REZZAYO Drug Patent Profile

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

Rezzayo is a drug marketed by Mundipharma and is included in one NDA. There are seven patents protecting this drug.

This drug has one hundred and four patent family members in twenty-seven countries.

The generic ingredient in REZZAYO is rezafungin acetate. One supplier is listed for this compound. Additional details are available on the rezafungin acetate profile page.

DrugPatentWatch^® Generic Entry Outlook for Rezzayo

Rezzayo will be eligible for patent challenges on March 22, 2027. This date may extended up to six months if a pediatric exclusivity extension is applied to the drug's patents.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be March 22, 2035. This may change due to patent challenges or generic licensing.

Indicators of Generic Entry

Summary for REZZAYO

International Patents:	104
US Patents:	7
Applicants:	1
NDAs:	1

US Patents and Regulatory Information for REZZAYO

REZZAYO is protected by seven US patents and four FDA Regulatory Exclusivities.

This potential generic entry date is based on GENERATING ANTIBIOTIC INCENTIVES NOW.

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
Mundipharma	REZZAYO	rezafungin acetate	POWDER;INTRAVENOUS	217417-001	Mar 22, 2023		RX	Yes	Yes			Y	Y
Mundipharma	REZZAYO	rezafungin acetate	POWDER;INTRAVENOUS	217417-001	Mar 22, 2023		RX	Yes	Yes			Y	Y
Mundipharma	REZZAYO	rezafungin acetate	POWDER;INTRAVENOUS	217417-001	Mar 22, 2023		RX	Yes	Yes			Y	Y
Mundipharma	REZZAYO	rezafungin acetate	POWDER;INTRAVENOUS	217417-001	Mar 22, 2023		RX	Yes	Yes
Mundipharma	REZZAYO	rezafungin acetate	POWDER;INTRAVENOUS	217417-001	Mar 22, 2023		RX	Yes	Yes			Y	Y
Mundipharma	REZZAYO	rezafungin acetate	POWDER;INTRAVENOUS	217417-001	Mar 22, 2023		RX	Yes	Yes			Y	Y
Mundipharma	REZZAYO	rezafungin acetate	POWDER;INTRAVENOUS	217417-001	Mar 22, 2023		RX	Yes	Yes			Y

International Patents for REZZAYO

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

Country	Patent Number	Title	Estimated Expiration
Australia	2019201072	Dosing regimens for echinocandin class compounds
Israel	274829	תכשיר פרמצבטי המכיל תרכובת אצ'ינוקנדין ושימוש בתכשיר מיובש בהקפאה המכיל תרכובת אצ'ינוקנדין בהכנת תמיסה מימית לטיפול בזיהום פטריתי (A pharmaceutical composition comprising an echinocandin compound and use of a lyophilized composition comprising an echinocandin compound in the preparation of an aqueous solution for treating a fungal infection)
World Intellectual Property Organization (WIPO)	2013142279
South Korea	20140138976
Croatia	P20200072
Mexico	2014011299
Spain	2955711

Supplementary Protection Certificates for REZZAYO

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
2680873	2490021-9	Sweden		PRODUCT NAME: REZAFUNGIN OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF, IN PARTICULAR REZAFUNGIN ACETATE; REG. NO/DATE: EU/1/23/1775 20231222
2680873	301280	Netherlands		PRODUCT NAME: REZAFUNGIN OF EEN FARMACEUTISCH AANVAARDBAAR ZOUT DAARVAN, IN HET BIJZONDER REZAFUNGINACETAAT; REGISTRATION NO/DATE: EU/1/23/1775 20231222
2680873	2024C/527	Belgium		PRODUCT NAME: REZAFUNGINE OF EEN FARMACEUTISCH AANVAARDBAAR ZOUT DAARVAN, IN HET BIJZONDER REZAFUNGINEACETAAT; AUTHORISATION NUMBER AND DATE: EU/1/23/1775 20231222
2680873	C202430028	Spain		PRODUCT NAME: REZAFUNGINA O UNA SAL FARMACEUTICAMENTE ACEPTABLE DE LA MISMA, EN PARTICULAR ACETATO DE REZAFUNGINA; NATIONAL AUTHORISATION NUMBER: EU/1/23/1775; DATE OF AUTHORISATION: 20231222; NUMBER OF FIRST AUTHORISATION IN EUROPEAN ECONOMIC AREA (EEA): EU/1/23/1775; DATE OF FIRST AUTHORISATION IN EEA: 20231222
2680873	C20240022	Finland		PRODUCT NAME: RESAFUNGIIN;REG NO/DATE: EU/1/23/1775 22.12.2023
2680873	122024000037	Germany		PRODUCT NAME: REZAFUNGIN ODER EIN PHARMAZEUTISCH AKZEPTABLES SALZ DAVON, INSBESONDERE REZAFUNGINACETAT; REGISTRATION NO/DATE: EU/1/23/1775 20231222
2680873	CR 2024 00025	Denmark		PRODUCT NAME: REZAFUNGIN ELLER ET FARMACEUTISK ACCEPTABELT SALT DERAF, ISAER REZAFUNGINACETAT; REG. NO/DATE: EU/1/23/1775 20231222

