NOURIANZ Drug Patent Profile

When do Nourianz patents expire, and what generic alternatives are available?

Nourianz is a drug marketed by Kyowa Kirin and is included in one NDA. There are two patents protecting this drug and one Paragraph IV challenge.

This drug has forty-nine patent family members in seventeen countries.

The generic ingredient in NOURIANZ is istradefylline. There is one drug master file entry for this compound. One supplier is listed for this compound. Additional details are available on the istradefylline profile page.

DrugPatentWatch^® Generic Entry Outlook for Nourianz

Nourianz was eligible for patent challenges on August 27, 2023.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be September 5, 2027. This may change due to patent challenges or generic licensing.

There has been one patent litigation case involving the patents protecting this drug, indicating strong interest in generic launch. Recent data indicate that 63% of patent challenges are decided in favor of the generic patent challenger and that 54% of successful patent challengers promptly launch generic drugs.

Indicators of Generic Entry

Summary for NOURIANZ

International Patents:	49
US Patents:	2
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	92
Clinical Trials:	3
Patent Applications:	907
Drug Prices:	Drug price information for NOURIANZ
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for NOURIANZ
What excipients (inactive ingredients) are in NOURIANZ?	NOURIANZ excipients list
DailyMed Link:	NOURIANZ at DailyMed

See drug prices for NOURIANZ

DrugPatentWatch^® Estimated Loss of Exclusivity (LOE) Date for NOURIANZ

Constraining patent/regulatory exclusivity:

8,318,201

NDA:

022075

Dosage:

TABLET;ORAL

^*The generic entry opportunity date is the latter of the last compound-claiming patent and the last regulatory exclusivity protection. Many factors can influence early or later generic entry. This date is provided as a rough estimate of generic entry potential and should not be used as an independent source.

Recent Clinical Trials for NOURIANZ

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Kyowa Kirin, Inc.	Phase 4
Georgetown University	Phase 4
ALS Association	Phase 1/Phase 2

See all NOURIANZ clinical trials

Paragraph IV (Patent) Challenges for NOURIANZ

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
NOURIANZ	Tablets	istradefylline	20 mg and 40 mg	022075	1	2025-08-13

US Patents and Regulatory Information for NOURIANZ

NOURIANZ is protected by two US patents.

This potential generic entry date is based on patent 8,318,201.

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-001	Aug 27, 2019		RX	Yes	No	7,727,993		Y
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-002	Aug 27, 2019		RX	Yes	Yes	8,318,201		Y
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-001	Aug 27, 2019		RX	Yes	No	8,318,201		Y
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-002	Aug 27, 2019		RX	Yes	Yes	7,727,993		Y

Expired US Patents for NOURIANZ

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-002	Aug 27, 2019	7,541,363
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-002	Aug 27, 2019	7,727,994
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-001	Aug 27, 2019	7,541,363
Kyowa Kirin	NOURIANZ	istradefylline	TABLET;ORAL	022075-001	Aug 27, 2019	7,727,994

EU/EMA Drug Approvals for NOURIANZ

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Kyowa Kirin Holdings B.V.	Nouryant	istradefylline	EMEA/H/C/005308Istradefylline is indicated in adults as an adjunctive treatment to levodopa based regimens in patients with Parkinson’s disease (PD) experiencing “OFF” time.	Refused	no	no	no		2022-01-06

International Patents for NOURIANZ

See the table below for patents covering NOURIANZ around the world.

Country	Patent Number	Title	Estimated Expiration
Austria	546450
Australia	2004236101	Microcrystal
Canada	2525037	MICROCRISTAL (MICROCRYSTAL)
China	100395245
China	1784405	Microcrystal
European Patent Office	1626049	Microcristal de (E)-8-(3,4-dimethoxystyryl)-1,3-diethyl-7-methyl-3,7-dihydro-1H-purine-2,6-dione (Microcrystal of (E)-8-(3,4-dimethoxystyryl)-1,3-diethyl-7-methyl-3,7-dihydro-1H-purine-2,6-dione)

Last updated: May 28, 2026

NOURIANZ market dynamics, revenue trajectory, and exclusivity outlook

NOURIANZ (istradefylline) sits in the Parkinson’s disease adjunct space for levodopa-treated patients with “off” episodes. The product’s financial trajectory is governed by (1) uptake vs. competing adjuncts in “wearing-off” management, (2) durability of payer coverage and formulary placement, and (3) near-term patent and regulatory timelines that determine generic and biosimilar-like entry risk for a small-molecule drug.

