TAZVERIK Drug Patent Profile

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

Tazverik is a drug marketed by Epizyme Inc and is included in one NDA. There are twenty-seven patents protecting this drug.

This drug has four hundred and ten patent family members in thirty-nine countries.

The generic ingredient in TAZVERIK is tazemetostat hydrobromide. One supplier is listed for this compound. Additional details are available on the tazemetostat hydrobromide profile page.

DrugPatentWatch^® Generic Entry Outlook for Tazverik

Tazverik was eligible for patent challenges on January 23, 2024.

By analyzing the patents and regulatory protections it appears that the earliest date for generic entry will be December 19, 2035. This may change due to patent challenges or generic licensing.

There have been eleven patent litigation cases 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 TAZVERIK

International Patents:	410
US Patents:	27
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	90
Clinical Trials:	15
Patent Applications:	132
Drug Prices:	Drug price information for TAZVERIK
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for TAZVERIK
What excipients (inactive ingredients) are in TAZVERIK?	TAZVERIK excipients list
DailyMed Link:	TAZVERIK at DailyMed

See drug prices for TAZVERIK

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

Constraining patent/regulatory exclusivity:

10,786,511

NDA:

211723

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 TAZVERIK

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

Sponsor	Phase
Weill Medical College of Cornell University	Phase 2
Genentech, Inc.	Phase 2
Applebaum Foundation	Phase 1

See all TAZVERIK clinical trials

Pharmacology for TAZVERIK

Drug Class	Methyltransferase Inhibitor
Mechanism of Action	Methyltransferase Inhibitors Multidrug and Toxin Extrusion Transporter 1 Inhibitors Multidrug and Toxin Extrusion Transporter 2 K Inhibitors

US Patents and Regulatory Information for TAZVERIK

TAZVERIK is protected by forty-six US patents and two FDA Regulatory Exclusivities.

This potential generic entry date is based on patent 10,786,511.

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
Epizyme Inc	TAZVERIK	tazemetostat hydrobromide	TABLET;ORAL	211723-001	Jan 23, 2020		DISCN	Yes	No	12,168,016
Epizyme Inc	TAZVERIK	tazemetostat hydrobromide	TABLET;ORAL	211723-001	Jan 23, 2020		DISCN	Yes	No	8,410,088		Y	Y
Epizyme Inc	TAZVERIK	tazemetostat hydrobromide	TABLET;ORAL	211723-001	Jan 23, 2020		DISCN	Yes	No	9,889,138
Epizyme Inc	TAZVERIK	tazemetostat hydrobromide	TABLET;ORAL	211723-001	Jan 23, 2020		DISCN	Yes	No	8,691,507
Epizyme Inc	TAZVERIK	tazemetostat hydrobromide	TABLET;ORAL	211723-001	Jan 23, 2020		DISCN	Yes	No	10,420,775
Epizyme Inc	TAZVERIK	tazemetostat hydrobromide	TABLET;ORAL	211723-001	Jan 23, 2020		DISCN	Yes	No	9,688,665
Epizyme Inc	TAZVERIK	tazemetostat hydrobromide	TABLET;ORAL	211723-001	Jan 23, 2020		DISCN	Yes	No	8,765,732

International Patents for TAZVERIK

When does loss-of-exclusivity occur for TAZVERIK?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

Australia

Brazil

Canada

China

Denmark

Eurasian Patent Organization

European Patent Office

Finland

Hungary

Israel

Japan

Lithuania

Mexico

New Zealand

Poland

Portugal

Singapore

Slovenia

South Korea

Spain

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

See the table below for additional patents covering TAZVERIK around the world.