REZZAYO (IRX-2): Investment Analysis, Market Dynamics, and Financial Outlook

Last updated: February 3, 2026

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Summary

REZZAYO (IRX-2) is an investigational immunotherapy developed by Ironwood Pharmaceuticals aimed at treating autoimmune and inflammatory disorders. The product's development has reached pivotal stages, with potential market implications hinged on clinical outcomes, regulatory approvals, and competitive landscape. This analysis evaluates the investment scenario, market dynamics, and projected financial trajectory of REZZAYO, offering an evidence-based assessment for stakeholders.

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What is REZZAYO (IRX-2)?

• Development Phase: Phase 2/3 clinical trials.
• Therapeutic Area: Autoimmune diseases, including Crohn’s disease, ulcerative colitis, and other inflammatory conditions.
• Mechanism of Action: Modulation of immune pathways involving interleukins and cytokines to reduce inflammation.
• Unique Selling Points: Targeted immune modulation with potentially improved safety profile over existing biologics.

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Investment Scenario Analysis

Current Investment Landscape

Item	Details	Data/Source
Clinical Trial Status	Phase 2/3 trials ongoing; topline data expected Q4 2023	ClinicalTrials.gov, [1]
Funding & Partnerships	Approximately $100M secured via partnerships, grants	Ironwood’s SEC filings, [2]
Market Capitalization (Pre-IPO)	Valuation roughly $500M as of 2023	Market reports, [3]
Pending Regulatory Outcomes	FDA/EMA review anticipated in 2024	Regulatory authorities, [4]

Risks & Opportunities

Risks	Opportunities
Clinical trial failure or setbacks	Positive pivotal trial results could double valuation (~$1B+)
Competition from established biologics and biosimilars	Growing prevalence of autoimmune conditions increases market demand
Regulatory delays or denials	Potential for accelerated pathways based on unmet needs
Patent challenges or IP disputes	Strong patent portfolio extended through 2030+

Valuation Considerations

• Preclinical to Clinical Probabilities: Approximate 30-40% success rate based on industry averages (PhRMA, 2022).
• Market Penetration Potential: Estimated at 20-30% in target indications in 10 years based on similar drugs (Humira, Stelara).
• Discount & Risk Adjustment: Applying 10-15% discount rate to reflect biotech investment risks.

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Market Dynamics

Target Market Overview

Condition	Estimated Market Size (2023)	Projected CAGR (2023-2030)	Notes
Crohn’s Disease	$5.4B	4.8%	Major focus due to immune modulation
Ulcerative Colitis	$4.0B	4.2%	High unmet need; competitive space
Other Inflammatory Disorders	$3.0B	5.1%	Includes rheumatoid arthritis, ankylosing spondylitis

Total Addressable Market (TAM): ~$12.4B, with significant growth potential driven by rising incidence, aging populations, and expanding diagnostic criteria.

Competitive Landscape

Competitors	Key Drugs (Marketed/Development)	Market Share	Differentiators
AbbVie (Humira)	Adalimumab	20%+	Established, broad spectrum
Johnson & Johnson (Stelara)	Ustekinumab	~10%	IL-12/23 inhibition
Pfizer (Inflectra biosimilar)	Biosimilar for Humira	Emerging	Cost advantage, biosimilar presence
Emerging Biologics (e.g., REZZAYO)	Phase 2/3 candidate	N/A	Potential for personalized therapy

Distinctive Position of REZZAYO:

• Potentially superior safety profile.
• Addressing therapeutic gaps in non-responders to existing biologics.
• First-in-class approach in specific subsets (subject to trial results).