NOURIANZ’s market performance is best modeled through three commercial forces: (a) conversion of new-to-class patients and formulary switching from other adjuncts, (b) price realization under commercial and government reimbursement pressure, and (c) channel inventory and patient persistence dynamics driven by add-on tolerability and dosing adherence.

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What market share and revenue trajectory does NOURIANZ have in Parkinson’s “off” episodes?

How is NOURIANZ positioned vs. other “off” episode adjunct therapies

NOURIANZ is an oral adenosine A2A antagonist used as adjunct therapy to levodopa/carbidopa to reduce “off” time. Commercial outcomes depend on how payers and prescribers compare it to other adjunct mechanisms:

• Other oral adjuncts
  • Safinamide (oral; adjunct to levodopa)
  • Opicapone and entacapone (COMT inhibitors; adjunct to levodopa)
  • Tolcapone (COMT inhibitor; less favored due to liver risk and restricted use)
• Device or infusion-adjunct category
  • Levodopa intestinal gel (device-associated pathway; different access dynamics)
• Dopamine agonist adjuncts
  • Pramipexole/ropinirole and others (often limited by tolerability in older patients)

NOURIANZ’s uptake tends to track with payer acceptance for an oral, non-injectable adjunct that does not require device implantation.

Revenue drivers that typically matter for NOURIANZ

Key variables impacting NOURIANZ revenue trajectory:

1. Share shift from existing adjuncts
   • Penetration rises when NOURIANZ is placed on formularies as a preferred oral option for reducing “off” time.
2. Adherence and persistence
   • Oral adjunct efficacy requires ongoing dosing; discontinuation reduces realized prescriptions and underlying demand.
3. Real-world tolerability
   • Discontinuation, adverse-event-related switching, and dose interruptions directly change net revenue.
4. Payer rebates and net price
   • Parkinson’s formularies are sensitive to budget impact, and net pricing is usually lower than WAC after contracting.

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What exclusivity timelines control NOURIANZ U.S. generic risk?

Core timing logic for a small-molecule launch

For a branded small-molecule Parkinson’s adjunct, generic risk is typically driven by:

• expiration of the latest composition-of-matter patent,
• expiration of method-of-use patents,
• and the end of any regulatory exclusivity that blocks ANDA approval.

The practical “generic launch window” is the date on which an ANDA can obtain approval (not just the date the product’s marketing exclusivity ends), plus any patent litigation delays.

How to interpret “exclusivity” vs. “patent expiry” for NOURIANZ

• Patent expiry determines when ANDA applicants can file freely without being blocked by composition and method-of-use claims.
• Orange Book exclusivity listing can delay approval even if patents expire.
• Paragraph IV and litigation can add a further stay, shifting the approval date.

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What patents protect NOURIANZ and what is the Orange Book status?

How patent estates determine NOURIANZ protection strength

For NOURIANZ, protection strength is assessed by:

• density of Orange Book-listed patents (how many are in-force),
• whether the last-to-expire items are composition or method-of-use,
• and whether there are multiple independent claim sets that require design-around for ANDA entries.

What an Orange Book “strong estate” looks like

A strong estate typically has:

• multiple overlapping formulation and/or method-of-use patents,
• last-to-expire patents that cover patient selection (e.g., levodopa-treated “off” time reduction) and dosing regimens,
• and limited room for generic labeling carve-outs.

Litigation-linked indicators for estate durability

Where there are Paragraph IV challenges, settlement agreements often:

• define “launch at risk” dates,
• impose stipulated entry delays,
• or require labeling restrictions tied to patent scopes.

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Are there any Paragraph IV filings against NOURIANZ, and what settlement patterns matter?

What Paragraph IV outcomes typically change for NOURIANZ

If Paragraph IV ANDA filings exist, they tend to change the commercial trajectory by:

• pushing approval dates out through 30-month stays,
• producing settlement-driven agreed launch timelines,
• or enabling partial design-around that forces label carve-outs.

Settlement-driven launch scenarios

Two common patterns in small-molecule Parkinson’s adjuncts:

1. Delayed launch settlement
   • Generic approval and commercial launch occur after a defined date aligned to the “last-to-expire” patent.
2. Design-around with label restrictions
   • Generic launch occurs earlier, but labeling is limited to avoid infringing method-of-use claims.

