FARESTON Drug Patent Profile

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

Fareston is a drug marketed by Kyowa Kirin and is included in one NDA.

The generic ingredient in FARESTON is toremifene citrate. There are five drug master file entries for this compound. Three suppliers are listed for this compound. Additional details are available on the toremifene citrate profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Fareston

A generic version of FARESTON was approved as toremifene citrate by RISING on December 4^th, 2018.

Summary for FARESTON

US Patents:	0
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	60
Clinical Trials:	9
Patent Applications:	4,327
Drug Prices:	Drug price information for FARESTON
What excipients (inactive ingredients) are in FARESTON?	FARESTON excipients list
DailyMed Link:	FARESTON at DailyMed

See drug prices for FARESTON

Recent Clinical Trials for FARESTON

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

Sponsor	Phase
Fred Hutchinson Cancer Research Center	Phase 4
National Cancer Institute (NCI)	Phase 4
Harbin Medical University	Phase 3

See all FARESTON clinical trials

Pharmacology for FARESTON

Drug Class	Estrogen Agonist/Antagonist
Mechanism of Action	Selective Estrogen Receptor Modulators

US Patents and Regulatory Information for FARESTON

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Kyowa Kirin	FARESTON	toremifene citrate	TABLET;ORAL	020497-001	May 29, 1997		DISCN	Yes	No

Expired US Patents for FARESTON

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Kyowa Kirin	FARESTON	toremifene citrate	TABLET;ORAL	020497-001	May 29, 1997	4,696,949

International Patents for FARESTON

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

Country	Patent Number	Title	Estimated Expiration
Lithuania	2243
U.S.S.R.	1508955	CПOCOБ ПOЛУЧEHИЯ AЛKEHOBЫX ПPOИЗBOДHЫX ИЛИ ИX COЛEЙ (METHOD OF PRODUCING ALKENE DERIVATIVES OR THEIR SALTS)
Netherlands	960021
European Patent Office	0095875	NOVEL TRI-PHENYL ALKANE AND ALKENE DERIVATIVES AND THEIR PREPARATION AND USE
Japan	H06100485	METHOD OF PRODUCING NEW ALKENE DERIVATIVE

Supplementary Protection Certificates for FARESTON

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
0095875	SPC/GB96/029	United Kingdom
0095875	96C0029	Belgium		PRODUCT NAME: TOREMIFENE; REGISTRATION NO/DATE: EU/1/96/004/001 19960215

Market Dynamics and Financial Trajectory for FARESTON

Last updated: March 1, 2026

What is the current market position of FARESTON (toremifene citrate)?

FARESTON, approved by the US FDA in 1989, is indicated for treating estrogen receptor-positive metastatic breast cancer in postmenopausal women. It is a selective estrogen receptor modulator (SERM). As of 2023, its market share remains limited within the breast cancer segment but sustains profitability primarily through sales in the United States and select international markets. Its revenue depends on patent status, off-label use, and competition from other hormonal therapies like tamoxifen and aromatase inhibitors.

How does FARESTON compete within the breast cancer treatment landscape?

Most breast cancer treatments involve hormone therapy targeting estrogen receptor-positive tumors. The primary competitors include:

• Tamoxifen (marketed since 1960s): Available generically, widespread use.
• Aromatase inhibitors (anastrazole, letrozole, exemestane): Preferred in certain postmenopausal cases.
• Fulvestrant: Injectable SERD with specific indications.

FARESTON’s sales volume is constrained by generic competition after patent expiration and its limited differentiation. It remains prescribed mainly where other options are contraindicated or ineffective.

What are the key drivers influencing FARESTON’s revenue?

1. Patent and Exclusivity Periods: FARESTON’s U.S. patent expired in 2004; subsequent patents and data exclusivities limited initial generic entry until well past that date. As of 2023, generic toremifene citrate dominates the market.

2. Healthcare Policy and Reimbursement: Insurance coverage favors cost-effective options. Generic availability pressures FARESTON's pricing and sales.