Country	Patent Number	Title	Estimated Expiration
Argentina	086008
Australia	2012242595
Brazil	112013026324
Brazil	122020006541
Canada	2832843
Canada	3086473
Chile	2013002898

Tazverik Market Dynamics, Financial Trajectory, Patent Exclusivity, and Competitive Outlook

Last updated: August 17, 2026

Tazverik, the brand name for tazemetostat, is an oral EZH2 inhibitor marketed by Ipsen for epithelioid sarcoma and follicular lymphoma. Its commercial profile is built on two orphan oncology indications, but revenue remains constrained by narrow eligibility, competing therapies, accelerated-approval obligations, and limited penetration in follicular lymphoma. Ipsen’s acquisition of Epizyme in 2022 transferred global commercial control to a larger oncology company and reduced standalone operating risk, but Tazverik remains a comparatively small product within Ipsen’s portfolio.

What is Tazverik approved to treat?

Tazverik is an oral small-molecule inhibitor of enhancer of zeste homolog 2, or EZH2. EZH2 is the catalytic component of the polycomb repressive complex 2 and regulates gene silencing through histone methylation.

The FDA approved Tazverik in two settings:

Indication	FDA approval	Patient population	Regulatory basis
Epithelioid sarcoma	January 2020	Adults and pediatric patients age 16 and older with metastatic or locally advanced disease not eligible for complete resection	Accelerated approval
Follicular lymphoma	June 2020	Adults with relapsed or refractory disease after at least two prior systemic therapies, or tumors with an EZH2 mutation after at least one prior therapy	Accelerated approval

Tazverik is supplied as 200 mg tablets. The labeled dose is 800 mg orally twice daily, taken with or without food. The drug is differentiated by oral administration and biomarker relevance in EZH2-mutated follicular lymphoma, although the FDA label also includes a treatment pathway for follicular lymphoma without an EZH2 mutation after at least two prior therapies.[1]

How large is the Tazverik addressable market?

The commercial market is concentrated in relapsed or refractory hematologic malignancies and a very small soft-tissue sarcoma population.

Follicular lymphoma market

Follicular lymphoma is the larger opportunity. It is an indolent B-cell non-Hodgkin lymphoma with repeated treatment cycles and multiple branded and generic alternatives. Tazverik competes after prior anti-CD20 therapy, chemotherapy, immunomodulatory therapy, phosphoinositide 3-kinase inhibitors, cellular therapy, bispecific antibodies, and other targeted agents.

The principal commercial constraints are:

• Tazverik is generally used after multiple prior therapies.
• Follicular lymphoma patients have numerous treatment options.
• EZH2 mutation testing is relevant to part of the label but does not define the entire approved population.
• Bispecific antibodies and CAR-T therapies have expanded the late-line competitive set.
• Oral treatment is convenient, but chronic dosing creates adherence and toxicity-management requirements.

Epithelioid sarcoma market

Epithelioid sarcoma is rare, aggressive, and frequently diagnosed in younger adults. The total patient population is small, but treatment alternatives are limited in advanced disease. Tazverik’s first-in-class positioning in this indication gives it a stronger regulatory and clinical identity than its revenue scale would suggest.

The U.S. approval was based on response data from a single-arm clinical trial. The indicated population is limited to patients with metastatic or locally advanced disease who are not candidates for complete resection. That restriction limits volume even when treatment need is high.

How has Tazverik revenue developed?

Epizyme commercialized Tazverik before Ipsen acquired the company. Early sales were affected by the COVID-19 pandemic, restricted oncology visits, limited field infrastructure, and the narrow initial patient population.

Public company filings reported the following approximate product-revenue progression:

Fiscal year	Commercial owner	Reported Tazverik product revenue	Market interpretation
2020	Epizyme	Approximately $14 million	Partial-year launch
2021	Epizyme	Approximately $34 million	Early uptake in both approved indications
2022	Epizyme/Ipsen transition	Approximately $45 million	Continued growth before and after acquisition
2023	Ipsen	Approximately €70 million to €80 million	Broader Ipsen commercialization and international expansion
2024	Ipsen	Approximately €90 million to €110 million	Growth continued, but the product remained a small contributor to Ipsen sales

The exact presentation of Tazverik sales differs between Epizyme’s U.S. filings and Ipsen’s consolidated reports. Epizyme reported U.S. net product revenue in dollars, while Ipsen reports portfolio sales in euros and may present geographic or product-level data differently.[2][3]

Ipsen acquired Epizyme in an all-cash transaction valued at approximately $247 million, with additional contingent value tied to milestones. The transaction closed in 2022. Ipsen obtained Tazverik and Epizyme’s EZH2 technology, while Epizyme shareholders received $1.45 per share at closing plus a non-transferable contingent value right.[4]

Why did Ipsen acquire Tazverik?

