PREMPHASE (PREMARIN;CYCRIN 14/14) Drug Patent Profile

Which patents cover Premphase (premarin;cycrin 14/14), and what generic alternatives are available?

Premphase (premarin;cycrin 14/14) is a drug marketed by Wyeth Pharms Inc and is included in one NDA.

The generic ingredient in PREMPHASE (PREMARIN;CYCRIN 14/14) is estrogens, conjugated; medroxyprogesterone acetate. There are three drug master file entries for this compound. One supplier is listed for this compound. Additional details are available on the estrogens, conjugated; medroxyprogesterone acetate profile page.

Summary for PREMPHASE (PREMARIN;CYCRIN 14/14)

US Patents:	0
Applicants:	1
NDAs:	1
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for PREMPHASE (PREMARIN;CYCRIN 14/14)

US Patents and Regulatory Information for PREMPHASE (PREMARIN;CYCRIN 14/14)

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Wyeth Pharms Inc	PREMPHASE (PREMARIN;CYCRIN 14/14)	estrogens, conjugated; medroxyprogesterone acetate	TABLET;ORAL-28	020303-002	Dec 30, 1994		DISCN	No	No

International Patents for PREMPHASE (PREMARIN;CYCRIN 14/14)

See the table below for patents covering PREMPHASE (PREMARIN;CYCRIN 14/14) around the world.

Country	Patent Number	Title	Estimated Expiration
Germany	69322497
Denmark	175317
Australia	711571
Germany	19775086
Luxembourg	91096

Supplementary Protection Certificates for PREMPHASE (PREMARIN;CYCRIN 14/14)

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
0136011	99C0003	Belgium		PRODUCT NAME: ESTRADIOL AND NORETHISTERONE; FIRST REGISTRATION NO/DATE: 403 IS 106 F3 19980928; FIRST REGISTRATION: SE 14007 19980306
0136011	SPC/GB97/032	United Kingdom		SPC/GB97/032: 20040802, EXPIRES: 20090801
0136011	980038	Netherlands		980038, 20090801, EXPIRES: 20130305
0136011	SPC/GB02/008	United Kingdom		SPC/GB02/008: 20040802, EXPIRES: 20090801
0136011	SPC/GB98/034	United Kingdom		SPC/GB98/034: 20040802, EXPIRES: 20090801

Investment Scenario and Fundamentals Analysis: PREMPHASE (PREMARIN; CYCRIN 14/14)

Last updated: February 4, 2026

What is PREMPHASE and its Current Market Position?

PREMPHASE is the brand name for Premarin, a conjugated estrogen hormone therapy primarily used to treat menopausal symptoms, osteoporosis prevention, and certain hormonal deficiencies. The drug's active ingredients originate from natural estrogen sources, with a long-standing market presence dating back to FDA approval in 1942.

Premarin's primary formulations include oral tablets, with the 14/14 cycle (14 days on, 14 days off) version being standard for hormone replacement therapy (HRT). CYCRIN 14/14 refers to a specific dosage form with a 14-day active phase and a 14-day break, aligning with hormone cycle mimicry used in HRT protocols.

What are the Market Dynamics and Revenue Drivers?

Market Size and Growth

The global hormone therapy market was valued at approximately USD 4.5 billion in 2021, with a projected CAGR of 4-6% over the next five years (source: Grand View Research). Premarin's sales have historically constituted a significant portion of this market, especially in the United States and Europe.

Launch and Competition

Premarin faces competition from:

• Bioidentical hormone therapies (e.g., estradiol-based products)
• Novel synthetic hormone formulations
• Non-hormonal alternatives for menopausal symptom management

Recent patent expirations and the entry of biosimilars have increased market competition. However, Premarin's well-established safety profile and physician familiarity sustain its position.

Patent and Regulatory Considerations

No recent patents are active on Premarin's core composition, increasing risk of generic entry. Regulatory hurdles for new hormone therapies favor existing drugs with proven safety profiles, making generic competition more likely as patents expire.