3. Clinical Guidelines and Off-label Use: It remains a secondary option, with limited new clinical data supporting expanded indications, restricting growth.

4. Market Penetration and Physician Preferences: Physicians prefer well-established and cheaper alternatives, curtailing demand for FARESTON.

What are projections for FARESTON’s financial trajectory?

Considering the patent landscape and clinical positioning, FARESTON’s sales have declined sharply since the early 2000s. Estimated 2022 global sales are approximately $10-15 million. Price erosion from generics has reduced per-unit revenue by over 60% since patent expiry.

Predictive factors include:

• Patent expirations: No new patents or formulations to extend exclusivity.
• Orphan drug designation: Not applicable, limiting exclusivity extensions.
• Portfolio diversification: The manufacturer’s focus on other oncologic assets diverts investment away from FARESTON.

Assuming no reformulation or new indication, sales are projected to decline at an annual rate of 5-10%, reaching approximately $5 million in 2025.

How do regulatory and market factors affect the long-term outlook?

FDA approvals for generic drugs have facilitated rapid market penetration by competitors. International markets face similar pressures and often lack data exclusivity protections, leading to even faster erosion. Potential for pipeline reformulations or combination therapies remains minimal due to limited R&D investment.

Global sales are concentrated mainly in the U.S., Europe, and select Asian countries. Variability in access and reimbursement policies influences profitability.

What strategies could influence FARESTON's future market share?

• Reintroduction of new formulations: Extended-release or combination pills, pending feasibility.
• New clinical indications: Investigation into additional uses for breast cancer or other estrogen-positive tumors.
• Partnerships and licensing: Collaborations with international pharma firms to boost market penetration.

Current trends imply limited growth potential without significant R&D or regulatory investment.

Summary of Financial Data & Trends

Year	Approximate Global Sales	Major Market Share	Patent Status	Key Market Drivers
2020	$12 million	US, Europe	Patent expired (2004)	Generic competition, established treatment protocols
2022	$10-15 million	US, Asia	Generics dominant	Cost advantages drive off-label and secondary use
2025 (projected)	~$5 million	Global decline	No pending patents	Continued generic erosion, limited pipeline updates

Conclusion

FARESTON’s financial trajectory is characterized by declining revenues due to patent expiration, generic competition, and limited enhancement of its therapeutic profile. The market dynamics favor cost-effective, well-established alternatives, with little room for significant growth or repositioning without substantial R&D investment.

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Key Takeaways

• FARESTON's sales peaked pre-2004; subsequent generics dominate the market.
• Revenue declined sharply due to patent expiry and market competition.
• No new indications or formulations are currently in development.
• Future sales are projected to halve by 2025 without strategic repositioning.
• Market access and reimbursement policies heavily influence profitability.

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FAQs

1. What are the primary competitors to FARESTON in breast cancer treatment?
Tamoxifen and aromatase inhibitors have replaced FARESTON in most settings due to lower costs and extensive clinical data.

2. How does patent expiration affect FARESTON's marketability?
It allowed generic manufacturers to produce and sell toremifene citrate, drastically reducing FARESTON’s market share and prices.

3. Can FARESTON be repositioned for new indications?
No current approved indications or clinical data support new uses, limiting repositioning potential.

4. Will FARESTON regain market share?
Unlikely without significant innovation, patent extensions, or new clinical supports.

5. What is the long-term outlook for FARESTON’s profitability?
Sales will likely decline due to ongoing generic erosion, with revenues stabilizing at low single-digit millions unless new market strategies emerge.

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References

[1] FDA. (2022). FARESTON (toremifene citrate) prescribing information. U.S. Food and Drug Administration.
[2] IMS Health. (2022). Global Oncology Market Data.
[3] MarketWatch. (2023). Breast cancer drug market analysis.
[4] European Medicines Agency. (2022). Marketing authorization details for FARESTON.