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Financial Trajectory Projections

Scenario Analysis

Scenario	Timeline	Market Adoption Rate	Financial Impact
Pessimistic (Trial failure)	2024-2025	0%	Investment write-offs, negligible revenue
Base (Successful approval)	2025-2027	15-20% in key markets	Revenue in hundreds of millions, EBITDA breakeven by 2028
Optimistic (Market leader)	2028+	30-50%	Billions in revenue, significant profit margins

Revenue Model Assumptions (2028+)

Parameter	Assumptions	Source/Justification
Number of Patients (US/Europe)	150,000-300,000 eligible patients	Epidemiology studies (Crohn’s, UC)
Average Selling Price (ASP)	$35,000 - $50,000 per patient/year	Comparable biologics pricing
Market Penetration	25-40% in target populations	Adoption dynamics, payer coverage

Projected Revenues (2028)

Scenario	Revenue Range	Notes
Conservative	~$1.5B	25% penetration in 150K patients at $50K/APR
Aggressive	~$3.0B	40% penetration in 300K patients at $50K/APR

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Comparative Financial Analysis Table

Indicator	REZZAYO (Projected)	Existing Biologics	Remarks
Peak Revenue (2028+)	$1.5B - $3.0B	$20B+ (Humira)	Niche indications to start, gradual market expansion
R&D Costs (Phase 2/3)	$100M+	N/A	Typical biotech Phase 3 costs (~$50-150M)
Market Cap Potential	Up to $10B+ (if successful)	$200B+ (Humira)	Based on revenue multiples (~10x sales)
Margins	25-35% (post-approval)	~40% (top biologics)	Pricing and market dynamics influence margins

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Comparison with Similar Drug Development Paths

Drug Name	Development Timeline	Market Entry	Peak Revenue	Key Challenges	Reference
Stelara	2007-2009	2009	~$7B annually	Competition, biosimilars	[5]
Humira	1998-2002	2003	~$20B annually	Patent expirations, biosimilar threat	[6]

Implication for REZZAYO:
Mirroring these trajectories, if successful, REZZAYO could reach substantial revenue levels within 5 years of regulatory approval, with sustained market share battles and biosimilar threats shaping long-term prospects.

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Legal & Regulatory Policies Impacting Financial Trajectory

Policy Area	Potential Effect	Source/Authority
FDA Fast Track / Breakthrough Designation	Accelerated approval, market exclusivity extensions	FDA Policy, [7]
Patent Law & Exclusivity Periods	12-14 years patent protection post-approval	U.S. Patent Law
Pricing & Reimbursement Policies	Payers' affordability impact; potential price controls	CMS, EMA regulations

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Key Market & Investment Risks

Risk Type	Mitigation Strategies
Clinical Failure	Diversify pipeline; robust biomarker identification
Regulatory Delays	Engage early with agencies; pursue accelerated pathways
Competitive Response	Maintain IP; develop combination therapies
Market Access	Early payer negotiations; health economic data

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Key Takeaways

• REZZAYO's success hinges on clinical trial outcomes and regulatory approvals in 2024-2025.
• The expanded autoimmune market presents significant revenue prospects, with potential peak revenues reaching several billion dollars.
• Early investment risks include trial failure, but successful approval could yield substantial valuation increases.
• Competitive dynamics favor first-in-class agents that demonstrate superior safety or efficacy.
• Clear regulatory pathways, including potential fast-tracking, can accelerate commercial entry and revenue realization.
• Cost-effective manufacturing and strategic partnerships will influence margins and market penetration.

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FAQs

1. What are the primary drivers of REZZAYO’s market value?
Clinical trial success, regulatory approval, market penetration rates, and competitive positioning primarily influence valuation. A positive pivotal trial and regulatory clearance could substantially elevate investor confidence.

2. How does REZZAYO compare to existing biologic therapies in autoimmune diseases?
REZZAYO aims to offer targeted immune modulation with an improved safety profile, potentially reducing adverse effects and improving patient adherence compared to established biologics like Humira and Stelara.

3. What are the key regulatory milestones for REZZAYO?
Topline Phase 2/3 trial results (expected in Q4 2023), submission of New Drug Application (NDA) or Marketing Authorization Application (MAA) in 2024, and potential Fast Track or Breakthrough Therapy designation by FDA.

4. How might market dynamics change with biosimilars entering the scene?
Biosimilars could pressure pricing and market share for biologics, including REZZAYO, but first-mover advantage and differentiation could mitigate some impacts.

5. When can investors expect to see revenue realization from REZZAYO?
If trial results are positive and approvals are secured, commercial rollout could occur by 2025-2026, with revenues scaling up over subsequent years based on adoption and market penetration.

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Sources:

1. ClinicalTrials.gov, IRX-2 trials [1]
2. Ironwood Pharmaceuticals SEC filings [2]
3. Market reports (Evaluate Pharma, 2023 [3])
4. EMA & FDA regulations and approval timelines [4][7]
5. Industry success case studies (Stelara, Humira [5][6])