What are the Key Investment Fundamentals?

Revenue and Sales Trends

In 2021, Premarin generated approximately USD 370 million globally, down from a peak in the early 2000s that exceeded USD 600 million. The decline reflects generic competition, declining menopausal symptom prevalence, and shifts toward alternative treatments.

Patents and Intellectual Property

Premarin's original patents expired decades ago. No current patents prevent generic competition in established markets. This limits revenue growth potential but sustains profit margins for existing formulations.

Development Pipeline and Lifecycle

Pfizer (now part of Pfizer-BioNTech for COVID-19 vaccines but retains older assets) does not currently have new formulations or biosimilars for Premarin. The absence of pipeline products diminishes long-term growth prospects.

Cost Structure and Profit Margins

Gross margins for Premarin are estimated at 60-70%, driven by low manufacturing costs relative to sale price. The revenue is primarily from mature markets with established payer coverage.

Legal and Regulatory Risks

Pending litigation includes potential lawsuits around Women's Health Initiative (WHI) findings linking hormone therapy to breast cancer risks. Although these do not threaten market access, they influence physician prescribing patterns.

Market Outlook and Growth Opportunities

Growth potential relies on expanding indications, such as osteoporosis and vaginal atrophy, or moving into emerging markets with increasing menopausal populations. Consumer trends favoring non-hormonal options pose long-term risk.

What are the Investment Risks?

• Patent expirations leading to generic substitution
• Declining demand due to safety concerns and alternative therapies
• Regulatory challenges in expanding indications
• Pricing pressures from healthcare systems and payers

What is the Competitive Landscape?

Product/Company	Description	Market Share (Est.)	Key Attributes
Premarin (Pfizer)	Conjugated estrogen HRT	Approx. 60% *	Long-market presence, established safety profile
Estrace (Allergan)	Estradiol-based estrogen therapy	Growing	Bioidentical, preferred for some indications
Multiple biosimilars	Entry since patent expiration	Increasing	Price competition, regulatory approval ongoing

*Estimated based on market reports; exact figures vary.

What is the Valuation and Investment Outlook?

Given steady decline in revenue and limited pipelines, Premarin currently functions as a mature asset with low growth potential. Investment considerations include:

• Use as income-generating asset in mature product portfolios
• Risks from patent expirations and competition
• Potential for market share stabilization with expanded indications or geographic expansion

High-risk investors might consider divestment; others may view stable cash flow as suitable for income-focused strategies.

Key Takeaways

• Premarin's market share is declining due to patent expirations and competition.
• The drug maintains profitability through established manufacturing and pricing strategies.
• Limited pipeline activity constrains long-term growth prospects.
• Market demand faces headwinds from safety concerns and the rise of bioidentical and non-hormonal options.
• Future growth depends on geographic expansion and indication diversification.

FAQs

1. Will Premarin regain market share against bioidentical hormones?
Likely not, as bioidentical hormones are gaining favor for perceived safety, despite mixed scientific consensus.

2. Are there any plans for patent extensions or new formulations?
No public evidence suggests Pfizer plans new formulations or patent extensions for Premarin.

3. How will regulatory changes impact Premarin?
Changes relating to safety disclosures and labeling could constrain prescribing but are unlikely to ban the drug outright.

4. Is Premarin suitable for long-term investment?
Its mature status and declining sales make it more suitable as a stable cash flow asset than high-growth investment.

5. What are the key regulatory concerns?
Litigation relating to past safety concerns and evolving guidelines on hormone therapy pose risks but have historically not prevented market access.

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Sources:

1. Grand View Research. Hormone Therapy Market Size, Share & Trends (2021).
2. Pfizer Annual Reports (2021–2022).
3. FDA Drug Database. Premarin Approval Details.
4. Women's Health Initiative Study Publications.