are not publicly disclosed on a standalone basis.
• The product’s remaining defenses are patient continuity, rare-disease infrastructure, sterile ophthalmic manufacturing, and switching friction.
• Generic entry is legally more feasible after orphan exclusivity expiration but commercially difficult because of the small patient population.
• The most likely financial trajectory is stable or gradually declining orphan-drug revenue rather than high growth.
• Cystaran’s valuation depends on retention, net pricing, supply reliability, Cystadrops penetration, and verified patent status.

FAQs About Cystaran Market and Exclusivity

Is Cystaran still FDA approved?

Yes. Cystaran remains an FDA-approved cysteamine hydrochloride ophthalmic solution for corneal cystine crystal accumulation associated with cystinosis.[1]

Does Cystadrops replace Cystaran automatically?

No. Cystadrops and Cystaran are separate prescription products with different concentrations, dosing regimens, formulations, and labeling. A switch generally requires prescriber and payer coordination.

Can a generic manufacturer launch Cystaran after 2019?

The expiration of orphan exclusivity removes that specific regulatory barrier, but a generic manufacturer must still address any active patents, FDA requirements, sterile ophthalmic manufacturing, and commercial scale.

Which product has the lower dosing burden, Cystaran or Cystadrops?

Cystadrops has the lower labeled dosing burden. Cystaran is administered every waking hour, while Cystadrops is administered four times daily.[1,4]

Is Cystaran revenue reported by its owner?

No standalone public revenue figure is routinely reported for Cystaran. The product is associated with a private rare-disease commercial structure, preventing the level of product-specific financial disclosure available for publicly traded pharmaceutical products.

References

1. U.S. Food and Drug Administration. (2012). Cystaran (cysteamine hydrochloride ophthalmic solution) prescribing information. FDA.

2. Elmonem, M. A., Venselaar, H., Goetz, B. A., et al. (2016). Cystinosis: A review. Orphanet Journal of Rare Diseases, 11, 47.

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

4. U.S. Food and Drug Administration. (2020). Cystadrops (cysteamine hydrochloride ophthalmic solution) prescribing information. FDA.