Ipsen acquired Tazverik to add an oncology product with:

• Two FDA-approved orphan indications.
• An established commercial base.
• A differentiated mechanism of action.
• Potential for geographic expansion.
• Synergies with Ipsen’s oncology infrastructure.

The acquisition also gave Ipsen control over further development, lifecycle management, manufacturing strategy, and international commercialization. For Epizyme, the transaction ended the need to fund a standalone commercial organization while the company was generating product revenue below the scale required to support independent operations.

The transaction price indicated that Ipsen valued Tazverik as a specialty oncology asset with option value rather than as a near-term blockbuster. Tazverik’s revenue has grown under Ipsen, but the product has not reached the scale of Ipsen’s leading oncology medicines.

What patents protect Tazverik?

Tazverik’s U.S. patent estate includes composition-of-matter and related intellectual-property claims covering tazemetostat and pharmaceutical use.

A publicly identified U.S. patent associated with Tazverik is:

Patent	Subject matter	Listed or estimated expiry
U.S. Patent No. 10,526,355	Tazemetostat-related composition and pharmaceutical claims	March 2034, before any applicable patent-term adjustment or pediatric extension

Patent-term calculations can differ from simple 20-year calculations because of patent-term adjustment, patent-term extension, terminal disclaimers, and regulatory exclusivity. The commercial protection period therefore should be assessed against the current FDA Orange Book entry and USPTO patent records rather than against a single nominal expiration date.[5][6]

Formulation and method-of-use protection

Tazverik’s protection is not limited to the active ingredient. Relevant secondary protection can include:

• Pharmaceutical compositions containing tazemetostat.
• Treatment of EZH2-mutated follicular lymphoma.
• Treatment of epithelioid sarcoma.
• Dosing and administration methods.
• Use in defined patient populations.

Method-of-use patents generally create weaker barriers than a valid composition-of-matter patent because a generic applicant may attempt a section viii carve-out for a patented indication. That strategy is less effective when the remaining unpatented indication has substantial commercial value or when the label and promotional conduct create induced-infringement exposure.

What is the Orange Book status of Tazverik?

Tazverik is an FDA-approved small molecule and is eligible for Orange Book listing. The relevant protection analysis includes:

1. Listed patents covering the drug or approved methods of use.
2. Five-year new chemical entity exclusivity from the first FDA approval.
3. Seven-year orphan-drug exclusivity for each orphan indication.
4. Any pediatric exclusivity awarded by FDA.
5. Patent-term adjustment or extension.

The FDA approved Tazverik in 2020. The five-year NCE period would ordinarily have expired in 2025, subject to the precise reference-product approval date and regulatory calculation. Orphan exclusivity is indication-specific and may extend beyond NCE exclusivity. The epithelioid sarcoma and follicular lymphoma approvals should therefore be analyzed separately rather than treated as one exclusivity period.[1][7]

When does Tazverik lose exclusivity?

The practical loss-of-exclusivity date is likely to be determined by patent protection rather than by regulatory exclusivity.

The key timing framework is:

Protection type	Likely relevance
NCE exclusivity	Expired or reached the end of its five-year term in 2025
Orphan exclusivity	Applies separately to the approved orphan indications and may extend into the late 2020s
Composition patent	Potential protection into approximately 2034, subject to official patent-term calculation
Method-of-use patents	May extend protection for specific indications beyond other rights
Generic litigation	Could shorten effective market protection through a court decision or settlement
Pediatric exclusivity	Could add six months if awarded

A generic company could file an abbreviated new drug application with a Paragraph IV certification before the relevant patents expire. The first Paragraph IV filer could seek 180-day generic exclusivity if it satisfies the statutory requirements. The commercial impact would depend on whether the challenge targets the composition patent, a method-of-use patent, or both.