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How does NOURIANZ compare with safinamide, opicapone, and other OFF-time adjuncts commercially?

Key competitive comparisons that affect formulary placement

Prescriber and payer choice for “off” episodes often hinges on:

• Route and administration
  • NOURIANZ is oral and fits broadly into outpatient medication routines.
• On/off phenotype coverage
  • How well efficacy maps to patient subgroups with wearing off vs unpredictable off periods.
• Safety and tolerability
  • Adverse events drive discontinuation and switching.
• Budget impact
  • Net pricing under rebates influences whether payers place it as preferred, or relegates it to non-preferred status.

Commercial consequence

If competitors undercut net price or have stronger payer narratives, NOURIANZ faces:

• lower conversion rates,
• higher patient churn to cheaper alternatives,
• and more use in narrower segments rather than broad formulary share.

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What FDA pathway and labeling scope influence NOURIANZ uptake?

Labeling scope and how it shapes “real-world” demand

Demand is strongly correlated with:

• label wording around levodopa adjunct use,
• prescriber comfort that dosing fits typical clinical workflows,
• and the presence or absence of restrictions tied to prior therapy.

Generic entry risk tied to labeling

Method-of-use coverage can make generic approval contingent on:

• whether the ANDA label can omit protected indications or regimens,
• whether the generic’s proposed labeling triggers infringement risk.

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What manufacturing or formulation patent barriers affect generic entry for NOURIANZ?

Formulation and process patents that matter most

Generic applicants typically try to avoid:

• crystalline form claims,
• specific polymorphs,
• extended-release or stability-related claims (if covered),
• and specific manufacturing process parameters.

How this impacts “at risk” entry

If the patent estate includes robust formulation and manufacturing claims, generic applicants often:

• pursue design-around,
• delay launch until patent expiry,
• or target a settlement path.

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How many years of revenue could NOURIANZ have left before generic entry?

Modeling approach for revenue horizon

A practical revenue horizon uses:

• latest in-force Orange Book patent expiry for ANDA relevance,
• any exclusivity that blocks approval,
• and any Paragraph IV litigation timelines.

The result is the date when sustained generic competition begins, not just the date when filing is permitted.

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What is the investment, licensing, and litigation landscape around NOURIANZ?

Licensing dynamics

In Parkinson’s, licensing usually concentrates around:

• rights to market or co-promote in specific territories,
• rights tied to distribution contracts and payer contracting,
• and rights tied to lifecycle management (new formulations, line extensions, or additional method-of-use indications).

Litigation dynamics

Litigation affects revenue trajectory by:

• controlling generic entry dates,
• influencing payer confidence in continued exclusivity,
• and altering net pricing during competitive anticipation periods.

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Key Takeaways

• NOURIANZ’s market dynamics are driven by formulary uptake for adjunct “off” time reduction, net price realization, and persistence.
• Commercial pressure will track competitively against oral adjuncts (e.g., COMT inhibitors and safinamide) based on tolerability and payer preferences.
• The pace of revenue erosion depends on the last-to-expire in-force patents relevant to ANDA labeling and method-of-use claims, plus any Paragraph IV-driven stays and settlements.
• Patent estate density and the presence of formulation or method-of-use claims are the primary indicators of whether generics face delayed entry or earlier design-around.

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FAQs

1) What payers are most likely to restrict NOURIANZ access first?
Commercial PBMs and Medicare Part D plans typically tighten access based on budget impact and comparative net pricing.

2) Does NOURIANZ face competitive substitution from COMT inhibitors or safinamide?
Substitution risk rises when NOURIANZ is non-preferred and competitors are preferred on formularies with stronger net pricing.

3) What patent types most often delay ANDA approval for Parkinson’s small molecules?
Method-of-use and formulation/polymorph/process patents typically create label and design-around barriers.

4) How do settlement agreements typically affect NOURIANZ’s generic launch timing?
They often define stipulated launch dates and labeling carve-outs that align with last-to-expire patent scopes.

5) What market events most affect NOURIANZ near-term revenue—new label, new competitors, or pricing changes?
Pricing and formulary tiering changes typically affect net sales faster than incremental label updates.

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DrugChatter Q&A for NOURIANZ

Is Nourianz used with Levodopa?