Which companies are challenging Tazverik?

There is no widely reported, high-profile Paragraph IV litigation campaign against Tazverik comparable to litigation involving major blockbuster drugs. Publicly visible competitive pressure has instead come from alternative therapies and the normal timing of future generic entry.

Potential challengers would likely include generic oncology manufacturers with experience in high-cost oral medicines. The most commercially meaningful challenge would target the core composition patent. A method-of-use-only challenge would have less impact if the generic label could omit protected indications without eliminating most of the market.

A future ANDA dispute would probably involve:

• Patent validity.
• Claim construction.
• Obviousness and written-description arguments.
• Whether the generic label induces use for protected indications.
• The scope of any patent-term adjustment.
• Settlement timing relative to the nominal patent expiry.

What regulatory risks affect Tazverik?

Both FDA approvals were accelerated approvals. Continued marketing requires post-approval evidence confirming clinical benefit or satisfying FDA’s regulatory requirements.

The largest regulatory risk is the follicular lymphoma confirmatory program. If a confirmatory trial fails to verify clinical benefit, is delayed materially, or does not support the approved population, FDA can require labeling changes or withdraw the indication under the accelerated-approval framework.[1]

The epithelioid sarcoma indication has a smaller commercial base but a more concentrated clinical rationale. Any regulatory action affecting the indication would have a limited revenue effect relative to follicular lymphoma, but it would reduce Tazverik’s differentiation in rare sarcoma.

How strong is the Tazverik patent estate?

Tazverik has a moderate-to-strong commercial patent position through the early 2030s if the core composition claims survive challenge. The estate is stronger than a product protected only by method-of-use patents, but it is less secure than a biologic protected by multiple layers of manufacturing, formulation, and clinical-use patents.

Strengths

• Small-molecule composition claims can block substitution across indications.
• Orphan exclusivity provides a regulatory barrier in the near term.
• Two approved indications increase the value of the active ingredient.
• Specialized manufacturing and quality-control requirements may add execution barriers for generics.

Vulnerabilities

• A single core composition patent may carry a large share of the protection burden.
• EZH2 inhibitor chemistry has been publicly studied by multiple companies.
• Generic applicants can challenge patents before expiry.
• Method-of-use claims can be narrowed through label carve-outs.
• The late-line follicular lymphoma market is highly competitive.

What generic-entry risks exist for Tazverik?

The most plausible entry scenarios are:

Scenario	Timing	Commercial impact
No early challenge	After core patent expiry	Standard price erosion after generic launch
Method-of-use challenge only	Before core patent expiry	Limited or moderate erosion, depending on label carve-outs
Successful composition challenge	Before 2034	High erosion across both indications
Settlement with licensed entry	Negotiated date	Moderate erosion beginning on the settlement date
Orphan-exclusivity expiration without patent entry	Late 2020s	No immediate substitution if patents remain enforceable

Because Tazverik is an oral oncology drug with a relatively small patient population, several generic manufacturers may wait for a clearer return on litigation investment. The expected value of a Paragraph IV challenge depends on annual sales, anticipated price erosion, the strength of the core patent, and the ability to obtain meaningful pharmacy and oncology-channel access.

How does Tazverik compare with competing drugs?

Product or class	Primary use	Competitive effect on Tazverik
Tazverik	EZH2 inhibition	Oral targeted option in selected late-line patients
Tazverik competitors in follicular lymphoma	CD20 antibodies, immunomodulators, PI3K inhibitors, bispecific antibodies, CAR-T therapies	Broaden treatment choice and reduce single-product dependence
Tazverik in epithelioid sarcoma	EZH2 inhibition	Limited direct competition because the disease is rare
Generic chemotherapy	Relapsed lymphoma and sarcoma treatment	Low-cost alternatives constrain pricing
Cellular and bispecific therapies	Advanced follicular lymphoma	Stronger efficacy perception in eligible patients, but higher administration complexity

Tazverik’s strongest commercial position is in patients seeking an oral therapy and in patients whose tumor biology or prior treatment history supports EZH2 inhibition. Its weakest position is in heavily pretreated follicular lymphoma where physicians increasingly use therapies with durable response data or immune-mediated mechanisms.

What is the financial outlook for Tazverik?

Tazverik is more likely to remain a growing specialty product than become a major Ipsen revenue driver.

The upside case depends on:

• Continued growth in relapsed follicular lymphoma.
• International reimbursement and launch expansion.
• Durable use in EZH2-mutated disease.
• Successful confirmation of clinical benefit.
• Additional combinations or earlier-line development.
• Limited near-term generic litigation.

The downside case includes:

• Confirmatory-trial failure or regulatory withdrawal.
• Intensifying competition from bispecific antibodies and CAR-T therapies.
• Limited adoption in epithelioid sarcoma because of disease rarity.
• Reimbursement restrictions.
• Patent litigation that accelerates generic entry.
• Declining treatment duration in late-line patients.

Tazverik’s revenue trajectory is therefore driven more by label durability and treatment-line expansion than by broad population growth. Ipsen’s ownership improves commercial execution and cost absorption, but it does not remove the product’s underlying market-size constraints.

Key Takeaways

• Tazverik is an oral EZH2 inhibitor approved for epithelioid sarcoma and relapsed or refractory follicular lymphoma.
• Follicular lymphoma is the principal revenue opportunity; epithelioid sarcoma provides regulatory differentiation but limited volume.
• Ipsen acquired Epizyme in 2022 for approximately $247 million upfront, plus contingent value rights.
• Product revenue increased from early launch levels under Epizyme to an estimated €90 million to €110 million range by 2024 under Ipsen.
• NCE exclusivity reached the end of its five-year period around 2025, while orphan exclusivity and patents provide additional protection.
• A core U.S. patent associated with Tazverik extends into approximately 2034, subject to official term adjustments and legal outcomes.
• No major public Paragraph IV litigation campaign has materially changed the current market profile.
• The principal commercial risks are confirmatory-trial execution, competition in follicular lymphoma, and eventual generic entry.
• Tazverik is a strategic specialty oncology asset, but its market dynamics do not support a blockbuster forecast without meaningful label expansion.

FAQs

Is Tazverik a chemotherapy drug?

No. Tazverik is a targeted small-molecule EZH2 inhibitor. It is not conventional cytotoxic chemotherapy.

Does Tazverik require EZH2 mutation testing?

Not for every approved use. The follicular lymphoma label includes patients with EZH2-mutated tumors after at least one prior therapy and a broader population after at least two prior therapies.[1]

Is Tazverik available outside the United States?

Ipsen has pursued international commercialization, but approval, reimbursement, and availability vary by jurisdiction. The U.S. remains the central reference market for Tazverik’s regulatory and patent analysis.

Can a generic Tazverik launch before 2034?

It could launch earlier if a generic applicant defeats the relevant patent, reaches a settlement allowing an earlier entry date, or relies on a non-infringing label. Without an early resolution, the core patent is the main barrier to broad generic substitution.

What would most increase Tazverik sales?

The strongest drivers would be earlier-line follicular lymphoma use, combination approvals, positive confirmatory evidence, broader international reimbursement, and clinical data showing advantages over bispecific antibodies or other late-line therapies.

References

1. U.S. Food and Drug Administration. (2020). Tazverik prescribing information. FDA.
2. Epizyme, Inc. (2021-2022). Annual reports and Form 10-K filings. U.S. Securities and Exchange Commission.
3. Ipsen S.A. (2023-2024). Universal registration document and full-year financial results. Ipsen.
4. Ipsen S.A. (2022). Ipsen completes acquisition of Epizyme. Ipsen corporate release.
5. U.S. Patent and Trademark Office. (n.d.). U.S. Patent No. 10,526,355. USPTO Patent Center.
6. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. FDA.
7. U.S. Food and Drug Administration. (2024). Orange Book: Approved drug products with therapeutic equivalence evaluations, exclusivity and patent listings. FDA.